Plasma etching method with usage of intermittent modulation of gaseous reagent

FIELD: processes, etching.

SUBSTANCE: usage: for receiving structures by means of plasma etching process through the mask. Concept of the invention: etching method of layer above support through the mask provides cyclic process of gases modulation during more then three cycles. Each cycle contains stage of protective layer formation operation implementation with usage of the first gaseous reagent with initial gaseous reagent, duration of which is preliminary 0.0055-7 seconds for each cycle, and stage of etching operation implementation for etching of device feature through the mask for etching of the second gaseous reagent using reactive gaseous reagent - etchant, duration of which is preliminary 0.005-14 seconds for each cycle. Protective layer formation operation contains stage of initial gas feeding and stage of plasma formation from initial gas. Each etching operation contains stage of reactive gas - etchant feeding and stage of plasma formation from reactive gas - etchant.

EFFECT: providing of regulation ability of critical dimensions during etching.

35 cl, 10 dwg

 

PREREQUISITES TO the CREATION of INVENTIONS

1. The technical field to which the invention relates.

The invention concerns a method of producing patterns on a semiconductor wafer by etching through patterns defined by the mask type photoresistive mask, hard mask, or a combination of the mask using plasma.

2. An overview of the state of the art to which this invention

When using plasma etching in semiconductors installation for plasma etching is usually used to transfer the pattern of the mask in a circuit pattern and lines of the corresponding thin film and/or film structure (conductors or used for isolation dielectrics on a semiconductor wafer. The transfer is carried out by etching the film (and film structures) under photoresistive materials in open areas of the pattern mask. This etching reaction can be initiated chemically active substances and electrically charged particles (ions)generated by the excitation of an electric discharge in a mixture of reagents in the vacuum chamber, also called a reactor or processing chamber. Ions can also be subjected to a further acceleration in the direction of motion to the materials of the semiconductor wafer by an electric field created between the gas mixture and the materials of the semiconductor wafer, that provides directional removal of materials subjected to etching, along the direction of the trajectory of the ions and is called anisotropic etching. At the end of the sequence of etching the masking material is removed by removing and as a result leaving in their place an exact copy of the horizontal patterns of a mask used as originals. This method of etching is illustrated in figa-C. In this way the process of plasma etching is used for direct transfer figure 104 photoresistive mask on the underlying thin dielectric film 108 oxide, as shown in figa. In the etching of the exposed contact window 112 and is, as shown in figv, destruction and damage of the photoresist 104. Next, as shown figs, the photoresist is removed, and the oxide 108 remains in the contact window 112. During etching and transfer of picture usually is the destruction and/or damage to the materials of the mask. Therefore, damage and erosion to some extent can also be transferred to the underlying layers and to cause such undesirable distortion of the picture, as broadcast, increasing the critical size, fasterova etc.

Therefore, the objectives of the methodology etching may include reduced erosion mask to enhance the accuracy of the transfer of the image drawing mask. With e the th end, it was proposed to include in the mix for reactive etching of the passivating gas. This passivating gas may be selected so that his presence provided a selective reducing the damage and erosion of the mask material during the etching relative to the speed of removal of material thin film is subjected to etching. Passivating gas can be chosen so that the surface of the mask material formed coating, inhibiting etching and acting as a barrier to reduce the reaction rate of the etching. Specifically passivating gas is chosen so as to further ensure the formation of the coating, inhibiting etching, on the vertical surfaces of the thin film structures subjected to etching, and to prevent the development of etching reaction in the absence of bombarding ions. As charged particles have a vertical trajectory, the etching can develop only in the vertical direction and practically does not develop in the horizontal direction, resulting in the formation of anisotropic etching profile. Thus, the presence of pestiviruses gas mixture for etching is very important from the point of view of improving the protection mask for etching and get vysokoporodnogo profile etching using a focused ion bombardment with relatively high energy.

Previously it was proposed to react the main gas mixture contained gases-stain and polymeropoulos components, in which polymeropoulos components used as pestiviruses gas. In this case, gases-stain emit highly reactive substances under the action excited by an electric discharge, which in turn provides the etching of thin-film materials subjected to etching as a mask material through the mechanism of the spontaneous reaction. The nature of spontaneous reactions reaction etching develops both vertical and horizontal surfaces and the result is isotropic etching profiles. The presence polymeropoulos component in the deposition of polymer on the surface as structures subjected to etching and masking materials can be used to simultaneously provide a high etching selectivity with respect to the mask material and the anisotropic etching with ion bombardment.

Previously it was suggested that the reactive gas mixture contained polymeropoulos gases and gas, initiating etching. The role of gas, initiating the etching is to ensure the possibility of separating the highly reactive substances as a result of interaction with polymeropoulos gases when excited by electric discharge. In another embodiment of the invention the coating, inhibiting etching, as the mother of the crystals, subjected to etching and masking materials can also be formed by chemical reactions appropriately selected pestiviruses gas directly from the surfaces of these materials.

A common disadvantage of the above methods is that the optimal conditions for different aspects of the requirements for etching usually do not coincide with each other, and when mixed gases are some of the unique properties of each gas precursor may be lost due to interactions. Optimization of the etching conditions are almost always involves making difficult tradeoffs in favor of a separate etching conditions, which may not be optimal, and which requires the separation of the various reagents used in the etching.

Option methodology etching is proposed in U.S. patent No. 5501893 entitled "Method of anisotropic etching of silicon", issued to Lermer (Laermer) with co on March 26, 1996 In this way involves the separation of gases, etching agents and polymerbased gases between two different phases, each of which uses only one type of chemicals and is not used by another. During deposition Lerner offers to form teleopathy polymer layer thickness of approximately 50 nm in the process of conducting phase osuzhdeni the duration of one minute. This allows to obtain a high etching rate at low energies bombarding ions, since at low energies bombarding ions can be achieved with high selectivity to the masking materials for some spontaneous reactions etching, if the activation energy for the reaction on the surface of the materials subjected to etching, is somewhat lower than for the reaction on the surface of the masking material.

The exception polymeropoulos component of the etch process, as I believe, leads to an isotropic etching at the time of the meeting due to the absence of the layer, inhibiting etching, to prevent etching in the horizontal direction. In addition, the lack pestiviruses gas mixture for etching may make it difficult to obtain a sufficient etching selectivity to the mask material in the case of the desire to use ions with higher energies. In many cases, the use of bombarding ions with high energy provides a process of etching an advantage in obtaining structures with a high ratio of height to width, for example in the case of structures with very small dimensions. Also believe that such processes are accompanied by the appearance of unwanted broadcasti and facetiously.

Other methods involve the use of schemes combiner the bath masking to increase the overall durability of the mask material for etching. This is illustrated figa-F. On figa depicts a layer 204 of the oxide. On FIGU layer 208 a hard mask is deposited on the oxide layer. Photoresist mask 212 is executed, as shown in figs, on top of the layer 208 of the hard mask. Photoresist mask 212 is used for forming the pattern layer 208 of the hard mask and the receiving layer 214 a hard mask, after which the layer of photoresist 212, as shown in fig.2D may be removed. Next, as shown file using a layer 214 of the hard mask as a mask, the layer 204 oxide by etching to expose the contact window 216. Then, as shown in fig.2F, the hard mask is removed, and the layer 204 oxide remains in contact 216.

The advantages of this method are that the presence of more inert hard mask to transfer patterns (circuits and lines) on the underlying film can significantly improve the characteristics of the etching, as well as significantly reduce the requirements for etching and photolithography. The disadvantages of the method are related to the fact that the introduction of new technological stages and new sets of devices in the sequence of the process accompanied by an increase in costs and decrease overall performance. In addition, the increased complexity of the process also adds to the difficulties. For example, to remove the hard mask of the Si used for etching contacts in dielectrics, is not as easy as autoresizing mask.

SUMMARY of the INVENTION

To achieve these objectives and in accordance with the present invention proposes a method of etching a topological element in the layer through a mask for etching on the substrate. The cyclic process of modulation gases perform for more than three cycles. Each cycle contains the runtime operation of forming the protective layer using the first gaseous reactant from the source gazoobraznym reagent, and the operation of forming the protective layer is carried out for about 0,0055-7 seconds for each cycle. The operation of forming the protective layer includes a step of feeding the source gas and the step of forming a plasma from the source gas. Each cycle further comprises the step of performing the etching operation for etching the topological element through a mask for etching using the second gaseous reactant, using reactive gaseous reagent is to provide the Etchant, where the first gaseous reactant is different from the second gaseous reactant, and the etching operation is performed in a period of approximately 0.005 to 14 seconds for each cycle. Each etching operation includes a step of feeding a reactive gas provide the Etchant and the step of forming a plasma of the reactive gas provide the Etchant.

In another example, the implementation proposed in the stop for the etching of topological element in the layer through a mask for etching on the substrate. Offered the processing chamber within which may be placed substrate. Features the first source of gaseous reagent for supplying a first gaseous reactant comprising a source of gaseous reagent. Offers a second source of gaseous reagent for supplying a second gaseous reactant comprising reactive gaseous reagent-provide the Etchant. Proposed controller, connected to the first source of gaseous reactant and a second source of gaseous reactant with the ability to control these sources, where the controller contains computer-readable media to perform a cyclic modulation process gases for more than three cycles. Computer-readable storage medium contains computer commands to perform the operation of forming the protective layer using the first gaseous reactant from the source of gaseous reagent, and the operation of forming the protective layer is within about 0,0055-7 seconds for each cycle containing a computer command for supplying the source gas and computer commands for forming a plasma from the source gas. Computer-readable media further comprises computer commands to perform etching for etching topologies the element through the mask for etching using the second gaseous reactant, using reactive gaseous reagent is to provide the Etchant, where the first gaseous reactant is different from the second gaseous reactant, and the etching operation is performed for approximately 0.005 to 14 seconds for each cycle containing a computer command for supplying a reactive gas provide the Etchant and computer commands for forming a plasma from the reactive gas provide the Etchant.

In another embodiment, the present invention proposes a method of etching a topological element in the layer through a mask for etching on the substrate. The cyclic process of modulation gases perform for more than three cycles. Each cycle includes a step of performing the first etching operation, the first operation to perform etching for about 0,0055-14 seconds for each cycle. The first etching operation includes a step of feeding the first gas provide the Etchant and the step of forming a plasma from the first gaseous provide the Etchant. Each cycle further comprises the step of performing the second operation of the etching and the second etching operation is performed in a period of approximately 0.005 to 14 seconds for each cycle. Every second etching operation includes a step of feeding the second gas provide the Etchant that is different from the first gaseous provide the Etchant, and the step of forming a plasma from the second g is sobrannogo of provide the Etchant.

A more detailed description of these and other features of the present invention makes reference to the attached figures, is provided below.

BRIEF DESCRIPTION of DRAWINGS

As an example and not to limit the creatures, the present invention is illustrated in the accompanying drawings in which the same items refer to the same elements and in which:

figa-With - schematic drawing of the process of formation of topological element with a contact window in the prototype;

figa-F - schematic drawing of the process of formation of topological element with a contact window in another prototype;

figure 3 - diagram of the sequence of operations in the embodiment of the invention;

figa-F - schematic drawing of the stages of the patenting process of forming the contact window;

5 is a schematic illustration of a system that may be used in carrying out the invention;

6 is obtained by scanning electron microscope micrograph top view showing the results of etching the matrix contacts high density, using the example of the invention;

7 is obtained by scanning electron microscope micrograph side view showing the results of etching the matrix contacts high density ISOE what Itanium example of the invention;

figa-E is a schematic illustration of the process of the buildup of material on the surface of patented quick Cycling using submodules;

figa-D - schematic illustration of the process of the buildup of material on the surface in the regime of slower Cycling;

figa and 10B illustrate a computer system corresponding to the requirements for the implementation of the controller used in the embodiments of the present invention.

A DETAILED DESCRIPTION of the PREFERRED embodiments

The following is a detailed description of the present invention with reference to some preferred embodiments, illustrated in the accompanying drawings. Considering the numerous particulars, the following description is intended to ensure full understanding of the present invention. However, the specialist in the art it is obvious that the present invention may be practiced without some or without any of those particulars. In other instances, detailed descriptions of well-known process operations and/or structures has been omitted that do not unnecessarily impede understanding of the subject matter.

I believe that the formation of protective layers, type layers, passivating the side walls, with a thickness of about 10 nm or more and subsequent etching and the use of protective layers as pestiviruses layer can lead to broadcasti and fasterova. Not taking into account the restrictions imposed by theory, believe that the layers of this thickness are not sufficiently conformal to ensure the required protection against broadcasti. Suppose that a thin protective layers, provided in accordance with the invention, significantly reduces broadcast. This thin protective layer can also reduce fasterova. In addition, I believe that it is possible to reduce the increase of critical size and provides control of critical size or regulation bias critical size, where the systematic error of the critical size defined as the change in critical dimension in the etching process.

The invention represents a new way of etching, which uses a cyclic etch process with modulation gases in-situ performed with the rotation operation of forming the protective layer, and etching to improve the General characteristics of etching without excessive losses from the standpoint of simplicity and cost efficiency. Modulation, in particular, includes a cyclic structure and/or relationships of the flow rates of the supplied process gases and may also include synchronized changes in RF power, gas pressure and temperature. The CEC is systematic process is characterized by the duration of the cycle and the relationship between the durations of the individual periods of the cycle, representing the relationship between the duration of the operation of forming the protective layer and the duration of the etching operation.

Application for U.S. patent No. 10/295601 entitled "method for improving the characteristics of the plasma etching", filed by Huang (Huang and co-authors on November 14, 2002 and incorporated by reference for all purposes, discloses that plasma processing of in-situ can be used to improve and/or repair of masks and/or vertical side walls of topological elements in the development process of etching. In this process step, chemical processing initiated for a short time before and/or after a semiconductor wafer has been subjected to plasma etching for the required duration.

In the present invention, this approach is modified so that the processing stage, providing protection masks and side walls, entered as a single operation cyclic modulation process gases, alternating with combined with her etching operation.

The process of forming the protective layer may be selected so that a thin film material formed on the surfaces of the mask and/or the side walls of the film is subjected to etching, to prevent erosion, facetiously and broadcasti etching. A thin coating can be made of material the material, combined with performed after the process of removal for ease of holding the end of the delete operation, but has a higher resistance to etching than the materials of the mask. For example, a thin film with a high carbon content and a very low content or absence of other elements may be used to cover photoresistive mask that protected topological elements of the mask are not subjected to the smooth fracture during subsequent etching process. In other words, it can change the surface composition of the picture of the mask so that the mask will behave like pseudoalloy mask having certain useful characteristics of etching the hard mask of amorphous carbon. In another embodiment of the invention the process of forming the layer can also be used in such a way that the formation of a thin coating on the pattern of the mask substantially compensates and/or restores the drawings masks, damaged/destroyed during the preceding etch process. The advantage of the relative inertness of the coating to the subsequent reaction of etching is that it allows not to change the ending balance received during etching. In another embodiment of the invention, a thin coating can be formed using the process conditions, is the quiet provide side walls smooth conformal coating, to prevent the appearance of broadcasta arising from uneven and/or wrinkled polymer coating on the side walls.

The mixture of gases-etching agents may contain particles provide the Etchant and particles pestiviruses substances, in order not to lose benefits associated with pestiviruses gas reagent for etching. The ratio between the components is stain and pestiviruses components along with many other treatment conditions are precisely balanced to achieve optimal treatment results, such as the selectivity of the photoresist, the anisotropy of the etching, the etching rate etc. Power electric discharge can save high, and the energy of the charged particles also remain high in order to obtain a high etching rate and a good anisotropy of etching structures with small dimensions. The cycle of formation of a protective layer and etching is repeated a large number of times until task etching.

To facilitate understanding of the invention, figure 3 shows the sequence of operations in the example embodiment of the invention. The layer is subjected to etching, to form a mask (step 304). This can be photoresist mask, a hard mask or a combined mask. Figa-F are schematic illustrations of the process. Figa shows photoresist mask 404, sformirovannuyu exposed etch layer 408 oxide on the substrate. The substrate accommodated in the processing chamber (step 306).

Figure 5 presents a schematic representation of the camera 500 processing, which can be used in the preferred embodiment of the invention. In this embodiment, the camera 500 plasma treatment contains a restrictive ring 502, the upper electrode 504, the lower electrode 508, a source 510 of gas and a suction pump 520. Source 510 gas contains source 512 gas for the protective layer, the source 514 gas provide the Etchant and an additional source 516 gas. Inside the chamber 500 plasma treatment is used as the substrate of the semiconductor wafer 580 with deposited oxide layer mounted on the lower electrode 508. The lower electrode 508 supplied with a corresponding locking mechanism of the substrate (for example, electrostatic or mechanical podarkticules or the like) for fixing the semiconductor wafer 580 used as the substrate. The upper portion 528 of the reactor includes a top electrode 504, located directly opposite the lower electrode 508. The upper electrode 504, the lower electrode 508 and the restrictive ring 502 define the boundaries of the field 540 localization of plasma. The gas is fed to the region of localization of the plasma using a source 510 of gas through the inlet 543, and pumped from the region of localization of the plasma through the bounding number is CA 502 and outlet suction pump 520. A suction pump 520 generates the gas outlet to the chamber of the plasma processing. RF source 548 electrically connected with the lower electrode 508. Wall 552 of the camera define the boundaries of the plasma compartment, which has a restrictive ring 502, the upper electrode 504 and the lower electrode 508. RF source 548 may include a power source with a frequency of 27 MHz and a power source with a frequency of 2 MHz. Various combinations of connection RF power to the electrodes.

In the preferred embodiment, of the invention can be used intended for dielectric etching system 2300 Exelan™ production Lam research Corporation (Lam Research Corporation™) (Fremont, CA), modified to provide the required in accordance with the invention, the duration of the cycle. The controller 535 is connected to the RF source 548, a suction pump 520, the first control valve 537 connected to a source 512 source gas, the second control valve 539, which is connected to the source 514 provide the Etchant gas, and the third control valve 541 connected to an additional source 516 gas, with the ability to control the operation of these devices. Inlet 543 may be connected with the spray head. Inlet 543 may be common to all sources of gas, or each history is nick gas can have its inlet or multiple inlet ports, or can be used in other combinations.

Next are preparing patterns for etching modulated (step 308). Such training may include the steps of the type of dissection of the layer of antireflective coating on the bottom surface.

Then perform a cyclic etch process with modulation gases (step 312). During cyclic etch process with modulation of the gases in the chamber 500 processing alternation is carried out at least two operations. One operation is the phase that is optimized for formation of a protective layer (step 316). Another operation - step, optimized for etching (step 326). The alternation of these operations is achieved by synchronized modulation of the velocity of the gas streams and, if possible, RF power, surface temperature, and gas pressure. In a preferred example implementation of the full cycle time does not exceed approximately 21 seconds. In a more preferred embodiment, the full cycle time is 0.01-10 seconds. In the most preferred embodiment, the full cycle time ranges from about 0.5 to 5 seconds. In a preferred embodiment, the ratio between the durations of the periods of the cycle (protection: etching) is 0.01-20. In a more preferred embodiment, the ratio between the durations of the periods of the cycle (protection: etching) varies in the range is the area of 0.05-5. In the most preferred embodiment, the ratio between the durations of the periods of the cycle (protection: etching) is 0.2-1. In a preferred embodiment, modulation of gases perform for approximately 3-50000 cycles. In a more preferred embodiment, the duration of the modulation of the gases is approximately 20-1000 cycles. In the most preferred embodiment, the modulation gases perform, at least, for approximately 100 cycles.

During operation, optimized for formation of a protective layer (step 316), the protective layer precipitated on the sides of topological elements subjected to etching, and, if possible, on the upper surface of the mask for etching. The deposition can be asymmetric, so that the amount of material deposited on the mask material will be greater than on the side walls. This may facilitate placement of the source reagent in the line of sight, as well as the selectivity of the selected deposition process. In other words, the source reagent may be selected so that the coating will preferably be formed on the mask material due to differences in the chemical reactivity of the materials. As you can see in figv, on the upper surface photoresistive mask 404 is formed over that is a simple protective layer 412, than on the exposed surface of the oxide at the bottom photoresistive mask and side walls photoresistive mask. It should be noted that other ratios between the dimensions in the drawings can be made not to scale. For example, the thickness of the protective layers may not match the scale of the thickness of the mask layer and subjected to etching, and such protective layers can be drawn for clarity thicker. In the preferred embodiment, the deposition performed in-situ in the chamber etching using a process stimulated by plasma chemical vapour deposition (PPHO), allowing deposition of a thin protective layer on the sidewall of the photoresist. In the deposition process can be used with some energy of bombarding ions, providing the selectivity of such deposition. In this process the thickness of the side walls may reach approximately two-thirds of the thickness of the layer on the top surface of the mask.

In other embodiments, the processing conditions can be changed by advancing front etching through the material being etched, in order to vary the thickness and spatial distribution of the protective layer. For example, it may be desirable formation of a thicker coating on the side wall film is subjected to etching by continuing the etching at large is loubinoux, to protect the side walls from further deformation during subsequent etching. This can be provided by changing the conditions of cyclic treatment with continued etching. Since the formation of the layer and etching are separate loop operations, the conditions for the operation of forming the layer can be optimized for this result, and not to affect the operation of etching. In another embodiment of the invention the full duration of the cycle and/or the relationship between the durations of the periods of the cycle can be adjusted by continuing the etching to ensure this change without any variation of the processing parameters for individual operations. In another preferred embodiment, the protective layer can be deposited on only the side walls.

During the operation of forming the protective layer, the ratio of fluorine to carbon in the feed gas does not exceed 2:1. Examples of reagents that can be used for stimulated plasma, PFHO, you can call CH3F, CH2F2C2H5F3H7F, C2H3F, CH4With2H4With2H6With2H2With3H8and SiH4Si(CH3)4Si(C2H5)4etc. is Preferred that these R the agents do not contain Halogens or the content of halogen to carbon does not exceed 2:1. Not taking into account the restrictions imposed by theory, believe that the reagent-based carbon forms a thin layer of amorphous silicon, which is resistant to etching. The silane SiH4use for forming a layer of amorphous silicon and the layer of polycrystalline silicon) on the photoresist. In addition, the protective layer can be modified some components containing F and N. The presence of other elements of type F can be used to provide selective activity on the surfaces of various materials, in which deposition will occur on one and not on other materials, such as materials photoresistive mask, not the layer of SiO2under the action of the corresponding ion bombardment. Other ways type spray can also be used for forming the protective layer.

To perform the looping modulated gas synchronized control system parameters of the etching can be carried out as follows. To initiate the step of forming a protective layer at the beginning of the cycle, the controller 535 may generate a command in accordance with which the first valve 537 ensures the supply of the source gas from the source of 512 source gas into the chamber 500 processing, and the second valve 539 blocks the gas flow-provide the Etchant from the source of the ICA 514 gas provide the Etchant in the processing chamber. The controller 535 may also regulate the power supplied by an RF source 548, and to control the suction pump 520 in synchronization with the control valve. The controller can also be used for regulating the gas pressure in the field of semiconductor wafer, the pressure is Not used to cool the back side of the semiconductor wafer, the bias on the substrate and different temperatures in synchronization with the control valve. Table I presents some of the parameters that can be used in the operation of forming the protective layer when performing a cyclic process in the preferred embodiment of the invention.

Table I
The preferred rangeA more preferred rangeThe most preferred range
The bias voltage>50 volts>100 volts>300 volts
Energy offset>50 eV>100 eV>300 eV

The offset can be achieved by application of DC voltage between the upper electrode above the substrate and the lower electrode under the substrate. In predpochtitel the nome example implementation polictial with a semiconductor wafer under the action of the RF voltage, affixed generator RF power can be generated electronegative potential (which thus supplies bias to the semiconductor wafer). The result is the attraction of positively charged particles to the electrically biased substrate with an energy determined by the electronegativity regulated by the amplitude of the RF voltage. So there is the possibility of filing and varying the energy of bombarding ions by adjusting RF power (and, therefore, the RF voltage)applied to polictial.

Operation 316 forming the protective layer is an independent operation in a cyclic process 312 etching, which may include various combinations of source gases required for different applications of etching applied to different materials, where the deposition can be obtained protective coating around the topological elements subjected to etching, including masking of topological elements. In a preferred embodiment, the duration of the cycle allocated for this operation is approximately 0.005 to 7 seconds. In a more preferred embodiment, the duration of the cycle allocated to this operation varies approximately in the range of 0.05 to 5 seconds. In the most preferred embodiment, d is italmost period of the cycle, allocated for this operation is approximately 0.25 to 2.5 seconds. In a preferred embodiment, during a single operation of forming a protective layer on the top surface and/or side walls is formed a layer with a thickness of less than 100 Å. In a more preferred embodiment, during a single operation of forming a protective layer on the top surface and/or side walls of the formed layer, the thickness of which varies approximately in the range of 0.1-50 Å. In the most preferred embodiment, during a single operation of forming a protective layer on the top surface and/or side walls of the formed layer, the thickness of which varies approximately in the range 1-10 Å. In the case of a layer thickness of less than about 10 Åmore precise is the description of coverage as piece of the monolayer. In one embodiment, the protective layer forms a single monolayer during a single operation of forming the protective layer. In another embodiment, the protective layer forms submodels, which is the layer that covers the surface with a single atomic or molecular layer is not completely, but instead can provide a certain percentage (e.g. 75%) of the coating surface during the single operation of formation of the deposits of the protective layer.

Operation 320 etching is an independent operation in a cyclic process 312 etching, which is performed to promote front 460 etching and receiving, as shown in figs, topological element 416 subjected to etching (step 320). Among the areas of application of the etching can be called etching of contacts in dielectrics, including contact with a high ratio of height to width (HARC), etching when demaskirovanie, etching grooves (shallow or deep) in the dielectric, etching samozavestna contacts, etching masks for the opening of the window under the gates, the eradicating of through holes in dielectrics, double demaskirovanie by etching, the etching grooves in the double demaskirovanie, etching conductors paddles, etching deep grooves in the guides, a small etching the insulating grooves, opening Windows in the hard masks etc.

In the preferred embodiment, when performing etching to provide directional etching using high energy ions. The operation of the etching, as shown, allows you to remove some parts or the entire protective layer 412 during a single etching operation. On some surfaces during a single etching operation can be removed, the entire protective layer. In this example, the protective layer forming side stink is on the photoresist 404, and on the bottom surface of topological item was deleted. Other parts of the protective layer can be removed only partially. In this example, only the area of the protective layer 412 on the upper surface of the photoresist 404 has been removed. In other embodiments may be implemented partial or full drain other areas of the protective layer. When performing etching to remove some section of the layer being etched, and push the front 460 etching.

For the operation of etching the part of the cycle, the controller 535 may generate a command in accordance with which the second valve 539 ensures the supply of gas provide the Etchant source 514 gas provide the Etchant into the chamber 500 processing, and the first valve 537 blocks the flow of the source gas from the source of 512 source gas into the processing chamber. The controller 535 may also regulate the power supplied by an RF source 548, and to control the suction pump 520 in synchronization with the control valve. The controller can also be used for regulating the gas pressure in the field of semiconductor wafer, the pressure is Not used to cool the back side of the semiconductor wafer, the bias on the substrate and different temperatures in synchronization with the control valve. Continuation of the cycle is the return to the Opera the AI formation of the protective layer, described above, and repeat alternating between operations cycle up until the required cyclic etch process. The controller 535 may generate a command in accordance with which the third valve 541 ensures a common gas source 516 total gases in the processing chamber during both operations cycle, if there is a common gas or mixture of gases necessary for the holding and the operation of forming the protective layer in the structure of the cycle and the etching operation.

Since during the operation of etching in a cyclic process uses ions with high energy to provide directional etching, then this operation can be carried out applying polymeropoulos gas. Among polymerbased gases include, for example, hydrocarbons, fluorocarbons and fluorocarbons type4F6C4F8CH3F, CH2F2CH4C3F6C3F8and CHF3. These polymeropoulos gases form a polymer layer, which is continuously deposited and is subjected to etching during the etching operation.

Table II is a table of some of the parameters that can be used when performing etching in the composition of the cyclic process in the preferred embodiment of the invention.

Table II
The preferred rangeA more preferred rangeThe most preferred range
The bias voltage>200 volts>300 volts>400 volts
Energy offset>200 eV>300 eV>400 eV

In a preferred embodiment, the duration of the cycle allocated for this operation is approximately 0.005 to 14 seconds. In a more preferred embodiment, the duration of the cycle allocated to this operation varies approximately in the range of 0.05-7 seconds. In the most preferred embodiment, the duration of the cycle allocated for this operation is approximately 0.25 to 2.5 seconds. In a preferred embodiment, during a single operation of the etching depth of the etching is increased by less than 500 Å. In a more preferred embodiment, during a single operation of etching the etching depth increases approximately in the range of 5-250 Å. In the most preferred embodiment, during a single operation of etching the etching depth increases approximately in the range of 10-50 Å. In case of change of the depth of the tra is of less than about 10 Å more precise is the description of this change, a fragment of a monolayer of material removed during a single etching operation. In one embodiment, the amount of material removed during a single etching operation, corresponds to approximately one monolayer. In another embodiment, the amount of material removed during a single etching operation, corresponds to less than one monolayer.

The depth of topological element in the figures may not match the scale. For example, the depth of etching can be shown far greater than the actual depth of the etching, so as to illustrate small changes in the depth of etching for the cycle can be difficult.

The cyclic process is repeated for many cycles. As shown in fig.4D, photoresist mask precipitated an additional protective layer 418. In this example, the remaining part of the old protective layer becomes part of a new protective layer 418. Then, as shown in figa, topological element is subjected to further etching through photoresist mask (step 312), resulting in a gain deeper contact window 416. In the preferred embodiment, this cycle or the modulation scheme gases with the provision of interchange transactions deposition and etching of torayca more than 3 times. In the preferred embodiment, this cycle is repeated more than 20 times. In the most preferred embodiment, this cycle is repeated at least 100 times.

In the absence of further etching the cyclic modulation process gas (step 312) ends. In the last cycle during the operation of etching can be carried out a complete etching of the protective layer, as shown in figa. However, subsequent processing stage after cyclic etch process can also be used to remove the protective layer and/or completion of the etch layer 408 oxide. To obtain the layer 408 oxide contact box 416, as shown in fig.4F can be performed additional processing steps of the type of relief photoresistive mask. Removing photoresists mask can be carried out in the chamber 500 treatment or after removal from the chamber 500 processing. Additional processing steps may also be required to remove the film on the bottom surface of the contact window.

In an alternative embodiment, the cyclic modulation process gases may be completed prior to the completion of the etching of the oxide that allows you to combine the stage conventional etching to the stage of completion of the etching. This may be desirable as a means to control the selectivity to the layer prevents etching, located on the oxide layer.

Examples of materials for photoresists masks can be called such photoresists new generation as a photoresist for the far UV, the photoresist to radiation with a wavelength of 193 nm photoresist to radiation with a wavelength of 157 nm, the photoresist for long-UV, electroporesis, roentgenologist and other Developed photoresist polymeric material of the old generation contain unsaturated connection-type double bonds C-C and phenolic groups, providing the desired high resistance to etching, namely, chemical inertness to a mixture of gases-etching agents. These ties are strong, and their destruction requires a high activation energy and therefore at relatively low energy ions photoresist old generation can have extremely low etching rate in a mixture of gases-etching agents. Photoresists more of the new generation, including photoresists for radiation with a wavelength of 193 nm and 157 nm may not contain these unsaturated bonds because these bonds absorb at the wavelength of the exposing radiation for lithography. The absence of these unsaturated bonds leads to a strong decrease in the resistance of photoresists for etching. Forming a protective coating on the photoresist when conducting cyclic etch process can significantly increase the resistance of the photoresist to trawley is even at high energy of bombarding ions. The high energy of bombarding ions, in which the invention improves the resistance of the photoresist for etching, are 50-2000 eV. In a preferred embodiment, the energy of the bombarding ions can be in the range of 200-1500 eV. In a preferred embodiment, the energy of the bombarding ions is 500-1000 eV.

Not taking into account the restrictions imposed by theory, believe that the cyclic processing provides an excellent (other) processing mode, since the properties of extremely thin films, deposited and subjected to etching in a short time scale, different from the properties of the thicker films. According to the method looping with modulation gases and short durations of periods of the cycle precipitated extremely thin protective layer of film on the side wall or film on the top surface of the photoresist. This film and the oxide film is subsequently etched in very small quantities during the next operation cycle. The thickness of the thin protective layer may vary in the range of values of the thickness of the monolayers (for example, submodules, monolayers or layers of a few atoms or molecules).

Getting thin protective layer in the range of values of the thickness of the monolayers depends on the deposition rate multiplied by the duration of deposition. Different is the combination of the deposition rate and the duration of deposition can be used to produce a thin protective layer in the range of values of the thickness of the monolayers. For example, a deposition process, providing the rate of deposition on the side wall of approximately 1 nm/s and the deposition rate on the top surface approximately 2 nm/s, allows to form a thin protective layer in the range of values of the thickness of the monolayers on the order of 0.5 nm, when the duration of the stage of deposition is in the cycle of 0.25-0.5 seconds (for example, a deposition rate of 1 nm/s × the duration of deposition of 0.5 seconds = layer thickness of 0.5 nm). The same range of values of the thickness of the monolayers can be obtained by increasing the deposition rate and reduce cycle time or by reducing the deposition rate and the increase in the duration of the cycle. This flexibility provides additional control variables.

Not taking into account the restrictions imposed by theory additionally believe that since the thickness of the protective film is approaching the size of the constituent molecules, for example when approaching monoclona the coating film can be purchased chemical and physical properties different from the bulk properties of the protective film. In this mode, the concept of a thin film can no longer be applied, and perhaps more precise is to consider a mixture of chemical particles on the surface and in the surface region of the material. Such particles may be present in the form of freely associated physically of Sorbian the x particles, as more strongly related chemisorbing particles or as part of larger entities, such as molecules, polymers, glasses or bulk crystals. These surface and near-surface particle will include protective particles deposited during the operation of forming the protective layer in the process of looping, but can also include particles, precipitated or selected during the operation of etching in the process looping, as well as other particles from the source substrate or particles that result from chemical reactions between different particles. The unique properties of the mode approaches the monolayer can follow from the interaction of these different from other surface and subsurface particles with one another and with the substrate material. These interactions are suppressed in the case of a thicker protective film that covers the substrate several or more numerous monolayers at each operation of forming the protective layer in the case which is why by the time of the beginning of the next operation of the etching remains open only the surface of the protective material.

Not taking into account the restrictions imposed by theory additionally believe that in the limiting case, when the surface during each cycle comes the unbounded flow, appropriate submonolayer the floor, during each operation of the protection and etching is implemented undoubtedly a new processing mode. In this case, the concept of alternating stages of processing becomes inaccurate in the microscopic scale, even though it is actually used for process control. A microscopic scale, the development of surface reaction occurs in accordance with the inlet and outlet of particles and chemical reactions of these particles. The reactions take place continuously, but may be interrupted by accidental exposure to particles with high energy ion type, which may cause high-temperature reactions. The most critical reaction proceeds during these brief moments of excitement. In the mode of formation of submonolayer when conducting loop surface shows a quasi-stable state when the flow of reactants reaching the surface, is essentially the average of the two different States of plasma reactions between mixtures of these particles.

I believe that this mode differs significantly from the traditional one-step etching at steady state as a mixture of particles reaching the surface, obtained from two different States of plasma. If the conditions of processing operations circular about the ECCA modulation gases combine in a single stage with maintaining a steady state, the resulting averaged in time the particle flux reaching the surface, will be modified due to the interaction of various gases in the plasma. I believe that the separation of state of the plasma in time when looping with modulation gases may allow to increase the controllability of the full mixture of substances reaching the surface, to a record extent. Conditions for two different loop operations can vary significantly from one another because of the possibility of modulation of the gaseous reagent. As a result of this you can get a variety of chemical species at different stages of the cycle and to create a mixture that cannot be obtained in the case of a one-step process at steady state. This mixture is a linear combination of the integrated UX densities of the two discrete States of the plasma generated by alternating loop operations. The ratio of these integrated flux densities is governed by the ratio of the durations of the periods of the cycle. Therefore, the ratio between the durations of the periods of the cycle becomes more variable process control.

Using the method of cyclic processing modulation allows gases to provide the mode of formation of the coating layer approaching the monolayer, and submonolayer (the range of values of the thickness of the mo is sloev), which can be implemented in the mode of short duration periods of the cycle. By sufficiently increasing the durations of the periods of the cycle can also implement the mode of formation of bulk protective layer with a thickness of the order of many monolayers, alternating with maintaining the conditions of etching. Between these two extreme cases, the durations of the periods of the cycle can be implemented in a great variety of modes to allow the balancing characteristics of desirable and undesirable results in two extreme cases of the method. Therefore patentable looping with modulation gases provides the flexibility to support all of these modes in this wide variety. Full cycle time therefore becomes an additional variable process control.

On figa-E presents a schematic illustration of the process of the buildup of material on the surface of patented quick Cycling using submodules. In this example, when each operation is a cyclic process to the surface attached particles, and the particles are attached at various operations. This is shown by the alternation of black and white circles above the surface for various operations. Circles represent molecules deposited substances in the gas f is see on the surface. On figa shows the original surface 804 of the side wall with vacant parcels 806 surface. Figv shows the result of the first operation is a cyclic process, during which the first particles 808 of molecules deposited substances in plasma during the first operation, deposited on areas 806 surface 804. You should note that not all sections 806 surface engaged during the first operation. Figs shows the result of the second operation, during which the deposited second particles 812 of molecules deposited substances obtained in the conditions of the plasma during the second operation, different from the first particles 808 of molecules deposited substances used during the first operation, due to modulation of the gaseous reagent and possibly other parameters of the process. As a result of the second operation to the surface treatment is added to less than one monolayer. Fig.8D shows the result of the first operation is a cyclic process next time. At this stage the formation of the monolayer is completed and begins the formation of the second layer. On file showing the result of several cycles, presents a mixed film, each layer of which is composed of different particles 808, 812, obtained during the first second operations.

On figa-D presents a schematic illustration of the process of the buildup of material on the surface in the regime of slower Cycling. This building is carried out under the same conditions as in the example illustrated in figa-E, with the only difference being the full cycle time is increased about ten times. On figa shows the original surface 904 with unoccupied areas 906. Figv shows the result of the first operation is a cyclic process, during which the first particles 908 of molecules deposited substances in plasma during the first operation, are deposited on the sections 906 surface 904 of the side wall. In this case, a few monolayers of the surface coating added during the first operation for the first time. Figs shows the result of the second operation is a cyclic process, during which the second particles 912 of molecules deposited substances obtained in the conditions of the plasma during the second operation, deposited on the layer formed by the first particles 908 of molecules deposited substances. During the second surgery for the first time to the surface treatment is added to a few monolayers. On fig.9D showing the result of one and a half cycles, the structure of two different alternating films, the image is affected multilayer film, composed of layers of the first particles 908 and second particles 912, each of which is received during a single operation of the cyclic process.

The presented examples demonstrate qualitatively different microscopic results that can be achieved when a full cycle time becomes comparable with the time required for the deposition of a single monolayer surface. I believe that various surface films formed in these two examples, can match the results of various processes on the structures of the semiconductor wafer, based solely on the variation of the full cycle time. This is a simple example of deposition as the only surface mechanism, but similar arguments can be applied to more complex combinations of surface mechanisms. For example, the surface, which in turn is exposed to the deposited substances and particles provide the Etchant in the rotation operations of the cyclic process, can also demonstrate the modification of their properties, when the total cycle time becomes comparable with the time required for deposition or etching of a single monolayer surface.

As stated above, I believe that the use of alternating stages of protection and etching poses which enables you to reduce broadcast, fasterova and provides improved controllability of the etching process. Not taking into account the restrictions imposed by theory, believe that to obtain the unique properties of the coating, which promotes the reduction of broadcasti and facetiously and to ensure better control of the etching process, you can manage and modify the mode of forming a protective coating layer approaching the monolayer, and submonolayer, the receipt of which is provided by cyclic modulation process gases, and protection when using the method of alternating stages of processing.

The layer is subjected to etching, may be a dielectric layer (silicon oxide), a conductor layer (a type of metal and silicon or another semiconductor type), a layer of hard mask (for example, nitride or oxynitride silicon) or a barrier layer (for example, nitride or silicon carbide). For etching of the conductor layer during etching can be used halogen-free type chlorine, fluorine or bromine, where the deposited material may contain chemicals used for the deposition of thin films with a high content of carbon or a thin film containing Si. In a preferred embodiment, the layer is subjected to etching, is made of a material of the dielectric type of silicon oxide, doped silicate glass, or in the form of a film of a dielectric with a low dielectric constant type organosilica the aqueous glass or SiLK.

The processing stage in the process loop with modulation gases can be performed using the same flow of carrier gas while forming the protective layer, and etching, while the reagents for the formation of a protective layer and a reagent for etching served with alternation. In addition, RF power, temperature and/or pressure can pulsate in sync with the flow of gas to ensure optimal conditions for conducting each operation in the cyclic modulation process gases.

In another embodiment, alternating delivery of the entire gas mixture of carrier gas and reactants. RF power, temperature and/or pressure may also pulsate in sync with the flow of gas to ensure optimal conditions for every stage in a cyclic process of modulation gases. In another embodiment, the same gases can be used to hold both phases, but the ratio of flow rates can vary at each stage. Therefore, to supply gaseous reagents at two different stages of cyclic modulation process gases, it is possible to use two completely different gas or the same carrier gas, and various active gases, or the same gases with different relations of speed p the currents.

In the example of various gaseous reactants and using the same flow of carrier gas while forming the protective layer, and etching during the formation of the protective layer of the gas-provide the Etchant source gas provide the Etchant in the plasma chamber is terminated. This can be done by stopping the supply of the component gas provide the Etchant or the source gas. For example, oxygen or oxygen-containing gas is a key component for gas provide the Etchant. Even in case of using With4F6in gas-provide the Etchant etching cannot be performed in this example by using4F6in the absence of oxygen. Therefore, the supply of oxygen or oxygen-containing gas during the operation of forming the protective layer is a way to provide for the interruption of gas supply-provide the Etchant during the operation of forming the protective layer, even if the power4F6in the process of forming the protective layer continues. In a preferred embodiment, the process of forming the protective layer to produce a protective coating is not accompanied by etching or the biggest accompanied neznachitelnym etching (the layer being etched is less than 10%). Such a deposition process may be carried out on m is todo-stimulated plasma, PFHO or spraying, as PFHA and the spray is not used for etching.

If the source gas is the same as polymeropoulos component when conducting stage of etching, the source gas can be fed during the operation of etching. In addition, to provide a directional etch bias during the operation of etching can be increased capacity.

Some of the operations of deposition and the presence polymeropoulos component to ensure polymerization during the operation of etching allows to increase the speed of etching and improve the anisotropy etching to use provide the Etchant ions with higher energy. Save passivating gases in a gas mixture of stain avoids unacceptable erosion and damage to the mask for etching using ions with a higher energy. In addition, during the operation of etching may be anisotropic etching. The use of a cyclic process with alternating operations of forming the protective layer and etching steps ensures optimization of the protection mask. This method allows you to avoid interactions of gaseous travita and gases, inhibiting etching, in the discharge. For example, can be selected original mix chemicals, forming more rigid and more durable coating than in the case of Messi for etching. In addition, the state parameters of the source reagents of the type of pressure and concentration can be chosen to optimize the properties of the formed protective layer, such as the composition and thickness.

Desirable may be preventing the mixing of some of the components of the source gas with the gaseous components provide the Etchant, as some mixing reduces the separation efficiency of operations deposition and etching. As a result, in such cases, the controller synchronizes the streams modulated gases so that the depletion of one gas came to add another gas.

When conducting independent operations of forming the protective layer and etching/passivation process conditions of temperature type, power, pressure, ion energy and process gases can be independently controlled and adjusted to the optimum conditions for carrying out each operation.

Argon or other inert gases can be used as carrier gases and the formation of a protective layer and etching. Another example of the inert gas is neon.

In the example of the invention, the wall areas of the camera that may come into contact with plasma (a mixture of chemicals and charged particles, supported by electrical discharge), are made so as to have as less PLO the location area and that they can maintain elevated temperatures. This helps prevent occurrence of so-called memory effect of the camera, which may be the selection of the chemical elements contained in the coating on the wall sections of the chamber formed at one stage of processing, and these chemicals can interfere with the conduct of the subsequent stages. By minimizing the full deposition at the wall parts of the camera, this effect can be reduced and undesirable interaction with secreted chemical elements when performing two different operations that contribute to the performance deterioration can be prevented.

Desirable can be the achievement of a very short time of passage of gas from the source of the precursor to the processing chamber. At the same time, stabilization of the gas flow, denoting the time required to establish the desired constant flow, and the time for complete disappearance of the mentioned gas from the processing chamber, is very short and the transition from one stable composition of the gas mixture to the next can be done very quickly. The purpose of this is to prevent possible mixing of chemicals when performing two different operations, which can degrade performance.

Desirable can also be achieving a high response speed of the electric system and the hildren management managing the conversion of electric power into the electric discharge on change of conditions of discharge and energy needs. In addition, desirable may be the possibility of rapid changes and stabilization of other, external to the camera processing conditions, such as the pressure of the gas mixture and the temperature of the substrate semiconductor wafer. Enabling rapid changes in such conditions can reduce the total time of the cycle and to vary the conditions of processing significantly between operations for individual optimization of each of the reactions. What is desired, therefore, can also be the presence of a computerized system capable of managing and synchronizing the fast modulation processing conditions. A computer system is used to send commands to the required periodic changes and synchronize these commands using the specified time delays for different devices, providing many changes of conditions in the processing chamber.

In other embodiments of the invention in the cyclic process can be entered one or more additional operations. For example, cyclic modulation process gas can consist of six operations: three operations deposition and three etching steps in a single cycle. The restriction on the introduction the of additional operations may be an increase in the complexity of each cycle.

In another embodiment, the etching operation can be performed without polymeropoulos gas. In another example embodiment of the invention may be two operations etching instead of the operation of the deposition and etching. In this embodiment, a single etching operation can be carried out under the condition processing by etching, providing a tapered profile, while the second etching operation can be carried out under the condition processing by etching, which involves retrieving curved profile. In the mode of short duration periods of the cycle when each operation cycle may be less than one modification, approximately one or more monolayers of the surface subjected to etching. In this case, the alternation of two different etching steps provides improved process control. Repeated use of the method of cyclic modulation of gases makes it possible to bring to the surface a mixture of particles that cannot be obtained in the case of a one-step process at steady state. By changing the relationship between the durations of the periods of the cycle is provided and easy to adjust the ratio between the particles obtained in each operation. In another example embodiment of the invention may be two operations aside the Oia and a single etching operation. In another example embodiment of the invention may be a single deposition operation and two operations etching. In still another example embodiment of the invention may be a sequence of cyclic processes of modulation gases, each cyclic process is different from other full duration of the cycle, the ratio between the durations of the periods of the cycle and/or treatment conditions for individual operations. These conditions include the compositions of the gases, the flow rate of gases, RF power, pressure and/or temperature.

Example

In the specific example application of the invention in the case of etching patterns of contact with a high ratio of height to width for camera 500 used intended for etching of dielectrics system Exelan® HPT production Lam research Corporation (Lam Research Corporation™) (Fremont, California). Semiconductor wafer used in this example, a layer of SiO2the thickness of 2.1 μm, photoresist the mask pattern and the antireflective coating on the bottom surface (BARC) between the layer of SiO2and photoresistive mask. A layer of SiO2in this example, receive as a result of deposition by the method of stimulated plasma, PFHO using tetraethylorthosilicate (TEOS) as precursor. On photoresistive mask to form the pattern according to the method fot the lithography with a wavelength of 193 nm to obtain the critical size of the contact of 0.16 μm or less.

In this example, the preparation of the structure (step 306) for cyclic etching modulated gas is a step of etching the BARC. In this example, the step of etching the BARC can be a one of many famous stages of etching the BARC.

After completion of the etching of the BARC perform cyclic process in the system Exelan HPT etching of dielectrics. In this example, which uses the system Exelan HPT etching of dielectrics without modification, the damping of the plasma is carried out twice in each cycle: at the end of operation 316 forming the protective layer, and at the end of operation 320 etching. Damping of the plasma provides flexibility during periods of transition. In this case, a few seconds is required to stabilize the flow of gas and pressure, and to prepare for the next stage of processing. But with suppressed plasma this transition has little impact on the results of the process or has no effect at all. For re-ignition of the plasma at the beginning of each operation of the etching in the first 2 seconds of phase etching using higher pressure and lower RF power than the rest of the time this operation. This period of operation, etching, during which the ignition of the plasma, is considered part of the full duration of the etching operation. When calculating the total processing time, total cycle time and relative is placed between the durations of the periods of the cycle are taken into account only periods of time burning plasma. Therefore, performing nominally 320-second cyclic process in real time actually lasts much longer. This inefficient use of time is the main drawback of this method. However, this method provides patentable results on an unmodified system.

Operation 316 forming the protective layer in a cyclic process is determined by the following technological parameters. The pressure in the field of semiconductor wafer 120 of millitorr, and applied RF power at frequencies of 27 MHz and 2 MHz to 500 watts. Speed of process gases under standard conditions is 500 cm3/min for argon and 30 cm3/min for CH3F. Electrostatic holder has a temperature of 35°C. the helium Pressure on the back side of the substrate from the side of the holder is 15 So In this example, the source 512 source of gas supplies CH3F, which is not available in the etching process. Argon can be supplied from an additional source 516 gas as argon is used for deposition and etching. To initiate an operation of forming a protective layer controller 535 opens the first valve 537 and closes the second valve 539. The controller also controls the flow of argon gas from the additional gas source. In addition, as indicated above, the controller 535 reg is the working capacity and other parameters.

Operation 320 etching cyclic process 312 is defined by the following process parameters. The pressure in the semiconductor wafer 55 of millitorr, and applied RF power at a frequency of 27 MHz is 1000 watts and at a frequency of 2 MHz to 1800 watts. The speed of the process gas at standard conditions is 270 cm3/min for argon, 9 cm3/min for C4F6and 10 cm3/min for O2. With4F6is polymeropoulos gas, which provides the polymerization in the process of etching. About2is gas, initiating etching. Despite the use of fluorine from C4F6when etching, fluorine in this example requires the presence of oxygen to initiate etching. The holder has a temperature of 35°C. the helium Pressure on the back side of the substrate from the side of the holder is 15 So In this example, the source 514 gas provide the Etchant supplies4F6and O2that is not served during the operation of forming the protective layer, but With4F6without oxygen may be used for deposition. To initiate an operation of etching the controller 535 closes the first valve 537 and opens the second valve 539. The controller also controls the flow of argon gas from the additional gas source. In addition, as indicated above,the controller 535 regulates power and other parameters.

In this example, within 50 seconds of conduct etching of the BARC (step 308). Then for 320 seconds perform cyclic process (step 312), and periods of suppressed plasma does not take into account the duration of the operation or the full duration of the cycle. The duration of the operation 316 forming the protective layer is 2 seconds. The duration of the operation 320 etching - 6 seconds, with 2 seconds on the plasma ignition. Therefore, the total cycle time is 8 seconds, and the ratio between the durations of the periods of the cycle - 1:3 (operation of forming the protective layer:etching operation). The cycle is repeated 40 times. After completion of the cyclic process (step 312), the photoresist is removed.

In figures 6 and 7 presents obtained by scanning electron microscope micrograph showing the results of etching the matrix contacts high density with a nominal critical dimension of the contact Windows of 0.16 μm. The total depth of etching was insufficient to achieve layer prevents etching, silicon nitride, so that these results represent a partial etching process, often used for evaluating the performance of the etching.

You should note that the contacts show a small degree of broadcasti observed in the form of the imperfect form of circles 604. The absence of cyclic obrabotkata usually in this case, the use of etching to the emergence of a much stronger broadcasti.

The figure 7 presents the side view of the etched contacts 704 after removal of the photoresist. You should note that the etching profile is clearly vertical neznachitelnym bend near the upper surface. Near the bottom surface of topological element has a taper that is usually characteristic of partial etching. This taper is usually removed at the completion of etching of topological element, for example at the opening of the layer prevents etching. The etching depth is approximately 2 μm. There are no signs of interruption of the etching, which could indicate a much smaller depth of etching some contacts in comparison with other contacts. The overall results of this etching point to the possibility of using a cyclic process during etching of the contact with a high ratio of height to width, allowing to obtain an acceptable etching profile and low broadcast and to avoid interrupting the etching. Despite the inability of optimization, this example helps to demonstrate that the invention allows to obtain excellent performance.

In the preferred embodiment, the process installation modify so as to provide the ability to perform this installation predpochtitel the wow version of the process, for fast modulation gases eventually stabilize stream <1 second. In this embodiment, the plasma remains lit for the duration of the cyclic process 312 and extinguish the plasma does not occur.

Figa and 10B illustrate a computer system 1000 with the ability to implement the controller 535 used in the embodiments of the present invention. On figa presents one possible physical form of the computer system. Of course, the computer system may have many physical forms ranging from integrated circuits, printed circuit boards and small handheld devices to large supercomputer. In the computer system 1000 includes a monitor 1002, the display 1004, building 1006, the drive 1008, keyboard 1010 and mouse 1012. Disk 1014 is a computer-readable media used to transfer data to the computer system 1000 and from the system.

On FIGU presents an example block diagram for a computer system 1000. To the system bus 1020 attached many subsystems. The processor(s) 1022 (also referred to as Central processing units or CPUs) connected with storage devices, including memory 1024. Memory 1024 includes a random access memory (RAM) and permanent memory (ROM). As is known to experts in the art, the memory ROM prednaznachendlya transfer data and commands in the same direction - to the CPU, a RAM is typically used to transfer data and commands in both directions. Storage device, both of these types can include any suitable computer-readable media described below. Non-removable disk 1026 is also connected to the CPU 1022 with the possibility of transfer data in two directions; this disc provides additional data storage, and may also include any computer-readable media described below. Non-removable disk 1026 may be used to store programs, data and TPI is typically a secondary storage medium (hard drive type), which has lower performance in comparison with the primary media. It should be understood that the information stored on non-removable disk drive 1026, as appropriate, may be included in a standard way in a virtual memory in memory 1024. Removable disk 1014 may take the form of any computer-readable media described below.

CPU 1022 is also connected to many devices, I/o, display type 1004, keyboard 1010, mouse 1012 and 1030 speakers. In General, the device I/o can be a video display, trackball, mouse, keyboard, microphone, touch screen, card reader Converter, the magnetic reader who or paper tapes, graphics tablet, stylus, voice recognition or handwriting, the reader, biometric data, or other computer. Using the network interface 1040 CPU 1022 can be connected to another computer or data transmission network. Assume that with such a network interface CPU will be able to receive information from the network or display information to the network during the execution of the phases described above. In addition, examples of the method which is the subject of the present invention can be implemented solely on the CPU 1022 or on a network such as the Internet in conjunction with a remote CPU that will perform part of the processing.

In addition, embodiments of the present invention is additionally related to software products for storage devices, computer-readable media on which is stored computer code for performing various computer-implemented operations. The media and computer code may be specially designed and created for the purposes of implementation of the present invention or they may be generally known and available to specialists in the field of software. Examples include computer-readable media can be called magnetic storage media type hard disks, floppy disks, and magnetic tape; the optical storage media such as CD-ROMs and holographic devices; magneto-optical storage media type fototechnik disks; and hardware devices that are specially configured to store and execute code, such as integrated circuits applied orientation (ASIC), programmable logic devices (PLD), and the storage device ROM and RAM; and other examples of computer code can be called computer code type code generated by the compiler, and files containing code higher level, which is executed by the computer using an interpreter. Computer-readable media may store computer code, the transmission of which by using a computer data signal on a carrier wave and represents a sequence of commands that are executable by the processor.

Although the present invention has been described in terms of several preferred embodiments, there are alterations, permutations, modifications of the invention and various alternative equivalents, is not beyond the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and facilities that are the subject of the present invention. Therefore, it should be borne in mind that the following claims should be interpreted taking into account all such MEAs the developments rearrangements, modifications of the invention and various alternative equivalents as not beyond the true essence and scope of the present invention.

1. Method of etching a topological element in the layer through a mask for etching on the substrate containing the execution phase of the cyclic modulation process gases for more than three cycles, each cycle consists of the steps:

the operation of forming the protective layer using the first gaseous reactant from the source of gaseous reagent, and the operation of forming the protective layer is carried out for about 0,0055-7 for each cycle, and this operation of forming the protective layer includes the steps of: feeding the source gas; and forming a plasma from the source gas;

and perform etching for etching the topological element through a mask for etching using the second gaseous reactant, using reactive gaseous reagent is to provide the Etchant, where the first gaseous reactant is different from the second gaseous reactant, and the etching operation is performed in a period of approximately 0.005 to 14 for each cycle, and the operation of etching includes the steps of: feeding a reactive gas provide the Etchant; and forming a plasma from the reactive gas provide the Etchant.

2. The method according to claim 1, Otley is audica fact, as a result of the operation of forming the protective layer a layer of a thickness of less than 100 Å.

3. The method according to claim 1, characterized in that the operation of forming the protective layer a layer thickness of approximately 1-10 Å.

4. The method according to claim 1, characterized in that the operation of etching includes the step of applying to the substrate the energy of bombarding ions above 200 eV.

5. The method according to claim 1, characterized in that the second gaseous reactant contains polymeropoulos component and the component initiating the etching.

6. The method according to claim 1, wherein the operation of forming the protective layer and the etching operation is performed in the total plasma chamber.

7. The method according to claim 1, characterized in that during the operation of forming the protective layer using non-directional deposition, and during the operation of etching using directional etching.

8. The method according to claim 7, characterized in that the non-directional deposition is carried out by chemical vapour deposition and/or sputtering.

9. The method according to claim 1, characterized in that the mask for etching is photoresist mask obtained by the method of photolithography with a length of radiation of 193 nm or less.

10. The method according to claim 1, characterized in that the step of the cyclic process is sa modulation gases further comprises a third operation.

11. The method according to claim 1, characterized in that at each operation of forming the protective layer receive submodels.

12. The method according to claim 1, characterized in that it further comprises the step of regulating the duration of the operation of forming the protective layer, and etching is performed to adjust the cyclic modulation process gases.

13. The method according to claim 1, characterized in that the cyclic process of modulation gases is carried out for more than 20 cycles.

14. The method according to claim 1, characterized in that the cyclic process of modulation gases is carried out for at least 100 cycles.

15. The method according to claim 1, characterized in that it further comprises the steps of: interrupting the cyclic modulation process gases prior to the completion of the etching layer; and carrying out an acyclic etching to complete the etching of the layer.

16. The method according to claim 1, characterized in that each cycle has a period of approximately 0.01 to 21 C.

17. Installation for etching topological element in the layer through a mask for etching on the substrate containing:

a processing chamber within which may be placed substrate;

the first source of gaseous reagent for supplying a first gaseous reactant comprising a source of gaseous reagent;

the second source of gaseous Reagan the and for supplying a second gaseous reactant comprising reactive gaseous reagent-provide the Etchant;

a controller, connected to the first source of gaseous reactant and a second source of gaseous reactant with the ability to control these sources, and the controller contains computer-readable media to perform a cyclic modulation process gases for more than three cycles in a computer-readable storage medium contains computer commands to perform the operation of forming the protective layer using the first gaseous reactant from the source of gaseous reagent, and the operation of forming the protective layer is within about 0,0055-7 for each cycle, and computer commands to perform the operation of forming the protective layer include:

computer commands to supply the source gas;

computer commands for forming a plasma from the source gas;

and computer commands to perform etching for etching the topological element through a mask for etching using the second gaseous reactant, using reactive gaseous reagent is to provide the Etchant, where the first gaseous reactant is different from the second gaseous reactant, and the etching operation is performed in a period of approximately 0.005 to 14 for each cycle, and computer to the team to perform etching contain computer commands for supplying reactive gas provide the Etchant; and computer commands for forming a plasma from the reactive gas provide the Etchant.

18. Installation according to 17, characterized in that it further comprises at least one source of RF power, controlled by the controller; at least one pressure regulator, controlled by the controller; and at least one temperature controller, controlled by the controller, and the controller further comprises computer commands to change the power from the source of RF power during the various operations of the cyclic modulation process.

19. Installation according to 17, wherein the computer commands to perform etching for etching topological element further containing computer commands for submission to the substrate energy of bombarding ions above 200 eV.

20. Installation according to 17, wherein the computer commands to perform the operation of forming the protective layer using the first gaseous reactant by deposition ensure the operation of forming a protective layer over 0.25 to 2.5 seconds for each cycle.

21. Installation according to 17, wherein the computer commands to perform etching for etching the topological element through a mask for etching using the second gaseous reactant, and the use of reactive gaseous reagent is to provide the Etchant, ensure the operation of etching within the 0.05-7 for each cycle.

22. Installation according to 17, characterized in that the second gaseous reactant contains polymeropoulos component and the component initiating the etching.

23. Installation according to 17, wherein the computer-readable code to perform the operation of forming the protective layer provides a non-directional deposition, and computer-readable code to perform the operation of etching provides directional etching.

24. Installation according to item 23, wherein the non-directional deposition is carried out by chemical vapour deposition and/or sputtering.

25. Installation according to 17, characterized in that the mask for etching is photoresist mask obtained by the method of photolithography with a length of radiation of 193 nm or less.

26. Installation according to 17, wherein the computer-readable storage medium for performing a cyclic process of modulation further comprises computer commands to perform the third operation.

27. Installation according to 17, wherein the computer-readable storage medium for performing a cyclic process of modulation gases ensures execution of cyclic modulation process gases for more than 20 cycles.

28. Installation PP and 27, featuring the jaś fact, computer-readable media to perform a cyclic process of modulation gases ensures execution of cyclic modulation process gases over more than 100 cycles.

29. Installation for etching topological element in the dielectric layer through a mask for etching on the substrate containing:

a processing chamber within which may be placed substrate;

the first source of gaseous reagent for supplying a first gaseous reactant comprising a source of gaseous reagent;

the second source of gaseous reagent for supplying a second gaseous reactant comprising reactive gaseous reagent-provide the Etchant;

a controller, connected to the first source of gaseous reactant and a second source of gaseous reactant with the ability to control these sources, and the controller contains computer-readable media to perform a cyclic modulation process gases for more than twelve cycles, and computer-readable storage medium contains:

computer commands to perform the operation of forming the protective layer using the first gaseous reactant from the source of gaseous reagent, and the operation of forming the protective layer is performed is camping for about 0.25 to 2.5 sec for each cycle, and computer commands to perform the operation of forming a protective layer containing computer commands to supply the source gas; and computer commands for forming a plasma from the source gas;

as well as computer commands to perform etching for etching the topological element in the dielectric layer through a mask for etching using the second gaseous reactant, using reactive gaseous reagent is to provide the Etchant, where the first gaseous reactant is different from the second gaseous reactant, and the etching operation is performed within about 0.05-7 for each cycle, with computer commands to perform the operation of etching include: computer commands for supplying reactive gas provide the Etchant containing polymeropoulos component and the component initiating the etching; computer commands for forming a plasma from the reactive gas provide the Etchant; and computer commands for feed on a substrate energy of bombarding ions above 200 eV.

30. Installation according to clause 29, characterized in that it further comprises:

at least one source of RF power, controlled by the controller;

at least one pressure regulator, controlled by the controller;

and at least one temperature controller, problemy controller, moreover, the controller further comprises computer commands to change the power from the source of RF power during the various operations of the cyclic modulation process.

31. Installation according to clause 29, wherein the computer commands to perform the step of forming a protective layer provide a non-directional deposition, and computer commands to perform etching provide the directional etching.

32. Installation p, characterized in that the non-directional deposition is carried out by chemical vapour deposition and/or sputtering.

33. Installation according to clause 29, wherein the mask for etching is photoresist mask obtained by the method of photolithography with a length of radiation of 193 nm or less.

34. Installation for etching topological element in the dielectric layer through a mask for etching on a substrate, comprising: a processing chamber within which may be placed substrate;

the first source of gaseous reagent-provide the Etchant for supplying a first gaseous reactant-provide the Etchant;

the second source of gaseous reagent-provide the Etchant for supplying a second gaseous reactant-provide the Etchant;

a controller, connected to the first source of gaseous reagent-provide the Etchant and the second source gotoblas the second reagent-provide the Etchant with the ability to control these sources, where the controller contains computer-readable media to perform a cyclic modulation process gases over at least three cycles in a computer-readable storage medium contains:

computer commands to perform the first operation of the etching, the first etching operation is performed for about 0,0055-14 for each cycle, and computer commands for performing the first etching operation contain computer commands to supply the first gas provide the Etchant; and computer commands for forming a plasma from the first gas provide the Etchant;

as well as computer commands to perform the second operation of the etching and the second etching operation is performed for about 0,0055-14 for each cycle, and computer commands to perform the second operation of the etching contain computer commands to supply the second gas provide the Etchant, where the first gas-provide the Etchant different from the second gas provide the Etchant; and computer commands for forming a plasma from the second gas provide the Etchant.

35. Method of etching a layer over the substrate containing the execution phase of the cyclic process for at least 3 cycles, and each cycle consists of the steps:

performing the first etching operation, and the first etching operation to perform Aut for about 0,0055-14 for each cycle, containing the steps: feeding a first gas provide the Etchant; and forming a plasma from the first gaseous provide the Etchant;

and performing a second etching operation and the second operation perform etching for about 0,0055-14 for each loop containing steps: feeding a second gas provide the Etchant, and the first gaseous provide the Etchant different from the second gaseous provide the Etchant; and forming a plasma from a second gaseous provide the Etchant.



 

Same patents:

FIELD: physics; electricity.

SUBSTANCE: etching system contains plasma-generating facilities for plasma generating in vacuum chamber, high-frequency displacement voltage source, supplying high-frequency displacement voltage to electrode-substrate, floating electrode opposite to electrode-substrate in vacuum chamber and supported in floating condition by electric potential, solid material placed on the side of the floating electrode directed to electrode-substrate to form film layer protecting from etching, and control unit for periodic supply of high-frequency voltage to floating electrode. Etching method includes repetition, in specified sequence, of substrate etching stage by means of etching gas supplied to vacuum chamber, and film layer formation stage protecting substrate from etching by sputtering of solid material opposite to substrate.

EFFECT: high etching selectivity when using mask as well as production of anisotropic profile and great etching depth.

22 cl, 7 dwg

FIELD: electronics; semiconductor devices and methods for etching structures on their wafers.

SUBSTANCE: plasmochemical etching of material is conducted by way of acting on its surface with ion flow of plasma produced from plasma forming gas filling evacuated camber, electron beam being used to act upon plasma forming gas for plasma generation. Constant longitudinal magnetic field with flux density of 20-40 Gs is built on axis, plasma-generating gas pressure is maintained within chamber between 0.01 and 0.1 Pa, and electron beam at current density of 0.1-1 A/cm2 ensuring ignition of beam-plasma discharge is used. Etching condition (energy and ion current density) can be controlled ether by modulating electron beam with respect to speed or by varying potential of discharge collector.

EFFECT: enhanced etching efficiency (speed) and quality of etching structures on semiconductor material surface: high degree of etching anisotropy preventing etching under mask, minimized material structure radiation defects brought in during etching.

2 cl, 1 dwg

FIELD: plasma reaction gas, its production and application.

SUBSTANCE: proposed plasma reaction gas has in its composition chain-structure perfluoroalkyne incorporating 5 or 6 atoms of carbon, preferably perfluorine-2-pentyne. This plasma reaction gas can be found useful for dry etching to produce precision structure, for plasma chemical precipitation from vapor phase, for producing thin film, and for plasma chemical incineration. Plasma reaction gas is synthesized by way of bringing dihydrofluoroalkyne or monohydroalkyne in contact with basic compound.

EFFECT: enhanced economic efficiency of highly selective gas production for plasma reaction on industrial scale.

18 cl

FIELD: production of dirt-free laser mirrors.

SUBSTANCE: proposed method for producing dirt-free surfaces of materials chosen from group incorporating GaAs, GaAlAs, InGaAs, InGaAsP, and InGaAs on mirror facets of chip for GaAS based laser resonators includes shearing of laser mirror facet in ambient atmosphere incorporating normal air, dry air, or dry nitric media. Oxides and other pollutants produced in the course of ambient atmosphere impact on mirror facets are removed by dry etching in vacuum. Then natural nitride layer is grown on mirror facets using nitrogen treatment. Such facet treatment ensures minimized light absorption and surface recombination.

EFFECT: facilitated procedure, enhanced economic efficiency and yield due to high reproducibility.

37 cl, 5 dwg

FIELD: microelectronics, micro- and nano-technology.

SUBSTANCE: proposed method for producing submicron and nanometric structure includes formation of embossed structures on substrate surface, application of film to reduce embossed structure size to submicron and nanometric dimensions, and etching, anisotropic and selective relative to film material and source embossed layer, in chemically active plasma of structure obtained together with substrate material until embossed structure of submicron and nanometric dimensions, twice as deep as its width, is obtained.

EFFECT: provision for transferring mask pattern to bottom layer of substrate measured in terms of submicron and nanometric values.

2 cl, 3 dwg

FIELD: engineering of semiconductor devices.

SUBSTANCE: invention concerns method and device for etching dielectric, removing etching mask and cleaning etching chamber. In etching chamber 40 semiconductor plate 56 is positioned. Dielectric 58 made on semiconductor plate is subjected to etching, using local plasma, produced by special device for producing local plasma during etching process. Mask for etching 60 is removed by means of plasma from autonomous source 54, generated in device for producing plasma from autonomous source connected to etching chamber. Etching chamber after removal of semiconductor plate is subjected to cleaning, using either local plasma, or plasma from autonomous source. To achieve higher level of cleaning, it is possible to utilize a heater, providing heating for chamber wall.

EFFECT: increased efficiency.

2 cl, 4 dwg

FIELD: process equipment for manufacturing semiconductor devices.

SUBSTANCE: plasma treatment chamber 200 affording improvement in procedures of pressure control above semiconductor wafer 206 is, essentially, vacuum chamber 212, 214, 216 communicating with plasma exciting and holding device. Part of this device is etching-gas source 250 and outlet channel 260. Boundaries of area above semiconductor wafer are controlled by limiting ring. Pressure above semiconductor wafer depends on pressure drop within limiting ring. The latter is part of above-the-wafer pressure controller that provides for controlling more than 100% of pressure control area above semiconductor wafer. Such pressure controller can be made in the form of three adjustable limiting rings 230, 232, 234 and limiting unit 236 on holder 240 that can be used to control pressure above semiconductor wafer.

EFFECT: enhanced reliability of pressure control procedure.

15 cl, 13 dwg

FIELD: plasma-chemical treatment of wafers and integrated circuit manufacture.

SUBSTANCE: proposed device that can be used in photolithography for photoresist removal and radical etching of various semiconductor layers in integrated circuit manufacturing processes has activation chamber made in the form of insulating pipe with working gas admission branch; inductor made in the form of inductance coil wound on part of pipe outer surface length and connected to high-frequency generator; reaction chamber with gas evacuating pipe, shielding screens disposed at pipe base, and temperature-stabilized substrate holder mounted in chamber base. In addition device is provided with grounded shield made in the form of conducting nonmagnetic cylinder that has at least one notch along its generating line and is installed between inductor and pipe; shielding screens of device are made in the form of set of thin metal plates arranged in parallel at desired angle to substrate holder within cylindrical holder whose inner diameter is greater than maximal diameter of wafers being treated. Tilting angle, quantity, and parameters of wafers are chosen considering the transparency of gas flow screen and ability of each wafer to overlap another one maximum half its area. In addition substrate holder is spaced maximum four and minimum 0.6 of pipe inner diameter from last turn of inductance coil; coil turn number is chosen to ensure excitation of intensive discharge in vicinity of inductor depending on generator output voltage and on inner diameter of pipe using the following equation:

where n is inductance coil turn number; U is generator output voltage, V; Dp is inner diameter of pipe, mm.

EFFECT: enhanced speed and quality of wafer treatment; reduced cost due to reduced gas and power requirement for wafer treatment.

1 cl, 6 dwg, 1 tbl

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying octafluoropropane. Method is carried out by interaction of crude octafluoropropane comprising impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that are able to remove indicated impurities up to the content less 0.0001 wt.-% from indicated crude octafluoropropane. The impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurities represent at least one compound taken among the group consisting of chloropentafluoroethane, hexafluoropropene, chlorotrifluoromethane, dichlorodifluoromethane and chlorodifluoromethane. Adsorbent represents at least one substance taken among the group consisting of activated coal, molecular sieves and carbon molecular sieves. Crude octafluoropropane comprises indicated impurities in the amount from 10 to 10 000 mole fr. by mass. Invention proposes gas, etching gas and purifying gas comprising octafluoropropane with purity degree 99.9999 wt.-% and above and containing chlorine compound in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluoropropane.

EFFECT: improved purifying method.

13 cl, 11 tbl, 12 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying octafluorocyclobutane. Method is carried out by interaction of crude octafluorocyclobutane containing impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that is able to eliminate indicated impurities up to the content less 0.0001 wt.-% from the mentioned crude octafluorocyclobutane. Impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurity represents at least one fluorocarbon taken among the group consisting of 2-chloro-1,1,1,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-1,1,2,2-tetrafluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, hexafluoropropene and 1H-heptafluoropropane. Adsorbent represents at least one of representatives taken among the group including activated carbon, carbon molecular sieves and activated coal. Crude octafluorocyclobutane interacts with the mentioned impurity-decomposing agent at temperature from 250oC to 380oC. Invention proposes gas, etching gas and purifying gas including octafluorocyclobutane with purity degree 99.9999 wt.-% and above and comprising fluorocarbon impurity in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluorocyclobutane.

EFFECT: improved purifying method.

26 cl, 13 tbl, 10 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying octafluorocyclobutane. Method is carried out by interaction of crude octafluorocyclobutane containing impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that is able to eliminate indicated impurities up to the content less 0.0001 wt.-% from the mentioned crude octafluorocyclobutane. Impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurity represents at least one fluorocarbon taken among the group consisting of 2-chloro-1,1,1,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-1,1,2,2-tetrafluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, hexafluoropropene and 1H-heptafluoropropane. Adsorbent represents at least one of representatives taken among the group including activated carbon, carbon molecular sieves and activated coal. Crude octafluorocyclobutane interacts with the mentioned impurity-decomposing agent at temperature from 250oC to 380oC. Invention proposes gas, etching gas and purifying gas including octafluorocyclobutane with purity degree 99.9999 wt.-% and above and comprising fluorocarbon impurity in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluorocyclobutane.

EFFECT: improved purifying method.

26 cl, 13 tbl, 10 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying octafluoropropane. Method is carried out by interaction of crude octafluoropropane comprising impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that are able to remove indicated impurities up to the content less 0.0001 wt.-% from indicated crude octafluoropropane. The impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurities represent at least one compound taken among the group consisting of chloropentafluoroethane, hexafluoropropene, chlorotrifluoromethane, dichlorodifluoromethane and chlorodifluoromethane. Adsorbent represents at least one substance taken among the group consisting of activated coal, molecular sieves and carbon molecular sieves. Crude octafluoropropane comprises indicated impurities in the amount from 10 to 10 000 mole fr. by mass. Invention proposes gas, etching gas and purifying gas comprising octafluoropropane with purity degree 99.9999 wt.-% and above and containing chlorine compound in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluoropropane.

EFFECT: improved purifying method.

13 cl, 11 tbl, 12 ex

FIELD: plasma-chemical treatment of wafers and integrated circuit manufacture.

SUBSTANCE: proposed device that can be used in photolithography for photoresist removal and radical etching of various semiconductor layers in integrated circuit manufacturing processes has activation chamber made in the form of insulating pipe with working gas admission branch; inductor made in the form of inductance coil wound on part of pipe outer surface length and connected to high-frequency generator; reaction chamber with gas evacuating pipe, shielding screens disposed at pipe base, and temperature-stabilized substrate holder mounted in chamber base. In addition device is provided with grounded shield made in the form of conducting nonmagnetic cylinder that has at least one notch along its generating line and is installed between inductor and pipe; shielding screens of device are made in the form of set of thin metal plates arranged in parallel at desired angle to substrate holder within cylindrical holder whose inner diameter is greater than maximal diameter of wafers being treated. Tilting angle, quantity, and parameters of wafers are chosen considering the transparency of gas flow screen and ability of each wafer to overlap another one maximum half its area. In addition substrate holder is spaced maximum four and minimum 0.6 of pipe inner diameter from last turn of inductance coil; coil turn number is chosen to ensure excitation of intensive discharge in vicinity of inductor depending on generator output voltage and on inner diameter of pipe using the following equation:

where n is inductance coil turn number; U is generator output voltage, V; Dp is inner diameter of pipe, mm.

EFFECT: enhanced speed and quality of wafer treatment; reduced cost due to reduced gas and power requirement for wafer treatment.

1 cl, 6 dwg, 1 tbl

FIELD: process equipment for manufacturing semiconductor devices.

SUBSTANCE: plasma treatment chamber 200 affording improvement in procedures of pressure control above semiconductor wafer 206 is, essentially, vacuum chamber 212, 214, 216 communicating with plasma exciting and holding device. Part of this device is etching-gas source 250 and outlet channel 260. Boundaries of area above semiconductor wafer are controlled by limiting ring. Pressure above semiconductor wafer depends on pressure drop within limiting ring. The latter is part of above-the-wafer pressure controller that provides for controlling more than 100% of pressure control area above semiconductor wafer. Such pressure controller can be made in the form of three adjustable limiting rings 230, 232, 234 and limiting unit 236 on holder 240 that can be used to control pressure above semiconductor wafer.

EFFECT: enhanced reliability of pressure control procedure.

15 cl, 13 dwg

FIELD: engineering of semiconductor devices.

SUBSTANCE: invention concerns method and device for etching dielectric, removing etching mask and cleaning etching chamber. In etching chamber 40 semiconductor plate 56 is positioned. Dielectric 58 made on semiconductor plate is subjected to etching, using local plasma, produced by special device for producing local plasma during etching process. Mask for etching 60 is removed by means of plasma from autonomous source 54, generated in device for producing plasma from autonomous source connected to etching chamber. Etching chamber after removal of semiconductor plate is subjected to cleaning, using either local plasma, or plasma from autonomous source. To achieve higher level of cleaning, it is possible to utilize a heater, providing heating for chamber wall.

EFFECT: increased efficiency.

2 cl, 4 dwg

FIELD: microelectronics, micro- and nano-technology.

SUBSTANCE: proposed method for producing submicron and nanometric structure includes formation of embossed structures on substrate surface, application of film to reduce embossed structure size to submicron and nanometric dimensions, and etching, anisotropic and selective relative to film material and source embossed layer, in chemically active plasma of structure obtained together with substrate material until embossed structure of submicron and nanometric dimensions, twice as deep as its width, is obtained.

EFFECT: provision for transferring mask pattern to bottom layer of substrate measured in terms of submicron and nanometric values.

2 cl, 3 dwg

FIELD: production of dirt-free laser mirrors.

SUBSTANCE: proposed method for producing dirt-free surfaces of materials chosen from group incorporating GaAs, GaAlAs, InGaAs, InGaAsP, and InGaAs on mirror facets of chip for GaAS based laser resonators includes shearing of laser mirror facet in ambient atmosphere incorporating normal air, dry air, or dry nitric media. Oxides and other pollutants produced in the course of ambient atmosphere impact on mirror facets are removed by dry etching in vacuum. Then natural nitride layer is grown on mirror facets using nitrogen treatment. Such facet treatment ensures minimized light absorption and surface recombination.

EFFECT: facilitated procedure, enhanced economic efficiency and yield due to high reproducibility.

37 cl, 5 dwg

FIELD: plasma reaction gas, its production and application.

SUBSTANCE: proposed plasma reaction gas has in its composition chain-structure perfluoroalkyne incorporating 5 or 6 atoms of carbon, preferably perfluorine-2-pentyne. This plasma reaction gas can be found useful for dry etching to produce precision structure, for plasma chemical precipitation from vapor phase, for producing thin film, and for plasma chemical incineration. Plasma reaction gas is synthesized by way of bringing dihydrofluoroalkyne or monohydroalkyne in contact with basic compound.

EFFECT: enhanced economic efficiency of highly selective gas production for plasma reaction on industrial scale.

18 cl

FIELD: electronics; semiconductor devices and methods for etching structures on their wafers.

SUBSTANCE: plasmochemical etching of material is conducted by way of acting on its surface with ion flow of plasma produced from plasma forming gas filling evacuated camber, electron beam being used to act upon plasma forming gas for plasma generation. Constant longitudinal magnetic field with flux density of 20-40 Gs is built on axis, plasma-generating gas pressure is maintained within chamber between 0.01 and 0.1 Pa, and electron beam at current density of 0.1-1 A/cm2 ensuring ignition of beam-plasma discharge is used. Etching condition (energy and ion current density) can be controlled ether by modulating electron beam with respect to speed or by varying potential of discharge collector.

EFFECT: enhanced etching efficiency (speed) and quality of etching structures on semiconductor material surface: high degree of etching anisotropy preventing etching under mask, minimized material structure radiation defects brought in during etching.

2 cl, 1 dwg

FIELD: physics; electricity.

SUBSTANCE: etching system contains plasma-generating facilities for plasma generating in vacuum chamber, high-frequency displacement voltage source, supplying high-frequency displacement voltage to electrode-substrate, floating electrode opposite to electrode-substrate in vacuum chamber and supported in floating condition by electric potential, solid material placed on the side of the floating electrode directed to electrode-substrate to form film layer protecting from etching, and control unit for periodic supply of high-frequency voltage to floating electrode. Etching method includes repetition, in specified sequence, of substrate etching stage by means of etching gas supplied to vacuum chamber, and film layer formation stage protecting substrate from etching by sputtering of solid material opposite to substrate.

EFFECT: high etching selectivity when using mask as well as production of anisotropic profile and great etching depth.

22 cl, 7 dwg

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