Plasmo-chemical low-pressure reactor for etching and depositing materials
FIELD: microelectronics techniques, micro- and nano-technologies, namely design of plasmo-chemical reactor in which processes for etching and depositing different materials are realized.
SUBSTANCE: plasmo-chemical reactor includes reaction chamber, inductor, substrate holder, thin-wall cylindrical metallic shield and heat removal struts whose properties provide rate of temperature change of screen and time period for setting is stationary temperature. Thin-wall cylindrical metallic screen is secured to heat removal struts inside reaction chamber and it is spaced from walls of reaction chamber.
EFFECT: possibility for separate control of basic content of plasma composition and for depositing high-quality coating.
2 cl, 1 dwg, 1 ex
The invention relates to the field of microelectronics, micronanotechnology, namely the design of the plasma-chemical reactor, which produced plasma etch processes and deposition of various materials, and can be used in the manufacture of semiconductor, MEMS devices and integrated circuits.
There are various designs of high-density plasma reactors of various types of discharges low pressure, which are designed to implement them in the processes of etching and deposition of various materials. This reactor in which the plasma generation is carried out using inductively coupled RF, microwave, microwave discharges. Among the presented plasma reactors (High density plasma sources. Desigh, Physics and Performance. Ed.O.Popov. N.Jersey. 1995. P.445. Patent no EP 0794553 from 1997-9-10. Applied Materials INC (US) and Inductively coupled HDP-CVD reactor. Patent no EP 0819780 from 1998-01-21. Applied Materials INC (US) you can select the reactor in which the plasma source is an inductively coupled RF discharge. In such reactors is generated plasma with high density and uniform over the cross section of the ion flow. Plasmachemical reactor consists of a reaction chamber, the inductor and the substrate holder. To control the energy of the bombarding processed wafer ions on the substrate holder served a certain RF voltage. Emerging tricatel the economic potential of samospaseniyu determines the energy of the incident ions. The density of the ion flow and radicals in the plasma is enclosed in the discharge RF power. Thus, in the high-density plasma reactors can now separately control both the density and energy of the ion flow, thereby controlling the characteristics of plasma-chemical etching and/or deposition.
Closest to the claimed combination of features is plasmachemical reactor low pressure for etching and deposition of materials, including reaction chamber with heated walls, the inductor and the substrate holder RF electrode (Chinzie y, Ichiki t
., Kurosaki R., J. kiuchi's SiO2etching employing indictively coupled plasma with hot inner wall. Jpn. J. Appl. Phys. 1996. V.35. Pt.1. N.4B. P.2472-2476).
In this reactor the temperature increase of the inner walls of the reaction chamber of a high-density fluorocarbon C4F8plasma flat RF induction discharge from 300 to 600 K leads to an increase in the concentration of CFn(n<3) more than ten times and the change in the ionic composition of the plasma. This leads to higher selectivity of etching silicon dioxide with respect to silicon in 2 times. Thus, effectively changing the concentration of radicals in the reactor is possible, by changing the temperature of the walls of the reactor. However, increasing the wall temperature to high temperature by forced heating is not technological, taktak this leads to the need of cooling water of the external walls of the reaction chamber.
The aim of the invention is the provision of independent control not only ionic, and radical composition of plasma.
This goal is achieved by the fact that in the known plasma-chemical reactor, comprising a reaction chamber, the inductor and the substrate holder inside the reaction chamber is set spatially isolated from its metal walls of the cylindrical screen. The screen may be covered with dielectric film or a film of semiconductor material.
The difference of the proposed reactor design from the well-known is that the inside of the reaction chamber is set spatially isolated from its walls metal thin-walled cylindrical screen.
An additional difference is that the screen is covered with a dielectric or semiconductor film.
Such a screen can be placed in the reactor with RF with induction plasma source gelikonnogo type (drawing) and flat induction discharge (drawing b). The design of the proposed reactor, schematically shown in the drawing, includes: an inductor (1), reaction chamber (2), the holder of the substrate (3) and screen (4).
The invention consists in that in plasma the screen is heated to a high temperature. As a result, its surface changes the coefficients of birth and death according to what cnyh charged and neutral excited particles radicals. This leads to a radical change of the plasma composition in the reactor. Thus, by varying the temperature of the screen, you can change the concentration of radicals in the plasma of reactive gases. The rate of temperature change of screen time to establish its stationary temperature determined by the heat removal properties of the rack, which is attached to the screen. For carrying out the process at a certain temperature of the walls of the screen they are pre-heated in the plasma of inert gas (e.g. argon), and then is loaded on the holder substrate, serves a necessary precursor gases and ignited plasma. Although the process of etching or deposition in such a reactor occurs when changing the temperature of the walls of the reactor, this is not a disadvantage, since during the process (usually 1-2 min) heating of the walls is negligible. In addition, the required temperature can be set by adjusting the heat sink through the rack. The advantages of this reactor design is particularly manifest when the etching of materials in plasma heavy fluorocarbon gases, such as C3F8C4F8, CHF3and other similar freon composition CnFm. In the plasma of these gases on the walls of the formed fluorocarbon film, which hampers the process. To implement repeatable processes it is odimo periodically clean the walls of the reactor to remove it. When heating the walls of the reactor over 500 For this polymer film on the walls of the reactor is almost not formed and the frequency of cleaning the walls of the reactor increases sharply. In the deposition of SiO2plasma SiH4+O2heating of the walls of the reactor will also contribute to the reduction of the deposition rate on them is silicon dioxide.
The claimed technical solution is not known from the prior art, which allows to make a conclusion about its novelty. In addition, it is not obvious from the prior art that speaks for its inventive step.
The invention is illustrated an example of the use of this design of the reactor when the etching of SiO2in fluorocarbon plasma.
Example 1. Selective etching of silicon dioxide with respect to silicon in the reactor with heated internal aluminum screen in C4F8plasma RF induction discharge.
Selective etching of SiO2/Si conducted in the reactor, inside the reaction chamber which was installed aluminum screen. The scheme of the reactor shown in the drawing, and. Experiments were performed in C4F8plasma RF induction discharge of low pressure when hot and cold walls of the screen. Samples served as a silicon wafer with a layer without layer of silicon dioxide on the surface of which was deposited film of photoresist. In the layer of photoresist is a method of optical lithography was formed mask pattern, representing a system of parallel strips with a width of 0.8, and 1.0...1.6 ám, and open area with a size of 500 μm. The samples were placed on polictial, which was applied RF-power offset. The thickness of the photoresistive mask on the basis of novolak was 1.2 μm, a SiO2- 0.8 μm. The etching was performed under the following parameters: pressure of 0.14 PA, a gas flow of 10 cm3/min (standard conditions), the discharge power is 900 W power RF bias is 200 watts. The shield temperature was 30 and 270°C. the etching Time was 2 min. depth of the etched steps in silicon and silicon dioxide were measured using TALYSTEP profilometer.
The experiments showed that when the wall temperature of the reactor 30°With the depth of etching of SiO2amounted to 0.74 μm, a Si - 0.18 micron, and at a temperature of walls 270°With the depth of etching of SiO2was equal to 0.72 μm, a Si - 0,07 mm. Thus, at low and high temperatures of the walls of the screen, the etching rate of the SiO2remained almost constant, and the selectivity of etching of SiO2/Si increased almost 2.5 times.
1. Plasmachemical reactor low pressure for etching and deposition of materials, including a reaction chamber, the inductor and the substrate holder, characterized in that it is equipped with a metallic thin-walled cylindrical screen and the cooling racks, t is VA which determine the rate of temperature change of screen time to establish its stationary temperature, when the metallic thin-walled cylindrical screen mounted on the cooling racks inside the reaction chamber spatially isolated from its walls.
2. Plasma-chemical reactor according to claim 1, characterized in that the thin-walled cylindrical metal screen covered with a dielectric or semiconductor film.
FIELD: semiconductor electrochemistry and semiconductor device technology.
SUBSTANCE: in addition to standard technology, n-type gallium arsenide semiconductor electrode surface is given chemical treatment in solutions of chalcogen-containing compounds prior to electrochemical evaporation of metal on this surface. Specimen is sequentially held at first for 3 minutes in 0.05 M aqueous solution of sodium sulfate (Na2S), then it is dipped for 1-2 seconds in warm (45-50 °C) distilled water, whereupon it is immersed for 3-4 minutes in 0.1 M aqueous solution of sodium selenite (Na2SeO3) and washed for 30 seconds in two portions of hot (60-70 °C) distilled water. In this way nanometric junction layer of arsenide and gallium chalcogenides is formed at metal-semiconductor interface which is coherently integrated with semiconductor and metal phases.
EFFECT: enhanced stability of electrophysical characteristics of metal-semiconductor rectifying contacts at high temperatures in oxidizing atmosphere.
1 cl, 2 tbl
FIELD: technology for producing semi-penetrable membranes for molecular filtration of gas flows and for division of reaction spaces in chemical reactors.
SUBSTANCE: method for producing gas-penetrable membrane includes two-sided electro-chemical etching of monocrystalline plate made of composition AIIIBV of n conductivity type or of semiconductor AIV with width of forbidden zone E≥1,0 electron volts and alloying level 1017-1020 1/cm3. Modes of aforementioned etching are set, providing for generation of simultaneously porous layers, while etching process is performed until moment of spontaneous stopping of electro-chemical process and generation of solid separating layer of stationary thickness on given part of plate area, determined using sharp bend on the curve of temporal dependence of anode current.
EFFECT: gas membrane, produced in accordance to method, has increased penetrability for molecules of light gases and increased selectivity characteristics at room temperature.
2 cl, 3 dwg, 3 ex
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: manufacture of microelectronic and nanoelectronic devices.
SUBSTANCE: selective etchant of AlAs and AlGaAs layers relative to GaAs has iodine I2 and organic solvent wherein iodine I2 is dissolved, proportion of mentioned components being as follows, mass percent: iodine, 0.1 - 4; organic solvent, 96 - 99.9. Isopropyl alcohol or acetone can be used as organic solvent. Enhanced selectivity of etching AlAs and AlGaAs layers including those with low Al content (below 40%), as well as their high selectivity relative to InAs and InGaAs are attained at room temperature.
EFFECT: ability of using proposed etchant in nanotechnology for separating upper layers in the order of several single layers.
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
SUBSTANCE: proposed method that can be used for photolytic etching of wafers in the course of manufacture of very large-scale integrated circuit includes etching of SiO2 surface in sulfur hexafluoride under action of vacuum ultraviolet emission of deuterium-vapor lamp. Argon is introduced in addition into etching gas.
EFFECT: enhanced selectivity of silicon dioxide etching with respect to monocrystalline and polycrystalline silicon.
3 cl, 1 tbl
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: semiconductor microelectronics; high-degree surface cleaning technologies.
SUBSTANCE: proposed method can be used in resource and energy conservation environmentally friendly and safe technology for integrated circuit manufacture, removal of positive photoresist from wafer surface, electrochemical etching of silicon, and degreasing of surfaces. Si surface is cleaned by detergent NH4HF2 of 0.1 - 4 M concentration activated by ozone at anode current density of 1 - 2 kA/m2, and waste solution is cleaned and activated by sequentially passing it through electrolyzer cathode and anode chamber.
EFFECT: enhanced quality and effectiveness of photoresist removal from semiconductor surface.
2 cl, 2 dwg
FIELD: polymer materials.
SUBSTANCE: method of applying high-resolution image of functional layers, e.g. for applying lithographic mask or other functional layers, comprises polymerization of monomers from vapor phase under action of finely focused electron beam with energy 1 to 1000 keV followed by injection of monomer vapors at pressure from 10-4 to 10 torr. Electron beam is introduced into working chamber through a small opening in membrane, which enables avoiding scattering of electrons on membrane and, at the same time, maintaining monomer vapor pressure in working chamber high enough to ensure acceptable growth time for thickness (height) of image line. Preferred image applying conditions are the following: electron energy in electron beam 10 to 500 keV and monomer vapor pressure 0.001 to 10 torr. For electron beam diameter 50 nm, image width 100-150 nm can be obtained. When improving electron beam focusing, accessible electron beam diameter may be further diminished.
EFFECT: enabled high-resolution image of functional layers directly from monomer in single-step "dry" process without using any solvents.
2 cl, 2 dwg, 8 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: manufacture of articles with protection coatings in different branches of industry, plasma technique of applying coatings such as injection system for injecting fluidic reagent to plasma flow, apparatuses and methods for applying coatings onto substrate.
SUBSTANCE: injector includes first portion 6 of duct 2 restricting flow of fluidic reagent and having such contour that inner walls of first portion of duct are parallel to first axis 9. Injector also includes second portion 8 of duct providing possibility for supplying fluidic reagent to first portion of duct. Second portion 8 of duct has such recess that inner walls of second portion diverge from first axis 9 by predetermined angle. Injector may include in addition mouthpiece protruding into plasma. Injector may be used in injection system with possibility of dismounting it out of base for working in plasma deposition system.
EFFECT: uniform distribution of fluidic reagent, lowered risk of clogging ducts at long-time usage of injector.
46 cl, 9 dwg
FIELD: methods and equipment for settling at least partially of a crystalline silicon layer on a substrate.
SUBSTANCE: the invention is pertaining to a method and a device for settling at least partially a crystalline silicon layer on a substrate and may be used in various branches of industry. Generate a plasma and a substrate is subjected to action of a silicon-containing liquid medium - a source and an auxiliary liquid medium capable to etching of the non-crystalline way bound atoms of silicon. On a path of motion of the both leaky mediums to the substrate create a pressure drop. The device has a plasma chamber, a reaction chamber and a means to feed the liquid medium-source. The reaction chamber contains a holder of a substrate and is in an open communication with the plasma chamber through a passing hole. The plasma chamber is supplied with a means to feed the auxiliary liquid medium and is provided with a pumping means for making pressure drop between the plasma chamber and the holder of the substrate. As a result forms a significantly high quality crystalline silicon layer on a substrate with a rather high speed of grow even at a rather low temperature.
EFFECT: the invention ensures a rather high speed grow of a crystalline silicon layer on a substrate with a high quality even at a rather low temperature.
21 cl, 2 dwg
FIELD: mineral protection coatings.
SUBSTANCE: invention relates to applying wear-resistant coatings for cutting tools used in metal machining. Method comprises vacuum-plasma deposition of two-layer coating, wherein basic coating is deposited under nitrogen pressure 8·10-4 Pa in interaction chamber and top layer is deposited under nitrogen pressure 4·10-3 Pa. Basic layer is constituted by titanium and aluminum nitrides or titanium and iron nitrides, or titanium and silicon nitrides. Top layer is formed from the same nitride constituents but alloyed with zirconium. In specific embodiments of invention, thickness of basic layer is 25-50% of the total thickness of coating and the latter is 3-9 μm.
EFFECT: increased wear and crack resistance of cutting tools.
2 cl, 1 tbl
FIELD: mineral protection coatings.
SUBSTANCE: invention relates to applying wear-resistant coatings for cutting tools used in metal machining. Method comprises vacuum-plasma deposition of two-layer coating, wherein basic coating is deposited under nitrogen pressure 8·10-4 Pa in interaction chamber and top layer is deposited under nitrogen pressure 4·10-3 Pa. Basic layer is constituted by titanium and aluminum nitrides or titanium and iron nitrides, or titanium and zirconium nitrides. Top layer is formed from the same nitride constituents but alloyed with silicon. In specific embodiments of invention, thickness of basic layer is 25-50% of the total thickness of coating and the latter is 3-9 μm.
EFFECT: increased wear and crack resistance of cutting tools.
2 cl, 1 tbl
FIELD: vacuum-arc sources of plasma devices for deposition of the coatings on the products in vacuum.
SUBSTANCE: the invention is pertaining to the devices for deposition of the coatings on the products in vacuum and may find application for production of the metal coatings on the inner surfaces of the tubular products with the solid walls and with the complex internal relief. The vacuum-arc source of plasma contains: the lengthy cylindrical cathode (1), the cathode current leads (2) and (11), the keep-alive electrodes (4) and (10), the tool of the arc quenching made in the form of the time relay with a wiring (5), which is connected by the breaking contact pair in the arc power circuit, and the anodes (7) and (9), which are made in the form of the peg-shaped yoke encompassing a coated tubular hardware product (8) and enveloping the being coated tubular product (8) and the electrically connected with the time relay with a wiring (5), and the switchboard (12). The anodes (7) and (9), the cathode current leads (2) and (11) and keep-alive electrodes (4) and (10) are arranged on the opposite ends of the lengthy cylindrical cathode (1). The ends of the cylindrical cathode (1) through the current leads (2) both (11) and the normally-closed and normally-opened contact of the first contacting pair of the switchboard (12) are connected to the negative pole of the arc power supply (3). Anodes (7) and (9) through the normally-closed and normally-opened contact of the second contacting pair of the switchboard (12) are connected through opening contacting pair of the time relay to the positive pole of the arc power supply (3). The keep-alive electrodes (4) both (10) through normally-closed and normally-opened contact of the third contacting pair of the switchboard (12) are connected to the positive pole of the wiring (5) of the time relay. Such a design of the source of plasma has allowed to exclude the poor adhesions of the coating on the inner surfaces of the complex relief tubular products.
EFFECT: the invention ensures exclusion of the poor adhesions of the coating on the inner surfaces of the complex relief tubular products.
1 dwg, 1 tbl
FIELD: metallurgy; devices for evaporation of materials; mechanical engineering and instrumentation engineering.
SUBSTANCE: proposed device is provided with evaporation crucible for placing the material to be evaporated. Evaporation crucible is surrounded by evaporating pipe consisting of at least two heating loops running in longitudinal direction at definite distance from each other; these loops are independently electrically controlled. Each heating loop consists of at least two heating sub-loops located on opposite sides of evaporating pipe which has its own upper heating section.
EFFECT: extended capabilities of evaporator; improved quality of coat.
9 cl, 4 dwg
FIELD: mechanical engineering; electronic industry; optical industry; other industries; methods of spraying of the vacuum-plasma coatings.
SUBSTANCE: the invention pertaining to the field of mechanical engineering and may be used for a spraying of the vacuum-plasma coatings in electron, optical and other industries. The method provides for deposition of the multilayered composites containing the complex carbides. Deposition of the layers with the width less than 100 nanometers is conducted out of plasma generated by the electric arc evaporators arranged in the vacuum chamber. The deposition of the layers is conducted in the additional ionic bombardment by ions of argon using the electric arc evaporators containing cathodes made out of titanium and black lead alloyed by silicon. The cathodes are placed on the side surface of the vacuum chamber at an angle of 120°C to each other. In the process of deposition of the layers the working tool with the fixed on it the treated details is uniformly rotating around its axis with the a simultaneous rotation around the axis of the support. The technical result of the invention is an increase of the operational properties of the details, such as the corrosion resistance and the microhardness of the details surfaces.
EFFECT: the invention ensures an increase of the details operational properties - the corrosion resistance and the microhardness of the details surfaces.
1 dwg, 1 ex
FIELD: production of composites with specific physico-chemical properties in vacuum; designing and production of special-purpose heat-resistant materials for protection of recoverable spacecraft, blades of gas-turbine engines of new generation.
SUBSTANCE: proposed method includes sedimentation of layers on preheated rotating substrate in vacuum. Sedimentation of layers of material is performed by boiling-off material from crucibles at their center-to-center distance of 0.55 to 0.8 of substrate diameter. Distance between crucibles and substrate is equal to 0.55-0.8 of crucible center-to-center distance. Temperature of substrate is no less than 0.3 of melting point of the most refractory material being boiled-off. Level of substrate roughness does not exceed 0.63RA. At interface of layers, thickness ranges from 0.001 to 0.005 mcm at smooth concentrated change from material of one layer to material of another layer.
EFFECT: wide field of varying structural and physico-mechanical properties of materials; enhanced thermal stability of structure.
16 dwg, 2 tbl
FIELD: application of wear-resistance coats on cutting tools; metalworking.
SUBSTANCE: proposed method includes vacuum-plasma application of wear-resistant coat on base of titanium/aluminum nitride or carbo-nitride. Used as alloying component is zirconium. Coat is applied with the aid of two opposite sectional cathodes located in horizontal plane containing titanium and aluminum with sectional cathode containing titanium and zirconium located between them.
EFFECT: enhanced serviceability of cutting tools.
1 tbl, 2 ex