Device for chemical-dynamical etching of germanium substrates |
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IPC classes for russian patent Device for chemical-dynamical etching of germanium substrates (RU 2520955):
 Canal matrix and method of its production / 2516612
In canal matrix in addition to plate of monocrystalline silicon of hole type with opened canals and deposited material on frontal surface of this plate intermediate dielectric layer of silicon dioxide is created and metal film is applied on the frontal surface of plate with opened canals which have specified diametrical dimension.
 Method and device to wash and dry substrates / 2510098
In the method to wash and dry substrates, each substrate is installed on a carrier, submerged into a washing bath with de-ionised water until full submersion of the substrate, then slowly raised from water into the drying chamber, washing it with the help of megasound radiation, and at the moment of substrate removal from water, vapours of organic dissolvent are supplied to the interface of the bath and air medium of the chamber and dried. The novelty in the method is the fact that zones of point contacts with the carrier are created on the substrate carrier, the substrate is installed onto the carrier so that the lower end of the substrate is arranged at a certain angle to the horizontal line, the substrate is submerged into the washing bath continuously, and when the substrate is raised, megasound radiation is directed to the entire width of the substrate.
 Method of cleaning and obtaining porous surface of semiconductor plates / 2507630
Removal of organic contaminants and obtaining of a porous surface of semiconductor plates are carried out jointly in a single step in HBF4 or NH4HF2 solutions activated with ozone with high concentration of 17% or higher. The semiconductor plates are etched in concentrated, more than 10%, HBF4 or NH4HF2 solutions.
 Method of cleaning surface of semiconductor plates / 2495512
Surface of semiconductor plates is cleaned in a bath with a detergent bifluoride solution activated with concentrated nitrogen and ultrasound at room temperature, followed by washing with dionised water.
 Method to preserve surface of substrates from gallium arsenide / 2494493
In the method to preserve surfaces of substrates from gallium arsenide, including chemical-dynamic polishing of semiconductor surface in a polishing etching agent, containing concentrated sulfuric acid, hydrogen peroxide and water at the ratio of H2SO4:H2O2:H2O=5:1:1, washing in deionised water, pasturing of a layer of residual oxide in aqueous solution of concentrated hydrochloric acid H2O:HCl=10:1 until hydrophobic properties of a pure surface of a substrate from gallium arsenide are manifested, washing in deionised water, drying in a centrifuge, treatment in selenium vapours, pasturing of the produced layer of gallium selenide in the aqueous solution of hydrochloric acid H2O:HCl=10:1, washing in deionised water, drying in the centrifuge, after drying the substrate is repeatedly treated in selenium vapours in the chamber of quasiclosed volume with formation of an epitaxial layer of gallium selenide (Ga2Se3) at substrate temperature - Ts=(310÷350)°C, temperature of chamber walls - Tw=(280÷300)°C, temperature of selenium - TSe=(230÷250)°C for 3÷10 minutes and then packaging is carried out without usage of inert medium.
Method of forming cavity in gallium arsenide substrate / 2488189
In the method of forming a cavity, via chemical etching, in a gallium arsenide substrate which is part of a semiconductor device, the cavity having a shape which narrows on the thickness of the substrate, the method including an etching step where the etchant used is a composition which includes aqueous phosphoric acid solution with concentration of at least 80 wt % and aqueous hydrogen peroxide solution with concentration of at least 30 wt %, according to the invention chemical etching is carried out in a single step using as the etchant, a composition obtained by mixing said aqueous phosphoric acid solution and said hydrogen peroxide solution in volume ratio of 2:3.
 Method for manufacturing nanoheterostructure chips and etching medium / 2485628
Method for manufacturing nanoheterostructure chips grown on a germanium substrate includes application of ohmic contact onto the reverse and frontal surfaces of the nanoheterostructure, partial removal of the nanoheterostructure frontal contact layer by way of chemical etching, application of an antireflective coating onto the nanoheterostructure fontal surface and the chips side surface passivisation with a dielectric. The structure division into chips is performed by etching through a photoresist mask on the side of the nanoheterostructure fontal surface to a depth of 10-30 mcm of the nanoheterostructure and the germanium substrate in an etching medium containing bromine hydride, hydrogen peroxide and water at specified components.
 Method for plasmochemical etching of microelectronics material / 2456702
In the method for plasmochemical etching of microelectronics material, the material is placed on a substrate holder in a vacuum chamber, working gas is fed into the vacuum chamber, plasma is ignited via radio-frequency induction discharge and radio-frequency power is fed to the substrate holder. Etching is carried out with division into repeating cycles. Each cycle consists of two phases: etching and passivation, wherein during the etching phase, radio-frequency power is fed to the substrate holder in the range of 208-300 W for 0.1-100 s, and at the passivation phase - in the range of 100-120 W for 0.1-40 s.
 Device for local plasma-chemical etching of substrates / 2451114
Device comprises a vacuum chamber with a cover, two electrodes, systems for pumping and supply of an orifice gas, the upper electrode is installed on a plate and is equipped with a template installed on a detachable bushing fixed on the electrode, and a mechanism to control parallelism of two electrodes relative to each other, arranged in the form of three micrometric heads rigidly installed in holes of the specified plate as capable of interaction with their lower end via ball supports accordingly with three vertical stands fixed on the chamber base. On each stand there are movable supports interacting with a mechanism for control of a gap between two electrodes arranged in the form of a precision lift, where a lower electrode is installed, being a substrate holder.
 Composition of gas mixture to form tantalum nitride metal gate by plasma etch chemistry / 2450385
Composition of gas mixture to form tantalum nitride metal gate in plasma is characterised by plasma generation in gas mixture containing boron trichloride and oxygen.
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FIELD: electricity. SUBSTANCE: in device for chemical-dynamical etching of germanium substrates including a platform with reaction vessels capable of orbital motion in horizontal plane the above platform is made as a chute with cylindrical baths, at that at the bath bottoms there are discs of inserts with horizontal plates placed with their substrate upwards, besides hub caps of the baths are capable to limit a thickness of the etchant layer on the plates surface and the bath bottom can be cooled by running water. EFFECT: increased efficiency and simplification of design. 3 dwg
The invention relates to electrical equipment and can be used for chemical-dynamic thinning of germanium substrates. A device (similar) chemical-dynamic etching of silicon wafers, Germany (see "Physical and chemical methods of surface treatment of semiconductors", edited by Bedloft, publishing, Radio and communication, 1982), which is a cylindrical reaction vessel made of fluoropolymer, placed on the axis of the motor, the angle of which can be adjusted from 0 to 90°. The speed of the reaction vessel is adjustable from 0 to 200 rpm Utonomy plate glued to a round PTFE disk using chemically resistant varnish or optical resin. During etching, the plate is rotated around its axis. The device allows you to process one sample. The disadvantage of this device is its low performance, in addition, near the edge of the plate is discharged more than in the center (the effect of "lentil"), resulting in reduced mechanical strength. The signs above analog common with the proposed device, the following: the presence of the reaction vessel, driven by a motor. A device for mixing fluids of the type LS 220(see Manual, passport CJSC "Laboratory equipment and arr the market", Saint-Petersburg, info@loip.ru 2010),adopted as a prototype, in which the platform is located here reaction vessels makes the orbital rotational motion with a given amplitude in the horizontal plane. All parts of the platform are moving along the same trajectory. The speed range from 0 to 400 rpm Platform is driven by the asynchronous motor with external rotor. The drawback of the prototype is that its application is limited to the area of mixing of the solutions. The characteristics of the prototype, shared with the proposed device, the following: the presence of the platform with the reaction vessels, making the orbital motion in the horizontal plane. Technical result achieved in the proposed device, chemical-dynamic etching of germanium substrates, is to improve performance and simplify the design. Distinguishing features of the proposed device chemical-dynamic etching of germanium substrates, determining its compliance with the criterion of "novelty", the following: the execution platform with the reaction vessels in the form of boxes and supplies its cylindrical trays on the bottom of the installed drives liners, which, in turn, horizontally arranged plate backing up, with roofs and-sleeve trays are designed to limit the thickness of the layer of provide the Etchant on the surface of the wafer, and the bottom trays made with the possibility of cooling by flowing water. To substantiate the proposed device the criterion of "inventive step" was the analysis of the known solutions according to literary sources, which are not found technical solutions containing a set of known and distinctive characteristics of the proposed device, giving the above technical result. Therefore, according to the authors, the proposed device chemical-dynamic etching of germanium substrates meets the criterion of "inventive step". The device chemical-dynamic etching of germanium substrates are presented in figure 1-3. Figure 1 - view of the tray Assembly with the plate, liner and cap-sleeve, figure 2 - view of the device platform chemical-dynamic etching of germanium substrates, figure 3 - type of insert with liner. The proposed device chemical-dynamic etching of germanium substrates used, as an example, in the technology of solar cells. Use the GE substrate with a diameter of 100 mm, a thickness of 145 μm with grown epitaxial layers of a triple junction structure. On the side of the substrate with the epitaxial layers create a photoresistive mask with a picture of the front contacts PV and diode l is unique etched area under the diode, sputtering and "explosion" photoresistive mask to create the front metallization, perform a Mesa-isolation of active areas of PV and diode. Form a protective coating using photoresist OP 2550. In a cylindrical bath 1(with an inner diameter of 105 mm), which is installed liners 2 flat disk, pour the solution provide the Etchant 3 composition HF÷H2About2÷N2O=1÷1÷4 volume 25 ml Plate 4 is placed in a bath 1 germanium substrate upwards. Set on Board each of the trays 1 cap-sleeve 5, the lower profiled side which specifies the thickness of the layer of provide the Etchant 3 above the surface of the plate 4 in the etching process. Baths in the amount of 8 units from the plates 4 are placed on the horizontal platform 7 in the form box, with the bottom of the trays 1 is washed under running water with a temperature of ~25°C to ensure the heat sink. The cooling water may be supplemented by a unit temperature control. Include the device chemical-dynamic etching through the control unit 8, the platform 7 with trays 1 performs an orbital movement in a horizontal plane with an amplitude of ~5 mm, a frequency of 200 rpm During movement of the platform 7 solution in the trays 1 rotates in a circle. The bottom side of the cap-sleeve 5 restricts the layer thickness of provide the Etchant 3 above the surface p of the plates 4. The smaller the layer thickness and flow velocity of provide the Etchant 3 above the surface of the plate 4, the lower the etching rate in this area, thus setting a specific configuration of the bottom side of the cover-sleeve - 5, and therefore, the profile provide the Etchant layer 3, line etching rates of the Central and peripheral areas of the plate 4. The etching rate of the substrate Germany iscf.=2 μm/min At the end of the first cycle of etching t=15 min (the thickness of the etched layer 30 μm) platform 7 stop, provide the Etchant used 3 pour, then without washing water baths 1 pour a fresh portion of the solution provide the Etchant include installation. At the end of the second cycle of the etching t=15 min platform 7 stop, fill trays 1 deionised water (to stop the etching process), then washed and extracted thinned wafer 4 using inserts 2. The need for liners 2 due to the adhesion layer of the plate 4 to the flat bottom of the tray 1. thickness of the germanium substrate after thinning is 70÷80 μm. In the absence of heat from the bottom surface of the tray 1, the temperature of provide the Etchant 3 reaches ~60°C, which leads to degradation of the protective properties of the photoresistive coating on the front side plate 4. Next remove the photoresist in dimethylformamide. Sprayed layers back of the metallization Cr/Au/Ag/Au thickness of 6 μm on the installation HAC 641. Wihout contacts at a temperature of 335°C, t=10 s installation ATVSRO 706. Annealing is necessary for the formation of ohmic contacts, in addition, annealing release tension elastic solid layer backside metallization. Align the plate 4 by cooling. Then open the optical window, venting contact semiconductor layer on the mask front metallization. Put antireflection coating Toh/Al2O3installation HAC 761. 0 pt. Cut out photo converters with integrated diode with a diamond disk with outer cutting edge at the facility DFD 6240. Additionally align the plane is made of solar cells by cooling, while the deviation from the plane PV size 40×80 mm is less than 0.15 mm The etching of the substrate Germany reduce the weight of the PV with 2.5 g when the initial thickness of the substrate 145 μm to 1.6 g when the thickness of the thinned substrate of 80 μm. The weight reduction of the battery cells in size S=40 m2is ~12 kg The proposed device chemical-dynamic etching of germanium substrates does not require the use of expensive equipment and supplies, eliminating the effect of the preferential etching of the wafer 4 in the area of edge effect "lentils"). Performance installation platform for 8 trays in in the Anenii germanium substrates with 145 to 80 μm is ~16 LP/hour. The device chemical-dynamic etching of germanium substrates, comprising a platform with reaction vessels with the possibility to perform an orbital motion in a horizontal plane, wherein the platform is designed in the form of a box and provided with a cylindrical puddles at the bottom of the trays installed drives liners, which are horizontally arranged plate backing up, in addition, cap-sleeve trays are designed to limit the thickness of the layer of provide the Etchant on the surface of the wafer, and the bottom trays made with the possibility of cooling by flowing water.
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