Method of producing mono-crystalline plates of arsenide-indium |
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IPC classes for russian patent Method of producing mono-crystalline plates of arsenide-indium (RU 2344211):
  
 Method of obtaining minerals and device for its realisation / 2341596
Method of obtaining minerals is realised in neutron reactor flow, minerals being placed in layers between layers of substance or mixture of substances, containing elements, absorbing thermal and resonance neutrons, layers being separated with aluminium interlayer and surrounded with filtering unit from substance or mixture of substances, containing elements, absorbing thermal and resonance neutrons, with cadmium screen, layer thickness and geometrical parameters of unit are calculated in such way that at the moment of exposure to radiation mineral temperature does not exceed 200°C, and "Фб.н./Фт.н." ≥10, where "Фб.н." is density of flow of fast neutrons with energy higher than 1MeV, "Фт.н." - density of thermal neutrons flow. Described is device for mineral irradiation, containing hermetical filtering unit, filled with substance or mixture of substances, containing elements, absorbing thermal and resonance neutrons, with axial hole, in which cadmium screen is placed and also placed is a case open from the bottom for partial filling with heat carrier, operation volume of case is filled with minerals, placed in layers between layers of substance or mixture of substances, containing elements, absorbing thermal and resonance neutrons, layers being separated with aluminium interlayer.
 Diamond working method / 2293148
Method comprises steps of acting upon crystal with electron beam whose integral flux is in range 5 x 1015 - 5 x 1018 electron/cm2; annealing crystal in temperature range 300 - 1900°C and acting with electron beam in condition of electric field having intensity more than 10 V/cm at least upon one local zone of crystal for imparting desired color tone to said zone. Local action of electron beams is realized through protection mask. As irradiation acts in condition of electric field local flaws such as bubbles or micro-inclusions are effectively broken.
Method of cleaning diamond / 2285070
Proposed method includes stage-by-stage treatment of diamond by mixture of acids under action of microwave radiation; at first stage, use is made of nitric acid and hydrogen peroxide at volume ratio of components of 10:1, respectively; at second stage, volume ratio of mixture of concentrated nitric acid, hydrochloric acid and hydrofluoric acid is 6:2:1, respectively; diamond is treated at temperature not higher than 210°C, pressure of 35 atm as set by loading ratio of autoclave equal to 1:10 at power of oven of microwave radiation of 1200 W; duration of each phase does not exceed 40 min. Proposed method ensures perfect cleaning of diamonds from contamination of mineral and organic nature including bitumen compounds on surface and in cracks of diamond.
Method for treating colored diamonds and brilliants for decolorizing them and releasing stresses / 2281350
Method is realized due to physically acting in closed reaction space upon samples of diamonds and brilliants by means of high pressure and temperature for time period sufficient for enhancing their quality. Pressure acting upon samples is in range 6 - 9 GPa in region of thermodynamic stability. Temperature during physical action upon samples is in range 1700 - 2300°C. Samples are subjected to physical action in medium of graphite powder filling reaction space. Heating till high temperature is realized due to applying AC to samples of diamond or brilliant through graphite powder at specific electric current power from 0.18 kWt/cm3 and more. Then electric power is gradually increased from zero till working value and further it is decreased and increased at least two times for some time interval at each change of electric power. Process of annealing samples is completed by smoothly lowering electric current power till zero. At physical action upon sample electric current intensity is lowered by 11 - 13 % and it is increased by 15 - 17 % for time interval from 8 min and more at each change of electric power. Sample is AC heated and it is cooled at rate no more than 0.05kWt/min per cubic centimeter of reaction volume of chamber.
 Method of shaping high-melting and chemically stable materials / 2252280
Method comprises etching the surface of articles made of high-melting chemically stable materials by applying the layer of an agent interacting the article material and heating the surface by laser pulse irradiating. The surface of the article is simultaneously affected by the laser pulses and vapors of a volatile composition, which is subjected to the pyrolytic decomposition to produce the above mentioned material. The amplitude of the laser pulse should be sufficient to cause the evaporation of the material.
The method of obtaining diamonds fancy red / 2237113
The invention relates to the field of processing (refining) of the diamond to give them a different color colouring and may find application in the jewelry industry
 A method of obtaining a piezoelectric single crystals with polydomain structure for precise positioning devices / 2233354
The invention relates to the field of obtaining single crystals of ferroelectric domain structure formed and can be used when creating and working appliances precise positioning, in particular probe microscopes, as well as during alignment optical systems
 The method of processing and improve the surface of materials using laser beam / 2206645
The invention relates to the field of material science and can be applied in manufacturing semiconductor devices
 Device for surface treatment of materials by a laser beam / 2206644
The invention relates to the field of materials science, and more specifically to a device for surface treatment of materials for micro - and optoelectronics laser methods, and can be used in manufacturing semiconductor devices
 The method of forming the impurity profile in the semiconductor and dielectric materials / 2197571
The invention relates to the technology of semiconductor and dielectric materials with specified impurity diffusion profiles and, in particular, can be used in the formation of ultra-fine and ultra-deep p - n junctions in semiconductor materials for purification from impurities in the semiconductor and dielectric materials, and for a total change of their optical properties and color
Method of hardening dislocation-free silicon plates / 2344210
Invention refers to process of production of dislocation free plates of semi-conducting silicon cut out of mono-crystals, grown by Czochralski method, and applied for producing integrated circuits and discrete electronic devices. Method of upgrading mechanical hardness of mono-crystalline dislocation-free silicon plates with oxygen contents at the level 6×1017-9×1017 cm-3 is performed by two-stages thermal treatment in inert medium, for instance, in argon, initially at the temperature of 1000÷1020°C during 10-15 minutes, and further at the temperature of 600-650°C during 7.5-8.5 hours with following cooling in the air.
 Method of producing mono-crystals of indium antimonide alloyed with tin / 2344209
Invention refers to process of production of AIIIBV semi-conducting compositions. Mono-crystals of indium antimonide alloyed with tin are produced by means of bombardment with a full specter of reactor neutrons with successive heating, annealing and cooling. Heating is carried out at the rate of 20÷40 deg/min to temperature of annealing, defined by the formula Tanneal=450+(tgNsn-14)-7 [°C], where Nsn is concentration of introduced alloying addition of tin [cm-3]; annealing is performed during 20 minutes, while the successive cooling is carried out at the rate of 5-10 deg/min to the temperature of 350÷400°C, and further at the rate of 20-40 deg/min to an ambient temperature.
 Mehgod of growing cadmium telluride monocrystal / 2341594
Method of manufacturing cadmium telluride monocrystal lies in loading polycrystal half-product into crucible, hermetization with further crucible vacuuming, melting of half-product, cooling of obtained ingot, its standing at certain temperature and further cooling to room temperature; polycrystal half-product is loaded into crucible together with pure cadmium sample, whose weight is determined by Clapeyron-Mendeleev equation, crucible is exhausted to pressure 10-6-10-7 mm of mercury, half-product is melted, ensuring temperature gradient on height 1-5°C/cm, half-product melt is stood at melting temperature during 2-4 hours, then half-product is cooled at rate 0.5-1,0°C/hour to full crystallization; obtained crystal is cooled at rate 40-60°C/hour to temperature 920-960°C, crystal is stood at said temperature during 8-12 hours, then it is cooled again at rate 40-60°C/hour to temperature 820-860°C and stood at during 8-12 hours, then crystal is cooled to temperature 700-720°C and stood during 8-12 hours, after which crystal is cooled at rate 10-20°C/hour to room temperature and removed from crucible as end-product.
 Method of fabrication of mono crystal spinel plates (versions) / 2334835
Invention refers to fabrication of items with spinel crystal structure, including such items as boules, plates and bases, and also refers to active units comprising such items. According to one variant the method of fabricating mono crystal spinel plates includes the following operations: obtaining a portion of melt in a crucible, formation of spinel mono crystal boule out of melt at process coefficient of mould determined as ratio of medium diameter of the boule to interior diameter of the crucible and equal approximately to not less than 0.44, at that the boule has common formula aAD.bE2D3, where A is chosen from the group, which includes Mg, Ca, Zn, Mn, Ba, Sr, Cd, Fe as well as their combinations, and E is chosen from the group which includes Al, In, Cr, Sc, Lu, Fe and their combinations, and D is chosen from the group which includes O, S, Se and their combinations, at that the ratio b:a> 1.5:1, so the spinel is concentrated E2D3, and then cutting the boule into plurality of plates. Such items possess reduced mechanical stress which facilitates increased output of ready items.
 Coloured diamonds / 2328563
Invention is related to the field of coloured diamonds preparation, which are used, for instance, in decorative purposes. Method of coloured single crystal diamond transformation into different colour includes stages, at which coloured single crystal diamond is prepared by method of chemical depositing from steam phase (CDSP) and prepared diamond is thermally treated at temperature from 1200 to 2500°C and pressure that stabilises diamond, or in inert or stabilising atmosphere. Prepared single crystal may be shaped as thick layer or fragment of layer, which is cut as precious stone.
Method of preparation of optically transparent single crystals of terbium-gallium garnet / 2328561
Invention is related to growing of garnets single crystals and may be used in laser equipment, magnet microelectronics (semi-conductors, ferroelectrics) and for jewelry purposes. Single crystals of terbium-gallium garnet are prepared by Chochralski method by means of melting primary stock, which includes clarifying calcium-containing additive, and further growing of single crystal from melt to primer. As primary stock mixture of terbium and gallium oxides is used, as calcium containing additive - calcium oxide or carbonate, and after growing crystal is annealed in atmosphere of hydrogen at temperature of 850-950°C for around 5 hours until orange paint disappears.
 Ultrahard diamonds and a method for preparation thereof / 2323281
Monocrystalline diamond grown via chemical precipitation from gas phase induced by microwave plasma is subjected to annealing at pressures above 4.0 GPa and heating to temperature above 1500°C. Thus obtained diamonds exhibit hardness higher than 120 GPa and crack growth resistance 6-10 Mpa n1/2.
 Method for preparing even-atom surface of gallium arsenide / 2319798
Method comprises steps of chemical-dynamic polishing of substrate surface in polishing etching agent containing sulfuric acid, hydrogen peroxide and water for 8 - 10 min; removing layer of natural oxide in aqueous solution of hydrochloric acid until achieving hydrophobic properties of purified surface of substrate; washing it in deionized water and drying in centrifuge. Then substrate is treated in vapor of selenium in chamber of quasi-closed volume while forming gallium selenide layer at temperature of substrate Ts = (310 -350)°C, temperature of chamber walls Tc = (230 - 250)°C, temperature of selenium Tsel = (280 - 300)°C for 3 - 10 min. After such procedure substrate is again placed in aqueous solution of hydrochloric acid in order to etch layer of gallium selenide. Invention allows produce even-atom surface of gallium arsenide at non-uniformity degree such as 3Å.
Method of coloring fianites / 2296825
Proposed method is used for coloring fianites (man-made diamonds) in green, blue and brownish-yellow colors; proposed method may be also used in optics for production of colored light filters withstanding temperatures above 1000°C. Proposed method includes preliminary application of cobalt on fianite surface to be colored and at least one metal whose oxide is liable to spinelle-forming with oxide of bivalent cobalt, iron and/or aluminum, for example. Then material is subjected to heat treatment in oxygen-containing atmosphere at temperature above 1000°C but not exceeding the fianite melting point. The procedure is continued for no less than 3 h. Coat is applied by thermal spraying of metals in vacuum. Said metals may be applied in turn and simultaneously. For obtaining bluish-green color of fianite, cobalt and aluminum are applied at atomic ratio of 1:1 to 1:2. For obtaining yellowish-green color, cobalt, aluminum and iron are applied at atomic ratio of 1:1 :0.1-0.2. For obtaining yellowish-brown color, cobalt and iron are applied at ratio of 1:1 to 1:2.
Diamond working method / 2293148
Method comprises steps of acting upon crystal with electron beam whose integral flux is in range 5 x 1015 - 5 x 1018 electron/cm2; annealing crystal in temperature range 300 - 1900°C and acting with electron beam in condition of electric field having intensity more than 10 V/cm at least upon one local zone of crystal for imparting desired color tone to said zone. Local action of electron beams is realized through protection mask. As irradiation acts in condition of electric field local flaws such as bubbles or micro-inclusions are effectively broken.
Method of producing mono-crystals of indium antimonide alloyed with tin / 2344209
Invention refers to process of production of AIIIBV semi-conducting compositions. Mono-crystals of indium antimonide alloyed with tin are produced by means of bombardment with a full specter of reactor neutrons with successive heating, annealing and cooling. Heating is carried out at the rate of 20÷40 deg/min to temperature of annealing, defined by the formula Tanneal=450+(tgNsn-14)-7 [°C], where Nsn is concentration of introduced alloying addition of tin [cm-3]; annealing is performed during 20 minutes, while the successive cooling is carried out at the rate of 5-10 deg/min to the temperature of 350÷400°C, and further at the rate of 20-40 deg/min to an ambient temperature.
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FIELD: metallurgy, crystal growing. SUBSTANCE: invention refers to semi-conductor technology of AIIIBV type compositions. The method is implemented by means of bombarding mono-crystalline plates of arsenide-indium with fast neutrons with following heating, annealing and cooling. The mono-crystalline plates are subject to bombardment with various degree of compensation at density of flow not more, than 1012 cm-2 c-1 till fluence F=(0.5÷5.0)·1015 cm-2 , while annealing is carried out at 850÷900°C during 20 minutes at the rate of heating and cooling 10 deg/min and 5 deg/min correspondingly. EFFECT: production of arsenide-iridium plate with upgraded uniformity and thermal-stability of electro-physical characteristics and with decreased degree of compensation. 2 ex, 1 tbl
The invention relates to the technology of semiconductor compounds of the type AIIIBVand can be used to obtain single crystals of indium arsenide with improved parameters. Produced in industry the single crystals of indium arsenide have several disadvantages: the heterogeneity of properties over the crystal volume, reaching 30÷50%, and in some cases above; low dimensional stability after heat treatment, the relatively low mobility of charge carriers. The widespread use of indium arsenide in the manufacture of electronic devices, a high degree of integration of devices put forward more strict requirements to the quality and geometrical dimensions of the single crystals. Improvement of material and metallurgical methods in the process of growing single crystals currently not practicable. The proposed method is to improve the parameters of indium arsenide (undoped and doped with different impurities to different concentrations) exposure to neutrons in a nuclear reactor and a subsequent heat treatment. The prototype serves as a method lies in the fact that the single crystals of indium arsenide irradiated with neutrons in a nuclear reactor (fluence f>7×1017cm-2) followed by heat treatment for 30 min at temperatures up to 800°C. Under the of faultless method is what to improve characteristics of indium arsenide is therefore unable. Large fluence neutrons result in increased hopping conductivity and deterioration of electrophysical parameters of the material due to the additional alloying of the tin. The temperature of annealing is low and does not give the desired effect. The proposed method differs in that the irradiation is subjected to the single crystals of indium arsenide with varying degrees of compensation; the irradiation is carried out only with fast neutrons (E > 0.1 MeV) flux densities of no more than 1×1012cm-2with-1to the fluence f=(0,5÷5,0)×1015cm-2and annealing is carried out at a temperature of 850÷900°C. to Cut off thermal neutrons using for cadmium exposure canisters or other known methods. The need to limit the density of neutron flux due to extreme heat and possible cracking of the material during irradiation. The physical meaning of what is happening in the material processes is the following. As a result of irradiation with fast neutrons in indium arsenide appear simple radiation defects (Frenkel pairs: the atom in the internode and vacancy). With the increase of irradiation dose increases the concentration of the injected defects, increases the probability of their interaction (coagulation) and the formation of more complex radiation defects (RD), a.k.a. the excavated areas of disordering (PR). The resulting EOS are getters for simple (point) defects formed in the crystal during irradiation and under cultivation. Subsequent heat treatment of the irradiated samples at a temperature of 850÷900°leads to the collapse of the PRS and the movement of simple defects on the surface and sinks (heat treatment at temperatures less than 850 and above 900°does not give the expected effect). Thus erases matrix from a large number of growth and other point defects. Looping samples (irradiation and heat treatment) also leads to a significant improvement in uniformity and thermal stability properties of the material. The heterogeneity of electrical characteristics in the volume of material does not exceed 5%. Thermal treatment of the samples at 900°C for 8 hours does not sensitive to changes of the parameters of the material, while in normal (non-irradiated) material heat treatment at 900°C for 30÷40 min already leads to significant changes in parameters. The use of radiation-modified indium arsenide in the production of semiconductor devices (VLSI, microwave and optoelectronic devices and other) opens new perspectives in microelectronics. Example 1. As the source material used single-crystal plate unalloyed ARS is Nida India e-type conductivity (n=1× 1016cm-3), with the degree of compensation K1=0,07. The heterogeneity of the electrical characteristics measured by a contactless method, equal δ1=25%. The neutron irradiation is carried out in the vertical channels of the reactor WWR-TS using cadmium canisters to eliminate thermal neutrons. Fluence of fast neutrons flux densities of ϕ=1×1012cm-2with-1and energy E>0.1 MeV is 5×1015cm-2. After the recession induced activity to an acceptable level the irradiated samples are heated in a sealed quartz ampoules with a speed of 10°C/min to a temperature of 900°C. the Annealing is conducted for 20 min and subsequent cooling are at 5°C/min to a temperature of 400°C, then cooled together with the furnace to room temperature. As a result, the indium arsenide electronic conductivity type with the heterogeneity of electrophysical properties δ2=4% and the degree of compensation K2=0,03. Heat treatment of the samples at 900°C for 8 h does not lead to noticeable changes in the electrophysical parameters of the material. Example 2. As the source material used monocrystalline wafer of indium arsenide electronic conductivity type doped to a concentration of n=1×1018cm-3with the degree of compensation K1=0,04 Neodnorodnosti electrical characteristics, measured by a contactless method, equal δ1=22%. The neutron irradiation is carried out in the vertical channels of the reactor WWR-TS using cadmium canisters to eliminate thermal neutrons. Fluence of fast neutrons flux densities of ϕ=5×1011cm-2with-1and energy E>0.1 MeV is 5×1014cm-2. After the recession induced activity to an acceptable level the irradiated samples are heated in a sealed quartz ampoules with a speed of 10°C/min to a temperature of 900°C. the Annealing is conducted for 20 min and subsequent cooling are at 5°C/min to a temperature of 400°C, then cooled together with the furnace to room temperature. As a result, the indium arsenide electronic conductivity type with the heterogeneity of electrophysical properties δ2=5% and the degree of compensation K2=0,02. Heat treatment of the samples at 900°C for 8 h does not lead to noticeable changes in the electrophysical parameters of the material. Examples of trials are shown in table 1. As starting material can be used, both undoped and doped with different impurities to different concentrations of indium arsenide in the form of monocrystalline wafers. The proposed method allows to obtain a plate of indium arsenide with improved uniformity and term the stability of the electrical properties and a reduced level of compensation. This material meets the requirements of modern micro - and optoelectronics and is in great demand in both domestic and foreign markets.
Sources of information 1. Ajanensis. The production of semiconductor materials. Moscow, metallurgy, 1989, 271 S. 2. Colin N.G., Oswanski V.B. have been, Rytov NS, Yurova Y.S. Electrical properties of indium arsenide irradiated with fast neutrons. FTP, t, issue 3, 521 (1987). A method of obtaining a monocrystalline wafer of indium arsenide by irradiation with fast neutrons, followed by heating, annealing and cooling, characterized in that irradiation of the exposed single-crystal plates with different degree of compensation at the flux density of not more than 1012cm-2with-1to the fluence f=(0,5÷5,0)·1015cm-2and annealing is performed at 850÷900°C for 20 min with heating rate and cooling 10 deg./min and 5 deg./min, respectively.
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