Method for producing of cabtilever of scanning probe microscope
SUBSTANCE: invention is related to the field of manufacture of micromechanical devices, namely to methods of formation of scanning probe microscope probes, in particular, cantilevers consisting of console and needle. In method of cantilever manufacture that includes formation of KDB on top surface of single-crystal silicic wafer with orientation (100) of cantilever needle by method of local anisotropic etching of silicon, formation of p-n transition on top side of wafer, local electrochemical etching of wafer from the back side to p-n transition with creation of silicic membrane, formation of cantilever console from the saidmembrane by means of local anisotropic etching of membrane from both sides of plate with application of mask that protects needle and top part of console, needle of cantilever is formed prior to formation of p-n transition. Depth of n-layer amounts to doubled thickness of console, and mask for local anisotropic etching of membrane is received by method of lift-off lithography with application of bottom "sacrificial" layer and top masking layer from chemically low-activity metal.
EFFECT: obtaining of cantilever with reproduced geometric parameters of console and higher resolution of needle.
3 cl, 15 dwg
The invention relates to the field of micromechanical devices, and in particular to methods of forming probes of a scanning probe microscopes, in particular cantilevers, which includes the console and the needle.
A known method of manufacturing the cantilever . It includes: forming on the upper side of the silicon substrate 100 orientation, needle-like protrusion anisotropic etching of silicon through local nitride mask, forming on the upper side of the substrate of the p-diffusion layer by diffusion of boron selective with respect to the p-diffusion layer anisotropic etching of silicon from the bottom side of the substrate through the local mask silicon nitride, the subsequent formation of cantilevers cantilever.
The disadvantages of this method is that to obtain good selectivity when etching silicon with different conductivity type, the diffusion of boron needed to high degrees of doping (not less than 1020cm-3). A high degree of alloying leads to the appearance in the crystal lattice of silicon uncompensated boron and, consequently, defects in subsequent operations oxidation of silicon, which negatively affects the quality of the tops of the needles of the cantilever. On the point of the needle appear the so-called "horns" (double top) and "screwdriver" (bevels vertices). In addition, when fo is the formation of the p-layer formed needle is a mask for the diffusion of boron. Because of this, on a reflective surface above the needle hole is formed, which leads to losses in the reflection.
The closest technical solution is the method of manufacturing the cantilever , which includes: forming on the bottom side of the silicon substrate protective coating of silicon nitride, phosphorous diffusion from the front side of the substrate forming a deep p-n junction, the depth of which is set equal to the sum of the length of the needle and the thickness of the console, remove the protective coating on the reverse side of the substrate, forming on the upper and lower sides of the silicon substrate protective coating of silicon nitride, forming on the upper side of the substrate local nitride mask, anisotropic etching of silicon from the top side of the substrate before the formation therein of an acicular protrusion, the formation of a local mask silicon nitride on the bottom side of the substrate for deep etching of silicon and local mask silicon nitride on the upper side of the substrate to protect the needle and the console of the cantilever, the formation of the silica membrane of the n-layer by electrochemical etching from the reverse side of the plate with a stop at the p-n junction, forming a console cantilever from the specified membrane by local anisotropic etching of the membrane on both sides of the wafer using a mask which protects the needle and the upper part of the console, subsequent removal of the mask.
In this way stop the process of deep etching of silicon is carried out automatically, as used electrochemical etching which is stopped when reaching the p-n junction due to the resulting surge . A sufficient degree of alloying is equal to 1015-1016cm-3that allows the formation of active structures.
The disadvantages of this method include the lack of an automatic thickness control console, which leads to the dispersion characteristics of the cantilevers over the plate, the need for a process of diffusion of phosphorus at great depths (15-20 microns), and the absence of reliable protection of the needle cantilever (as in photolithography, the tip of the needle is not completely closed by the photoresist), affect the quality of the top of the needle, which reduces the resolution of the cantilever.
The purpose of the invention is to obtain cantilever with reproducible geometrical parameters of the console and in the resolution enhancement needle cantilever.
This objective is achieved in that in the method of manufacturing a cantilever, comprising forming on the upper surface of the monocrystalline silicon substrate KDB with orientation (100) needle cantilever using local anisotropic etching of cu is mnia, local electrochemical etching of the substrate from the back side to the p-n junction with the formation of the silicon membrane, the formation of the console cantilever from the specified membrane by local anisotropic etching of the membrane on both sides of the wafer using a mask that protects the needle and the upper part of the console, provides for the following differences: the tip of the cantilever is formed before forming the p-n junction, while the depth of the n-layer is twice the thickness of the console, and the mask for the local anisotropic etching of the membrane produced by the method of "explosive" lithography using bottom "sacrificial" layer and an upper mask layer of a chemically inactive metal.
When the formation of a local mask for the needle and console method "explosive" lithography as a "sacrificial" layer using the polycrystalline silicon, and as chemically inactive metal use platinum.
The proposed method of manufacturing a cantilever of a scanning probe microscope based on the electrochemical stop etching includes forming on the upper side of the monocrystalline silicon wafer (KDB) with orientation (100) local mask for anisotropic etching of silicon, the formation of needle cantilever anisotropic etching of silicon through vysheupomjanutoe the local mask to remove a local mask. The height of the needle is determined by the size of the local masks and has a value of from 14 to 16 microns. Further diffusion of phosphorus from the upper side of the plate is formed of the p-n junction. The degree of alloying is equal to 1015-1016cm-3. The depth of the p-n junction corresponds to double the size of the console of the cantilever. Then on the top side of the substrate is formed a protective mask for the needle and the console. At the same time protective mask is deposited on the lower side of the plate for subsequent deep etching of silicon. Lokalnoy mask of the protective layer for the needle and the console was formed by the method of explosive lithography. On the upper side of the silicon wafer is deposited polysilicon, which serves as the bottom, the "sacrificial" layer when the explosive lithography. Next, polysilicon is formed local mask on which is deposited chemically inactive metal and held the explosive process of lithography. Then on the top side of the wafer obtained through the mask of the metal is formed local mask of the protective layer for the needle and the console of the cantilever. At the same time on the bottom plate form a local mask for anisotropic etching of silicon, conduct thermal deposition of aluminum on the upper side of the plate to create ohmic contact to n-silicon, carry out electrochemical stop-tra is of silicon from the bottom side of the plate. The etching stops automatically when the n-layer. This forms a silicon membrane of a given thickness (double the thickness of the console). The formation of the console cantilever carry out anisotropic etching of the silicon membrane on both sides of the plate, then remove metals and two-layer masks with a needle and consoles cantilever.
In the proposed invention the objective is achieved by using in the process method explosive lithography, allowing through an intermediate metal mask to get on the needle and console cantilever local protective mask for anisotropic etching of silicon. Direct photolithography cannot be reliably protect the tip of the cantilever, since the photoresist does not close the needle tip, which podraschivaetsya further etching steps. The homogeneity of the geometric dimensions of the console of the cantilever in this way is achieved by the thickness control of the console when the anisotropic etching from both sides of the plate are pre-manufactured silicon membrane of a specified thickness.
A method of manufacturing the cantilever is illustrated in figure 1-15, which shows the cross patterns at different stages of the formation of the cantilever.
Figure 1 shows the cross section of the plate (1) after applying a two-layer mask on the oxide basis (2) and is of Frida silicon (3) on both sides of the plate.
Figure 2 presents the cross-section of the plate (1) formed on the upper side of the local two-layer mask of the oxide (2) and silicon nitride (3).
Figure 3 presents the cross-section of the plate (1) after the formation of needle cantilever (4).
4 shows the cross section of the plate (1) after the process of diffusion of phosphorus (5).
Figure 5 presents a cross-section of the plate (1) after removal of the lower side plate of silicon nitride (3).
Figure 6 presents a cross-section of the plate (1) is coated on the upper side of the protective two-layer mask of the oxide (2) and silicon nitride (3) and a layer of polysilicon (6).
Figure 7 presents a cross-section of the plate (1) with the local mask of polysilicon (6).
On Fig presents a cross-section of the plate (1) with a spray on the upper side of the metal (7).
Figure 9 presents a cross-section of the plate (1) after the process of explosive lithography.
Figure 10 presents a cross-section of the plate (1) after removal through a metal mask (7) a protective layer of oxide (2) and silicon nitride (3) with the upper side of the plate and the local mask from the bottom side of the plate.
Figure 11 presents a cross-section of the plate (1) with thermally deposited aluminum (8).
On Fig presents a cross-section of the plate (1) after the process of electrochemical stop etching and formation of the membrane (5).
On Fig presents behold the giving plate (1) after removal of the metal layers.
On Fig presents a cross-section of the plate (1) after removal of the membrane anisotropic etching of silicon on both sides of the plate.
On Fig presents a cross-section of the plate (1) with the obtained needle (4) and the console (5) of the cantilever after removing the protective mask.
An example implementation of the method
For the fabrication of the cantilever was used monocrystalline silicon wafer KDB-12 (1 in figure 1) with orientation (100). Thermal oxidation on both sides of the plate were formed protective oxide layer of a thickness of 0.3 microns (2 to 1). At his deposition in the gas phase deposited silicon nitride (3 in figure 1) with a thickness of 0.1 μm. The photolithography of the two-layer coating was formed local mask on the upper side of the plate. In a supersaturated solution of potassium hydroxide at a temperature of 130°was carried out With anisotropic etching of silicon with the upper side of the plate to the etched oxide silicon (lower layer local mask). When this silicon nitride upper layer (local mask slips obtained with needle height of not less than 12 microns (4 figure 3.). Further diffusion of phosphorus from the upper side of the plate in silicon was formed n-layer depth phosphorus 4 μm and a surface concentration of 1016cm-3(5 in figure 4). Then liquid etching in phosphoric acid with the lower side of the plate was removed, a protective layer nitri is and silicon (figure 5). Thermal oxidation at a temperature of 1100°on the upper side of the wafer was formed a silicon oxide layer with a thickness of 0.3 μm (2 to 6). Deposition in the gas phase under reduced pressure on both sides of the plate formed a layer of silicon nitride with a thickness of 0.1 μm (3 to 6). Deposition in the gas phase by a double-layer mask on the top side of the wafer was formed a layer of polysilicon with a thickness of 0.6 μm (6 on 6).
By photolithography on the upper side of the plate formed local mask of polysilicon (6 7). Magnetron sputtering on the upper side of the plate was applied a layer of platinum with a thickness of 0.2 μm. (7 Fig). Chemical etching in 30% solution of potassium hydroxide on the top side of the wafer was formed a local mask of platinum (7 figure 9). Plasmochemical through local mask on the upper side of the plate was exposed n-silicon (removed the nitride layer and oxide silicon) (5 figure 10), and simultaneously with the lower side of the plate was removed, the nitride and the oxide silicon (figure 10) (opening Windows for deep etching of silicon). Next, on the upper side of the plate was thermally deposited aluminum to obtain ohmic contact with the electrochemical etching of p-silicon (8 to 11). Electrochemical stop etching in 30% aqueous solution of potassium hydroxide at a temperature of 90°formed of silicon membranes with the thickness of 4 μm (5 Fig). The metal layers on the top side of the plate was removed by chemical etching in solutions of hydrochloric and nitric acid (Fig). Through the obtained two-layer mask of oxide and silicon nitride on the cantilever tip was carried out anisotropic etching of the silicon membrane on both sides of the plate at the same time a 30% solution of potassium hydroxide until the open holes (Fig). Then the liquid by the first etching in phosphoric, then in a solution containing hydrofluoric acid, deleted local two-layer mask with two sides of a silicon wafer (Fig).
The result is a cantilever with a needle having a radius less than 10 nm, the angle at the vertex of not more than 22°and precisely reproducible geometrical parameters of the console. The cantilever with these parameters has a good resolution, which greatly expands the possibilities of application of scanning probe microscopes, including research facilities for nanotechnology, molecular electronics, and biological systems.
1. Patent RU No. 2121657, CL G01 15/00, H01J 37/28.
2. Bykov V.A. Micromechanics for scanning probe microscopy and nanotechnology. Microsystem engineering, N1, 2000, 21-32.
3. Ehipassiko, Ubido. Microsystem engineering, N1, 2000, 16-20.
1. A method of manufacturing a cantilever for scanning zondo the CSOs microscope, including the formation on the upper surface of the monocrystalline silicon substrate KDB with orientation (100) needle cantilever using local anisotropic etching of silicon, forming on the upper side of the substrate p-n junction, the local electrochemical etching of the substrate from the back side to the p-n junction with the formation of the silicon membrane, the formation of the console cantilever from the specified membrane by local anisotropic etching of the membrane on both sides of the wafer using a mask that protects the needle and the upper part of the console, characterized in that the tip of the cantilever is formed before forming the p-n junction, while the depth of the n-layer is twice the thickness of the console, and the mask for the local anisotropic etching of the membrane produced by the method of "explosive" lithography using bottom "sacrificial" layer and an upper mask layer of a chemically inactive metal.
2. The method according to claim 1, characterized in that when forming the local mask for the needle and console method "explosive" lithography as a "sacrificial" layer using the polycrystalline silicon.
3. The method according to claim 1 or 2, characterized in that as a chemically inactive metal use platinum.
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
SUBSTANCE: invention pertains to compositions used for treating surfaces and the method of treating the surface of a substrate, using such a composition. The essence of the invention is that, the cleaning solution contains water, hydrogen peroxide, an alkaline compound and 2,2-bis-(hydroxyethyl)-(iminotris)-(hydroxymethyl)methane as a chelating additive. The alkaline compound is preferably chosen from a group containing an organic base, ammonia, ammonium hydroxide, tetramethylammonium hydroxide, and most preferably from a group containing ammonia and ammonium hydroxide. Content of the chelating additive is 1000-3000 ppm. The cleaning solutions are used for the process of treating the surface, including cleaning, etching, polishing, and film-formation, for cleaning substrates, made from semiconductor, metal, glass, ceramic, plastic, magnetic material, and superconductors. The method involves treatment of semiconductor substrate(s) using a cleaning solution and drying the given semiconductor substrate(s) after washing in water.
EFFECT: increased stability of the solution at high temperature and increased degree of purification of surfaces.
3 cl, 2 tbl, 15 dwg, 3 ex
FIELD: methods for manufacture of semi-conductor instruments and microcircuit chips.
SUBSTANCE: method and system are suggested for treatment of base plates for treatment of semi-conductor instruments with creation of liquid meniscus that is shifted from the first surface to the parallel second one, which is installed nearby. System and method suggested in invention may also be used for meniscus shift along base plate edge.
EFFECT: invention provides efficient cleaning and drying of surfaces and edges of semi-conductor plates, with simultaneous reduction of quantity of water or washing liquid drops that are accumulated on plate surface, which leave dirty traces on plate surface and edge after evaporation.
20 cl, 20 dwg
FIELD: electric engineering.
SUBSTANCE: invention relates to electric engineering equipment and may be used for application of coatings by electrochemical process. The device for one-side treatment of semiconductor plates comprises a galvanic bath with anode and a substrate holder with a set of electrode conducting contacts and support posts whereto a semiconductor plate is pressed. The device incorporates additionally a horizontal support frame with an angular flange and three needle-type stops with ring-like marks, the substrate holder being provided with a guiding angular recess and mounted on the support frame flange. Also, the device comprises the current source control unit and a system of forced mixing of electrolyte made up of a magnetic mixer with a shielding plate.
EFFECT: increased quality of galvanic treatment of semiconductor plates, simpler design of the device.
FIELD: semiconductor engineering; chemical treatment of single-crystalline silicon wafer surfaces chemically resistant to open air and suited to growing epitaxial semiconductor films.
SUBSTANCE: proposed method for treatment of single-crystalline silicon wafer surface positioned on Si(100) or Si(111) plane includes cleaning of mentioned surface followed by passivation with hydrogen atoms. Silicon surface is first cleaned twice by means of boiling trichloroethylene solution for 10-20 minutes involving washing with deionized water and then with ammonium-peroxide aqueous solution of following composition: 5 volumes of H2O, 1 volume of 30% H2O2, 1 volume of 25% NH4OH at 75-82 °C or with salt-peroxide aqueous solution of following composition: 6 volumes of H2O, 1 volume of 30% H2O2, 1 volume of 37% HCl at 75-82 °C, followed by three 5- or 10-minute steps of washing with deionized water; passivation with hydrogen atoms is conducted by treatment first with 5-10 mass percent HF solution and then with aqueous solution of NH4OH and NH4F mixture at pH = 7.6-7.7 for 40-60 s followed by washing with deionized water and drying out under normal conditions.
EFFECT: ability of producing wafers capable of retaining their serviceability for long time in storage and in transit, in open air, without oxidizing their surfaces.
1 cl, 3 dwg
FIELD: semiconductor device manufacture; pre-heat cleaning of silicon substrate surfaces from organic and mechanical contaminants.
SUBSTANCE: proposed method for cleaning silicon substrates includes their double-stage treatment in two baths filled with two solutions: first bath is filled with solution of sulfuric acid H2SO4 and hydrogen peroxide H2O2 in H2SO4 : H2O2 = 10 : 1 proportion at temperature T = 125 °C; other bath is filled with solution of aqueous ammonia NH4OH, hydrogen peroxide H2O2, and deionized water H2O in proportion of NH4OH : H2O2, : H2O at temperature T = 65 °C. Resulting amount of dust particles is not over three.
EFFECT: ability of removing all organic and mechanical contaminants and impurities from silicon substrate surface, reduced substrate treatment time.
FIELD: manufacturing semiconductor devices including removal of resistive mask from silicon wafer surfaces upon photolithographic operations.
SUBSTANCE: proposed method for removing resistive mask includes silicon wafer treatment upon photolithographic operations to remove photoresist from surface; treatment is conducted in two stages; first stage includes treatment in sulfuric acid (H2SO4) and hydrogen peroxide (H2O2) solution of 3 : 1 proportion at temperature T = 125 °C for 5 minutes; second stage includes washing first in warm deionized water (H2O) at T = 65-70 °C for 5 minutes followed by washing in two baths, each having spillover points in four sides, at water flowrate of 400 l/h and wash time of 5 minutes in each bath; wafers are checked for adequate cleaning by focused incident light beam at maximum six luminous points.
EFFECT: reduced number of operations required to remove resistive mask, ability of attaining clean surfaces free from photolithographic contaminants.
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: semiconductor device manufacture; silicon-wafer surface post-oxidation etching, boron and phosphor sublimation.
SUBSTANCE: proposed method for removing crystallites from silicon wafer surface includes pre-oxidation of wafer surface in oxygen environment at temperature of 850 °C for 20 minutes followed by chemical treatment in hydrofluoric acid and ammonium fluoride solution, proportion of ingredients being 1 : 6.
EFFECT: provision for complete removal of crystallites from silicon wafer surface after heat treatment, reduced wafer treatment time.
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.
SUBSTANCE: invention refers to production of semiconductor materials and can be used in semiconductor nanotechnologies. Substance of invention: production method implies that nanostems are made of cadmium selenide by melt evaporation and gas deposition on cold substrate. Process is carried out at argon pressure 7-9 MPa within 5-20 minutes. Method allows producing nanostems CdSe of diameter 5-15 nanometers and purity 99,999%.
EFFECT: production of nanostems CdSe.
SUBSTANCE: invention refers to methods of producing nano crystal alloy on base of titanium nickelide and can used, for example, in medicine for creation of biocompatible materials on base of titanium nickelide possessing high physic-mechanical properties. The method includes multiple reduction of a heated blank at temperature of heating 150-250°C and degree of reduction 15-20%.
EFFECT: improved physic-mechanical properties of alloy.
1 ex, 2 dwg, 1 tbl
FIELD: technological processes.
SUBSTANCE: invention may be used in electronic industry as optical marks and dashes in manufacture of current-conducting paths in different instruments, and also in manufacture of different luminescent instruments. Method of brittle nonmetal materials cutting includes preliminary making of cut along cutting line at the edge of billet, heating of material along cutting line with laser bundle at relative displacement of billet and bundle and local cooling of heating zone with the help of coolant in the form of air-water aerosol. Cooling of cutting line is carried out with coolant in the form of two-level disperse system that consists of dispersed air medium and two-phase composition of dispersed phase, which includes water drops as the first dispersed phase, and colloidal composition or hard microparticles with size from 1 nm to 100 micrometer as the second dispersed phase.
EFFECT: development of method for crack parameters control during thermal splitting for preparation of visible cutting line with preset width and depth.
8 cl, 5 dwg, 5 ex
FIELD: technological processes.
SUBSTANCE: method includes preparation of direct or reverse micelles with further reduction of metal precursors in them. Prior to preparation of micelles they are concentrated from water solutions by means of ion flotation or flotation extraction with application of surface agents and hydrocarbons. As water solutions artificial mixtures of dissolved water solutions are used, sewage waters, solutions of ores or their wastes that are poor in platinum metals, solutions of anode slimes of metals electrolytic cleaning.
EFFECT: preparation of platinum metals nanoparticles from wastes of mining industry; ores poor in platinum metals and sewage waters.
FIELD: engines and pumps.
SUBSTANCE: mixer has a cylindrical casing with the loose material loading device arranged at the casing top. A loose material rotor spreader is mounted below the loading device. A tapered branch pipe discharging the mix of loose material and nanopowder is arranged at the casing bottom. An air- or liquid-operated mechanical nozzle connected with the nanopowder feed injector is arranged below the rotor spreader.
EFFECT: higher quality of the mix.
SUBSTANCE: invention can be used for efficient control of optical properties of nanocomposite applied in nonlinear optics, information engineering, development of optical memory facilities etc. Method of nanocomposite optical properties control consists in that nanocomposite structure is introduced and consistently connected by nanoparticles with transient binding molecules, i.e. particles modifying spatial configuration as affected by external light, and bonded molecules i.e. particles with optical properties visualised near nanoparticles. Nanocomposite is irradiated with light of wavelength modifying spatial configuration of transient binding molecule.
EFFECT: efficient control of nanocomposite optical properties.
SUBSTANCE: invention relates to semi-conducting nanotechnology and thin film material science, namely to devices for thin film and dielectrics coating. Device consists of chamber with working capacity in cylindrical form where basis, support for film coating, reagents and cushion gas inlet system, heating elements and motor with shaft are located. Working surfaces of basis and support are made flat and even to form adjusting clearance between them due to changing of cushion gas pressure counteracting with load weight located on the support to adjust clearance between support and basis. Motor shaft is not rigidly fixed. Movable coupling is installed on the said shaft to transfer rotary motion to support with regard to fixed basis. Hollows are made on basis working surface. Hollows length does not exceed basis working surface diameter. There are openings in hollows to inlet reagents into clearance volume.
EFFECT: increase in thin film buildup speed in semi-conductors and dielectrics.
5 cl, 3 ex, 3 dwg
SUBSTANCE: invention refers to powdered metallurgy, particularly to antifrictional composite powdered material, and can be used, for example, in metal working industry and paper processing industry at fabricating of wear resistant antifrictional materials. The composite material contains a copper powder of 100-160 mcm size at amount of 63.8-64.3 mass.%, granules of copper-plated graphite of 160-200 mcm size; at amount of 16-17% with copper contents in copper-plated graphite granules of 70-75 mass.%, granules of copper-plated polymer of 50-200 mcm size at amount of 7-9 mass.% with copper content in granules of copper-plated polymer granules 50-60 mass.%, granules of copper-plated nickel of 100-200 mcm size at amount of 3-5 mass.% with copper contents in granules of copper-plated nickel 25-35 mass.%, granules of copper-plated chromium of 25-75 mcm size at amount of 6-8 mass.% with copper content in granules of copper-plated chromium granules 30-40 mass.% and carbon nano pipes at amount of 0.2-0.7 mass.%. Such composition facilitates increased service life of friction units, upgraded hardness of a powdered matrix and increased wear resistance of composite material.
EFFECT: producing antifrictional composite powdered material facilitating increased service life of friction units, increased hardness of powdered matrix and increased wear resistance of composite material.
SUBSTANCE: invention can be used for the obtaining of power supply, superhard and composite materials, catalysts, medicinal materials. Ground graphite and/or shungite with the normalised composition with carbon not less than 20% mix with preliminarily ground catalyst. As a catalyst use a carbide-forming metal from the group which includes Fe, Ni, Mn or Co, or lanthanum hydride, or the oxide of yttrium or LaNi5. The received material is subjected to great dispatch-shift influence in a force field with power density of more than 3 W/c·g in an inert environment, for example in argon, not less than 10 minutes. Fullerene, obtained by solid-phase synthesis, is extracted and separated.
EFFECT: invention allows to carry out synthesis of fullerenes with smaller power expenses and to simplify hardware maintenance.
4 tbl, 10 dwg, 6 ex
FIELD: technological processes.
SUBSTANCE: substance of invention is the method of manufacturing of field-emission cathode with emission layer from carbon nanofiber material via evaporating oxygen from graphitic heater inside gasostat, containing the following operations: purging the working cavity of gasostat, followed by filling the cavity with pressurised working gas, heating, conditioning at given temperature, followed by cooling to room temperature, manufacturing of cathode bed via processing basic graphitic element of the bed in alcoholic solution of metallocene, followed by drying and mechanical processing. Then, this bed is placed inside the gasostat on heater surface. After that, the process of carbon evaporation from graphitic source is started by heating. The evaporation process is accompanied by growing of carbon-nitrogen nanofiber on the bed. Instead of metallocene alcoholic solution, the same solution of ferrocene can be used.
EFFECT: invention allows to produce a ready-to-use field-emission cathode with increased nanomaterial adhesion to bed.
5 cl, 4 dwg
FIELD: carbon materials.
SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.
EFFECT: increased proportion of diamond structure in product and increased its storage stability.