Method for formation of nanosized structures on semiconductors surface for usage in microelectronics
FIELD: electrical engineering.
SUBSTANCE: method for formation of nanosized structures on semiconductors surface for usage in microelectronics includes formation of a monoatomic thickness buffer layer of gold with formation of an orderly 2D underlayer Si(111)-Si(111)-α√3×√3-Au, subsequent precipitation of 1-3 fullerene layers of onto the 2D underlayer Si(111)-Si(111)-α√3×√3-Au to form a fullerite-like lattice and precipitation of a 0.6 - 1 gold monolayer onto the prepared substrate under extra-high vacuum conditions, the substrate temperature being 20°C.
EFFECT: invention enables controllable formation of ultrathin gold nanofilms with the preset electric conductivity value on a semiconductor substrate surface.
2 cl, 3 dwg
The invention relates to the technology of nanostructured elements of semiconductor devices and can be used to create solid-state electronic devices.
The problem of creating conductive films ultra-small thickness, having a high conductivity, is currently particularly relevant in the field of semiconductor devices. Great interest in this regard are attracted by the possibility of obtaining such conductive films using fullerenes. It is known that there is the ability to control the state of the silicon substrate by forming on her surface reconstructions of atoms of metals such as silver or gold, with the inclusion of fullerenes. In particular, layer-by-layer growth of fullerenes observed on the surface of Si(111)-α-√3×√3-Au using the method of scanning tunneling microscopy [A.V.Matetskyi, D.V.Gruznev, A.V.Zotov, A.A.Saranin, Modulated With60monolayers on Si(111)√3×√3-Au reconstructions // Phys. Rev. B, 2011, v.83, p.195421].
Such layers of ordered two-dimensional layer of fullerenes can be of great practical value, for example, as an organic semiconductor in electrical circuits, for example, in the manufacture of thin-film transistors; as a conductive material in organic electroluminescent elements and devices; as electron acceptor in photoact the main layer in the photodiodes; in the production technology of semiconductor devices, particularly field-effect transistors and other
The literature describes various methods of obtaining ultrafine conductive films on semiconductor surfaces.
The known method of forming ultra-thin silver films, which consists in the deposition of silver on the surface of the silicon Si(111)7×7 in ultrahigh vacuum conditions. A significant drawback of this method of producing films is their formation only at low temperature (83 K). In the case of deposition of silver on the surface of Si(111)7×7 at room temperature is observed islet film growth, the morphology of which also depends on the deposition rate of silver. This method of growth significantly reduces the conductivity of the silver film and further leads to the grain size. Thus the conductivity of a film of silver is formed at a temperature of 83 K, is detected only when the floor is greater than 1 monolayer [S.Heun, J.Brange, R.Schad, M.Henzler, Conductance of Ag on Si(111): a two-dimensional percolation problem // J. Phys. Condens. Matter, 1993, v.5, p.2913].
There is also known a method of forming an ordered metal films, consisting in the deposition of indium on the surface of Si(111)√3×√3-in ultrahigh vacuum conditions at room temperature. The surface is reconstructed from the √3×√3 2×2, then √7×√3, which is met lechaschau. The drawback of this method is that when the floor more than four monolayers of India observed islet film growth India, as well as the fact that coverage about one monolayer film India (reconstruction of the 2×2) has a low surface conductivity (of the order of ~2×10-5Ω-1/□) [S.Takeda, X.Tong, S.Ino, S.Hasegawa, Structure-dependent electrical conduction through indium atomic layers on the Si(111) surface // Surf. Sci., 1998, v.415, p.264].
Closest to the claimed invention to the technical essence and the achieved result is a method of forming ultra-thin gold films on the surfaces of Si(111)7×7 and Si(100)2×1 [D.A.Tsukanov, S.V.Ryzhkov, S.Hasegawa, V.G.Lifshits, Surface Conductivity of Submonolayer Au/Si System // Phys. Low-Dim. Struct., 1999, v.7/8, p.149] (prototype), which includes the following stages:
preliminary obtain atomically clean silicon surface by high-temperature annealing (1250°C) in ultrahigh vacuum conditions;
the deposition of the required number of gold prepared by the above method, the substrate in ultrahigh vacuum conditions at a temperature of 20°C.
The disadvantage of this method is that such ultrathin films with coatings of gold from 0 to 4 MS deteriorate the electrical conductivity of the substrate, which is caused by the process of silicidation, which significantly alters the morphology of the film surface, increasing its roughness. This results in the significant scattering of charge carriers in the surface region of the film, that reduces their mobility, and hence the electrical conductivity of such films in General.
The claimed invention solves the problem of creating conductive films extremely small thickness on the surface of a semiconductor substrate having a high electrical conductivity.
The technical result that can be obtained when implementing the present invention is the ability for the controlled formation of ultrafine nano-structures on the surface of a semiconductor substrate with a specific conductivity value.
The problem is solved by the claimed method of forming nanoscale structures on semiconductor surfaces, including deposition of a buffer layer of gold of thickness 0.9 monolayer on atomically clean silicon surface (111) at a temperature of 600°C in ultrahigh vacuum conditions with the formation of ordered two-dimensional substrate Si(111)-α-√3×√3-Au, subsequent deposition from 1 to 3 layers of fullerenes at a temperature of 20°C and deposition at a temperature of 20°C over a is formed fullerites lattice layer of gold from 0.6 to 1 monolayer of gold in the quantity necessary to obtain the given conductivity.
With one monolayer of gold, deposited on the silicon surface, corresponds to the atomic concentration of 7.8×1014cm-2to surface the surface of the silicon (111).
Distinctive features of the proposed method are:
- formation of a buffer layer of gold monatomic thickness with the formation of ordered two-dimensional substrate Si(111)-α-√3×√3-Au;
- deposition on a two-dimensional sublayer Si(111)-α-√3×√3-Au from 1 to 3 layers of fullerenes at a temperature of 20°C with the formation of fullerites lattice;
- deposition on the prepared surface from 0.6 to 1 monolayer of gold.
A preliminary stage of implementation of the invention is to prepare the surface of Si(111) by heating the sample at a temperature of 1250°C for 20 ° C in ultra high vacuum of not more than 1×10-7PA; receive an atomically clean surface of Si(111) with a concentration of structural defects less than 3%.
On the cleaned surface of the silicon Si(111) create a buffer layer representing the surface reconstruction of Si(111)-α√3×√3-Au of gold atoms and silicon monatomic thickness, with the property that the fullerene molecules deposited on the layer at room temperature, do not enter into chemical reaction with silicon atoms and gold, and freely flowing on the surface of the atomic terraces, condense on them, forming a layer of monomolecular thickness with a lattice period of fullerite. The floor of fullerenes from 1 to 3 layers (1 monolayer of fullerene corresponds to their surface concentration of 1.1×10 cm-2it is essential to be sure to cover the surface of the substrate as a continuous layer. The role of fullerenes is that they assume the electrons, which in the absence of fullerenes gold atoms could dhiravat in the substrate and thus to influence the properties of the space charge in the surface layer of the substrate. The use of fullerenes leads to the fact that the space-charge layer does not change or changes only slightly. In the electric conductivity of the substrate remains stable at the initial stages of the formation of a film of gold, unlike the prototype.
The invention is illustrated by drawings:
figure 1 - the technological sequence of the formation of nanofilms Au on the surface of the silicon substrate Si(111);
figure 2 presents an image of the surface with nanoplasma gold under a layer of fullerenes 0.5 monolayers (a), 1 monolayer (b), 2 monolayer (b) and 4 monolayer (g);
figure 3 presents the results of the conductivity measurements of the samples.
This image of the surface represented in figure 2, obtained in a scanning tunneling microscope (Omicron" VT STM; image size 21×21 nm2. These images show that the fullerene molecules form a continuous ordered layer, which repeats the two-dimensional surface topography is of odlaa Si(111)-α√3×√3-Au (figure 2 and clearly visible domain boundaries). The adsorbed gold atoms penetrate through a layer of fullerenes and form a first islets (figure 2,a-b), and then a continuous film (figure 2,b-d), while the fullerene molecules continue to be on top, experiencing only a small displacement from their positions in the lattice due to the stretching surface and/or interaction with adsorbed gold atoms.
The inventive method of forming nanoscale structures on semiconductor surfaces is as follows.
On the cleaned surface in ultrahigh vacuum conditions precipitated atoms of gold with a thickness of 0.9 monatomic layer (MS). Gold precipitated from effusions cell at a rate of 0.5 MLS/min, the temperature of the substrate during deposition to 600°C. as a result, the surface of the substrate, a surface reconstruction of Si(111)-α-√3×√3-Au monatomic thickness [.Nagao, S.Hasegawa, K.Tsuchie, S.Ino, C.Voges, G.Klos, H.Pfn··ur, and M.Henzler, Structural phase transitions of Si(111)-(√3×√3)R30°-Au: Phase transitions in domain-wall configurations, Phys. Rev. B, 1998, v.57, p.10100] (Fig.1,a).
On the formed surface of the Si(111)-α-√3×√3-Au at a temperature of 20°C is precipitated by the fullerene molecule with a thickness in the range from 1 to 3 MS; thus precipitated molecules are condensed on the atomic terraces with education fullerites lattice (Fig.1,b).
At the final stage on the thus prepared surface at a temperature of about 20 the C precipitated the necessary amount of gold to achieve the desired conductivity value (1,in).
It is found experimentally that when the deposition of gold on the surface reconstruction of Si(111)-α-√3×√3-Au without fullerene layer at the gold coating from 0 to 1.5 monolayers, a deterioration of the conductivity of the obtained film of gold, which is confirmed by the measurement results presented in figure 3.
To characterize the conductivity of the formed layers of gold films with fullerenes were measured conductivity depending on the thickness of the gold films directly after the formation of these films in ultrahigh vacuum conditions.
Enablement of the claimed invention is illustrated by examples of its implementation.
Example 1. On the surface of the substrate Si(111) formed with a buffer layer of Si(111)-α√3×√3-Au and besieged him with a layer of fullerenes sprayed 0.6 monolayer of gold in ultrahigh vacuum conditions at a temperature of the substrate equal to 20°C. the electrical conductivity Measurements show that the conductivity of such substrate increased (0,25±0,09)×10-4Ω-1/□.
Comparing this example with the results of electrical measurements of the prototype shows that with the same gold coating conductivity of the substrate Si(111)7×7 (prototype) practically does not change. The same result is observed if under the same conditions as in example 1, sadati,6 monolayer of gold, but without applying a layer of fullerenes (see, for example, Fig 3).
Example 2. On the surface of the substrate Si(111) formed with a buffer layer of Si(111)-α√3×√3-Au and besieged him with a layer of fullerenes sprayed 0.2 monolayer of gold in ultrahigh vacuum conditions at a temperature of the substrate equal to 20°C.
The electrical conductivity measurements show that the conductivity of such a substrate is not changed, while a deterioration of the conductivity of the substrate Si(111)-α√3×√3-Au, but without applying a layer of fullerenes (figure 3); the deterioration of the conductivity of the sample obtained in similar conditions, is observed also in the way that, taken as a prototype. Thus, the experimental data show that the gold coating deposited on the surface of the substrate, should not be less than 0.2 monolayers.
Example 3. On the surface of the substrate Si(111) formed with a buffer layer of Si(111)-α√3×√3-Au and besieged him with a layer of fullerenes sprayed in ultrahigh vacuum conditions 1 monolayer of gold at the temperature of the substrate equal to 20°C. the electrical conductivity Measurements show that the conductivity of such substrate increased (0,40±0,07)×10-4Ω-1/□, which is also greater than the conductivity of the prototype.
The measured conductivity of the substrate Si(111) with super-thin gold films obtained by sputtering under conditions of ultra high vacuumisolated on the surface of Si(111)-α-√3×√3-AU, covered with a layer of molecules of fullerenes, and on the surface of Si(111)-α-√3×√3-Au layer without fullerenes. In both cases, the measurements show different values of electric conductivity depending on the thickness of deposited gold (figure 3). This suggests that using the state of the surface of the semiconductor substrate and the amount of deposited gold, you can get a nanoscale structures with a given conductivity value.
Experimental data show that the optimal number of sputtered gold is from 0.6 to 1 monolayer, allowing to form nanostructures ultrafine sizes with optimum conductivity values. If the gold coating will be less than 0.6 monolayer, the contribution of this layer of gold in the conductivity of the substrate will not be noticeable against the background conductivity of the substrate with the buffer layer. When the gold coating more than 1 monolayer values of conductivity will be determined by the surface morphology and the interaction of the adsorbed layer with fullerene molecules. In this case, the conductivity can be close to the prototype.
Comparative analysis of the essential features of the claimed method from the essential features unique and prototype demonstrates its compliance with the criterion of "novelty".
This set is great for the positive features of the proposed method enables not only the formation of ultra-thin nanofilms of gold on the surface of a semiconductor substrate with improved conductivity, but also allows you to control the process of creating nanostructures provides the possibility of the formation of ultra-thin nanofilms with a given conductivity value.
The practical significance of the proposed method lies in the possibility of creation on the basis of nanofilms obtained by the claimed method, the electrical contacts and conductive elements for integrated circuits. The inventive method is proposed to use in the technology of semiconductor devices nanometric scale, which can be used in digital electronics, microwave electronics, sensors and gas sensors, thermal or radiation.
1. The method of forming nanoscale structures on semiconductor surfaces for use in microelectronics, including creation of a sublayer of gold on an atomically clean surface of Si(111)7×7, characterized in that the first form a buffer layer coating 0.9 monolayer of gold at a temperature of 600°C in ultrahigh vacuum conditions with the formation of ordered two-dimensional substrate Si(111)-α√3×√3-Au, after which the precipitated fullerenes with subsequent deposition on the prepared substrate from 0.6 to 1 monolayer of gold in ultrahigh vacuum conditions at a temperature of the substrate equal to 20°C.
2. The method according to claim 1, characterized in that precipitated from 1 to 3 the Loew fullerenes at a temperature of 20°C with the formation of fullerites lattice.
SUBSTANCE: in the method of making an ohmic contact to GaAs, a mask is formed on the surface of an n-GaAs plate, having a doped layer, in order to carry out a lift-off lithography process. To clean the surface in the windows of the mask, the n-GaAs plate is treated in aqueous H2SO4 or HCl solution and then washed in deionised water and dried. Further, via electron-beam and/or thermal evaporation in a vacuum at residual pressure lower than 5x10-6 torr, Ge and Cu are deposited with total thickness of 100-500 nm and weight content of germanium in the double-layer composition equal to 20-45%. Further, in a single vacuum cycle, the n-GaAs plate undergoes first thermal treatment at temperature T1=150-460°C in an atmosphere of atomic hydrogen with hydrogen atom flux density on the surface of the plate equal to 1013-1016 at.cm2 s-1. The n-GaAs plate is removed form the vacuum chamber, and after removing the mask, undergoes second thermal treatment in an atmosphere of an inert gas or in a vacuum at temperature T2=280-460°C for t=0.5-30 min.
EFFECT: lower value of reduced contact resistance.
2 cl, 1 dwg
SUBSTANCE: method of obtaining a thin-film copper-germanium joint involves successive deposition of Ge and Cu layers on the surface of a plate and forming a thin-film copper-germanium joint which is carried out over a time t≥0.5 minutes in an atmosphere of atomic hydrogen at temperature T=20-120°C and hydrogen atom flux density on the surface of the plate equal to 1013-1016 at.cm-2 s-1.
EFFECT: lower temperature and shorter time for obtaining a thin-film copper-germanium joint.
7 cl, 6 dwg
FIELD: material engineering.
SUBSTANCE: method of application of metallic nanolayers in chemical method involves the technology of chemical sedimentation of metals, in particular of copper (Cu) at the speed 1 μm/min with the solution temperature 50 to 60°C. As the basic copper-containing reagent for applying metallic nanolayers on silver electric contacts of silicon solar cells the inorganic copper salts are used. Technical result of the invention is the thickening of frontal electric contact of solar cell by sedimentation of metals, in particular copper, with good electric conductivity, in order to compensate or improve its increased electric conductivity.
EFFECT: increased effectiveness of solar cell operation during transformation of high-density radiation and decreased self-cost of its manufacturing.
4 cl, 4 dwg
SUBSTANCE: in the method to manufacture Cu-Ge ohmic contact on the surface of the plate n-GaAs or epitaxial heterostructure GaAs with n-layer a resistive mask is developed, fims of Ge and Cu are deposited, the first thermal treatment is carried out in the atmosphere of atomic hydrogen at the temperature from 20 to 150°C and density of hydrogen atoms flow to the surface of the plate equal to 1013-1016 at.cm-2 s-1. Plates are withdrawn from a vacuum chamber of a spraying plant, the resistive mask is removed before or after the first thermal treatment, and the second thermal treatment is carried out.
EFFECT: reduced value of the given contact resistance.
7 cl, 1 dwg
SUBSTANCE: method to metallise elements in products of electronic engineering includes application of a sublayer of a metallising coating on one of substrate surfaces with previously formed topology of elements in an appropriate product, and this sublayer is a system of metals with the specified thickness, providing for adhesion of the main layer of the metallising coating, formation of topology - protective photoresistive mask of the main layer of metallising coating, local application of the main layer of the metallising coating, removal of protective mask, removal of a part of the sublayer arranged outside the topology of the main layer of the metallising coating. Application of the sublayer of the metallising coating is carried out with the total thickness of 0.1-0.5 mcm, directly onto the specified sublayer additionally a technological layer is applied from an easily oxidable metal with thickness of 0.1-0.5 mcm, and formation of the metallising coating topology is carried out on the technological layer from the easily oxidable metal. Prior to local application of the main layer of the metallising coating a part of the technological layer is removed from the easily oxidable metal via the specified protective mask, and removal of the remaining part of the technological layer from the easily oxidable metal is carried out prior to removal of a part of the sublayer of the metallising coating arranged outside the topology of the main layer of the metallising coating.
EFFECT: increased quality of the metallising coating and reliability of electronic engineering products, improved electrical characteristics, increased yield of good products.
6 cl, 3 dwg, 1 tbl
SUBSTANCE: proposed method comprises pre-cleaning of GaSb p-junction conductance by ion-plasma etching to depth of 5-30 nm with subsequent deposition by magnetron sputtering of adhesion titanium 5-30 nm-thick layer and platinum 20-100 nm-thick barrier layer, evaporating thermally of 50-5000 nm-thick silver layer and 30-200nm-thick gold layer for contact with ambient medium.
EFFECT: reproducible ohmic contact with low specific junction resistance.
2 cl, 1 dwg
SUBSTANCE: method of depositing platinum layers onto a substrate involves pre-formation of an intermediate adhesion layer from a mixture of platinum and silicon dioxide nanocrystals on a silicon oxide and/or nitride surface. The intermediate adhesion layer with thickness 1-30 nm can be formed via simultaneous magnetron sputtering using magnetrons with platinum and silicon dioxide targets, respectively.
EFFECT: high quality of elements, processes, reliability during prolonged use, adhesion of the deposited layers to the substrate.
8 cl, 3 dwg
SUBSTANCE: method of making an ohmic contact to GaAs based on thin Ge and Cu films involves formation a mask on the surface of an n-GaAs wafer in order to perform lift-off lithography, deposition of thin Ge and Cu films onto the surface of the n-GaAs wafer, first thermal treatment in a single vacuum cycle with the deposition process, removing the n-GaAs wafer from the vacuum chamber, removing the mask and second thermal treatment. First thermal treatment is carried out in an atmosphere of atomic hydrogen at temperature 150-460°C and hydrogen atom flux density on the surface of the n-GaAs wafer equal to 1013-1016 at.cm2 s-1.
EFFECT: low value of the reduced contact resistance of the ohomic contacts made.
4 cl, 1 dwg
SUBSTANCE: method of making interconnections of a semiconductor device involves formation of a silicon structure in an insulating layer, in which semiconductor devices are formed, contact wells and trenches under future interconnection conductors, successive deposition of an adhesive-wetting layer and a solid catalyst layer at the bottom and wall of the contact wells and trenches, filling the depressions of contact wells and trenches with carbonaceous material through stimulated plasma chemical deposition of the carbon structure from the gas phase on the solid catalyst layer and planarisation of the surface of the silicon structure.
EFFECT: high thermal stability and reduced heating of IC interconnections in conditions of reduction of their cross-sectional area and high current density, low resistivity of the interconnection material compared to carbon nanotubes.
3 cl, 3 dwg
SUBSTANCE: in manufacturing method of multi-level copper metallisation of VLSIC, which involves application operations of metal and dielectric layers, photolithography and selective etching of those layers, chemical mechanical polishing of dielectric layers, to plate of silicium, which is coated with dielectric material with vertical conductors of underlying structure, which protrude on its surface, there applied is multi-layered conducting film consisting of adhesive barrier, etched and auxiliary layers; grooves are formed in auxiliary layer before etched layers by electrochemical method; copper horizontal conductors are grown inside grooves in open sections of etched layer till grooves are fully filled; the second auxiliary layer is applied to surface of plate, and in that layer holes are made to the surface of horizontal copper conductors; vertical copper conductors are grown by electrochemical method in open sections of horizontal conductors till holes for vertical conductors are fully filled; then, auxiliary layers are removed; conducting layers between horizontal copper conductors are removed; dielectric layers are applied to surface of the plate by smoothing and filling methods, and then dielectric material layers are removed above vertical conductors by means of chemical and mechanical polishing method.
EFFECT: improving quality of copper conductors.
16 cl, 11 dwg, 1 tbl
FIELD: measurement equipment.
SUBSTANCE: manufacturing method of a glass probe with a conducting core involves placement into a glass tube of low-melting metal or metal alloy, the fusion temperature of which is much lower than softening temperature of the glass that constitutes the glass tube, local heating of hollow glass tube till its softening and further tension of the tube till its breakage.
EFFECT: improving resolution ability, mechanical properties and durability.
FIELD: machine building.
SUBSTANCE: plant includes a frame with a vacuum chamber arranged on it, a mechanism for fastening of a part with a socket and a back poppet, a part rotation mechanism, and a plasmatron with mechanism of its longitudinal movement, a powder material supply mechanism with shape memory effect, the first pyrometer for temperature measurement of the part before the front of plasma arc, a control device, a device for surface-plastic deformation (SPD) of the part for formation of a nanostructured layer, the second pyrometer, a step-down transformer, a gas-flame burner for gas-flame spraying, a process module for ionic cleaning of the processed part with a power supply and a part surface cooling device. Gas-flame burner and device for SPD are arranged on longitudinal plasmatron movement mechanism; at that, burner is installed at an angle of 45° or 90° to the part surface. Positive side of the power supply of the process module of ionic cleaning is connected to housing of vacuum chamber, and its negative side is connected to back poppet of the part fastening mechanism. The second pyrometer is installed in SPD zone and connected to the control device related to powder material supply mechanism and longitudinal plasmatron movement mechanism and the first pyrometer. Step-down transformer is connected to SPD device to provide an additional heating of the part surface. Cooling device is connected to longitudinal plasmatron movement device that is installed on the longitudinal movement mechanism at an angle of 46-50° to the part surface.
EFFECT: improving functional properties and reliability of the part coatings.
2 cl, 1 dwg, 2 ex
SUBSTANCE: invention relates to nanostructured polymers, production and use thereof. The conjugated diene-based nanostructured polymers are obtained in the presence of catalysts which are based on compounds of rare-earth metals, followed by reaction with a nano-linking agent. The obtained polymers have bimodal molecular weight distribution. The high-molecular weight component has average molecular weight higher than 2000000 g/mol and is in amount of 1-20 wt % with respect to the polymer. Content of gel in the polymer is less than 1% and content of 1,2-vinyl links with respect to the polymer ranges from 0.3 wt % to 1 wt %.
EFFECT: disclosed polymers have good processing properties, rubber mixtures based on said polymers have an improved set of properties and higher tear resistance.
5 cl, 3 dwg, 3 tbl, 10 ex
SUBSTANCE: invention relates to modification of the surface of inorganic fibre by forming a highly developed surface of inorganic fibre used as filler by forming carbon nanostructures on the surface of the fibres and can be used in producing high-strength and wear-resistant fibre composite materials. The method of modifying the surface of inorganic fibre involves the following steps: (a) soaking inorganic fibre with a solution of an α2 sinter fraction in organic solvents; (b) drying the soaked fibre; (c) heat treatment of the soaked inorganic fibre at 300-600°C; (d) depositing a transition metal salt onto the surface of the fibre heat treated according to step (c); (e) reducing the transition metal salt to obtain transition metal nanoparticles; (f) depositing carbon onto the transition metal nanoparticles to obtain carbon nanostructures on the surface of the fibre. The composite material contains modified fibre made using the method given above and a matrix of polymer or carbon.
EFFECT: high strength of the composite material in the cross direction relative the reinforcement plane by preventing surface deterioration when modifying with carbon nanostructures.
9 cl, 3 ex, 1 tbl, 5 dwg
SUBSTANCE: invention relates to physics of low-temperature plasma and plasma chemistry, as well as electrical engineering and electrophysics, and specifically to acceleration techniques and can be used to generate high-enthalpy jets of carbon-bearing electrodischarge plasma and obtain ultrafine crystalline phases of hard and superhard materials. The method involves conducting a plasma chemical synthesis in the shock wave of an impact-wave structure of a hypervelocity pulsed jet of carbon-bearing electrodischarge plasma which flows into a closed sealed volume filled with nitrogen gas, wherein synthesis is carried out in a shock wave arising from the reaction of two synchronous equal-enthalpy hypervelocity jets of carbon-bearing electrodischarge plasma, flowing in opposite directions on the same axis from shafts of two identical accelerators, wherein the hypervelocity pulsed jets of the carbon-bearing electrodischarge plasma are generated at equal pulse current of the power supply of the accelerators with amplitude of 140 kA, discharge power of 145 MW and delivered energy of 30 kJ. The method is realised in apparatus which is in form of a cylindrical electroconductive shaft placed coaxially inside a solenoid 8 and made from graphite, inside which there is a fuse 5 made from ultrafine carbon material which electrically connects the beginning of the cylindrical electroconductive shaft and a centre electrode, which is connected to one terminal of the power supply circuit of the accelerator, the second terminal of which is connected to the end of the solenoid 8, further from the centre electrode; the second end of the solenoid 8 is electrically connected to the beginning of the shaft; the vertex of the centre electrode, the beginning of the shaft and the beginning of the solenoid lie in one plane which is perpendicular to the axis of the shaft, and the housing 7 of the centre electrode unit is made from magnetic material and overlaps the area where the fuse 5 is located, the length of the part which overlaps the area where the fuse is located being equal to 40-50 mm, and its outer surface is cone-shaped, wherein the shaft of the accelerator is in form of an inner 1 and an outer 2 current-conducting cylinder, coaxially placed one inside the other and electrically connected on the entire mating surface, and the centre electrode is composed of a tip 3 and a tail 4; the inner cylinder 1 and the tip 3 are made from graphite, the outer cylinder 2 is made from hard nonmagnetic metal and the tail 4 is made from structural metal with high electroconductivity; the free ends of the shafts of both accelerators are mounted by through insulator-sealers 20 in axial holes of disc-shaped metal covers 21, which are hermetically connected to opposite ends of the cylindrical metal housing 22 of the reactor chamber, while providing opposite, coaxial and symmetrical arrangement of shafts on the longitudinal axis of the reactor chamber which is filled with nitrogen gas.
EFFECT: invention increases output of the expected phase of carbon nitride and reduces content of impurities in the dynamic synthesis product.
2 cl, 1 dwg
SUBSTANCE: invention refers to nanotechnology. Essence of the invention: in the method for obtaining volume nanostructured material on the substrate by metal electroplating from electrolyte on the substrate from conductive material that is indifferent in relation to the deposited metal, a volumetric frame of multi-layer carbon nanotubes is formed on the cathode, and metal deposition from electrolyte is performed on it; as a result, remotely separated metal nanoparticles are obtained. Deposition of metal nanoparticles is performed at the value of the flowing charge until the area of the applied metal exceeds approximately by 2 times the side surface of the frame elements, and synthesis of new nanotubes with the diameter depending on the size of nanoparticles is performed on the surface of the applied metal.
EFFECT: invention provides electrical conductivity, high specific surface of the material obtained after deposition of metal nanoparticles, high mechanical strength of nanocomposite material, its heat and chemical stability, formation of through pores in deposited metal particles and wider range of functional properties of carbon nanotubes by providing them with necessary magnetic, biomedical and catalytic properties.
10 dwg, 2 tbl
FIELD: process engineering.
SUBSTANCE: invention may be used in power engineering, chemical and electronic industries. Electrically conducting electrodes are made from selected material. HV pulsed voltage is fed to electrodes to generate high-current discharge so that electrodes are heated and evaporated. Thereafter, produced vapours are cooled and condensed to obtain nanoparticles. Said electrodes are placed in evacuated medium of plasma-forming gas. Said HV pulsed voltage is fed to electrodes unless plasma is formed in interelectrode space to be maintained therein.
EFFECT: higher efficiency.
6 cl, 10 dwg, 1 tbl
SUBSTANCE: invention relates to the technology of making integrated circuits on the basis of complementary transistors with the structure of metal - oxide - semiconductor (CMOS IC). The method to produce local low-resistance areas of titanium silicide in integrated circuits consists in generation of active and passive elements of CMOS IC on the basis of areas of n and p type of conductivity in a silicon substrate and a layer of polycrystalline silicon, deposition of a blocking layer, formation of a photoresistive mask, etching of the blocking layer, removal of the photoresistive mask, cleaning of the silicon surface, application of the titanium layer onto the surface of silicon and the blocking layer, annealing of the titanium layer in nitrogen, removal of titanium, which did not react with silicon, and additional annealing in nitrogen. The blocking layer is a film of titanium nitride with thickness of 5-20 nm, produced by means of physical spraying of a titanium target in nitrogen atmosphere, and the blocking layer is removed in process of removal of titanium, which did not react with silicon.
EFFECT: preservation of electrophysical and structural parameters of active and passive elements in integrated circuits on the basis of complementary transistors with a structure of metal - oxide - semiconductor when generating titanium silicide.
5 dwg, 1 tbl
SUBSTANCE: carbon nanofiller - carbon nanofibres or globular nanocarbon - is added to a polymer nanocomposite based on bisphenol A polyhydroxy ether, with the following ratio of components: bisphenol A polyhydroxy ether - 99.975-99.5%, nanofiller - 0.025-0.5%. When producing the nanocomposites, the carbon nanofiller is pre-activated sulphuric acid solution with concentration of 20-60% while heating at temperature of 70-100°C for 45-60 minutes. The treated carbon nanofiller is added the polymer in situ.
EFFECT: invention enables to obtain polymer nanocomposites based on bisphenol A polyhydroxy ether and activated carbon nanofiller with high output and reduced viscosity with improved hardness and resistance to aggressive media.
2 cl, 1 tbl, 6 dwg, 3 ex
SUBSTANCE: in the method to prepare a powdery nanomodifier for a concrete mixture, including mixing of a plasticiser and a mineral component in a mixer of cyclic action and their further grinding in an activator, the plasticiser is a hyperplasticiser on the basis of polycarboxylates, the mineral filler is a mixture of siftings from crushing of broken concrete and microsilica in the weight ratio of 3:1, and when preparing the nanomodifier, the specified hyperplasticiser and the mineral component in amounts of accordingly 2-3 wt % and 97-98 wt % are mixed in the mixer of cyclic action for 1-2 minutes, and grinding is carried out in an industrial activator with a vertical working chamber of AKRK series to produce a powdery nanomodifier with nanoparticle size of less than 100 nm in amount of 5-7 wt %, dusty parties with size from 100 nm to 100 mcm 20-25% and particles with size from 100 to 300 mcm - balance.
EFFECT: concrete strength improvement.
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.