Three-dimensionally structured semiconductor substrate for field-emission cathode, method for its obtaining, and field-emission cathode

FIELD: electricity.

SUBSTANCE: proposed invention relates to electrical engineering, and namely to a method for obtaining a three-dimensionally structured semiconductor substrate for a field-emission cathode, and it can be used in different electronic devices: SHF, X-ray tubes, light sources, ion beam charge compensators, etc. Creation of a three-dimensionally structured semiconductor substrate, onto which an emitting film of field-emission cathodes is applied in the form of a microacicular quasi-regular cellular-spiking structure with an aspect ratio of at least 2 (the ratio of height of spikes to their height), allows improving emission performance of cathode, which is the technical result of the proposed invention. A semiconductor substrate for formation of the required microacicular structure on it is subject to photoelectrochemical etching in aqueous or nonaqueous electrolyte, thus changing modes of etching and illumination intensity. Besides, the invention proposes a structured semiconductor substrate for a field-emission cathode from crystalline silicon of p-type with conductivity of 1 to 8 Ohm*cm and a field-emission cathode itself with such substrate, which has increased emission characteristics.

EFFECT: obtaining a three-dimensionally structured semiconductor substrate for a field-emission cathode.

6 cl, 5 dwg

 

The technical field

The invention relates to the field of high-performance field emission source of electrons, which can be used in electron microscopes, vacuum microwave devices, x-ray tubes, light sources, expansion joints charge of ion beams and other applications.

The prior art.

In order to initiate electron emission from a field emission source, it is necessary to apply a negative voltage with respect to the outer electrode. Therefore, the field emission electron source is also often referred to as field emission cathode (in the English-language literature uses the term "field emission cathode"). Since the initiation of the emission from such a cathode is enough just put it in an external electric field and does not require heating, it is often also used another name such field emission electron source is a cold cathode (in the English-language literature "cold cathode"). Later in this text uses the terms "field emission cathode" or "automated".

There are two main types of field emission cathodes on the type sold roughness: microgastrinae field emission cathodes and field emission cathodes based on nanostrukturirovannyh films, deposited on a conductive substrate. In microstrain autoemission the puff cathodes, the cathode surface is modified by the processing in such a manner, to create the surface roughness was optimal, namely represented as an array of microstrip. In this case, the cathode may be made of metal or semiconductor.

There are various ways to obtain macrostring cathodes. Regular and controlled with high precision arrays microstrip on silicon are formed are well known and widely used in microelectronics methods of lithography and plasma-chemical etching. For example, in the article "Fabrication of silicon field-emission arrays using masks of amorphous hydrogenated carbon films (Microelectronics Journal, v.38, 2007, pp.31-34) and "Electron field emission from microtip arrays" (Vacuum, v.82, 2008, pp.1062-1068) outlines the sequence and modes of conduct all manufacturing operations, allowing to structure the silicon substrate and to get on the source substrate regular arrays of silicon microstrip suitable for use as field emission cathode. However, the technology of microelectronics very expensive and their use is becoming justified only under conditions of mass production of manufactured semiconductor structures.

Microgastrinae structure may also be formed on a silicon substrate when exposed on the surface of high-power pulsed radiation. However, as was shown in the article "Field emission of electrons from laser produced silicon tip arrays" (Semiconductr Phys, Quantim Electronics &Optoelectronics, v.3, 2000, N4, pp.474-478), emission characteristics of such cathodes is low.

In the application for European patent EP 1003196 "Carbon material, method for manufacturing the same material, field-emission type cold cathode using the same material and method for manufacturing the same cathode", publ. 24.05.2000, describes carbon microgastrinae structure and method of reception with the use of technology plasma etching.

The disadvantage macrostring cathodes is that when working with a large emission current residual gas ion bombardment leads to topline points and, thereby, reduce local electric field intensity and decrease of emission current. In addition, the tip is strongly warmed up and may even melt. Therefore, it is preferable to use field emission cathodes based on nanostructured films deposited on a conductive substrate. To obtain high values of the emission current is usually sufficient use of nanostructured films and the substrate may be flat. The preferred material for the formation of such nanostructured films is carbon, because it allows to obtain field emission structure with the highest density of emission current at relatively low electric fields.

Example tako what about the field emission cathode based on carbon nano-crystalline film, deposited on the surface of the substrate is described in particular in patent RF №2194328 "Holodnokatannyj film cathode and method thereof".

A significant drawback of solid nanostructured emitting films is that during their deposition on the whole or part of its surface density location nanorazmernyh emission centers can be excessive, leading to their mutual electrostatic shielding and thus reduce the local values of the electric field intensity and decrease the density of the emission current. It is known that the optimal density of emission centers is ~106cm-2that corresponds to the average distance between them is ~10 µm. In order to avoid uneven distribution area of automated emission centers, emission of carbon film precipitated a two-dimensional structured. While on a flat surface of a substrate with a lithographic methods locally applied metal catalyst in the form of an array of spots, asked geometry which determines the position and concentration of the emission centers. Different ways to obtain a two-dimensional structured carbon emission and film field emission cathodes based on them are described, for example, in the article "Study of electron field emission from arrays of multi-walled carbon nanotubes synthesized unit by hot-wire dc plasma-enhancd chemical vapor deposition" (J. of Non-Crystalline Solids, v.352, 2006, pp.1352-1356), Area effect of patterned carbon nanotube bundle on field electron emission characteristics" (Applied Surface Science, v.254, 2008, pp.7755-7758), "Crowth of vertically aligned arrays of carbon nanotubes for high field emission" (Thin Solid Films, v.516, 2008, pp.706-709), "Field emission properties of carbon nanotube pillar arrays" J. of Appl. Phys, v.103, 2008, 064312), or "Selective placement of single-walled carbon nanotubes on pre-defined micro-patterns on SiO2surface based on a dry lift-off technique", Current Applied Physics, v.9, 2009, pp.S38-S42). Similar structures are also described in the application for European patent EP 2375435 "Field emission cathode", publ. 12.10.2011, and U.S. patent N 8048397 "Laser-based method for making field emission cathode", publ. 01.11.2011.

Using three-dimensional structured substrate, the desired roughness which determines the position and concentration of the emitting centers, allows to further improve the emission characteristics of autocatalog.

Such structuring of the substrate can be carried out by plasma-chemical etching of the silicon surface through lithographic methods mask. In particular, as a mask material may be used a metal, which is the catalyst for growth of carbon nanotubes, which allows the growth of nanostructured carbon film selectively only on the tops protected by the mask and therefore the remaining newyrovdenyj columns. Such silicon structures and automated based on them are described, in particular, in the article "Large current carbon nanoube emitter growth using nickel as a buffer layer (Nanotechnology, v.l8, 2007, 095604).

The three-dimensional structure in the silicon substrate can be created by electrochemical etching, stimulated optical radiation through lithographically created on the surface of a silicon substrate a mask. A method of obtaining such a structured substrate itself and the resulting substrate is described in U.S. patent N 6790340 "Method and apparatus for radiation assisted electrochemical etching and etched product", publ. 14.09.2004.

However, as noted above, lithographic technologies microelectronics very expensive and their use is becoming justified only under conditions of mass production of manufactured semiconductor structures. In addition, the use of masks often requires additional processing of the obtained columnar structures with a view to their placing for the formation of microgastrinae structure.

Therefore, it is preferable to use nelitografichesky methods of structuring a substrate, in which the formation of the desired microgastrinae patterns within the generated emitting structure is the result of self-organizing process, and its geometrical parameters are determined processing mode of the substrate as a whole. Known variant of the three-dimensional-structured silicon substrate and the field emission cathode based on it having a pyramid structure, resulting in Prov is Denia anisotropic liquid etching of the original silicon wafer. Automated based besieged on such pyramidal structured silicon wafer nanocrystalline carbon film described in the article “Field emission from carbon nanosheets on pyramidal Si(100)” (Nanotechnology, v.l8, 2007, 185706). It should be noted, however, that anisotropic etching is implemented only for silicon p-type, and to obtain the field emission of electron sources with high emission characteristics, it is preferable to use the silicon of n-type having a high concentration of free electrons. In addition, the aspect ratio of the formed pyramids with this method of forming roughness close to 1, which is not enough to obtain a highly efficient field emission source.

The known method of forming a field emission cathode on microstructured silicon columnar structure with high aspect ratio, obtained by the method of reactive ion etching initially planar substrate, covered with a field emission film of nanocrystalline carbon (nd), described in the article "Effect of ballast-resistor and field-screening on electron emission from nanodiamond emitters fabricated on micropatterned silicon pillar arrays" J. Vac. Sci. Technol. B, v.30, No.1, 2012, 012201). However, in this case deposited nanodiamond film after creating a lithographic method of the pattern formed microstructure served as a mask for plasma etching of silicon, and the sweat is mu received a microstructured structure is an array of columns, though high aspect ratio (>5), but with a flat top, i.e. obtained by this method the microstructured automated is not Microstream that it is not enough to obtain automated with high emission characteristics.

To avoid these effects, negatively affect the technical characteristics and service life of field emission cathodes, it is advisable to apply nanostructured emitting film on the three-dimensional-structured substrate having microgastrinae surface structure with high aspect ratio (ratio of the height of the needles to their height). Field emission cathode based coated nanocrystalline carbon film microgastrinae metal cathode is described in the article "Field-emission properties of carbon nanotubes grown on a submicron-sized tungsten tip in terms of various buffer layers" (Diamond &Related Materials, v.17, 2008, pp.1826-1830).

In the article "Diamond coated silicon field emitter array" (J. Vac. Sci. Technol. A, v.17, No.4, 1999, pp.2104-2108) describes automated, including an array of microstrip with aspect ratio ~1,5 formed on a silicon substrate, on top of which was deposited nanostructured carbon film. Described in the article substrate field emission cathode, its preparation and field emission cathode taken as prototypes, but they are not without the aforementioned disadvantages.

Task statements the military group of the invention is to eliminate the disadvantages of the nearest equivalent.

The claimed group of inventions provides the technical result consists in the development of ways to create the backing field emission cathode with such quality characteristics, which would provide a reliable and uninterrupted operation of the cathode.

Disclosure of inventions

This technical result is achieved in the following way. Structurally, the field emission cathode is usually performed in the form of a structure consisting of a conductive substrate with formed therein emitting region. The substrate may be of various forms, but for the purposes of the present invention, without loss of generality, we assume its planar. Emitting region can also be performed in different form, and represent a single spot, the combination of several spots or an array of them. For the purposes of the present invention, without loss of generality, we assume emitting region is made in the form of a circular spot with a diameter of the order of several millimeters, which is typical for most concrete implementations. It is important to emphasize that the size of the emitting region significantly, by an order of magnitude or more larger than the typical sizes of the emission structures discussed next.

Generally, for practical applications it is important is full emissioner the current. In addition, the specific implementation of the device, which is installed in automated, determines the shape, the geometrical dimensions of the emission region. In aggregate, the setpoint value of the total current and the size of the emission region determine the value of the required density of the emission current of the electron beam.

From theory of autoemission electrons it is known that the emission current density field emission cathode is an exponential function of the magnitude of the electric field strength, which is such a cathode. In order to get a large density of emission current of the electron beam, the cathode surface is rough. Then near the peaks of the roughness implement a local enhancement of the electric field strength, which allows to obtain high density of emission current with a relatively small values applied to the electrode voltage, which is important for practical applications of such devices.

Also for practical applications it is important that the production technology autocatalog provided high reproducibility of emission characteristics in their manufacture. This is especially important in the case where the operation mode automated assumes its functioning when the density values of the emission current is close to the limit at which the body p is zrusenie emission structures. Therefore, the aim of the present invention is to provide a substrate for forming a field emission cathode, on which the deposition of carbon emitting film may be obtained automated with a high degree of reproducibility attainable current density autoemission electrons.

This technical result is achieved by a method of obtaining three-dimensional-structured semiconductor substrate for a field emission cathode, which according to the invention the surface is prepared prior washing of the substrate from contamination, and then chemically or mechanically protects the surface area that is not subject to etching, leaving an open area in which to carry out etching. The substrate is placed in a cell with electrolyte-provide the Etchant. Exercise photoelectrochemical etching within the surface area intended for subsequent deposition of the field emission carbon film. And photoelectrochemical etching is carried out in the modes that form on the surface of the substrate by microgastrinae or quasi-regulated cellular-pickaway patterns formed by the combination of the cone-shaped wells with aspect ratio at least 2.

In private embodiments of the method photoelectrochemical etching is performed with the electrolyte when concentratie HF from 0 to 23 M, C2H5OH from 0 to 16 M, H2About 0 to 55 M at a temperature of from 25 to 60°C in a solution of HF-C2H5OH-H2O when the illumination light directed from the outside through the exposed etching the semiconductor substrate, preferably containing in the spectrum of radiation at wavelengths in the region close to the border of the transmittance of the material of the semiconductor substrate so that the photogenerated pairs "electron-hole" has reached the surface of the semiconductor wafer in contact with the electrolyte-provide the Etchant.

Use electrolytes are water-based, such as HF:H2O, HF:DMSO:H2O, HF:C2H5OH:H2O, HF:HNO3, KOH:H2O, or anhydrous electrolyte, for example acetonitrile, dimethylformamide, HF.

Use a solution having an HF concentration from 0 to 23 M, C2H5OH from 0 to 16 M, H2O 0 to 55 M, the temperature is from 20 to 60aboutC. the intensity of the illumination is from 0 W/cm2to 0.7 W/cm2at wavelength from the near UV to the far IR. The distance from the illumination source is from 0.01 m to 0.5 m

Three-dimensional-structured semiconductor substrate for a field emission cathode made of crystalline silicon p-type conductivity from 1 to 8 Ohm*cm method according to any of the preceding claims 1-4.

Field emission cathode includes a substrate, ispolnennuyu under item 5 of the formula, besieged on her nanostructured carbon film.

Brief description of drawings

The group of inventions is illustrated by drawings.

Figure 1 presents a diagram of the device cells for photoelectrochemical etching of silicon.

On figa and 2B depict microgastrinae silicon structures produced by the method of photoelectrochemical etching of silicon of n-type and p-type respectively.

On figa and 3b presents microgastrinae structure with a film of nanocrystalline graphite obtained on silicon substrates of n - and p-type respectively.

Figure 4 shows Raman spectra of the emission of the films of nanocrystalline graphite grown on the substrate obtained by the method photostimulated electrochemical etching. The spectra shown in figa and 4B correspond to the silicon n-type etching time of 12 min and 90 min, respectively, and the spectra shown in figv and 4G, the silicon p-type and time of etching 12 min and 25 min, respectively.

Figure 5 shows the emission characteristics of the field emission cathode formed on substrates of various types of silicon. The emission characteristics of the silicon n-type shown in figa, silicon p-type - figb.

The implementation of the invention.

It should be noted that the inventive method of obtaining a three-dimensional structured pressurizat rodnikovoy substrate for a field emission cathode includes the formation of three-dimensional structures in silicon using photoelectrochemical etching. When this semiconductor substrate can be made of silicon of any type. The resulting three-dimensional structures have the form of microstrip or quasi-regulated cellular-pickaway patterns formed by the combination of the cone-shaped channels of different shapes and sizes that range from a few microns to several hundred microns.

As a light source can be used with various types of lamps, halogen lamps, incandescent lamp, sodium lamps and fluorescent lamps. You can also use light emitting diodes (LED) and lasers. Often using different filters for separation of different frequencies. Incandescent lamps have a broad spectrum and high intensity, but of greater intensity IR leads to the heating of silicon and filters. Sodium lamps have the best characteristics, but there is a problem with the intensity adjustment. LEDs are preferred, if they are monochromatic radiation. The intensity of radiation can change rather quickly and can be easily adjusted. If it is important to ensure high selectivity in the coverage of the sample, it is advisable to use lasers.

Used for etching silicon electrolytes can be characterized by the content of the acid. Aqueous electrolytes are usually dominated by the processes e is actrocities etching of silicon. However, sometimes use anhydrous electrolytes: acetonitrile, dimethylformamide and HF. In practice, for photoelectrochemical etching of silicon used by a variety of mixtures, such as HF:H2O, HF:DMSO:H2O, HF:C2H5OH:H2O, HF:HNO3, KOH:H2O, and others

Next will be described an example implementation of the method.

Took substrate of n-type measuring 100 mm in diameter and p-type size 125 mm using Scriber cut substrate of the desired size, in the particular case it was the record size of 5 mm×7 mm was Prepared samples are cleaned in a chemical solution to remove the external oxide and dirt. In our case, the washing of the samples was carried out in a 5% solution of hydrofluoric acid for 10 minutes After this procedure, the substrate is set in the electrochemical cell, diagram of the device which is shown in figure 1.

The housing of the electrochemical cell was made of Teflon. Electric circuit cell includes a source 6 with a current regulator (can also be connected to the source voltage), two electrodes - an anode 2 and the cathode 5, the connecting wires. The electrodes 2 and 5 were made of copper and platinum, respectively. From the side where the contact of the silicon wafer 1 with the electrolyte solution 4, it is pressed through the rubber seal 3 to the wall e is trohimenko cells. In the wall of the cell and the rubber seal was made holes for passage of radiation from the source 7, which in the Assembly were combined. The diameter of the holes in the example implementation was ~3 mm, reverse the electrochemical cell side of the silicon wafer 1 is in contact with the electrode 2. During Assembly, the electrode 2 is attached to the housing of the electrochemical cell with four screws, pressed to the silicon wafer 1, which provides the electrical contact. The electrode 2 also has an opening which, when the Assembly is placed in the appropriate holes in the Teflon and rubber seal. The electrode 2 is in contact with only the back side of the substrate 1 and is isolated from contact with the electrolyte 4.

In the example embodiment of the invention, the Assembly is placed vertically, but other variants are possible orientation, as well as the geometrical dimensions of the silicon substrate, the shape and size of the holes, ensure the contact of the semiconductor wafer with the electrolyte and access optical radiation in the electrochemical cell. After fixing the substrate to fill the cells with electrolyte 4, include a halogen lamp 7 and the current source 6. On the platinum electrode 5 serves "-" on the copper electrode 2 "+". All parameters of the experiment is controlled using a computer. In an hour the nom case of realization of the method, the electrolyte concentration was: HF 0.84 M, C2H5OH - 1,66 M, H2O - 53,92 M (which corresponds to the volumetric concentration of the electrolyte components HF:C2H5OH:H2O, is equal to 5 ml: 12 ml: 102 ml).

The obtained electrochemical method the substrate is formed field emission cathode obtained by deposition on the surface macrostring nanocarbon structures emitting film by any known method (Microwave Plasma Enhanced Chemical Vapor Deposition, microwave plasma chemical deposition from the gas phase, ICP PECVD and SS PECVD - plasma chemical deposition using inductively confined plasmas and capacitive plasma, respectively, RP PECVD - RF plasma-chemical deposition from the gas phase, EVE PECVD - plasma chemical deposition from the gas phase, stimulated by an electron beam, HF CVD - plasma chemical deposition from the gas phase in the reactor with a hot thread, Sputtering - sputtering in magnetron discharge, laser spraying and other).

In the example of the field emission cathode on the substrate obtained by the method according to the present invention, it was formed by deposition formed on the substrate for a field emission cathode of nanocrystalline graphite through chemical synthesis from the gas phase with the excitation of the plasma by DC discharge. The composition of the nanocrystalline graphite film obtained in this way may include education follow what she morphology: the crystals of graphite, graphene plane, carbon nanotubes, nanodiamond crystals, amorphous carbon.

It is important to note that a significant feature of the photocatalytic formation macrostring structures using chemical solutions is that no additional surface treatment to create on the surface of the silicon centers of nucleation and growth of nanocrystalline graphite. Structuring of silicon using the described method allows you to change the number of nucleation centers by increasing the time of etching silicon and, thus, the amount deposited nanocrystalline graphite due to changes in the number of nucleation centers. Moreover, changing the time of receipt of the structured silicon, it is possible to vary both the number of the besieged three-dimensional nanocrystalline graphite and its composition: from the film, mainly composed of multilayer nanotubes, to film consisting of multilayer graphene structures, including a relatively small number of multi-layer and single-layer nanotubes.

Nanocrystalline graphite film is characterized by a Raman spectrum (spectrum of Raman scattering). The main peaks and their designations are shown in figure 4. Raman spectrum of the studied samples range from 300 to 2700 cm-1(f is, 4(a)-(d)). In the spectrum are well-known peak of crystalline silicon (c-Si) at 524 cm-1and his second order of 1000 cm-1respectively. Raman spectrum of the carbon film grown on the received photoelectrochemical etching of porous silicon, is represented by several well-known lines in the range 1100-2800 cm-1. Peaks at 1288 cm-1and 1580 cm-1called D and G modes. It is well known that D fashion is associated with structural defects within the graphene planes and their final size (on the border). The relationship between D and G modes I(D)/I(G) describes the structural imperfection of the studied films. As can be seen in figure 5, a significant difference between I(D)/I(G) for carbon films on two types of silicon. D and G modes have approximately the same intensity for films grown on n-type silicon I(D)/I(G) ~1 and for p-type silicon I(D)/I(G) ~0.6. This result suggests that nanocrystalline graphite grown on silicon of n-type, has a better quality than those grown on silicon p-type.

With increasing time of etching increases the depth of the pores. Grown on a substrate for a field emission cathode with deeper pores emission film of nanocrystalline graphite is characterized by an increase in the intensity of Raman peaks (figure 4(a)-(b), (C)-(d)). Based on this, it is so conclusion, that with increasing time of etching increases the number of nucleation centers, which leads to the difference in carbon structures grown on substrates, obtained at different times photostimulated electrochemical etching.

The key difference thus obtained substrates for field emission cathode is that for growing on them nanocarbon films with high emission characteristics, there is no need for further processing of the silicon surface before the growth of the field emission structures. Emission characteristics for different types of silicon are manifested in the fact that PA silicon p-type patterns of nanocrystalline graphite are only on the edges, which leads to the fact that there is no field screening emitting centers during emission testing. Silicon n-type film covers the entire sample and in fact no different from the usual substrates with a sowing made by other methods. The calculations show that microstrip amplification of zero to 50%, which explains the increase of emission current of 6 A/cm2. Curves Fowler-Northam show that at small fields emission occurs mainly with long nanotubes, and at large with small.

1. A method of obtaining three-dimensional structured the semiconductor, Nikolai substrate for a field emission cathode, characterized in that the surface is prepared prior washing of the substrate from contamination, chemically or mechanically protects the surface area that is not subject to etching, leaving an open area in which to carry out the etching, the substrate is placed in a cell with electrolyte-provide the Etchant, and implement photoelectrochemical etching within the surface area intended for subsequent deposition of the field emission carbon film, and photoelectrochemical etching is carried out in the modes that form on the surface of the substrate by microgastrinae quasi-regulated cellular-pickaway patterns formed by the combination of the cone-shaped wells with aspect ratio at least 2.

2. The method according to claim 1, characterized in that the photoelectrochemical etching is performed with the electrolyte with a concentration of HF from 0 to 23 M, C2H5OH from 0 to 16 M, H2About 0 to 55 M at a temperature of from 25 to 60°C in a solution of HF-C2H5HE-H2About when the illumination light directed from the outside through the exposed etching the semiconductor substrate, preferably containing in the spectrum of radiation at wavelengths in the region close to the border of the transmittance of the material of the semiconductor substrate so that the photogenerated pairs "electron-hole" has reached the surface of the semiconductor wafer, in contact with the electrolyte-provide the Etchant.

3. The method according to claim 1, characterized in that the use of electrolytes, water-based, such as HF:H2O, HF:DMSO:H2O, HF:C2H5OH:H2O, HF:HNO3, CON:N2Oh, or anhydrous electrolyte, for example acetonitrile, dimethylformamide, HF.

4. The method according to claim 1, wherein the use solution has a concentration from 0.1 M to 23 M HF, C2H5OH from 0 M to 16 M of water from 0 to 55 M, the temperature is from 20 to 60°C, the intensity of illumination is from 0 W/cm2to 0.7 W/cm2at wavelength from the near UV to the far IR, and the distance from the source of illumination is from 0.01 m to 0.5 m

5. Three-dimensional-structured semiconductor substrate for a field emission cathode, characterized in that the crystalline silicon p-type conductivity from 1 to 8 Ohm*cm method according to any one of claims 1 to 4.

6. Field emission cathode, characterized in that it contains a substrate made according to claim 5, besieged it nanostructured carbon film.



 

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7 cl, 1 dwg

FIELD: electricity.

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

FIELD: physics.

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

FIELD: electricity.

SUBSTANCE: method of MDM-cathode manufacturing is intended to increase a density of emission current and homogeneity of its distribution along the surface. A metal lower electrode based on a molybdenum film, then two layers of resistors where the pattern is generated by means of electron-beam lithography are deposited in sequence to a substrate, then a continuous film of molybdenum is sprayed. The nanofluidic structure is obtained by explosion of the resist mask in the form of pyramids with the base of 260 nm, vertex of 40 nm, height of 250 nm and density of 3·108 cm-2.

EFFECT: improvement in even distribution of emissive centres and the density of emission current.

2 dwg

FIELD: electricity.

SUBSTANCE: result is obtained by using composite material for field-emission cathode that contains particles of metal surrounded by nanostructured carbon material (carbon or carbon-nitrogen nanotubes, carbon nanofibres, fullerene and similar materials). In order to increase efficiency of field emission the following activities are performed during fabrication of field-emission cathode: additional mechanical treatment with removal of cathode surface layer and subsequent polishing, chemical and plasma etching of operating surface. The resultant cathode provides density of field-emission current of about 10-20 mA/cm2 with high stability and homogeneity.

EFFECT: obtaining stable field-emission cathode with high specific density; metal ensures low specific resistance, high thermal conductivity and mechanical strength while nanocarbon material ensures high emission properties of cathode.

4 dwg

FIELD: electrical engineering.

SUBSTANCE: in order to form a periodic circuit from micro-tips at surface of monolithic carbon substrate the method of grouped micro-tipping in low-temperature plasma of HF charge in oxygen or in mix of oxygen and inert gas media is used as micro/nano-sized treatment.

EFFECT: increase of density for field-emission current due to formation of micro-tip carbon structure.

FIELD: electrical engineering.

SUBSTANCE: multipoint autoemissive cathode matrix is manufactured on single-crystal silicon plates in microvolt gas discharge plasma by way of precipitation from vapours of carbon-containing substances such as ethanol using the phenomena of submonolayer carbon coatings self-organisation and structuring into nanoisland formations and subsequent high temperature annealing. To increase of the electric field amplification coefficient and thus to reduce operating voltages during production of increased autoemission current values one performs formation of emission centres in the shape of integral columnar nanostructures with height equal to several tens of nanometres which structures are produced by way of anisotropic etching of silicon plates using the resultant carbon nanoisland formations as mask coating.

EFFECT: improving emission stability and efficiency.

FIELD: chemistry.

SUBSTANCE: tin oxide based electrode, formed from a composition which contains a basic component consisting of tin oxide (SnO2) and additives consisting of CuO, ZnO, as well as additives which alter resistivity. The total amount of CuO and ZnO is not more than about 0.3 wt % and the amount of ZnO is in the range from about 0.1 wt % to about 0.19 wt %.

EFFECT: electrode is in form of a rectangular body which does not have macroscopic cracks since the disclosed composition enables to obtain industrial size tin oxide based electrodes which do not have internal cracks.

15 cl, 7 dwg, 1 tbl, 2 ex

FIELD: electricity.

SUBSTANCE: synthesis of a material of a multi-spike field-emission cathode is carried out in a plasma of a microwave gas discharge from vapours of carbon-containing substances, for instance, ethanol, in the range of process parameters, in which a transition is realised from deposition of graphite films to deposition of diamond films. The produced composite material represents a graphite matrix with inclusions of nanodiamond crystallites. The matrix of the multi-spike field-emission diode is manufactured in accordance with the technology compatible with the technology of integrated circuits production.

EFFECT: higher mechanical and electric strength, density of field-emission currents and degradation resistance when operating with higher voltages.

2 dwg

FIELD: physics.

SUBSTANCE: invention relates to electronics and can be used in making vacuum microelectronic devices. The essence of the invention lies in that the integrated field-emission element has a substrate coated with a dielectric layer, a cathode structure consisting of one or more layers of electroconductive material and lying on the outer surface of said substrate, a support structure lying on the top surface of said cathode structure and having through-holes inside of which cathodes are formed based on nanodiamond coatings, lying on the outer surface of the cathode structure, an anode layer made from electroconductive material lying on the outer surface of said support structure and having working holes superimposed with said holes in the support structure The nanodiamond coating-based emitter is made in a single process cycle with formation of anode structures without a further process of superimposing the anodes with the cathode structure.

EFFECT: use of nanodiamond coatings as emitter material, said coatings being carbon films containing nanostructured diamond components, which results in higher resistance to disintegration, current density and low operating voltage in integrated vacuum nano- and microelectronic devices.

4 cl, 8 dwg

FIELD: electricity.

SUBSTANCE: carbon-containing nanomaterial with low field electron emission threshold (LFEET) represents a disperse powder with particle size of less than 50 mcm, consisting of a nucleus and a surface layer, at the same time the nucleus is formed of dielectric (DE) or semi-conductor (SC) material, and a surface layer of graphite-like carbon (GLC) with thickness of 0.5-50 nm. The methods to produce nanomaterial (versions) are realised in the following manner: 1. Powders of DE or SP material are thermally treated in the medium of carbohydrates at the temperature that exceeds temperature of their thermal decay, during the time required to produce a layer of GLC on surface of powder particles with thickness of 0.5-50 nm. 2. Powders of diamond are thermally treated in the inert medium or vacuum at the temperature that exceeds temperature of diamond transition into graphite, during the time required to produce a layer of GLC on surface of diamond particles with thickness of 0.5-50 nm. 3. Powders of covalent or metal-like carbides are thermally treated in chlorine at the temperature that exceeds temperature of their interaction with chlorine to form gaseous chlorides and carbon, during the time required to produce a layer of GLC on surface of powder particles with thickness of 0.5-50 nm.

EFFECT: production of disperse materials with low field electron emission threshold and simplified technology of their manufacturing.

8 cl, 1 dwg

FIELD: physics.

SUBSTANCE: proposed electron emitter is coated by material with low work function, high electron emitting properties and high reproducibility that allow eliminating differences in electron-emitting properties between electron emitters. Prior to coating material structure with low work function, metal oxide layer is produced on said structure.

EFFECT: possibility to display images with low brightness fluctuations for long time.

15 cl, 27 dwg, 8 ex

FIELD: metallurgy.

SUBSTANCE: according to invention panel consists of front substrate containing scanning electrode, supporting electrode, dielectric layer and protective layer and of back substrate containing address electrode, barrier ribs and fluorescent material applied on internal walls of grooves formed with barrier ribs. The procedure consists in generation of film MgO with orientation (111) by sedimentation method from the vapour phase with rate of sedimentation amounting to 280 Ǻ /sec or more and at temperature of substrate of 120°C or less.

EFFECT: simplified production process, facilitating fabrication of layer MgO with orientation due to reduced temperature of sedimentation.

6 cl, 24 dwg

FIELD: electricity.

SUBSTANCE: result is obtained by using composite material for field-emission cathode that contains particles of metal surrounded by nanostructured carbon material (carbon or carbon-nitrogen nanotubes, carbon nanofibres, fullerene and similar materials). In order to increase efficiency of field emission the following activities are performed during fabrication of field-emission cathode: additional mechanical treatment with removal of cathode surface layer and subsequent polishing, chemical and plasma etching of operating surface. The resultant cathode provides density of field-emission current of about 10-20 mA/cm2 with high stability and homogeneity.

EFFECT: obtaining stable field-emission cathode with high specific density; metal ensures low specific resistance, high thermal conductivity and mechanical strength while nanocarbon material ensures high emission properties of cathode.

4 dwg

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