Method of producing high-frequency transistor with nanometer gates

FIELD: electronic equipment.

SUBSTANCE: invention is intended to create discrete devices and microwave integrated circuits with the help of field-effect transistors. Method of making field-effect transistor, including creation of drain and source contacts on the contact layer of semiconductor structure and extraction of active region, metal or metal and dielectric mask is applied directly on the surface of contact layer, formation of submicron slot in the mask for further etching operations of contact layer etching and application of T-shaped gate metal through resist mask, after application of the first metal mask lithography for opening windows is carried out when one of the edges coincides with location of Schottky gates in manufactured transistor, and after opening windows the second metal or dielectric mask is applied on the whole surface, remove resist and by lithography create window in resist surrounding slits formed between two metals or between metal and dielectric, perform selective etching of contact layer, after which spray metal films to form T-shaped gates. As a result, edges of T-shaped gate heads on both sides resting on metal or metal and dielectric masks. Then, via selective etching the mask is removed from under the "wings" of T-shaped gate and from the surface of transistor active area. After that, the surface of transistor active area, containing drain, source contacts and Schottky gates, is coated with a passivating layer of dielectric so that under "wings" of T-shaped gate cavities are formed filled with vacuum or gas medium.

EFFECT: technical result is production of gated with length less than 100 nm, as well as reduced thickness of the metal mask and elimination of intermediate layer of dielectric placed between the active region surface and mask.

1 cl, 1 dwg

 



 

Same patents:

FIELD: electricity.

SUBSTANCE: method for manufacture of powerful SHF transistor includes application of a solder layer to the flange, shaping of pedestal, application of a sublayer fixing the transistor crystal to the pedestal, formation of p-type conductivity oriented at the plane (111) at the base substrate of single-crystalline silicon and auxiliary epitaxial layers, application of the basic layer and buffer layer for growing of epitaxial structure of a semiconductor device based on wide-gap III-nitrides, application of heat conductive layer of CVD polycrystalline diamond to the basic layer, removal of the basic substrate with auxiliary epitaxial layers up to the basic layer, growing of heteroepitaxial structure based on wide-gap III-nitrides on the basic layer and formation of the source, gate and drain. The heat conductive layer of CVD polycrystalline diamond is used as a pedestal; nickel is implanted to its surficial region and annealed. Before formation of the source, gate and drain an additional layer of insulating polycrystalline diamond and additional layers of hafnium dioxide and aluminium oxide are deposited on top of the transistor crystal; the total thickness of the above layers is 1.0-4.0 nm.

EFFECT: invention allows increased heat removal from the active part of SHF-transistor and minimisation of gate current losses.

6 cl, 4 dwg

FIELD: physics.

SUBSTANCE: invention relates to semiconductor technology. Proposed method comprises removal of photoresist from at least one surface of conducting layer with the help of the mix of chemical including first material of self-optimising monolayer and chemical to remove said photoresist. Thus self-optimising monolayer is deposited on at least one surface of said conducting ply. Semiconductor material is deposited on self-optimising monolayer applied on conducting layer without ozone cleaning of conducting layer.

EFFECT: simplified method.

15 cl, 4 dwg

FIELD: electricity.

SUBSTANCE: semiconductor device comprises a thinned substrate of single-crystal silicon of p-type conductivity, oriented according to the plane (111), with a buffer layer from AlN on it, above which there is a heat conducting substrate in the form of a deposited layer of polycrystalline diamond with thickness equal to at least 0.1 mm, on the other side of the substrate there is an epitaxial structure of the semiconducting device on the basis of wide-zone III-nitrides, a source from AlGaN, a gate, a drain from AlGaN, ohmic contacts to the source and drain, a solder in the form of a layer including AuSn, a copper pedestal and a flange. At the same time between the source, gate and drain there is a layer of an insulating polycrystalline diamond.

EFFECT: higher reliability of a semiconducting device and increased service life, makes it possible to simplify manufacturing of a device with high value of heat release from an active part.

3 cl, 7 dwg

FIELD: electrical engineering.

SUBSTANCE: method for manufacture of a powerful UHF transistor includes formation of the topology of at least one transistor crystal on the semiconductor substrate face side, formation of the transistor electrodes, formation of at least one protective dielectric layer along the whole of the transistor crystal topology by way of plasma chemical application, the layer total length being 0.15-0.25 mcm, formation of the transistor crystal size by way of lithography and chemical etching processes. Prior to formation of the transistor crystal size, within the choke electrode area one performs local plasma chemical etching of the protective dielectric layer to a depth equal to the layer thickness; immediately after that one performs formation of protectively passivating dielectric layers of silicon nitride and diozide with thickness equal to 0.045-0.050 mm; plasma chemical application of the latter layers and the protective dielectric layer is performed in the same technological modes with plasma power equal to 300-350 W, during 30-35 sec and at a temperature of 150-250°C; during formation of the transistor crystal size ne performs chemical etching of the protectively passivating dielectric layers and the protective dielectric layer within the same technological cycle.

EFFECT: increased power output and augmentation ratio or powerful transistors with their long-term stability preservation.

4 cl, 1 dwg, 1 tbl

FIELD: electricity.

SUBSTANCE: method for UHF high-power transistors manufacturing includes formation of transistor topology semiconductor substratum on the face side by electronic lithography and photolithography methods, metals spraying on, dielectrics application and etching, cathodic electrodeposition of gold, formation of preset size grooves on the face side outside the transistor topology, substrate thinning, formation of grounding through holes for the transistors source electrodes, formation of a common integrated heat sink, formation of a integrated heat sink for each transistor crystal, semiconductor substrate division into transistor crystals; one uses a semiconductor substrate with the preset structure of active layers having two stop layers with the preset distance between them, the stop layers ensuring minimum thermal resistance; the semiconductor substrate reverse side thinning is performed down to the stop-layer located close to such side; grounding through holes are formed immediately on the source electrodes with the common integrated heat sink thickness is set by the type of the transistor crystal subsequent mounting.

EFFECT: enhanced output capacity through reduction of thermal resistance, parasitic of the electric resistance in series and source electrodes grounding inductance; increased yield ratio, repeatability and functionalities extension.

4 cl, 1 dwg, 1 tbl

FIELD: electricity.

SUBSTANCE: field transistor manufacturing method includes creation of source and drain contacts, active area identification, application of a dielectric film onto the contact layer surface, formation of a submicron chink in the dielectric film for the needs of subsequent operations of contact layer etching and application of gate metal through the resistance mask; immediately after the dielectric film application one performs lithography for opening windows in the dielectric at least one edge whereof coincides with the Schottky gates location in the transistor being manufactured; after the window opening a second dielectric layer is applied onto the whole of the surface with the resistance removed; then, by way of repeated lithography, windows in the resistance are created, surrounding the chinks formed between the two dielectrics; selective etching of the contact layer is performed with metal films sprayed on to form the gates.

EFFECT: simplification of formation of under-gate chinks sized below 100 nm in the dielectric.

6 dwg

FIELD: electricity.

SUBSTANCE: manufacturing method of microwave transistor with control electrode of T-shaped configuration of submicron length involves formation on the front side of semi-insulating semi-conductor plate with active layer of the specified structure of a pair of electrodes of transistor, which form ohmic contacts by means of lithographic, etching method and method of sputtering of metal or system of metals, formation of transistor channel by means of electronic lithography and etching, application of masking dielectric layer, formation in masking dielectric layer of submicron slot by means of electronic lithography and etching; at that, submicron slot is formed with variable cross section decreasing as to height from wide upper part adjacent to the head of the above control electrode to narrow lower part adjacent to transistor channel, formation of topology of the above control electrode by means of electronic lithography method, formation of the above control electrode in submicron slot by means of sputtering of metal or system of metals; at that, configuration of its base repeats configuration of submicron slot. During formation of submicron slot with variable cross section in masking dielectric layer, which decreases throughout its height, by means of electronic lithography and etching, the latter of masking dielectric layer is performed in one common production process in high-frequency plasma of hexafluoride of sulphur, oxygen and helium and discharge power of 8-10 W.

EFFECT: increasing output power and amplification factor, increasing reproducibility of the above output parametres and therefore yield ratio, simplifying and decreasing labour input for manufacturing process.

2 cl, 1 dwg, 1 tbl, 5 ex

FIELD: electronic engineering; high-power microwave transistors and small-scale integrated circuits built around them.

SUBSTANCE: proposed method for producing high-power microwave transistors includes formation of transistor-layout semiconductor wafer on face side, evaporation of metals, application and etching of insulators, electrolytic deposition of gold, formation of grooves on wafer face side beyond transistor layout for specifying transistor chip dimensions, thinning of semiconductor wafer, formation of grooves on wafer underside just under those on face side, formation of through holes for grounding transistor leads, formation of integrated heat sinks for transistor chips around integrated heat sink followed by dividing semiconductor wafer into transistor chips by chemical etching using integrated heat sinks of transistor chips as mask.

EFFECT: enhanced power output due to reduced thermal resistance, enhanced yield, and facilitated manufacture.

2 cl, 1 dwg, 1 tbl

FIELD: technologies for making transistors.

SUBSTANCE: method includes following stages: precipitation of electric-conductive material on substrate of semiconductor material, forming of shape of first parallel band electrodes with step, determined by appropriate construction rules, while areas of substrate in form of stripes between first electrodes are left open, precipitation of barrier layer, covering first electrodes down to substrate, alloying of substrate in open areas, precipitation of electric-conductive material above alloyed areas of substrate with forming of second parallel band electrodes, removal of barrier layer, near which vertical channels are left, passing downwards to non-alloyed areas of substrate between first and second electrodes, alloying of substrate in open areas of lower portion of channels, filling channels with barrier material, removal of first electrodes, during which gaps between second electrodes are left and substrate areas are opened between them, alloying of open areas of substrate in gaps, from which first electrodes were removed, removal of electric-conductive material in said gaps for restoration of first electrodes and thus making an electrode layer, containing first and second parallel band electrodes of practically even width, which are adjacent to alloyed substrate and separated from each other only by thin layer of barrier material, while, dependent on alloying admixtures, used during alloying stages, first electrodes form source or discharge electrodes, and second electrodes - respectively discharge or source electrodes of transistor structures, precipitation of insulating barrier layer above electrodes and separating barrier layers. Precipitation of electric-conductive material above barrier layer and forming in said electric-conductive material of shape of parallel band valve electrodes, directed transversely to source and discharge electrodes, thus receiving structures matrix for field transistors with very short channel length and arbitrarily large width of channel, determined by width of valve electrode.

EFFECT: ultra-short channel length of produced transistors.

11 cl, 17 dwg

FIELD: chemistry.

SUBSTANCE: first step includes obtaining low-hydroxylated insoluble fullerenols by reacting concentrated fullerene solution in o-xylene with aqueous ammonia solution in the presence of a tetrabutylammonium hydroxide phase-transfer catalyst at 35-40°C. At the second step, the obtained low-hydroxylated insoluble fullerenols are hydroxylated to transform them into a water-soluble form by mixing with 6-15% aqueous hydrogen peroxide solution and heating for 4-5 hours at 65°C. Water-soluble fullerenols are then precipitated from an alcohol-containing solution.

EFFECT: simplifying the method while preserving quality characteristics and full extraction of the end product.

2 cl, 1 dwg, 4 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to nanotechnology, particularly a method of producing aspirin nanocapsules in a carrageenan envelope. The disclosed method includes preparing an aspirin suspension in benzene; dispersing the obtained mixture into a carrageenan suspension in butanol in the presence of an E472c preparation while mixing at 1000 rps; adding tetrachloromethane; filtering the obtained nanocapsule suspension and drying at room temperature.

EFFECT: method provides a simpler and faster process of producing nanocapsules and increases mass output.

1 dwg, 4 ex

FIELD: chemistry.

SUBSTANCE: invention relates to encapsulation, particularly to a method of producing albendazole nanocapsules in a sodium alginate envelope. The disclosed method includes adding albendazole to a sodium alginate suspension in hexane in the presence of an E472c preparation while mixing at 1000 rps. The weight ratio of albendazole and sodium alginate is 1:3 or 3:1. Further, 1,2-dichloroethane is added. The obtained suspension of nanocapsules is filtered, washed and dried. The process of producing the nanocapsules is carried out at 25°C for 20 minutes.

EFFECT: invention provides a simpler and faster process of producing nanocapsules, reduces losses during production thereof (high mass output).

3 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to encapsulation, particularly a method of producing resveratrol nanocapsules in an envelope made of low- or highly esterified apple or citrus pectin. According to the disclosed method, resveratrol is dispersed in a suspension of low- or highly esterified apple or citrus pectin in benzene in the presence of an E472c preparation while stirring at 1000 rps. Tetrachloromethane is then added. The obtained suspension of nanocapsules is filtered and dried. The process of producing the nanocapsules is carried out at 25°C for 10 minutes.

EFFECT: invention provides a simpler and faster process of producing nanocapsules, reduces losses during production thereof (high mass output).

9 ex, 1 dwg

FIELD: nanotechnology.

SUBSTANCE: according to the invention method, albendazole is added to the suspension of sodium alginate in butanol in the presence of the preparation E472s when stirring at 1000 revolutions per second. The mass ratio of albendazole and sodium alginate is 1:3 or 3:1. Then acetonitrile is added. The resulting suspension of the nanocapsules is filtered, washed, and dried. The process of production of nanocapsules is carried out at 25°C for 20 min.

EFFECT: simplification and acceleration of the process of production of nanocapsules, reduction of losses in their production.

1 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: according to the method a suspension of resveratrol in heptane was dispersed into a suspension of xanthan gum in butanol in the presence of E472c under stirring at the rate of 1000 rev/s. A mixture of benzene and water taken at a volume ratio of 5:1 or 3:1 was added to the said suspension. The resulted suspension of nanocapsules was filtered, washed and dried. The process was performed at a temperature of 25°C within 10 min.

EFFECT: simplified and fast process of nanocapsule production, reduced process losses.

4 ex, 2 dwg

FIELD: nanotechnology.

SUBSTANCE: suspension of aspirin in benzene is produced. The resulting mixture is dispersed into suspension of sodium alginate in butanol in the presence of the preparation E472s when stirring at 1000 rpm/sec. Then chloroform is poured, the resulting suspension of nanocapsules is filtered and dried at room temperature.

EFFECT: simplification and acceleration of the process of production of the nanocapsules, and increase in the yield by weight.

1 dwg, 4 ex

FIELD: medicine.

SUBSTANCE: invention represents a method for preparing a sterile nanoemulsion of perfluororganic compounds (PFOC) involving: adding a PFOC mixture to an aqueous solution of a stabilising agent; homogenising the PFOC mixture with the aqueous solution of the stabilising agent to produce a PFOC pre-emulsion; mixing the PFOC pre-emulsion with a salt-water solution to produce the PFOC nanoemulsion; keeping the PFOC nanoemulsion at a temperature from 2 to 10°C for at least 18 hours. The method can be also implemented as follows: pre-filling a circulation loop of a PFOC nanoemulsion generating plant with the aqueous solution of the stabilising agent; adding the PFOC mixture to the aqueous solution of the stabilising agent; homogenising the PFOC mixture with the aqueous solution of the stabilising agent to produce the PFOC pre-emulsion; mixing the PFOC pre-emulsion with the salt-water solution to produce the PFOC nanoemulsion.

EFFECT: higher stability of the PFOC emulsion and prolonging the storage life.

30 cl, 7 ex, 5 tbl, 1 dwg

FIELD: nanotechnology.

SUBSTANCE: shell of the nanocapsules is used as apple or citrus high- or low-esterified pectin, and the core - as L-arginine. According to the inventive method, L-arginine is suspended in benzene, the resulting mixture is dispersed into a suspension of apple or citrus high- or low-esterified pectin in benzene in the presence of the preparation E472s while stirring 1000 revolutions per second. Then carbon tetrachloride is added, the resulting suspension of the nanocapsules is filtered and dried at room temperature. The process is carried out for 15 minutes.

EFFECT: simplification and acceleration of the process of producing the nanocapsules, and increase in the yield by weight.

6 ex

FIELD: nanotechnology.

SUBSTANCE: method of production of nanocapsules of vitamin in sodium alginate is characterized in that the shell is used as sodium alginate, and the core - as the vitamin, in a weight ratio of core:shell as 1:3. According to the method of preparing the nanocapsules the vitamin is added to a suspension of sodium alginate in benzene in the presence of the preparation E472s while stirring at 1300 rev/sec. Then hexane is added, the resulting suspension is filtered and dried at room temperature.

EFFECT: simplification and acceleration of the process of production of the nanocapsules, and increase in the yield by weight.

3 dwg, 8 ex

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.

2 cl

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