Research and Production Company Micran

Tomsk, Russia

Research and Production Company Micran

Tomsk, Russia

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Erofeev E.V.,Tomsk State University of Control Systems and Radioelectronics | Fedin I.V.,Research and Production Company Micran | Kutkov I.V.,Research and Production Company Micran | Yuryev Y.N.,Tomsk Polytechnic University
Semiconductors | Year: 2017

High-electron-mobility transistors (HEMTs) based on AlGaN/GaN epitaxial heterostructures are a promising element base for the fabrication of high voltage electronic devices of the next generation. This is caused by both the high mobility of charge carriers in the transistor channel and the high electric strength of the material, which makes it possible to attain high breakdown voltages. For use in high-power switches, normally off-mode GaN transistors operating under enhancement conditions are required. To fabricate normally off GaN transistors, one most frequently uses a subgate region based on magnesium-doped p-GaN. However, optimization of the p-GaN epitaxial-layer thickness and the doping level makes it possible to attain a threshold voltage of GaN transistors close to Vth = +2 V. In this study, it is shown that the use of low temperature treatment in an atomic hydrogen flow for the p-GaN-based subgate region before the deposition of gate-metallization layers makes it possible to increase the transistor threshold voltage to Vth = +3.5 V. The effects under observation can be caused by the formation of a dipole layer on the p-GaN surface induced by the effect of atomic hydrogen. The heat treatment of hydrogen-treated GaN transistors in a nitrogen environment at a temperature of T = 250°C for 12 h reveals no degradation of the transistor’s electrical parameters, which can be caused by the formation of a thermally stable dipole layer at the metal/p-GaN interface as a result of hydrogenation. © 2017, Pleiades Publishing, Ltd.


Erofeev E.V.,Tomsk State University | Kazimirov A.I.,Tomsk State University | Fedin I.V.,Tomsk State University | Kagadei V.A.,Research and Production Company Micran
Semiconductors | Year: 2016

The systematic features of the formation of the low-resistivity compound Cu3Ge by low-temperature treatment of a Cu/Ge two-layer system in an atomic hydrogen flux are studied. The Cu/Ge two-layer system is deposited onto an i-GaAs substrate. Treatment of the Cu/Ge/i-GaAs system, in which the layer thicknesses are, correspondingly, 122 and 78 nm, in atomic hydrogen with a flux density of 1015 at cm2 s–1 for 2.5–10 min at room temperature induces the interdiffusion of Cu and Ge, with the formation of a polycrystalline film containing the stoichiometric Cu3Ge phase. The film consists of vertically oriented grains 100–150 nm in size and exhibits a minimum resistivity of 4.5 µΩ cm. Variations in the time of treatment of the Cu/Ge/i-GaAs samples in atomic hydrogen affect the Cu and Ge depth distribution, the phase composition of the films, and their resistivity. Experimental observation of the synthesis of the Cu3Ge compound at room temperature suggests that treatment in atomic hydrogen has a stimulating effect on both the diffusion of Cu and Ge and the chemical reaction of Cu3Ge-compound formation. These processes can be activated by the energy released upon the recombination of hydrogen atoms adsorbed at the surface of the Cu/Ge/i-GaAs sample. © 2016, Pleiades Publishing, Ltd.


Osipov K.Y.,Tomsk State University of Control Systems and Radioelectronics | Velikovskiy L.E.,Research and Production Company Micran
Semiconductors | Year: 2012

The technology of through metallized holes to sources of high-power GaN/SiC high electron mobility transistors is studied. The dependences of the reactive ion etch rate of SiC in the inductively coupled plasma discharge on the pressure of the SF 6/O 2/Ar gas mixture (5-40 mTorr), the high-frequency power applied to the bottom electrode (200-300 W), the working gas flow ratio (5:1:(0-10)), and the bottom electrode temperatures (5-50°C) are studied. Based on these dependences, the hole etching process on 76-mm-diameter SiC substrates 50 and 100 μm thick is developed. The process features smooth etched-surface morphology, a high rate (1 μm/min), and low high-frequency power deposited into the inductively coupled plasma discharge (1000 W). The developed process of hole etching in SiC substrates is characterized by the selectivity coefficient S = 12 and the anisotropy coefficient A = 13. Films based on NiB are recommended as masks for etching through holes into SiC substrates. The processes of through-hole metallization by the electrochemical deposition of Ni and Au layers are developed. © 2012 Pleiades Publishing, Ltd.


Erofeev E.V.,Research and Production Company Micran | Fedin I.V.,Tomsk State University of Control Systems and Radioelectronics
International Conference of Young Specialists on Micro/Nanotechnologies and Electron Devices, EDM | Year: 2016

In this paper the high voltage (220 V) lateral Schottky barrier diodes (SBD) based on AlGaN/GaN heterostructure grown by Metal Organic Chemical Vapor Deposition (MOCVD) on silicon substrate are presented. A low turn-ON voltage (<0.7 V), low specific ON-resistance (RON, SP) (1.79 mΩ·cm2) and a high reverse breakdown voltage (UBV) (220 V) were simultaneously achieved in devices with 7μm anode-cathode distance. Resulting power figure-of-merit (UBV)2/RON, SP is 27 MW·cm-2. © 2016 IEEE.


Osipov K.Y.,Tomsk State University of Control Systems and Radioelectronics | Velikovskiy L.E.,Research and Production Company Micran | Kagadei V.A.,Research and Production Company Micran
Semiconductors | Year: 2014

The features of the formation of Ta/Ti/Al/Mo/Au ohmic contacts to a Al0.26Ga0.74N/AlN/GaN heterostructure grown on semi-insulating Si(111) substrates are studied. The dependences of the contact resistance on the Al (90, 120, 150, 180 nm) and Ti (15, 30 nm) layer thickness and optimal temperature-time annealing conditions are determined for each studied metallization scheme. It is shown that the minimum achievable contact resistance monotonically increases from 0.43 to 0.58 Ω mm as the Al layer thickness increases from 90 to 180 nm at unchanged Ta, Ti, Mo, Au layer thicknesses. A change in the Ti layer thickness from 15 to 30 nm has no significant effect on the minimum contact resistance. The least contact resistance of 0.4 Ω mm is achieved for Ta/Ti/Al/Mo/Au layers with thicknesses of 10/15/90/40/25 nm, respectively. The optimal annealing temperature for this metallization variant is 825°C at a process duration of 30 s. The grown ohmic contacts have smooth contact-area edges and flat morphology of their surface. © 2014 Pleiades Publishing, Ltd.


Kagadei V.,Research and Production Company Micran | Erofeev E.,Scientific Research Institute of Electrical Communication Systems
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The work investigates the influence of the mode and conditions for deposition of a Ti thin film on the specific contact resistance and thermal stability of Ge/Au/Ni/Ti/Au based ohmic contacts to n-GaAs. Deposition techniques of a Ti diffusion barrier were discovered in which a fifty-fold reduction in specific contact resistance was observed, and also an increase in the thermal stability of the surface morphology on the edge of the contact areas. The factors influencing the specific contact resistance are: the angle at which the titanium atoms impact on the GaAs surface, the rate of deposition of the Ti film, and also the residual pressure during deposition. The factor which has an influence on the thermal stability of the morphology of the contact edges appears to be the angle of incidence of the Ti atoms. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Erofeev E.,Scientific Research Institute of Electrical Communication Systems | Kagadei V.,Research and Production Company Micran
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The work investigated the formation processes of Ge/Cu ohmic contacts to n-GaAs with a germanium content of 30-55% in the film. A comparative analysis was undertaken of the influence of the conditions of a first preliminary annealing carried out in situ with the metallization deposition process, on the value of the specific contact resistance obtained after a second annealing carried out ex situ in a nitrogen environment. It was shown that when the first preliminary annealing is carried out in a flow of atomic hydrogen with a flow density of atoms of 1013-1016 at. cm2 s -1 a reduction in specific contact resistance of 2-2.5 times is observed, and also a more homogeneous metallization is formed with a finer microcrystal structure, in comparison with when the first, preliminary annealing is carried out under vacuum. The reduction in specific contact resistance is apparently connected with the action of the hydrogen atoms which minimise the rate of the oxidizing reactions and activate solid phase reactions forming the ohmic contact during the thermal treatment process. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Erofeev E.V.,Research and Production Company Micran | Arykov V.S.,Research and Production Company Micran | Anishchenko E.V.,Research and Production Company Micran | Kagadei V.A.,Research and Production Company Micran | And 2 more authors.
IEEE Journal of the Electron Devices Society | Year: 2013

This paper presents the results of electrical performance studies of the newly developed GaAs pHEMT transistors with Al-based metallization of the ohmic and barrier contacts, and fully copper metallization of interconnects, air bridges, and backside. The transistors exhibited a source-drain saturation current of Idss = 280 mA/mm and a maximum transconductance of gm = 450mS/mm at Uds = 1.5 V. The current cut off frequency for transistors with 600μm total gate width was 80 GHz at Uds = 1.5 V and Ugs = -0.35 V, and the power gain limiting frequency was 100 GHz. Output power at 1dB gain compression with matched input and output load an impedance was P1db = 26 dBm or 670 mW/mm at an efficiency level of about 28% and the transistor gain G = 11 dB. Measurements were performed at Uds = 8 V, Ids = 1/3 of Idss at 12 GHz. The obtained results demonstrate the promise of Al and Cu metallization in the low cost manufacture of microwave transistors and monolithic integrated circuits based on them. © 2014 IEEE.


Gorevoy A.V.,Research and Production Company Micran
CriMiCo 2014 - 2014 24th International Crimean Conference Microwave and Telecommunication Technology, Conference Proceedings | Year: 2014

The article presents the application results of the method obtaining sub-Hz frequency resolution in the wideband microwave generator. Using the method there was built an unique instrument with the functional capabilities of classical generators and only 2.5 W of power consumption. © 2014 CriMiCo'2014 Organizing Committee, CrSTC.


Gorevoy A.V.,Research and Production Company Micran
CriMiCo 2014 - 2014 24th International Crimean Conference Microwave and Telecommunication Technology, Conference Proceedings | Year: 2014

The present paper describes a method to achieve sub-Hz frequency resolution in a microwave frequency synthesizer using commercially available digital PLL components. The key feature of this method is the spectral purity and frequency resolution comparable with the solutions based on direct digital synthesizer chips. The last ones are not used in the described method that allows obtaining the substantial economy in size, cost and power consumption of the system. © 2014 CriMiCo'2014 Organizing Committee, CrSTC.

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