DIAMOND COATED ALGAN/GAN HIGH ELECTRON MOBILITY TRANSISTORS – EFFECT OF DEPOSITION PROCESS ON GATE ELECTRODE

1 VANKO Gabriel
Co-authors:
2 IŽÁK Tibor 1 Babchenko Oleg 2 KROMKA Alexander
Institutions:
1 Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava, Slovak Republic
2 Institute of Physics, Czech Academy of Sciences v.v.i, Cukrovarnická 10, 162 00 Prague 6, Czech Republic, izak@fzu.cz
Conference:
7th International Conference on Nanomaterials - Research & Application, Hotel Voronez I, Brno, Czech Republic, EU, October 14th - 16th 2015
Proceedings:
Proceedings 7th International Conference on Nanomaterials - Research & Application
Pages:
168-173
ISBN:
978-80-87294-59-8
ISSN:
2694-930X
Published:
11th January 2016
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
50 views / 13 downloads
Abstract

We studied the influence of the diamond deposition on the degradation of Schottky gate electrodes (i.e. Ir or IrO2) and on the electrical characteristics of AlGaN/GaN high electron mobility transistors (HEMTs). Thermally stable Schottky gate electrodes are necessary to withstand high temperatures and aggressive conditions (>95% hydrogen-containing plasma) during diamond chemical vapour deposition (CVD) process. In present study, the diamond films were selectively deposited on the AlGaN/GaN circular HEMT by focused (ellispoidal cavity reactor) and linear antenna (surface wave) microwave plasma at different temperatures from 400°C to 1100°C. The preliminary results on electrical measurements on the diamond-coated c-HEMTs showed degraded electrical properties comparing to c-HEMTs before deposition process, which was attributed to degradation of the Ir gate electrodes even at temperatures as low as 400°C. On the other hand, metal oxide gate electrode layer (IrO2) can withstand diamond CVD process even at high temperatures (~900°C) which make it suitable for fabrication of all-in-diamond c-HEMT devices for high-power applications.

Keywords: GaN HEMT, CVD diamond, iridium oxide, thermal stability, IV characteristics

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