The gate-length dependent performance of AlGaN/GaN HFETs with silicon nitride passivation

Author

Davies, R.A. ; Bazley, D.J. ; Jones, S.K. ; Lovekin, H.A. ; Phillips, W.A. ; Wallis, R.H. ; Birbeck, J.C. ; Martin, T. ; Uren, M.J.

Author_Institution

Marconi Caswell Ltd., Towcester, UK

fYear

2000

fDate

2000

Firstpage

76

Lastpage

81

Abstract

A comparison has been made of the performance of AlGaN/GaN HFETs, with gate-lengths in the range 0.2 to 2.0 μm, both with and without silicon nitride passivation. Values of I_DSS up to 750 mAmm ^-1 were seen with pulsed measurements, which eliminate self-heating. For a gate-length of 0.2 μm, a f_t value of 32 GHz and f_max of 72 GHz were seen, increasing to 37 GHz and 79 GHz respectively, after passivation. Passivation also caused an increase in V_p, particularly at short gate-lengths. An explanation, based on the contribution of stress in the passivation layer, is proposed. It gives qualitative agreement with measurements

Keywords

III-V semiconductors; aluminium compounds; gallium compounds; junction gate field effect transistors; passivation; silicon compounds; wide band gap semiconductors; 0.2 to 2.0 micron; 37 GHz; 79 GHz; AlGaN-GaN; AlGaN/GaN HFET; Si₃N₄; current gain cut-off frequency; film stress; gate length; pinch-off voltage; power gain cut-off frequency; pulse I-V characteristics; self-heating; silicon nitride passivation; Aluminum gallium nitride; Fabrication; Gallium nitride; HEMTs; MODFETs; Passivation; Power amplifiers; Power generation; Silicon; Stress;

fLanguage

English

Publisher

ieee

Conference_Titel

High Performance Electron Devices for Microwave and Optoelectronic Applications, 2000 8th IEEE International Symposium on

Conference_Location

Glasgow

Print_ISBN

0-7803-6550-X

Type

conf

DOI

10.1109/EDMO.2000.919033

Filename

919033