Title :
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
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 IDSS up to 750 mAmm -1 were seen with pulsed measurements, which eliminate self-heating. For a gate-length of 0.2 μm, a ft value of 32 GHz and fmax of 72 GHz were seen, increasing to 37 GHz and 79 GHz respectively, after passivation. Passivation also caused an increase in Vp, 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;
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
DOI :
10.1109/EDMO.2000.919033
