Title :
ALD AI2O3 passivated MBE-grown AIGaN/GaN HEMTs on 6H-SiC
Author :
Kim, D.-H. ; Kumar, V. ; Chen, G. ; Dabiran, A.M. ; Wowchak, A.M. ; Osinsky, A. ; Adesida, I.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Illinois, IL
Abstract :
The effects of atomic-layer-deposited (ALD) Al2O3 passivation layer on AlGaN/GaN HEMTs on SiC were studied. Improved pulsed I-V characteristics and a relatively small decrease in the unity gain cutoff frequency (fT) and the maximum frequency of oscillation (fmax) were observed in the devices passivated using a 45 nm-thick ALD Al2O3 layer. For 0.12 mum gatelength devices, fT (fmax) decreased to 92 GHz (115 GHz) from 120 GHz (140 GHz), while for 0.25 mum devices, fT (fmax) decreased to 58 GHz (120 GHz) from 65 GHz (137 GHz). At a drain bias of 15 V, an output power of 3 W/mm with an associated gain of 5.0 dB and PAE of 33% were obtained for the 0.25 mum gatelength devices
Keywords :
alumina; aluminium compounds; gallium compounds; high electron mobility transistors; molecular beam epitaxial growth; passivation; silicon compounds; 92 to 140 GHz; Al2O3; AlGaN-GaN; HEMTs; SiC; atomic-layer-deposited passivation layer; frequency of oscillation; gain; pulsed I-V characteristics;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:20073550
