30-nm-Gate AlGaN/GaN Heterostructure Field-Effect Transistors with a Current-Gain Cutoff Frequency of 181 GHz
2006; Institute of Physics; Volume: 45; Issue: 11L Linguagem: Inglês
10.1143/jjap.45.l1111
ISSN1347-4065
AutoresMasataka Higashiwaki, Takashi Mimura, Toshiaki Matsui,
Tópico(s)Metal and Thin Film Mechanics
ResumoWe fabricated Al0.4Ga0.6N(8 nm)/GaN heterostructure field-effect transistors (HFETs) with a gate length (LG) of 30 nm on a sapphire substrate. The AlGaN/GaN HFETs, which had a 2-nm-thick SiN passivation and gate-insulating layer formed by catalytic chemical vapor deposition, showed a maximum drain current density of 1.49 A/mm, a peak extrinsic transconductance of 402 mS/mm, a current-gain cutoff frequency ( fT) of 181 GHz, and a maximum oscillation frequency of 186 GHz. From a delay time analysis of fT for the HFETs with LG=30–150 nm, the electron velocity overshoot was not observed even when LG was decreased to 30 nm.
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