Fabrication and Characterization of Self-Aligned InAlAs/InGaAsSb/InGaAs Double Heterojunction Bipolar Transistors
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Published:2011-10-04
Issue:6
Volume:41
Page:117-127
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ISSN:1938-5862
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Container-title:ECS Transactions
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language:
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Short-container-title:ECS Trans.
Author:
Lo Chien-Fong,Chang C. Y.,Chen S.-H.,Chang C.-M.,Wang S.-Y.,Chyi J.-I.,Kravchenko I. I.,Pearton S. J.,Ren F.
Abstract
A trilevel resist system was employed to fabricate self-aligned, submicron emitter finger In0.52Al0.48As/In0.42Ga0.58As0.77Sb0.23/ In0.53Ga0.47As double heterojunction bipolar transistors (DHBTs). Selective wet-etchants were used to define the emitter fingers and to form an InGaAs guard-ring around the emitter fingers. Due to the low energy bandgap of the InGaAsSb base layer and type II base-collector junction, a low turn-on voltage of 0.38 V at 1 A/cm2 and a high dc current gain of 123.8 for a DHBT with a 0.65 x 8.65 µm2 emitter area were obtained. A unity gain cut-off frequency (fT) of 260 GHz and a maximum oscillation frequency (fmax) of 485 GHz at JC = 302 kA/cm2 were achieved.
Publisher
The Electrochemical Society