A 277-GHz f/sub max/ transferred-substrate heterojunction bipolar transistor

Abstract

We report a AlInAs-GaInAs transferred-substrate heterojunction bipolar transistor (HBT). The transferred-substrate process permits fabrication of narrow and aligned collector-base and emitter-base junctions, reducing the collector-base capacitance and increasing the device f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> . A device with aligned 0.7-μm emitter and 1.6-μm collector stripes has extrapolated 277 GHz f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">max</sub> and 127 GHz f/sub /spl tau//, respectively.