A<400 GHz f/sub max/ transferred-substrate heterojunction bipolar transistor IC technology

摘要

We report transferred-substrate AlInAs/GaInAs bipolar transistors. A device having a 0.6 /spl mu/m/spl times/25 /spl mu/m emitter and a 0.8 /spl mu/m/spl times/29 /spl mu/m collector exhibited f/sub /spl tau//=134 GHz and f/sub max/<400 GHz. A device with a 0.6 /spl mu/m/spl times/25 /spl mu/m emitter and a 1.8 /spl mu/m/spl times/29 /spl mu/m collector exhibited 400 GHz f/sub max/ 164 GHz f/sub /spl tau//. The improvement in f/sub max/ over previous transferred-substrate HBT's is due to improved base Ohmic contacts, narrower emitter-base and collector-base junction areas, and slightly reduced transit times. The transferred-substrate fabrication process provides electroplated gold thermal vias for transistor heat-sinking and a microstrip wiring environment on a low dielectric constant polymer substrate.