A GREATER-THAN-400 GHZ F(MAX) TRANSFERRED-SUBSTRATE HETEROJUNCTION BIPOLAR-TRANSISTOR IC TECHNOLOGY

We report transferred-substrate AlInAs/GaInAs heterojunction bipolar t ransistors. A device having 0.6 mu m x 25 mu m emitter and a 0.8 mu m x29 mu m collector exhibited f(tau) = 134 GHz and f(max) > 400 GHz. A device with a 0.6 mu m x 25 mu m emitter and a 1.8 mu m x 29 mu m coll ector exhibited 400 GHz f(max) and 164 GHz f(tau). The improvement in f(max) over previous transferred-substrate HBT's is due to improved ba se Ohmic contacts, narrower emitter-base and collector-base junction a reas, and slightly reduced transit times. The transferred-substrate fa brication process provides electroplated gold thermal vias for transis tor heat-sinking and a microstrip wiring environment on a low dielectr ic constant polymer substrate.