Thermal resistance characterization of 200 GHz F/sub t/ InGaAs/InAlAs HBTs

We present the results of measurements of the thermal resistivity of InP-based HBTs with cutoff frequencies, f/sub t/ /spl sim/200 GHz and with f/sub max/ over 300 GHz. The measurements were on full-thickness 3" InP wafers at T/sub amb/ from 30 - 210/spl deg/C and three separate emitter current densities. We present data on three device sizes and two device layouts and discuss the relationship of V/sub be/ to temperature at these elevated power and temperature levels.