Hot-electron InGaAs/InP heterostructure bipolar transistors with f/sub T/ of 110 GHz

Abstract

A hot-electron InGaAs/InP heterostructure bipolar transistor (HBT) is discussed. A unity-current-gain cutoff frequency of 110 GHz and a maximum frequency of oscillation of 58 GHz are realized in transistors with 3.2*3.2- mu m/sup 2/ emitter size. Nonequilibrium electron transport, with an average electron velocity approaching 4*10/sup 7/ cm/s through the thin (650 AA) heavily doped (p=5*10/sup 19/ cm/sup -3/) InGaAs base and 3000-AA-wide collector space-charge region, results in a transit delay of 0.5 ps corresponding to an intrinsic cutoff frequency of 318 GHz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>