Diffusive base transport in narrow base InP/Ga/sub 0.47/In/sub 0.53/As heterojunction bipolar transistors

Abstract

Summary form only given. The sub-picosecond transit times measured in InP/Ga/sub 0.47/In/sub 0.53/As heterojunction bipolar transistors (HBTs) were widely interpreted in terms of quasi-ballistic base transport. The ballistic transport mechanism, however, is ruled out by the results presented here, which indicate that the common emitter current gain of narrow base InP/Ga/sub 0.47/In/sub 0.53/As HBTs is inversely proportional to the square of the base width, as expected for diffusive base transport.<>