Design and evaluation of a planar GaAlAs-GaAs bipolar transistor

Abstract

A planar GaAIAs-GaAs bipolar transistor using a new technological processing technique is presented: a p-type diffusion through the emitter layer is used for base contacting, making possible the use of a low Al content emitter, and leading to low values of the base resistance. A transition frequency of 1 GHz and a maximum oscillation frequency of 450 MHz have been measured on large annular geometry devices.