Dependences of the Characteristics of an InGaP/GaAs HBT for Applications in Power Amplifiers on the Structural Parameters

In this paper, InGaP/GaAs heterojunction bipolar transistor (HBT) devices were fabricated with various distances between the electrodes and the collector mesa, various widths of the emitter electrode and various thicknesses of the nitride passivation film. Cutoff frequencies and maximum oscillation frequencies of the devices were above 40 GHz and above 62 GHz, respectively. These values are considered sufficient for applications to power amplifiers at frequencies up to 5.5 GHz. On the other hand, the devices designed to obtain reproducibility through fabrication process showed a slight degradation in the frequency characteristics but a substantial enhancement of uniformity at the emitter-collector breakdown voltage (BVceo). KCI Citation Count: 1