InP-based heterojunction bipolar transistors: performance status and circuit applications

Abstract
The present status and prospects of heterojunction bipolar transistors configured with InP, InGaAs and/or InAlAs on InP substrates are reviewed. The importance of ultrahigh electron velocity is highlighted. Self-aligned fabrication techniques are described, and devices with wide bandgap collectors for microwave power applications and with low turn-on voltage for digital applications are presented. Applications are discussed. Frequency dividers configured with these devices have operated to 17 GHz.