SiGe, GaAs, and InP Heterojunction Bipolar Transistors

Preface

Advances in wireless communication and information processing systems require implementation of very high performance electronic systems. In recent years, heterojunction bipolar transistors (HBTs) have emerged as a leading contender to satisfy these demands. The use of wide-bandgap heterojunction emitters allows design of HBTs with very high base doping levels, which significantly reduce base resistance and increase device speed. The low emitter-base turn-on voltage and device scaling to submicron dimensions significantly reduce power consumption in circuit operation. With the increasing demand placed on voice and data communications, transmitting, receiving, and processing information at high frequencies and high speeds using both microwave and optical means has become another area where heterojunction bipolar transistors have become increasingly important.

This book is intended for use by senior undergraduate or first-year graduate students in applied physics, electrical engineering, and materials sciences, and as a reference for engineers and scientists involved in semiconductor device research and development. It is assumed that the reader has already acquired a basic understanding of bipolar device operation. With this as a basic, the present book elaborates on the high-speed and radio-frequency (RF) aspects of heterojunction bipolar transistor performance. Many important aspects of SiGe-, GaAs-, and InP-based HBTs are presented in a unified manner.

In Chapter 1