Introduction

Abstract

The evolution of digital intergated circuit technology went through several phases starting with bipolar in the 1950s and 60s to NMOS in the 70s until the 1980s when CMOS became the mainstream technology. The demand for superior performance, which has motivated the relentless search and development of new technologies, was behind the emergence of BiCMOS. It is the technology which merges old rivals, namely, CMOS and bipolar, to complement each other so that the strength of one covers the weakness of the other. This concept was first proposed by Lin et al. in 1969 [1]. The progress achieved in the silicon processing technology in the ?0s and the 80s motivated the revival of the idea of merging CMOS and bipolar. Since the mid 80s enormous resources have been devoted towards the development of several versions of BiCMOS processes, and real BiCMOS products and systems have been shipped out.