BiCMOS process integration and device optimization: Basic concepts and new trends

The process integration issues and the aspects of CMOS and bipolar transistor optimization in BiCMOS technology are reviewed in this article. In one section, a sample BiCMOS fabrication process is discussed to provide an entry to the subject for readers who are not familiar with the details and the nomenclature of semiconductor technology. The remainder of the paper deals with questions related to state-of-the-art BiCMOS and addresses new directions in BiCMOS processing. The convergence of the structural requirements for the bipolar and CMOS devices with miniaturization and the modular concepts of current BiCMOS are described and highlighted by various examples. The prospects of BiCMOS in the fast evolving broadband and wireless communications markets are addressed.