EPI active devices

Abstract

Using UHV/CVD low temperature epitaxy to deposit pseudomorphic Si1-χGeχ layers on silicon, the bandgap and doping profile of a bipolar transistor can be tailored to obtain a level of performance not achievable using conventional techniques. This paper discusses the material and growth issues, the electrical characteristics of SiGe-base devices, and their implications as far as material properties and device design. Analytic and numerical calculations are used to explain the device physics and to assess the potential circuit advantages of SiGe for present and future technologies.