Explorations for high performance SiGe-heterojunction bipolar transistor integration

Presents a SiGe HBT integration-study, introducing a low-complexity integration-scheme. We demonstrate a stepped box-like SiGe base-profile designed to reduce reverse Early effects, achieving f/sub T/=55 GHz and BV/sub CEO/=2.7 V. The transistor characteristics are well modeled by Mextram 504.