AlGaAs/GaAs Pnp HBT with 54 GHz f/sub max/ and application to high-performance complementary technology

A self-aligned AlGaAs/GaAs Pnp HBT (heterojunction bipolar transistor) with a maximum frequency of oscillation of 54 GHz is reported. Improvements in device speed over previous work were obtained by optimization of epitaxial structure and reduction of base contact resistance. The PnP epitaxial structure was grown by nonarsine MOVPE (metal-organic vapor-phase epitaxy), with silicon and carbon as the donor and acceptor dopants. The Pnp HBT epitaxial structure was incorporated into recessed areas in wafers with a previously grown Npn HBT epi structure, and the two device types were fabricated simultaneously. Pnp and Npn devices on a single wafer achieved f/sub max/ of 50 and 90 GHz, respectively.