High-performance emitter-up/down SiGe HBT's

The experimental results in this paper provide evidence of high-performance symmetric and emitter-down operation of SiGe-HBT's. SiGe-base transistors were fabricated by using Atmospheric-Pressure Chemical Vapor Deposition (APCVD) for the epitaxial growth of SiGe and Si layers, and a novel self-aligned device structure. Current gains of 2000 and 120, cutoff-frequencies of 64 GHz and 14 GHz, and maximum oscillation frequencies of 23 GHz and 10 GHz have been achieved for emitter-up and emitter-down operation, respectively.>