A Simplified High-Speed Bipolar Process with Ti Salicide Metallization: Implementation of in situ p-doped polysilicon emitter
A simplified double-polysilicon bipolar process utilizing only four photolithography steps has been developed. The process features full self-alignment of emitter-base module and titanium self-aligned silicide metallization. The simplified process has been used as a test vehicle in implementation of an in situ phosphorus doped polysilicon technology. The base and collector currents demonstrated nearly ideal behavior in the Gummel plot resulting in high common-emitter current gain around 200. High-frequency measurements revealed a peak cut-off frequency of 9GHz measured directly on the silicide. The results from the simplified process have been shown to be directly transferable to a full-scale bipolar technology.