W. Kaplan et al., A simplified high-speed bipolar process with Ti salicide metallization: Implementation of in situ p-doped polysilicon emitter, PHYS SCR, T79, 1999, pp. 318-321
A simplified double-polysilicon bipolar process utilizing only four photoli
thography steps has been developed. The process features full self-alignmen
t 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 i
n high common-emitter current gain around 200. High-frequency measurements
revealed a peak cut-off frequency of 9 GHz measured directly on the silicid
e. The results from the simplified process have been shown to be directly t
ransferable to a full-scale bipolar technology.