RAPID THERMAL ANNEALING OF INSITU PHOSPHORUS-DOPED POLYSILICON EMITTERS

Rapid thermal annealing of in situ phosphorus-doped polysilicon emitte r transistors in the temperature range 850-1000-degrees-C greatly redu ces the emitter resistance R(E) al the cost of a slight increase in ho le back injection, seen as a decrease in emitter Gummel number G(E). A nnealing at 1000-degrees-C for 5 s gives low emitter resistance (R(E) almost-equal-to 100 OMEGA mum2) while maintaining good suppression of back injection (G(E) greater-than-or-similar-to 10(14) scm-4). Anneali ng at temperatures below 1000-degrees-C fails to reduce R(E) sufficien tly for use in high-speed devices.