A p-MOSFET structure with solid-phase-diffused drain (SPDD) is proposed for future 0.1 mu m and sub-0.1 mu m devices. Highly doped ultra-shallow p(+) source and drain junctions have been accomplished by solid-phase diffusion from the highly doped BSG sidewall. The resulting shallow, high-concentration drain profile significantly improves short channel effects without increasing parasitic resistance. At the same time, an in situ highly boron-doped LPCVD poly-silicon gate is introduced to prevent the transconductance degradation which arises in ultra-small p-MOSFET's with lower process temperature as a result of depletion formation in the p(+)-poly-silicon gate. It is confirmed that excellent electrical characteristics and good hot-carrier reliability are achieved, thus making the structure suitable for future 0.1 mu m and sub-0.1 mu m devices.
