Dopant segregated Schottky S/D and application to high performance MOSFETs

Physics and technology of dopant-segregated Schottky (DSS) MOSFETs are reported. A novel approach to achieve low Schottky barrier height (phi_b) is proposed and demonstrated. The segregated dopants at the metal/semiconductor interface effectively modulate phi_b. The DSS junction significantly improves the current drivability of metal-source/drain transistors. We, for the first time, demonstrated CMOS ring oscillator with metal-source/drain transistors. DSS MOSFETs show superior short channel effect immunity and current drivability over conventional (Conv) MOSFETs. The current drivability improvement is based on a reduction in parasitic resistance and an enhancement of the carrier velocity. In conclusion, DSS technology is promising to realize the ultimate MOS performance in the coming near-ballistic regime. At the same time, combination of DSS source/drain with other technology boosters, such as metal gate, high-k gate dielectrics have not well examined yet.