The electrical properties of poly-SiGe gated PMOSFETs have been investigated and compared to the conventional poly-Si gated device. Both types of PMOSFETs use ultra-thin nitride gate dielectric. Poly-SiGe gated devices exhibit 10% higher inversion capacitance, improved subthreshold properties, and superior current drivability. The improvements are contributed to the suppression of the poly-gated depletion effect and the enhanced carrier mobility.
- Poly-gate depletion