Demonstration of high-performance PMOSFETs using Si-SixGe1-x-Si quantum wells with high-kappa/metal-gate stacks

Abstract

Through a systematic approach, PMOSFETs with strained quantum wells (QWs) in the Si-Ge system exhibiting high performance and low OFF-state leakage currents comparable to optimized gate stacks on Si are demonstrated. The encouraging results are due to selectively depositing Si-Si(x)Ge(1-x)-Si heterostructure QWs, where it appears that the critical thickness requirements for these thin films based on the lattice constant mismatch are relaxed. Furthermore, the use of optimal advanced high-kappa dielectric and metal-gate electrode helped realize the good device characteristics.