Mobility enhancement by strained channel CMOSFET with single workfunction metal-gate and fabrication method thereof

摘要

The present invention provides a complementary metal-oxide-semiconductor (CMOS) device and a fabrication method thereof. The CMOSFET device includes a compressively strained SiGe channel for a PMOSFET, as well as a tensile strained Si channel for an NMOSFET, thereby enhancing hole and electron mobility for the PMOSFET and the NMOSFET, respectively. As such, the threshold voltages of the two types of transistors can be obtained in oppositely symmetric by single metal gate.