Material and structure design for advanced CMOS channels

This paper reviews recent our studies of CMOS channels based on the concept of subband structure engineering. This device design concept can be applied to strained-Si channel MOSFETs, ultra-thin SOI MOSFETs and Ge-on-insulator (GOI) MOSFETs. As for the electron mobility enhancement, an important factor is the introduction of larger subband energy splitting between the 2-fold and the 4-fold valleys on a (100) surface, which can be obtained in strained-Si and ultra-thin body (UTB) channels based in S. Takagi et al. (1997).