Pocket Implant-Dependent Channel Mobility in Advanced p-MOSFETs With Strain Engineering

A new approach to channel mobility engineering using strained-Si technology is described with a complete data analysis. It is discussed that [110]/(100) Si channel mobility in p-MOSFET with embedded SiGe source/drain and compressive stress liner can be strongly dependent on pocket implant dose, resulting from a change in piezoresistance coefficient as a function of p-type carrier dopant concentration in the vicinity of the channel, whereas channel mobility of n-MOSFETs shows weaker dependence on pocket implant dose due to: 1) smaller piezoresistance coefficient of n-channel and 2) less channel strain relative to p-MOSFETs.