Hole mobility enhancement by [110] uniaxial compressive strain in(110) oriented ultra-thin body pFETs with SOI thickness of less than 4 nm

Mobility enhancement in (110) oriented ultra-thin body (UTB) SOI pFETs under uniaxial compressive stress has been demonstrated for the first time. The mobility enhancement ratio is approximately three times higher than that by uniaxial tensile stress. The physical origin of the hole mobility enhancement is discussed with subband calculation, and it is found that the enhancement is mainly caused by the conductivity mass change.