Mobility enhancement by CESL strain in short-channel ultrathin SOI MOSFETs

The electrical properties of front and back channels in advanced SOI MOSFETs (ultrathin film, short length, metal-gate/high-K stack, thin BOX) are used to reveal the impact of tensile and compressive CESL strain. The benefit of compressive strain is maximized in 100 nm long MOSFETs, where the hole mobility can be increased by a factor of two. In shorter devices, the mobility gain fades away due to neutral defects and remote Coulomb scattering. The short-channel scattering and strain mechanisms are identified by low temperature measurements and explained by an original physics-based model.