[21p-C105-1~11] 13.5 Semiconductor devices/ Interconnect/ Integration technologies

[21p-C105-1] Validity of electron mobility of Si nMOSFETs at cryogenic temperature determined by a nonlinear model of surface roughness scattering

〇Kei Sumita¹, Min-Soo Kang¹, Kasidit Toprasertpong¹, Mitsuru Takenaka¹, Shinichi Takagi¹ (1.U. Tokyo)

Keywords:semiconductor, MOSFET, mobility

Surface roughness (SR) scattering is a dominant scattering mechanism of electrons in the extremely-thin-body channels and at cryogenic temperature in parallel. Recently, we have proposed the revised nonlinear mobility model of SR scattering considering the strong higher order perturbations. However, the validity of our nonlinear model at cryogenic temperature has been not researched yet. Therefore, in this study, the electron mobility of Si nMOSFETs at cryogenic temperature is evaluated experimentally and theoretically. As a result, the experimental mobility of Δ4 electrons is much lower than the theoretical mobility, which is attributable to that the localized tail states.