Role of remote Coulomb scattering on the hole mobility at cryogenic temperatures in SOI p-MOSFETs**Project supported by the National Natural Science Foundation of China (Grant Nos. 61674008, 61421005, and 61804003), the National Key Research and Development Program of China (Grant No. 2016YFA0202101), and the China Postdoctoral Science Foundation (Grant Nos. 2018M630034 and 2019T120017).

Abstract

The impacts of remote Coulomb scattering (RCS) on hole mobility in ultra-thin body silicon-on-insulator (UTB SOI) p-MOSFETs at cryogenic temperatures are investigated. The physical models including phonon scattering, surface roughness scattering, and remote Coulomb scatterings are considered, and the results are verified by the experimental results at different temperatures for both bulk (from 300 K to 30 K) and UTB SOI (300 K and 25 K) p-MOSFETs. The impacts of the interfacial trap charges at both front and bottom interfaces on the hole mobility are mainly evaluated for the UTB SOI p-MOSFETs at liquid helium temperature (4.2 K). The results reveal that as the temperature decreases, the RCS due to the interfacial trap charges plays an important role in the hole mobility.