Inversion layer electron transport in 4H‐SiC metal–oxide–semiconductor field‐effect transistors

Abstract

AbstractSilicon carbide is the only compound semiconductor with silicon dioxide as its native oxide and can form metal–oxide–semiconductor field‐effect transistors. In this article, we review the inversion layer electron transport properties of 4H‐SiC/SiO2. The inversion layer electron transport theories developed for the Si/SiO2 system have been reviewed to highlight the behaviour of inversion layer electrons at an ideal interface. The 4H‐SiC/SiO2 interface, is currently far from ideal and so we discuss the inversion layer electron transport for several techniques of oxidation of the (0001) 4H‐SiC including nitridation of thermal oxides and sodium enhanced oxidation of 4H‐SiC. Inversion layer mobility of nitrided oxides is dominated by Coulomb scattering at low surface electric field values and surface roughness scattering at high surface electric field values. In sodium enhanced oxidation samples no trapped charge is found at the interface close to the conduction band edge, but the temperature dependence of mobility shows that the samples are not limited by phonon scattering and therefore not ideal. We also review the results of inversion layer transport on alternate faces of 4H‐SiC. We conclude highlighting the future work remaining in the field and the behaviour of inversion layer electron mobility we expect to see in an ideal 4H‐SiC/SiO2 interface. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)