Effective channel mobility in phosphorus-treated 4H-SiC (0001) metal-oxide-semiconductor field-effect transistors with various p-body doping concentrations

Abstract

Phosphorus treatment, which can substantially reduce the interface state density (D it), was used to investigate the impact of D it on effective channel mobility (μ eff) of 4H-SiC (0001) metal-oxide-semiconductor field-effect transistors (MOSFETs). A high μ eff of 126 cm2 V−1 s−1, which exceeds the reported phonon-limited mobility of 83 cm2 V−1 s−1 determined from Hall mobility of nitridation-treated MOSFETs, at a high effective normal field of 0.57 MV cm−1 was obtained in MOSFETs fabricated on a high-purity semi-insulating 4H-SiC substrate at room temperature. This high mobility may be caused by the difference of the density of electrons trapped at the interface states.