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 cm 2 V −1 s −1 , which exceeds the reported phonon-limited mobility of 83 cm 2 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.