A physical model of the abnormal behavior of hydrogen-terminated Diamond MESFET

Hydrogen-terminated Diamond MESFET exhibits abnormal gate capacitance-voltage (CV) relationship, with an insulator barrier-like plateau followed by an abrupt increase in capacitance at large gate bias. A new model is proposed by assuming inhomogeneous band gap in the Interfacial Layer (IL). With this model, various experimental gate CV, as well as gate leakage curves can be matched well with TCAD simulations. This model also offers possible explanation of the double-bumps in transconductance measurements in some experiments.