Electrical modeling of compound semiconductor interface for FET device assessment

A unified model for GaAs and InP metal-insulator-semiconductor (MIS) systems is presented. It involves particular types of U-shaped distributions of interface states, localized and nonlocalized states, and tunneling processes. Detailed experimental data including the
C-V
data, frequency dependence of MIS admittance, photocapacitance transient spectroscopy, and deep-level transient spectroscopy, support the model. Formation of a disordered nonstoichiometric semiconductor region is suggested to be the most probable mechanism for the anomalous distributions of interface states. Effects of interface states on microwave MISFET's, and implications of the model for logic applications are briefly discussed.