Frequency-dependent capacitance-voltage characteristics for amorphous silicon-based metal-insulator-semiconductor structures

A frequency-dependent capacitance-voltage model for the a-Si:H-based MIS structure is presented along with an alternative direct measurement method. The static C-V model is derived based on the static I-V model developed using the simplified CFO band model for the a-Si bulk bandgap states and the simplified Davis-Mott model for the surface states. The frequency variation of the measured capacitance, using a somewhat modified TFT, is modeled with the lateral flow transmission line model. These models can be used to monitor TFT-fabrication parameters and to extract accurate capacitance model parameters of TFTs.<>