Self-heating and kink effects in a-Si : H thin film transistors

We describe a new physics based, analytical de model accounting for short c hannel effects for hydrogenated amorphous silicon (a Si:H) thin film transi stors (TFT's), This model is based on the long channel device model. Two im portant short-channel phenomena, self-heating and kink effect, are analyzed in detail. For self-heating effect, a thermal kinetic analysis is carried out and a physical model and an equivalent circuit are used to estimate the thermal resistance of the device. In deriving the analytical model for sel f-heating effect, a first order approximation and self-consistency are used to give an iteration-free model accurate for a temperature rise of,up to 1 00 degrees C. In the modeling of the kink effects, a semi-empirical approac h is used based on the physics involved. The combined model accurately repr oduces the de characteristics of a-Si:H TFT's with a gate length of the 4 m u m. Predictions for a-Si:PI TFT's scaled down to 1 mu m are also provided, The model is suitable for use in device and circuit simulators.