The improvement of MOSFET prediction in space environments using the conversion model

The modeling of MOS device response to a low dose rate irradiation has been performed. The existing conversion model based on the linear dependence between positive oxide charge annealing and interface trap buildup accurately predicts the long time response of MOSFETs with relatively thick oxides but overestimates the threshold voltage shift for radiation hardened MOSFETs with thin oxides. To give an explanation to this fact, the authors investigate the impulse response function for threshold voltage. A revised model, which incorporates the different energy levels of hole traps in the oxide improves the fit between the model and data and gives an explanation to the fitting parameters dependence on oxide field