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 dep endence between positive oxide charge annealing and interface trap bui ldup accurately predicts the long time response of MOSFETs with relati vely thick oxides but overestimates the threshold voltage shift for ra diation hardened MOSFETs with thin oxides. To give an explanation to t his fact, we investigate the impulse response function for threshold v oltage. A revised model, which incorporates the different energy level s of hole traps in the oxide improves the fit between the model and da ta and gives an explanation to the fitting parameters dependence on ox ide field.