The effects of 6oCo γ-ray on the linearity and output characteristics of MOSFETs were investigated. The relations of oxide-trapped charge and Si/SiO2 interface state density to the decrease of mobility p and transconductance gm

and the shift of the output curves for both P-MOSFETs and N-MOSFETs were qualitatively described. It was shown that degradation of analog characteristics

for P-MOSFETs

resulted from both oxide-trapped charge and interface state

but the degradation for N-MOSFETs was mainly due to the increase of radiation induced Si/SiO2 interface state density.