Impact on the back gate degradation in partially depleted SOI n-MOSFETs by 2-MeV electron irradiation

Degradation of the electrical performance in partially depleted SOI MOSFETs by 2-MeV electrons is presented. The degradation behavior of the 2nd transconductance (gmf) peak and its dependence on the back gate voltage is discussed taking into account the degradation of the back gate. The drain current in the subthreshold region is increased by irradiation. This is caused by the turn-on of the parasitic edge transistor. The 2nd peak in the transconductance (gmf) tends to decrease after irradiation, while less degradation is observed in the 1st gmf peak. The decrease of the 2nd gmf peak enhances by the application of a negative VBG and the result can be explained by the degradation of the Si/buried oxide interface and the increase of the sidewall leakage, which gives rise to a lowering of the body potential.