Analysis of 80-MeV Carbon and 80-MeV Nitrogen Ion Irradiation Effects on N-Channel MOSFETs

摘要

N-channel depletion MOSFETs were irradiated with 80 MeV Carbon (C6+) and 80 MeV Nitrogen (N6+) ions in the dose range from 100 krad (Si) to 30 Mrad (Si). The electrical characteristics of MOSFET such as threshold voltage (V-th), density of interface trapped charges (Delta N-it), density of oxide trapped charges (Delta N-ot), transconductance (g(m)), mobility (mu), leakage current (I-L) and drain saturation current (I-DSat) were studied as a function of dose. A considerable increase in Delta N-it and Delta N-ot and decrease in V-th, g(m), mu, and I-D Sat was observed after irradiation. The mu was correlated with Delta N-it and it is found that the contribution of Delta N-ot in degrading the mobility of charge carriers is negligible. The ion irradiated results were compared with Co-60 gamma irradiated results and found that the degradation is more for Co-60 gamma irradiated devices at lower doses, whereas at higher doses, the degradation is more for heavy ion irradiated devices.