Interpretation of 60Co radiation effects in metal-oxide semiconductors in terms of the mobility and interface trap density with a drain current-gate voltage model

The voltage-dependent current is a crucial parameter for determining the electrical properties of microelectronic devices. In this study, we aimed to extend a generic dc model to successfully explain the drain current (Id) for metal-oxide semiconductors (MOSs) and thin-film transistors (TFTs) based on the gate voltage (Vg), where the threshold voltage (Vth) could also be obtained from this model in a nature manner. This dc model meets the requirements for compact modeling, including modeling computer circuit simulators. The application of this model to p-type MOS and n-channel MOS transistors irradiated by 60Co showed that this generic dc model covers all the regimes for MOS or TFT linear and saturation operation above Vth, sub-threshold, and reverse biasing. In addition, the radiation-induced shift location of Vth was found using this model. The mathematical relationships are defined between the Vth and radiation dosage (D), so the 60Co enhancement effect on the mobility, μ, and interface trap density are also successfully explained by D.