AC-bias annealing effects on radiation-induced interface traps [MOS transistors]

High-frequency AC-bias annealing effects on interface traps are extensively discussed and explained using a model with AC-bias-activated carriers. AC-bias annealing causes a reduction in the broad peak above the midgap in the energy distribution of interface traps. The phenomenon is independent of gate electrode materials in MOS transistors. There is an offset voltage window for decreasing interface-trap density. The frequent transition between accumulation and inversion is responsible for AC-bias annealing effects. A model is proposed in which the AC-bias-activated electrons recombine with holes and the resultant excess energy changes the defect silic·on state into another state. The proposed model is supported by a recombination enhanced defect reaction process and verified by analyzing the temperature dependence of the AC-bias annealing