TEMPERATURE AND GATE BIAS EFFECTS ON GAMMA-IRRADIATED AL-GATE METAL-OXIDE-SEMICONDUCTOR TRANSISTORS

The annealing of irradiated Al-gate metal-oxide-semiconductor (MOS) transistors at elevated temperature (115-degrees-C), without gate bias, for P-channel metal-oxide-semiconductor (PMOS) transistors, and with/without gate bias (+9 V) for N-channel metal-oxide-semiconductor (NMOS) transistors, has been investigated. The experimental data obtained are analyzed in terms of physicochemical and electrophysical processes responsible for creation of gate oxide charge and interface traps, as well as their anneal. The decrease of positive charge density in irradiated transistors during thermal annealing is caused by electrons tunneling from the silicon into the oxide. The rate of neutralization of positive centers depends on the irradiation dose level.