Radiation-Induced Interface States of Poly-Si Gate MOS Capacitors Using Low Temperature Gate Oxidation

The effect of gate oxidation temperature on radiation-induced flatband and threshold voltage shifts and interface state buildup for steady-state Co60 irradiation have been studied for poly-Si gate MOS capacitors with pyrogenic and dry gate oxides. The smallest radiation-induced flatband and threshold voltage shifts can be achieved with a pyrogenic oxide grown at 850°C. Total dose effects, applied gate bias during the irradiation and oxide thickness dependence were also evaluated for low temperature pyrogenic oxide MOS capacitors. We obtained a 2/3 power law dependence of radiation-induced interface states on the total dose and the oxide thickness.