Electrical Correlation of Double-Diffused Metal-Oxide-Semiconductor Transistors Exposed to Gamma Photons, Protons, and Hot Carriers

Double-diffused metal-oxide-semiconductor n-channel power transistor devices were subjected to a high electric-field stress, gamma photons (Co-60), and 10-MeV proton radiation, and were comparatively analyzed. The direct-current current-voltage and high-frequency capacitance-voltage techniques were used to characterize the two different regions under the gate oxide in this kind of devices. The Si-SiO2 interfaces at the channel side and at the drain side are characterized after thermal annealing. The correlation of the interface states with the trapped charge is a good quantitative tool to compare the effects from different degradation mechanisms. It is shown that, under given conditions, each kind of stress exhibits its own signature in the interface states versus the oxide charge plot.