Temperature accelerated gate oxide degradation under plasma-inducedcharging

Gate oxide charging during plasma processing of submicron devices becomes a serious yield and reliability concern, especially when oxide thickness and device dimensions shrink to the nanoscale region. This paper shows that wafer temperature is a crucial parameter for charging-induced oxide degradation due to plasma processing. Experimental results from plasma damaged submicron MOS transistors, namely low-level gate leakage and degraded charge-to-breakdown characteristics are analyzed from the point of view of conditions of electrical stress. Laboratory experiments simulating plasma charging, performed at 150°C, confirmed that elevated temperature during plasma processing strongly accelerates oxide degradation and even at low-level stress leads to effects observed in plasma damaged devices