GATE OXIDE LEAKAGE DUE TO TEMPERATURE ACCELERATED DEGRADATION UNDER PLASMA CHARGING CONDITIONS

Plasma-induced gate charging and resulting damage to the gate oxide du ring fabrication of submicron devices becomes a serious yield and reli ability concern, especially when oxide thickness and device dimensions shrink to the nanoscale region. In this paper experimental results fr om plasma damaged submicron MOS transistors, namely low-level gate lea kage and degraded charge-to-breakdown characteristics, are analyzed wi th respect to conditions of electrical stress. It is demonstrated that wafer temperature is a crucial parameter for charging-induced oxide d egradation due to plasma processing. Laboratory experiments simulating plasma charging showed that low-level oxide leakage is the result of oxide breakdown after electrical wear-out under low-level injection co nditions. High field stress, performed at 150 degrees C, confirmed tha t elevated temperature during plasma processing strongly accelerates o xide degradation and even at low-level stress leads to the effects obs erved in plasma damaged devices. (C) 1998 Published by Elsevier Scienc e Ltd.