The effect of copper on gate oxide integrity

Abstract

We have studied the effect of copper contamination after the front-end metal-oxide-semiconductor capacitor fabrication on gate oxide integrity. The significant effect of Cu contamination on the pretunneling current, in combination with insensitive dependence of the Fowler-Nordheim tunneling current, oxide charge density, and breakdown field on the Cu concentration, suggests that the current leakage mechanism may be due to neutral traps generated by Cu inside oxide. In addition to pretunneling oxide leakage, a small amount of Cu contamination increases the interface trap density that may degrade the device performance. (C) 2000 The Electrochemical Society. S0013-4651(00)03-073-1. All rights reserved.