Implementation of Fast Wafer Level Reliability Monitoring Strategy for Wafer Fab Process Monitoring

Abstract

In wafer foundry it is important to make use of reliability monitoring strategy as part of process monitoring. A fast reliability monitoring strategy has been developed, which enables a fast feedback to the production line. The three main critical reliability failure mechanisms associated with the CMOS device are hot carrier effects, gate oxide breakdown and electromigration. The fast wafer level reliability (WLR) methodology was employed for monitoring of the critical reliability failure mechanisms in the wafer fab. Using substrate current measurement as monitoring parameter for hot carrier effects, accelerated testing for electromigration and monitoring gate oxide integrity through standard production tests, the new methodology has proved to help the fab decrease test time while increasing monitoring frequency.