Investigation of post-NBTI stress recovery in pMOSFETs by direct measurement of single oxide charge de-trapping

Abstract

A novel method to study post-NBTI stress recovery in pMOSFETs is demonstrated by direct measurement of single-hole de-trapping behavior. Individual trapped hole emission in NBTI recovery is observed for the first time, which is manifested by the step-like evolution of channel current. By measuring trapped hole emission times and corresponding current jump, the dependence of NBTI recovery on stress hardness, recovery gate voltage and temperature, and gate length is characterized. An analytical model based on thermally-assisted tunneling of trapped oxide charges can successfully reproduce measured recovery characteristics.