Effect of dynamic stress on off leakage of small-dimension pMOSFETs at high temperature

Abstract

The degradation of the off leakage current I-off in small-dimension pMOSFETs is investigated experimentally while applying a dynamic stress to the pMOSFETs. During the OFF-state stress, the dynamic stress induced an increase of I-off due to generation of negative oxide charges N-ox in the gate dielectric, and in the shallow trench isolation (STI) near the gate edge. When channel width W decreased, negative N-ox in STI increase I-off significantly, and the degradation of I-off is more critical than degradation of V-th. These observations indicate that the effect of the dynamic stress in pMOSFETs on I-off should be seriously considered when evaluating small-dimension pMOSFETs. (C) 2014 The Japan Society of Applied Physics