Physical model of the PBTI and TDDB of la incorporated HfSiON gate dielectrics with pre-existing and stress-induced defects

Abstract

We have clarified the impact on reliability of La incorporation into the HfSiON gate dielectrics nMOSFETs (PBTI, TDDB). Although La incorporation is effective for pre-existing defect suppression, stress induced defect generation is more sensitive to stress voltage and temperature. This is caused by the elevation of the energy level of oxygen vacancy and high ionicity of La-O bond. The origin of defects is thought to be oxygen vacancy related defects, generated under positive stress and they are common to PBTI and TDDB degradation.