Time-Dependent Dielectric Breakdown and Stress-Induced Leakage Current Characteristics of 0.7-nm-EOT HfO2 pFETs

In this paper, we examine the time-dependent dielectric breakdown (TDDB) reliability of p-type field-effect transistor devices with 0.7-nm-equivalent-oxide-thickness HfO2 gate dielectric layers. The TDDB distributions indicate ten-year lifetime with operating voltages in excess of 1 V. The reason for this high reliability lies in the high Weibull slopes (similar to 1.2) of the measured TDDB distributions. In order to understand the mechanism behind the high Weibull slope, a detailed study of the defect generation by stress-induced leakage current (SILC) measurements is presented. The layers show different defect generation behavior as a function of temperature where the SILC generation rate at high temperature is stress voltage dependent.