Neutral interface traps for Negative Bias Temperature Instability

Negative Bias Temperature Instability (NBTI) is a critical reliability issue and becoming more and more seriously in the modern CMOS technology. Many models have been proposed to account for the NBTI phenomena, but most of the models are based on the popular hydrogen reaction-diffusion (R-D) mechanisms. For the first time, in this work, a neutral interface-trap model due to the random variations of bond angles and lengths of Si··Si, Si··O and Si··N bonds is applied to explain the NBTI phenomena. The unified compact model with the neutral interface traps can very well characterize stressed device performance. The neutral interface traps with energy distribution in the silicon energy gap can very well account for the root cause of NBTI fast recovery. The model is verified by TCAD simulation and experimental measurement with excellent agreement.