Consistency of the two component composite modeling framework for NBTI in large and small area p-MOSFETs

Abstract

Consistency of the recently proposed deterministic composite modeling framework for Negative Bias Temperature Instability (NBTI) in large area devices is verified for stochastic NBTI in small area devices. The framework has two independent and uncoupled components, interface trap generation (ΔV_IT) and hole trapping in pre-existing defects (ΔV_HT). The time evolution of mean threshold voltage shift (ΔV_T), from multiple ultra-fast measurements in small area devices under diverse stress and recovery conditions, is predicted by the deterministic composite framework. It is shown that although the physical mechanism of NBTI remains the same as the device area is scaled, there can be significant differences in the relative ΔV_IT and ΔV_HT contribution to ΔV_T between large and small area devices, which can alter the overall model parameters. A stochastic simulation framework, fully consistent with the deterministic framework, is developed, which is shown to predict experimentally measured mean time evolution of ΔV_T in small area devices.