Charge trapping & NBTI in high k gate dieectric stacks

Abstract

In recent years, there has been increasing research and development efforts to replace SiO2 with high dielectric constant (κ) materials such as HfO2, HfSiO, Al2O3. An important transistor reliability issue is the threshold voltage stability under prolonged stressing. In this paper, we discuss two main causes of threshold voltage instability: charge trapping and negative bias temperature instability (NBTI) in high κ gate dielectric stacks. Experimental and modeling studies for these threshold voltage instabilities are reviewed. copyright The Electrochemical Society.