Dominant Device Instability Mechanism in Scaled Metal–Oxide–Semiconductor Field-Effect Transistors with Hafnium Oxide Dielectric

Abstract

The negative-bias temperature instability (NBTI) and positive-bias temperature instability (PBTI) of metal–oxide–semiconductor field-effect transistors (MOSFETs) with high dielectric constant (k) gate dielectrics have been studied by varying the physical thickness of high-k dielectric. Both PBTI and NBTI were reduced with decrease in the high-k dielectric thickness, but NBTI reduction saturated in the thin high-k region. Since residual NBTI is sufficiently large to cause device instability, NBTI is still a dominant reliability concern in scaled MOSFETs.