Impact of Metal Wet Etch on Device Characteristics and Reliability for Dual Metal Gate/High-k CMOS

This paper presents a comparative study of the impact of metal wet etch on carrier mobility and metal gate/high-k device characteristics and reliability. A TaSiN metal wet etch process that is highly selective to the underlying HfO
₂
dielectric has been developed. While the metal wet etch slightly degraded the electron mobility, it did not affect hole mobility. It did not show any effect on fast transient charge trapping, and, in fact, improved negative bias temperature instability (NBTI) and positive bias temperature instability (PBTI)