Microstructure modified HfO/sub 2/ using Zr addition with Ta/sub x/ C/sub y/ gate for improved device performance and reliability

For the first time we report on the development of a novel hafnium zirconate (HfZrO x ) gate dielectric with a Ta x C y metal gate. Compared to HfO 2 , the new HfZrO x gate dielectric showed: (1) higher transconductance, (2) less charge trapping, (3) higher drive current, (4) lower NMOS V t , (5) reduced C-V hysteresis, (6) lower interface state density, (7) superior wafer-level thickness uniformity, and (8) longer PBTI lifetime. We attribute these improvements to a microstructure that is modified by addition of Zr to HfO 2