Remote surface roughness scattering in fully depleted silicon-on-insulator devices with high-κ/SiO_2 gate stacks

摘要

We investigate remote surface roughness (RSR) scattering by the SiO_2/HfO_2 interface in Fully Depleted Silicon-on-Insulator devices using Non-Equilibrium Green's Functions. We show that the RSR mobility is controlled by cross-correlations between the surface roughness profiles at the Si/ SiO_2 and SiO_2/HfO_2 interfaces. Therefore, surface roughness and remote surface roughness cannot be modeled as two independent mechanisms. RSR tends to enhance the total mobility when the Si/ SiO_2 interface and SiO_2 thickness profiles are correlated, and to decrease the total mobility when they are anti-correlated. We discuss the implications for the high-k/Metal gate technologies.