Influences of Remote Coulomb and Interface-Roughness Scatterings on Electron Mobility of InGaAs nMOSFET with High-k Stacked Gate Dielectric

A physics-based electron-mobility model including remote Coulomb scattering by fixed charge in high-k dielectric and remote interface-roughness scattering originated from the fluctuation of high-k/interlayer interface is established for InGaAs MOSFET, and the validity of the model is confirmed by good agreement between simulated results and experimental data. Effects of structural and physical parameters of the devices on the electron mobility are analyzed using the model, and the results show that smoother high-k/interlayer interface, reasonably high permittivities for the interlayer and high-k dielectric, and less fixed charge in the high-k dielectric are desired to enhance the electron mobility and simultaneously keep further scaling of equivalent oxide thickness.