Electron mobility in silicon and germanium inversion layers: The role of remote phonon scattering

We calculate the electron mobility in Si and Ge inversion layers in single-gate metal-oxide-semiconductor field effect transistors. Scattering with bulk phonons, surface roughness and remote phonons is included in the mobility calculations. Various high-κ dielectric materials are considered for both Si and Ge substrates. Overall, Ge outperforms Si, but in general Ge is more affected by the use of high-κ dielectrics. HfO₂ degrades the mobility substantially compared to SiO₂ for Si substrates and may prohibitively degrade performance. HfO₂ with Ge yields an improvement over Si with a mobility enhancement ≈3× at an electron sheet density of 1×10¹³ cm⁻³.