Fig. 4

Dominance of scattering mechanisms over hole mobility. Degradation of the hole mobility in sub-10-nm channels turns out to be dominated by the surface roughness scattering (SRS). In 10 nm × 10 nm channels, the dominance of SRS in determination of the mobility becomes larger than 50 % exceeding that of the phonon scattering (PH) when channels are strongly inverted with a line density of carriers (λ(ρ))>∼10⁶ cm⁻¹. The dominance of SRS generally increases as channels become narrower, and the increase becomes more rapid in [110] channels. Consequently, in [110] channels, SRS dominates PH regardless of carrier densities at cross-sections ≤ 8 nm × 8 nm, while the same pattern is observed in [100] channels at cross-sections ≤ 5 nm × 5 nm