Impact of oxidation induced atomic disorder in narrow Si nanowires on transistor performance

Theoretical investigations are presented for the effects of atomic disorder, which is always present in Si/SiO₂ interface, on the device performance for the first time. We show that the drain current is significantly reduced by a factor of 2 due to random configuration of Si atoms near the Si/SiO₂ interfaces in a nanowire with 2.7 nm width. NFET is more easily affected by the disorder because of localized states near the conduction-band bottom. Suppression of the atomic disorder is a key to obtain good performance of nanowire FETs.