Extraction of additional interfacial states of silicon nanowire field-effect transistors

摘要

Interfacial states of silicon nanowire field-effect transistors with rectangular-like cross-sections (wire height of 10 nm and widths of 9 and 18 nm) have been evaluated from the transfer characteristics in the subthreshold region measured at cryogenic temperatures, where kinks in the drain current becomes prominent. It is found that the kinks can be well-explained assuming local interfacial states near the conduction band (Ec). The main extracted local states have been shown to exist at 10 and 31 meV below E_c with the densities of 1.3 ×10~(13) cm~2/eV and 5.4 × 10~(12) cm~(-2)/eV, respectively. By comparing two field-effect transistors with different wire widths, the former states can be assigned to the states located at the corner and the side surface of the wire, and the latter to the top and the bottom surfaces.