Trapping mechanism on oxygen-terminated diamond surfaces

Mechanisms of the hole trap and detrap on the oxygen-terminated diamond surfaces measured by diamond in-plane-gated field-effect transistors (FETs) have been investigated. Reproducible hysteresis characteristics are observed in the IDS-VGS characteristics of the diamond in-plane-gated FETs. They are caused by carrier trapping in the oxidized diamond surface and detrapping under a light irradiation, the wavelength of which affects the hysteresis width. Carriers are trapped by continuous surface states deeper than 2.0eV from the valence band maximum in the oxidized diamond surface, where the position of the highest occupied level (Fermi level) is located between 2.0 and 2.4eV.