イオン化蒸着法によるダイヤモンド状炭素の成膜と集束イオンビームによるデバイスの作製

抄録

In this study, we have attempted to synthesize the Gallium-implanted diamond-like carbon (DLC) film for new functional devices as substituting Si based materials. Intrinsic-DLC films (energy gap: 1.45eV) were deposited by the ionization vapor method with applying the negative pulsed-bias voltage (frequency: 2kHz, duty ratio: 30%, peak voltage: 500V) to SiO₂ substrates. Gallium (Ga) atoms were implanted to i-DLC films as accepters utilizing by focused ion beam irradiation system. The Raman scattering spectra of i-DLC and Ga-DLC films showed typical DLC characteristics which consisted of I(D) and I(G) peaks. In order to evaluate working function of the Ga-DLC film, several electrode materials (Au, Pt, Cu, Al and Sn) were deposited on the films. Current-voltage characteristics of Au and Pt electrodes on Ga-DLC films showed Ohmic-contacts, and Cu, Al and Sn electrodes were Schottoky-contacts. These results suggested that a work function of the Ga-DLC film was in the range of 4.47eV to 4.58eV. To apply these contact properties to DLC semiconductive devices, we produced the DLC Schottoky-diode using Al and Pt electrodes deposited on the Ga-DLC film. A current-voltage characteristic of DLC Schottoly-diode showed diode property which amount of a forward voltage and a backward voltage were 7.0V and 17.0V respectively. The ideality factor n of produced diode was 11.3.