Tetrahedral carbon film by hydrogen gas reactive rf-sputtering of graphite onto low temperature substrate

Abstract

Hydrogenated amorphous carbon film with high ratio (more than 80 %) of sp 3 (single C-C) bond was for the first time deposited by means of hydrogen gas reactive rf-sputtering method from a graphite target onto low temperature (room temperature ∼ 150 °C) substrate. The optical gap was 1.4 ∼ 2.8 eV, which increased with the contents of hydrogen atoms in the film. The resistivity was ∼10 12 Ωcm. The content of hydrogen in the film was 0.8 ∼ 1.0 by H/C ratio which decreased with increasing rf-power or decreasing gas pressure. Microcrystalline diamond could be observed by TEM and electron diffraction pattern in the annealed film at 1000 °C in vacuum.