Amorphous carbon films prepared by photo-CVD from acetylene

Abstract

An attempt has been made to deposit carbon films by photo-CVD, utilizing 185 nm light from a low-pressure mercury lamp to photolyze acetylene. The produced films are electrically resistive and optically transparent in the infrared, but they are soft. Comparing the present results with those obtained by plasma CVD, it becomes clear that the presence and acceleration of carbon ions play important roles in determining the physical properties, such as refractive index and hardness. Possibilities of producing hard amorphous or diamond-like carbon films using photoinduced effects are discussed.