Photo-Catalytic and Photo-Conductive Properties of SiO_2/TiO_2 Multilayer Film Prepared by Vacuum-Deposition Method(<Special Issue>Ceramics Integration)

Amorphous carbon thin films containing sulfur were synthesized from thiophene (C_4H_4S) by the r.f. (13.56 MHz) plasma CVD. The r.f. power was applied intermittently to control the deposition temperature (T_d). While maintaining a constant r.f. power (200 W) and reactive pressure (13.3 Pa), we investigated the effect of T_d on the film chemical structures and properties: specifically microroughness, density, microhardness and internal stress. The deposition rate and microroughness of the films decreased with increasing T_d, while the film density, microhardness and internal stress increased with increasing T_d. X-ray photoelectron spectroscopic (XPS) analysis indicated that S/C ratio of the films remained constant and has no connection with T_d. XPS and Raman spectroscopic analyses showed that the films were composed of two kinds of microdomains with sp^3 and sp^2 bonds similar to the diamond-like carbon (DLC) film. Sulfur incorporation into the film significantly reduced the internal stress.