Silicon Carbide, Silicon Carbonitride, and Silicon Oxycarbide Thin Films Formed by Remote Hydrogen Microwave Plasma CVD

Abstract

Background: Silicon-based thin films produced by remote microwave hydrogen plasma chemical vapor deposition (RP-CVD) from 1,1,4,4-tetramethyldisilaethylene, 1,1,3,3-tetramethyldisiloxane and 1,1,3,3- tetramethyldisilazane precursors are compared. The structure of these compounds differs in atomic composition of the central unit which links the two dimethylhydrosilane moieties. Objective: The effect of temperature on the kinetics of film growth rate induced by RP CVD process, chemical composition and structure as well as same characteristic parameters of resulting amorphous hydrogenated silicon carbide (a-SiC:H), silicon oxycarbide (a-SiOC:H), and silicon carbonitride (a-SiCN:H) films is discussed. Conclusion: It was found that RP CVD process is controlled by adsorption, in which there are two temperature ranges for the formation of the CVD layers. At low-temperature range soft polymer-like material is formed containing organic groups whereas at high-temperature range a transformation to high-density ceramic- like material occurs. Based upon the results of the studies, mechanisms of the initiation step, as well as growth and crosslinking steps in the film formation during RP CVD deposition are proposed. The films were also characterized in terms of their representative properties, such as density, refractive index and biocompatibility. Owing to the high density, defect-free surface and excellent optical parameters the films may be useful as coatings for optoelectronics applications and in medicine for steel implants. Keywords: Remote hydrogen plasma, CVD process, silicon-based precursor, silicon carbide film, silicon oxycarbide film, silicon carbonitride film, properties of thin films, biocompatibility.