Deposition of microcrystalline silicon-carbon films by PECVD

Hydrogenated microcrystalline silicon-carbon (muc-Si(1-x)C(x):H) films have been grown in a plasma enhanced chemical vapour deposition system from silane-methane gas mixtures highly diluted in hydrogen. The effects of RE power, hydrogen dilution and substrate temperature on muc-Si(1-x)C(x):H properties have been investigated. The increase in RE power reduces the average crystallite size of Si, enhances the carbon fraction, C/(C + Si), and causes a decrease in dark conductivity. The hydrogen dilution ratio R, [H(2)]/([SiH(4)]+[CH(4)]), strongly affects the structure of the films. For R<100 the hydrogenated silicon-carbon films are amorphous, while for Rgreater than or equal to100 the alloys are microcrystalline. Under suitable deposition conditions muc-Si(1-x)C(x):H films can be grown in the substrate temperature range of 200-400 degreesC.