Deposition of microcrystalline silicon–carbon alloys in low power regime

Hydrogenated silicon–carbon films have been grown in a PECVD system over a wide range of RF power by silane+methane gas mixtures highly diluted in hydrogen. The effect of RF power on the properties of the deposited films has been explored. The RF power appears to control the transition from microcrystalline to amorphous phase. The increase in RF power modifies the hydrogenated microcrystalline silicon–carbon (μc-Si1 − xCx:H) growth from columnar silicon crystals to crystallites uniformly dispersed in an amorphous matrix and enhances the carbon content in the films increasing their energy gap. μc-Si1 − xCx:H samples with higher dark conductivity are deposited at lower RF power and those having carbon content x⩾0.074 exhibit photoluminescence in the visible region at room temperature.