Growth of nanocrystalline silicon carbide thin films by plasma enhanced chemical vapor deposition

Nanocrystalline silicon carbide thin films have been deposited by plasma enhanced chemical vapor deposition (PECVD) using SiH4, CH4, and H2 gases. The effects of gas mixing ratio (CH4/SiH4), deposition temperature, and RF power on the film properties have been studied. The growth rate, refractive index, and the optical energy gap depends critically on the growth conditions. The dependence of the growth rate on the gas flow ratio is quite different from the results obtained for the growth using C2H2 gas instead of CH4. As the deposition temperature is increased from 300 .deg. C to 600 .deg. C, hydrogen and carbon content in the film decreases and as a result the optical gap decreases. At the deposition temperature of 600 .deg. C and RF power of 150 W, the film structure si nanocrystalline, As the result of the nanocrystallization the dark conductivity is greatly improved. The nanocrystalline silicon carbide thin films may be used for large area optoelectronic devices such as solar cells and thin film electroluminescence devices