Deposition of nanocrystalline SiC films using helicon wave plasma enhanced chemical vapor deposition

Abstract

Hydrogenated nanocrystalline SiC films have been deposited by using helicon wave plasma enhanced chemical vapor deposition (HW-PECVD) in H 2 , SiH 4 and CH 4 gas mixtures at different RF powers. Their structural and optical properties have been investigated by Fourier transform infrared absorption (FTIR), atomic force microscopy (AFM) and ultraviolet-visible (UV-VIS) transmission spectra. The results indicate that RF power has an important influence on properties of the deposited films. It is found that in a 300 o C low substrate temperature, only amorphous SiC can be deposited at the radio frequency (RF) power of lower than 400 W, while nanocrystalline SiC can be grown at the RF power of equal to or higher than 400 W. The analyses show that the high plasma density of helicon wave plasma source and the high hydrogen dilution condition are two key factors for depositing nanocrystalline SiC films at a low temperature.