The effects of hydrogen plasma treatment on the plasma-enhanced chemical vapor deposition a-SiC : H films

Abstract

Amorphous hydrogenated silicon carbide (a-SiC:H) films were deposited using plasma-enhanced chemical vapor deposition (PECVD) process. Reducing silane flow rate increased the carbon concentration and optical band gap in the a-SiC:H films, but decreased the refractive index and dielectric constant. X-ray photoelectron spectroscopy (XPS) data revealed that the carbon concentration decreased as the methane flow rate increased, but the silicon concentration increased. Increasing the carbon concentration in the a-SiC:H film reduces the dielectric constant of the film. The carbon-rich a-Si0.24C0.68:H,, films treated with hydrogen plasma for various periods, were converted into films with more silicon content. Increasing the hydrogen plasma treatment period gradually roughened the surface even though the original film had a smooth surface, with a roughness <0.231 nm. The leakage current density of the hydrogen plasma treated a-Si0.24C0.68:1-1, films declined as the duration of the hydrogen plasma treatment period decreased.