Effect of gas temperature on the structural and optoelectronic properties of a-Si: H thin films deposited by PECVD

摘要

The effect of gas temperature (T_g) in the process of plasma-enhanced chemical vapor deposition (PECVD) on the structural and optoelectronic properties of the grown a-Si:H thin film has been examined using multiple characterization techniques. Gas temperature was confirmed to be an important parameter for the optimization of fabrication process and the improvement of structural and optoelectronic performances of the thin films. The structural properties of the thin films were examined using atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and electronic-spin resonance (ESR). Furthermore, the spectroscopic ellipsometry (SE), the optical transmission measurement in ultraviolet-visible region and the electrical measurement were used to investigate the optical and electrical properties of the thin films. It was found that the changes in T_g can modify the surface roughness, the amorphous network order, the hydrogen bonding modes and the density of the thin films, and eventually improve the optical and electrical properties.