Hydrogenated nanocrystalline silicon thin film prepared by RF-PECVD at high pressure

摘要

The deposition of hydrogenated nanocrystalline silicon (nc-Si:H) on float glass substrate at a relative high working pressure (100 Pa-500 Pa) is performed by using a conventional Radio Frequency Plasma Enhanced Chemical Vapor Deposition (RF-PECVD). Film characterizations were performed by X-ray diffraction (XRD), Raman spectrum and Field emission electron microscopy. The crystalline volume fraction was determined from Raman spectra. Correlation between the crystallinity and deposition parameters, such as working pressure, flow rate ratio of H2/SiH4, and RF power was studied. It was found that deposition at a relative high pressure (500 Pa) and with hydrogen dilution ratio 300-500 led to higher crystallinity of the films. The high deposition pressure also resulted in a higher deposition rate.