非晶氮氧化硅薄膜中新发光缺陷态的研究

Investigation on New Luminescent Defect State in Amorphous Silicon Oxynitride Films

利用等离子体增强化学气相淀积（PECVD）方法在室温下制备出非晶氮氧化硅（a-SiNxOy）薄膜。通过调节薄膜中的Si/N比例,可使其光致发光峰位在450-600nm的较宽波长范围内连续可调。对比a-SiNx薄膜和aSiNxOy薄膜的发光特性,发现此薄膜发光来源于由氧引入的新发光缺陷态。由光吸收谱的测量结果可以推断出此发光缺陷态在光吸收边之下约0.65eV处的禁带中。并且,通过傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）测量,证实了这种新发光缺陷态与薄膜中存在的O-Si-N键合结构有关。

Amorphous silicon oxynitride （a-SiNxOy） films were prepared at room temperature by plasma enhanced chemical vapor deposition （PECVD） techniques. By controlling the Si/N ratio, photoluminescence （PL） from a-SiNxOy films can be tuned in a wide range from 450 nm to 600 nm continuously. According to the comparative study on luminescent characteristics between a-SiNxOy and a-SiNx films, the origin of light emission from a-SiNxOy film has been found to be from a new luminescent defect state induced by the element of oxygen. From the results of the optical absorbance spectrum, the location of this new luminescent defect state was preliminarily determined to be about 0. 65 eV underneath the absorption edge. Moreover, based on the analysis of Fourier transform infrared （FTIR） spectra and X-ray photoelectron spectrum （XPS）, it was inferred that this new luminescent defect state was most likely to be associated with O-Si-N bonding configuration.