富硅氮化硅薄膜的制备及其光学带隙研究

Preparation and Optics Band Gap Characterization of Si-rich Silicon Nitride Thin Films

采用双极脉冲磁控反应溅射法在不同参数条件下制备了一系列氮化硅薄膜。利用数字式显微镜和紫外-可见光光谱仪研究了沉积薄膜的表面形貌及其光学带隙,利用共焦显微拉曼光谱仪比较了硅衬底、氮化硅薄膜退火前后的拉曼光谱。结果表明,氮气流量对薄膜的光学带隙影响较大,制备的薄膜主要为富硅氮化硅薄膜。原沉积薄膜的拉曼光谱存在明显的非晶硅和单晶硅峰,退火处理后非晶硅峰减弱或消失,表明薄膜出现明显的结晶化;单晶硅峰出现频移现象,表明薄膜中出现硅纳米颗粒,平均尺寸约为6.6 nm。

Silicon nitride （ SiNx ） thin films were deposited by bipolar pulse reactive magnetron sputtering technique with different experiment parameters. Digital microscope and UV-Vis spectroscopy were used to study the surface structure and optics band gaps of the films. Confocal microscopy Raman spectrometer was used to study the Raman spectra of the silicon suhstrate, the as-deposited films and the annealed films. It is found that the films are Sirich SiNx films and the most important influence factor on optics band gaps is the flow of nitrogen. The results of the Raman investigation show that the amorphous and crystalline silicon peaks appear in the film. After annealing, the amor- phous silicon peaks were weakened or disappeared. It indicates that the crystallization appears in the film apparently. The shift of crystalline silicon peaks shows that silicon nanocrystals appear in the film, and the average size is about 6.6 nm.