沉积温度对PECVD法制备SiN_x薄膜光致发光峰的影响

Effect of Temperature on Photoluminescence of SiN_x Films Deposited by Plasma Enhanced Chemical Vapor Deposition

SiNx薄膜已经被广泛地应用于晶体硅太阳能电池表面作为减反和钝化膜,所以对SiNx薄膜的光学性质研究很有必要。本文采用等离子体增强化学气相沉积(PECVD)技术,在p型单晶硅(111)衬底上成功地制备了不同温度条件下的SiNx薄膜。室温下,在352 nm光源激发下,每个样品有2个发光位置,所有样品总共观测到了4处不同的发光峰位:390、471、545、570 nm,并且发现温度对390 nm处的发光峰位置无影响。由于杂质的引入在带间形成了局域化的缺陷能级,缺陷态能级和导带以及价带之间的跃迁是其主要的跃迁机制。因此,可以通过控制薄膜的生长条件来控制各个缺陷态密度,从而可以实现氮化硅薄膜在可见光范围内的可控发光。

SiNx film has widely been used in the surface of crystalline silicon solar cells as antireflection and passivation film. There- fore, research on the optical properties of SiNx film is very important. In this paper, under different growth temperature, silicon nitride （SiNX） thin films were deposited successfully on Si （ 111 ） substrates by plasma enhanced chemical vapor deposition （PECVD）. Pho- toluminescence（PL） spectra was measured at room temperature under 352 nm light. We observed 390 nm, 471 nm, 545 nm and 570 nm peaks and found that temperature had no effect on the peak position of 390 nm light. The impurities existed in the film possible formed localized defect energy levels in the band gap and the transition between the conduction band and the valence band became the main transition. Therefore, we can control the film growth conditions to control the density of each defects state level, which can be a- chieved to control the silicon nitride film photoluminescence in the visible light range.