Influence of ignition condition on the growth of silicon thin films using plasma enhanced chemical vapour deposition

• Published in: Chinese physics B 2012, Vol.21 (1), p.314-319
• Main Author: 张海龙 刘丰珍 朱美芳 刘金龙
• Format: Article
• Language: English
• Subjects: Constants; Crystallinity; Ignition; Modulation; PECVD; Plasma (physics); Plasma enhanced chemical vapor deposition; Silicon; Silicon films; Thin films; 发射光谱; 微观结构; 生长方向; 硅薄膜; 等离子体增强化学气相沉积; 等离子体点火; 等离子点火
• ISSN: 1674-1056; 2058-3834; 1741-4199
• DOI: 10.1088/1674-1056/21/1/015203

The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition （PECVD） on the interfaces and the microstructures of hydrogenated microcrystalline Si （μc-Si：H） thin films are investigated. The plasma ignition condition is modified by varying the ratio of Sill4 to H2 （RH）. For plasma ignited with a constant gas ratio, the time-resolved optical emission spectroscopy presents a low value of the emission intensity ratio of Ha to Sill＊ （Iuα//SiH＊） at the initial stage, which leads to a thick amorphous incubation layer. For the ignition condition with a profiling RH, the higher IHα/ISiH＊ values are realized. By optimizing the RN modulation, a uniform crystallinity along the growth direction and a denser αc-Si：H film can be obtained. However, an excessively high IRα/ISIH＊ may damage the interface properties, which is indicated by capacitance-voltage （C-V） measurements. Well controlling the ignition condition is critically important for the applications of Si thin films.