等离子体增强化学气相沉积法制备氢化硅膜的自晶化倾向性

Self-crystallization of Hydrogenated Silicon Film in Plasma Enhanced Chemical Vapor Deposition

为了探寻生长过程中硅膜的自晶化沉积,采用等离子体增强化学气相沉积(PECVD)法沉积了氢化硅薄膜,系统研究了不同沉积阶段所得硅膜微观结构的迁变规律。结果表明,硅膜的显微结构依赖于沉积时间,当沉积时间仅为30min时,所得硅膜的结构为非晶;而当沉积时间延至60min时,硅膜形成微晶颗粒;此后随着沉积时间的增加,晶化程度提高,且非晶区域面积相应减小。另外,硅膜的沉积速率也随沉积时间的增加而增加。在硅膜沉积过程中,随时间不断变化的界面状态可能为其自晶化的主要原因。

In order to investigate the self-crystallized deposition of silicon film in a deposition growth process,hydrogenated silicon thin films were deposited viaaplasma enhanced chemical vapor deposition(PECVD)technique.The microstructure of silicon films obtained at different deposition durations was investigated.The results indicate that the microstructure of the films depends on the deposition duration.The film obtained at the deposition duration of 30 min is amorphous.When the deposition time is 60 min,the crystalline grains can appear in the film.The crystallinity and grain size increase and the amorphous degree in the film decreases when the deposition time increases.In addition,the deposition rate of the film also increases as the deposition time increases.In the deposition process,the surface state change of silicon film with the deposition time could be the major factor for the self-crystallization of silicon film.