非晶硅薄膜连续激光晶化结构研究

Structure Study of Amorphous Silicon Thin Films Crystallized with the Continuous Laser

为了研究连续激光晶化的非晶硅薄膜的结构特性,采用等离子体增强化学气相沉积技术在玻璃衬底上沉积了非晶硅薄膜,用波长为532 nm的连续激光对非晶硅薄膜进行晶化,并采用喇曼光谱仪、傅里叶红外吸收光谱仪和原子力显微镜对激光晶化前后薄膜的结构和形貌进行表征。结果表明,固定激光照射时间为45 s、激光功率密度为1.914×105 W/cm2时,非晶硅薄膜开始晶化。当激光功率密度达到4.016×105 W/cm2时,薄膜晶化效果最佳。随着激光功率密度进一步增至4.872×105 W/cm2时,薄膜晶化效果变差。当固定激光功率密度保持4.016×105 W/cm2,激光照射时间为10 s时,非晶硅薄膜开始晶化,激光照射时间为45 s时晶化效果最佳。上述研究结果对采用连续激光晶化法制备多晶硅薄膜具有一定的指导意义。

In order to study the structure characteristics of amorphous silicon （a-Si） films crystalized by the continuous laser, the amorphous silicon thin films were deposited on the glass by the plasma enhanced chemical vapor deposition （PECVD） method. The crystallization of the films were carried out by 532 nm continuous laser, and the structure and morphology of the films before and after the crystallization were characterized by the Raman spectroscopy, Fourier infrared absorption spectroscopy and atomic force microscope. The results show that with the irradiation time fixed at 45 s, the amorphous silicon films are to be crystallized under the laser power density of 1. 914 ×10^5 W/cm2. The crystallization effect of films becomes the best with the laser power density up to 4. 016 × 10^5 W/cm2. With the further increase of the laser power density to 4. 872 ×10^5 W/cm2 , the crystallization effect becomes worse. While with the laser power density fixed at 4. 016 ×10^5 W/cm2 , when the irradiated time is 10 s, the amorphous silicon films become crystal, and when the irradiated time is 45 s, the crystallization effect become the best. The research results provide a reference for the preparation of the polycrystalline silicon thin films by the continuous laser crystallization method.