多晶硅薄膜的铝诱导晶化法制备及其晶粒的择优取向特性

采用铝诱导非晶硅薄膜晶化技术制备了多晶硅薄膜,并研究了多晶硅的成核和生长特性。非晶硅薄膜采用等离子体增强化学气相沉积法制备,其表面沉积铝薄膜后经不同温度的氮氛围退火处理。结果表明,退火后的硅薄膜层与铝层发生置换,所生长的多晶硅颗粒的平均尺寸约为150nm。X射线衍射分析结果揭示,薄膜的晶向显著依赖于退火温度,较低温度下,铝诱导晶化速率较慢,薄膜的优化晶向与非晶硅薄膜中团簇的初始原子排列趋势紧密相关。而较高温度下,铝诱导晶化促使多晶硅(111)择优成核及随后的固相生长。

Aluminum-induced crystallization and grain preferred orientation characteristics of polysilicon thin films

Polycrystalline silicon(poly-Si) films were prepared from amorphous silicon(a-Si) films by aluminum-induced crystallization(AIC) method,and the nucleation and growth mechanism of the poly-Si films was studied.Amorphous silicon(a-Si) films were deposited on glass substrate by plasma enhanced chemical vapor deposition(PECVD),and then annealed in N2 atmosphere at different temperatures after aluminum(Al) layer was sputtered on a-Si film’s surface.The results show that the film sequence of Si layer and Al layer was exchanged after annealing,and the average grain size of the poly-Si was about 150 nm.X-ray diffraction results reveal that the film’s crystal orientation was particularly dependent on the annealing temperature.At the low temperature,the AIC speed was at a lower level,and the crystal orientation was related on atom arrangement trend of the a-Si film’s initial cluster.While at high temperature,the AIC played a key role on preferential nucleation of the poly-Si(111) and the subsequent solid phase growth process.