488nm连续激光晶化本征非晶硅薄膜的喇曼光谱研究

Raman Spectroscopic Study of the Crystallization of Intrinsic Amorphous Silicon Thin Films with a 488 nm Continuous-wave Laser

利用等离子增强化学气相沉积系统制备了本征非晶硅薄膜,并选用488nm波长的连续激光进行晶化.采用喇曼测试技术对本征非晶硅薄膜在不同激光功率密度和扫描时间下的晶化状态进行了表征,并用514nm波长与488nm波长对样品的晶化效果进行了比较.测试结果显示:激光照射时间60s,激光功率密度在1.57×105 W/cm2时,能实现非晶硅向多晶硅的转变,在功率密度达到2.7 56×105 W/cm2时,有非晶开始向单晶转变,随着激光功率密度的继续增加,晶化结果仍为单晶;在功率密度为2.362×105 W/cm2下,60s照射时间晶化效果较好;在功率密度为2.756×105 W/cm2和照射时间为60s的条件下,用488nm波长比514nm波长的激光晶化本征非晶硅薄膜效果较好,并均为单晶态.

Intrinsic amorphous silicon thin films were prepared by plasma enhanced chemical vapor deposition method,and the crystallization of the films by 488 nm and 514 nm continuous-wave laser under different power densities and irradiation time were studied by micro-Raman spectroscopic measurements.It is shown that intrinsic amorphous silicon films are able to be crystallized within 60 s at laser power densities is above 1.575×105 W/cm2.When the power density reaches to 2.756×105 W/cm2,there is transformation from amorphous silicon to single-crystalline silicon.With the increase of the laser power density,it is still single-crystalline silicon.At the laser power density of 2.362 ×105 W/cm,60 s irradiation time crystallized the effect is better;and at the power density of 2.756×105 W/cm2,the effect of crystallization with 488 nm wavelength is better than that of with 514 nm in 60 s,and they are all single-crystalline silicon.