飞秒激光多光束干涉光刻硅表面减反微结构20121211讲解.doc

飞秒激光多光束干涉光刻硅表面减反微结构 贺锋涛1周强1,2杨文正2龙学文2白晶2程光华*,2 ( 1 西安邮电大学电子工程学院，陕西 西安710121) ( 2 中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室，陕西 西安710119) 摘要 本文利用空间光调制器实现飞秒激光多光束干涉，形成了分布均匀，周期可控的空间点阵，利用聚焦的空间点阵在单晶硅表面烧蚀得到规则分布的凹坑状结构，并通过改变附加给空间光调制器的相位实现了对微结构分布特征及间距的控制。扫描电子显微镜(SEM)和分光光度计分别对结构的形貌特征和光学特性进行了测量。结果表明：采用底角为2o的四棱锥镜相位形成四光束干涉，通过10×物镜聚焦，在激光功率25 mW，曝光时间30 s时，可以形成间距约为3.3 μm的密排凹坑微结构；所形成的凹坑结构具有良好的减反效果，在1.2 μm-2 μm波段的透过率相对抛光硅平均提高了11.5%。 关键词 飞秒激光；空间光调制器；多光束干涉；单晶硅；减反微结构 中图分类号TN249；TN25 文献标识码A Femtosecond Laser Multi-beam Interference Lithography Anti-reflective Microstructure on Silicon Surface Fengtao He1 Qiang Zhou1，2 Wenzheng Yang2 Xuewen Long2 Jing Bai2 Guanghua Cheng*,2 (1 School of electron and engineer, Xi’an University of post telecommunication, Xi’an, Shaanxi 710049,China) (2 State Key Laboratory of Transient Optics and Photonics , Xi’an Institute of Optics and Precision Mechanics ,Chinese Academy of Sciences, Xi’an, Shaanxi 710119, China) Abstract Femtosecond laser multi-beam interference was realized by spatial light modulator (SLM), and the uniform distribution multi-spots with the controllable period were generated. By using these multi-spots, we fabricated the regular distribution concave structures on silicon surface, the distribution character and period of which was flexible controlled by shift the phase masks on SLM. The morphology and optical character of the microstructure was measured with scanning electron microscopy (SEM) and spectrophotometer. Experimental results show that the close-packed concave structure with the period of about 3.3 μm was fabricated on the silicon surface under a special parameter (10× focusing lens, laser power is 25 mW, exposing time is 30 s) by loading the phase of 4-facet pyramid lens with the base angle of 2o, and the formed structure shows good effect of anti-reflection, its transmission between 1.2 μm-2 μm enhance 11.5% compare with the polished silicon. Keywords Femtosecond laser；Spatial Light Modulator；ilicon；Anti-reflecti