多光束纳秒紫外激光制作硅表面微结构

使用波长351 nm的半导体泵浦全固态脉冲激光器作为光源,经过位相光栅分束,形成干涉光场,在硅表面直接刻蚀微结构,制作了周期为0.55 μm,槽深可达55 nm的一维微光栅和周期为1.25 μm,刻蚀深度45 nm的正交微光栅结构.给出了微光栅形貌结构的扫描电子显微镜和原子力显微镜的测量结果.正交微光栅的一级衍射效率在1.8%～6.3%之间.该研究是改变硅表面微结构,优化硅材料特性的一种新方法,并扩展了大功率激光刻蚀在表面微加工领域的应用.

Fabricating Microstructure on the Surface of Silicon Using Multiple Beam of Nanosecond UV Laser

The micro-grating structures (MGSs) were fabricated by ablation directly on the silicon wafers using the interference laser of 351 nm diode-pumped solid-state laser (DPSSL) pulses. The measuring result of atomic force microscopy (AFM) and scanning electron microscope (SEM) were carried out. The depth of grooves could be 55 nm for one-dimensional micro-grating and 45 nm for cross MSGs, while the period of MGSs were 1. 25 μm and 0. 55 μm, respectively. And the first-order diffraction efficiency of the two-dimensional cross MSGs varies between 1. 8% and 6. 3%. This research is about introducing a novel method for changing the microstructure on the surface of silicon and optimizing the photoelectric peculiarity of it. And it extends the application of high power laser ablation in the field of micromachining as well.