采用时域有限差分(FDTD)法对中红外波段(3~5 μm)硅基底的圆锥形仿生蛾眼微纳结构进行了仿真模拟。通过对微纳结构占空比、周期和刻蚀深度等参数的分析, 获得了具有良好抗反射特性的微纳结构的组合参数。为了更好地指导实际加工, 对不同参数进行了公差分析。制作中应用二元曝光技术和反应离子刻蚀技术在硅基底上制备得到该圆锥形仿生蛾眼微结构, 并且使用热场发射扫描电子显微镜得到了该微结构的表面形貌图。采用红外成像光谱仪对单面微结构的测试结果表明, 仿生蛾眼微结构的反射率在中红外波段约为5%。

The finite difference time domain(FDTD) method was adopted for simulation of the conical bionic moth-eye micro-nano structure on silicon substrate in middle infrared band(3-5 μm). A parameter-optimized combination of the micro-nano structure which was of low reflection was obtained by analyzing the parameters of the micro-nano structure, such as fill factor, period and etching depth. In order to guide the actual processing better, tolerance analysis of different parameters was carried out. The binary exposure and reactive ion etching technology were applied to fabricate the conical bionic moth-eye micro structure on silicon substrate in processing. The surface topography of the micro structure was acquired by thermal field emission scanning electron microscopy. The test of the silicon wafer with single-sided micro structure polishing by the infrared imaging spectrometer demonstrates that the reflectivity of the bionic moth-eye micro structure vibrates approximately 5% in middle infrared band.