紫外光刻-湿法刻蚀硅中阶梯光栅的研制  

Fabrication of Silicon Echelle Grating by Ultraviolet Lithography Combined with Wet Etching

作　　者：杨子江 潘俏 朱嘉诚 沈为民 Yang Zijiang;Pan Qiao;Zhu Jiacheng;Shen Weimin(Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province,Suzhou 215006,Jiangsu,China;Key Lab of Modern Optical Technologies of Education Ministry of China,Suzhou 215006,Jiangsu,China;School of Optoelectronic Science and Engineering,Soochow University,Suzhou 215006,Jiangsu,China)

机构地区：[1]江苏省先进光学制造技术重点实验室,江苏苏州215006 [2]教育部现代光学技术重点实验室,江苏苏州215006 [3]苏州大学光电科学与工程学院,江苏苏州215006

出　　处：《光学学报》2023年第13期1-10,共10页Acta Optica Sinica

基　　金：国家自然科学基金(62205229,62105230);中国博士后科学基金(2020M681700)。

摘　　要：湿法刻蚀技术作为中阶梯光栅的主要制备方法之一,具有制造成本低、周期短、杂光少、所制作光栅的闪耀角误差小等优点。为解决某高分辨率光谱仪在近红外波段(800~1100 nm)的分光需求,尝试选择70.52°槽顶角的湿法刻蚀硅中阶梯光栅来代替90°槽顶角的传统中阶梯光栅。依据(100)硅光栅的结构特点以及光学设计给出的光栅工作条件,利用有限元数值计算法求解电磁场分布,理论分析了硅中阶梯光栅在工作波段内多个级次的衍射特性。在此基础上,利用紫外光刻-湿法刻蚀技术,在单晶硅基底上制作了槽密度为42 lp/mm、闪耀角为54.74°、有效面积超过46 mm×28 mm的对称V形槽光栅,并根据制备实验结果分析讨论了工艺过程中硅光栅质量的重要影响因素。测试结果表明,该光栅在各工作级次对应闪耀波长下的衍射效率均在45%~55%范围内,满足指标要求。Objective The echelle grating,with a high spectral resolution and large angular dispersion,is the core component of high-resolution spectrometers.The main preparation method of echelle grating is mechanical holographic lithography combined with ion beam etching and wet etching.The gratings fabricated by the traditional mechanical method have a high cost,a rough groove surface,and a Roland ghost.The holographic lithography combined with ion beam etching can hardly fabricate echelle gratings and has a long production cycle.The wet etching method is a good supplement to the preparation method,and ultraviolet(UV)lithography combined with wet etching has the advantages of few equipment requirements,a low preparation cost,a short preparation period,little stray light,an accurate blazed angle,etc.At present,domestic research on echelle gratings is mostly on the design and application of instruments with echelle gratings.The research on the manufacturing technology of echelle gratings,especially wet etching technology,starts late and has few reports.The diffraction efficiency and groove quality of most silicon-based echelle gratings reported in the existing papers are low,and thus,they cannot be applied in practice.To meet the spectral requirement of the high-resolution spectrometer in nearinfrared(NIR)bands(800-1100 nm),this paper chooses the wet-etched silicon echelle grating with an apex angle of 70.52°instead of the traditional echelle grating with an apex angle of 90°.In addition,the factors affecting the quality of the wetetched grating are analyzed.It is necessary to develop an echelle grating that can meet the requirement of instruments and has high groove quality and practical application capability.Methods According to the crystal characteristics of(100)silicon and grating working conditions given by optical design,the electromagnetic field distribution is solved by the finite-element numerical calculation method,and the diffraction efficiency of working orders is obtained.On this basis,the diffraction charac

关 键 词：光栅 中阶梯光栅 硅光栅 紫外光刻 湿法刻蚀 衍射效率 

分 类 号：TN214[电子电信—物理电子学] TN305.7