聚甲基丙烯酸甲酯材质硬X射线组合Kinoform透镜的制作  

Fabrication of PMMA hard X-ray compound Kinoform lenses

作　　者：刘静[1] 伊福廷[1] 盛伟繁[1] 常广才[1] 张伟伟[1] LIU Jing;YI Fu-ting;HENG Wei-fan;CHANG Guang-cai;ZHANG Wei-wei(Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院高能物理研究所,北京100049

出　　处：《光学精密工程》2017年第11期2817-2822,共6页Optics and Precision Engineering

基　　金：国家自然科学基金青年基金资助项目(No.11605226;No.11305202)

摘　　要：为提高硬X射线聚焦元件的聚焦性能,利用LIGA(Lithographie,Galvanoformung,Abformung)技术,制备了深度为60μm的聚甲基丙烯酸甲酯(PMMA)材质硬X射线组合Kinoform透镜(CKL),并获得了良好的面形。制备的CKL以宽度为几个微米的细窄线条为主要结构,包括曲面和直角面形,线条最窄宽度为2μm。为保证CKL良好的曲面及直角结构,样品制备分为三部分:过渡掩模板的制备,LIGA掩模板的制备,以及最终样品的硬X射线曝光制备。在LIGA掩模板制备过程中,采用制备有纳米柱阵列的硅衬底有效解决了光刻胶脱胶的问题。在最终样品制备过程中,选用分子量较高的PMMA片作衬底,提高了PMMA刚度,有效缓解了细窄线条的倒塌黏连问题,保证了CKL的良好面形。在北京同步辐射光源(BSRF)成像站测试了CKL透镜的性能,结果显示其对于8keV的X射线,聚焦焦斑的半高全宽(FWHM)为440nm。To improve the focusing performance of hard X ray focusing elements,a hard X ray Compound Kinoform Lens(CKL)based on Polymethyl methacrylate(PMMA)with a depth of60μm is fabricated by LIGA(Lithographie,Galvanoformung,Abformung)technology,and its excellent morphology is obtained.The main structure of CKL is a narrow pattern with a few micron widths,including the curve and the rectangular surfaces,and the width of the narrowest pattern is only2μm.The fabrication of the CKL is divided into three parts to ensure its excellent morphology:the transitional mask preparation,LIGA mask preparation,and hard X ray exposure to get the finial samples.The nanopillar arrays on silicon substrate are used to solve the falling off problem of the photoresist during the LIGA mask preparation.Then the PMMA sample with a high molecular weight is selected as the substrate to improve the rigidity of the PMMA and to relieve the adhesion and collapse of the narrow pattern in the final sample preparation.The focusing performance of CKL is tested at X ray microscope beam line of Beijing Synchrotron Radiation Facility(BSRF).The experiment result for an8keV X ray at transmission shows its full width at half maximum(FWHM)peak size for focusing spot is440nm.

关 键 词：Kinofomi镜 X射线聚焦透镜 聚甲基丙烯酸甲酯(PMMA) IIGA技术 

分 类 号：O434.19[机械工程—光学工程] TN305.7[理学—光学]