电子束直写大深宽比Si_(3)N_(4)薄膜支撑的光栅X射线准直器  

Grating X-ray collimator supported by Si_(3)N_(4) membrane with large aspect ratio written directly by electron beam

作　　者：李艺杰 肖君 陈宜方 童徐杰 穆成阳 LI Yijie;XIAO Jun;CHEN Yifang;TONG Xujie;MU Chengyang(Nanolithography and Application Research Group,School of Information Science and Technology,Fudan University,Shanghai 200433,China)

机构地区：[1]复旦大学信息科学与工程学院纳米光刻与应用科研组,上海200433

出　　处：《光学精密工程》2022年第10期1181-1188,共8页Optics and Precision Engineering

基　　金：上海STCSM项目(No.19142202700);国家自然科学基金项目(No.61927820)。

摘　　要：为了开发新的X射线准直器,利用电子束光刻(EBL)技术,结合电镀和湿法化学刻蚀工艺,在悬空的Si_(3)N_(4)隔膜上制作了大面积、高深宽比、微米周期的Au光栅。调整场拼接区域的曝光剂量解决了大面积的EBL光刻问题;用加强筋结构克服了制作高深宽比、高密度光刻胶模板时线条倒塌问题;通过在Si_(3)N_(4)隔膜下面保留很薄一层Si(25 nm厚)和改善显影工艺,克服了厚光刻胶在300 nm厚的Si_(3)N_(4)隔膜上显影时,光刻胶的断裂问题。实验结果显示,所制备的2μm周期、深宽比为5.5,面积为400μm×1000μm的Au光栅可以对光子能量为8 keV的X射线进行调制。所制备的Au光栅狭缝可以用作线平行X射线断层成像系统的探测器准直器件,或面平行X射线断层成像系统的光源准直器件,提高系统的成像速度。The objective of this study was to develop a new X-ray collimator.Electron beam lithography(EBL)technology was coupled with electroplating and wet chemical etching technology to fabricate gold micron gratings involving a large area and high aspect ratio on a suspended silicon nitride membrane.The exposure dose in the field splicing area was adjusted to solve the large area EBL problem.The grating line collapse in high-aspect ratio and high-density photoresist templates was overcome by using a reinforced structure.The thick photoresist spin-coated fracture on the 300-nm Si_(3)N_(4) membrane was prevented by keeping an extremely thin layer of silicon(25 nm thick)under the thin Si_(3)N_(4) membrane;therefore,im⁃proving the development process.The results demonstrated that the gold gratings with a 2-μm period,5.5 aspect ratio,and 400-μm by 1000-μm area can modulate the 8-keV energy X-rays.The fabricated gold gratings can be used as detector collimators in line-parallel X-ray tomography systems or as source collimators in area-parallel X-ray tomography systems to improve the imaging speed.

关 键 词：X射线准直器 Au光栅 电子束光刻 大深宽比 金电镀 

分 类 号：O436.[机械工程—光学工程]