Study on Fabrication of High Power Electrostatic Microactuators Using High Aspect Ratio X-ray Lithography

1.研究了紧凑同步辐射光源高纵横比x射线光刻工艺条件的优化。在1996年春天安装的最小的超导SR光源“AURORA”上设置了LIGA工艺的独家光束线。立命馆大学，并运作。建立了PMMA暴露和显影的工艺条件，并在暴露剂量为3 A min和32 A min的条件下制备了深度为200 mm和100 mm的PMMA微结构。制作了用于LIGA的x射线掩模。利用CAD系统设计掩模图案。x射线掩膜由2 μ m厚的SiC膜和5 μ m厚的Au吸收剂组成，以优化x射线曝光的对比度。利用x射线掩模，曝光并显影了宽2 μ m、高200 μ m、长径比为100的PMMA抗蚀剂结构，并利用Ni电铸制备了Ni微结构，设计、制作并评价了3.3 d大功率微致动器。微致动器的基本结构是由作为固定电极和活动电极的Ni微结构、Ni种子层、作为隔离层和牺牲层的SiO_2和Si衬底组成的。Ni组织的尺寸为高100 μ m，最小线宽2 μ m，最小间隙2 μ m，最大纵横比50 μ m。采用SR光源高宽高比x射线光刻和电铸相结合的LIGA工艺制备了梳状驱动静电微动器和静电微摆动电机。通过分别施加65V脉冲电压和125V-12相脉冲电压，确定梳状驱动静电微执行器和静电微摆动电机的运动状态。

1.Optimization of process conditions for high aspect ratio X-ray lithography (LIGA) using the compact synchrotron radiation (SR) light source has been investigated. An exclusive beam-line for LIGA process has been set-up on the smallest super conductive SR light source "AURORA", installed in 1996, spring. in Ritsumeikan Univ., and operated. Process conditions for exposure and development of PMMA, were founded, and PMMA microstructures of 200 mum-deep and 100 mum-deep were fabricated under exposing dosage of 3 A min and 32 A min.2.An X-ray mask for LIGA has been fabricated. Mask patterns were designed using a CAD system. The X-ray mask is consisted of 2 mum-thick SiC membrane and 5 mum-thick Au absorber in order to optimize contrast for X-ray exposure. Using the X-ray mask, PMMA resist structures with 2 mum-wide, 200 mum-high and aspect ratio of 100 were exposed and developed, and Ni microstructures were produced using Ni electroforming.3.3-D high power microactuators have been designed, fabricated and evaluated. The basic structure of microactuators is consisted of Ni microstructures as fixed electrodes and movable electrodes, a Ni seed layer, SiO_2 as an isolation layer arid a sacrificial layer, and Si substrate. Dimensions of Ni microstructures were height of 100 mum, minimum line width of 2 mum, minimum gap of 2 mum and maximum aspect ratio of 50. A comb-drive electrostatic microactuator and an electrostatic micro wabble motor were fabricated by LIGA process combined high aspect ratio X-ray lithography using SR light source and electroforming. The comb-drive electrostatic microactuator and electrostatic micro wabble motor were confirmed to move by applying 65V pulse voltage and 125V-12 phases pulse voltage, respectively.