Fabrication of Large-Area Silicon Spherical Microlens Arrays by Thermal Reflow and ICP Etching
Yu Wu,
Xianshan Dong,
Xuefang Wang,
Junfeng Xiao,
Quanquan Sun,
Lifeng Shen,
Jie Lan,
Zhenfeng Shen,
Jianfeng Xu,
Yuqingyun Du
Affiliations
Yu Wu
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Xianshan Dong
Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory, Guangzhou 511370, China
Xuefang Wang
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Junfeng Xiao
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Quanquan Sun
Shanghai Aerospace Control Technology Institute, Shanghai 201109, China
Lifeng Shen
Shanghai Aerospace Control Technology Institute, Shanghai 201109, China
Jie Lan
Shanghai Aerospace Control Technology Institute, Shanghai 201109, China
Zhenfeng Shen
Shanghai Aerospace Control Technology Institute, Shanghai 201109, China
Jianfeng Xu
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Yuqingyun Du
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
In this paper, we proposed an efficient and high-precision process for fabricating large-area microlens arrays using thermal reflow combined with ICP etching. When the temperature rises above the glass transition temperature, the polymer cylinder will reflow into a smooth hemisphere due to the surface tension effect. The dimensional differences generated after reflow can be corrected using etching selectivity in the following ICP etching process, which transfers the microstructure on the photoresist to the substrate. The volume variation before and after reflow, as well as the effect of etching selectivity using process parameters, such as RF power and gas flow, were explored. Due to the surface tension effect and the simultaneous molding of all microlens units, machining a 3.84 × 3.84 mm2 silicon microlens array required only 3 min of reflow and 15 min of ICP etching with an extremely low average surface roughness Sa of 1.2 nm.
