Wu Yu, Dong Xianshan, Wang Xuefang, Xiao Junfeng, Sun Quanquan, Shen Lifeng, Lan Jie, Shen Zhenfeng, Xu Jianfeng, Du Yuqingyun
State Key Laboratory of Intelligent Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory, Guangzhou 511370, China.
Micromachines (Basel). 2024 Mar 29;15(4):460. doi: 10.3390/mi15040460.
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 mm 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.
在本文中，我们提出了一种结合热回流和电感耦合等离子体（ICP）蚀刻来制造大面积微透镜阵列的高效高精度工艺。当温度升高到玻璃化转变温度以上时，聚合物圆柱体会由于表面张力效应回流成光滑的半球体。回流后产生的尺寸差异可以在接下来的ICP蚀刻工艺中利用蚀刻选择性进行校正，该工艺将光刻胶上的微观结构转移到衬底上。研究了回流前后的体积变化以及使用诸如射频功率和气体流量等工艺参数的蚀刻选择性的影响。由于表面张力效应以及所有微透镜单元同时成型，加工一个3.84×3.84毫米的硅微透镜阵列仅需3分钟的回流时间和15分钟的ICP蚀刻时间，平均表面粗糙度Sa极低，仅为1.2纳米。
