为进一步提高聚酰亚胺薄膜光学器件的表面质量, 提出了一种聚酰亚胺薄膜的反应离子刻蚀抛光方法, 对其抛光原理和抛光实验进行了研究。利用光刻胶流体的低表面张力及流动特性, 通过在聚酰亚胺薄膜表面涂覆光刻胶对其表面缺陷进行填补; 结合聚酰亚胺与光刻胶的反应离子高各向异性等比刻蚀工艺, 将光刻胶光滑平整表面高保真刻蚀转移至聚酰亚胺表面, 从而实现聚酰亚胺薄膜的反应离子刻蚀抛光。实验结果表明: PV、RMS分别为1.347 μm和340 nm的粗糙表面, 通过二次抛光其粗糙度可降低至75 nm和13 nm; PV、RMS分别为61 nm和8 nm的表面, 其粗糙度可降低至9 nm 和1 nm。该抛光方法能有效提高聚酰亚胺薄膜的表面光洁度, 可为以聚酰亚胺薄膜为代表的高分子柔性光学器件的精密加工提供新的工艺思路。

To improve the surface quality of polyimide (PI) optics, a polishing method for polyimide membranes based on Reactive Ion Etching (RIE) was proposed. The working principle and experimental research for the proposed method were discussed in this study. Owing to the low surface tension and mobility of the PR fluid, surface defects on the PI surface were required to be filled by a PR coating. In addition, owing to the highly anisotropic and identical RIE rates for PR and PI, the smooth PR surface could be precisely transferred onto the PI surface. The polishing of PI membranes then was realized. Experimental results indicate that for a surface roughness with PV of 1.347 μm and RMS of 340 nm, the respective values can be reduced to 75 nm and 13 nm after double polishing. Furthermore, for a surface roughness with PV of 61 nm and RMS of 8 nm, the values can be reduced to 9 nm and 1 nm, respectively. Hence, the proposed polishing method based on RIE can efficiently improve the surface finish of PI membranes, which in turn can provide novel schemes for precision manufacturing of PI-based flexible polymer devices.