基于SU—8光刻胶的微光学元件制备工艺研究

Research on fabrication process of micro-optical components based on SU—8 photoresist

面向光学传感器微型化需求,针对传统光学元件体积偏大和不易集成等问题,探索了使用SU—8光刻胶制备聚合物微型透镜等光学元件的全套制备工艺。对工艺中存在的问题进行逐一解决,创新性地使用长时间45℃低温前烘技术解决了厚SU—8结构制备过程中易脱落和侧壁均匀程度差的问题。并根据光刻胶使用场景的不同,给出了在平面结构上的甩胶和沟槽结构中的喷胶工艺参数及方法,为光学元件微型化提供了解决方案。经过显微镜和台阶仪测试,平面结构上SU—8光刻胶最大制备厚度可达180μm,沟槽结构中使用喷胶工艺制备厚度可达200μm以上,结构厚180μm时,侧壁顶部与底部最大线宽差小于2μm,使用光学平台和激光器对微光学元件进行了简单测试,均符合设计预期。

In view of the miniaturization requirements of optical sensors, aining at the problems that the complete preparation process is explored using SU—8 photoresist to prepare optical components such as polymer micro-lenses in view of large size and difficult integration of traditional optical components.Solve the problems in process one by one, innovatively use long time 45 ℃ low temperature pre-baking technology to solve the problems of easy falling off and poor sidewall uniformity during the preparation of thick SU—8 structure.And according to the different use scenarios of photoresist, the process parameters and methods of the photoresist spinning on the planar structure are given and the photoresist spraying in groove structure are given and a solution for the miniaturization of optical components is provided.Tested by microscope and step meter, the maximum preparation thickness of SU—8 photoresist on planar structure can reach 180 μm, and it can be more than 200 μm by spraying process in groove structure.When the thickness of the structure is 180 μm, the maximum line width difference between top and bottom of sidewall is less than 2 μm, and the micro-optical components are simply tested using an optical platform and a laser, which are all in accord with the design expectations.