太赫兹金属双光栅超厚胶光刻工艺

Terahertz metal bi-grating fabrication using ultra-thick photoresist process

介绍了制备某太赫兹频率真空辐射光栅的超厚胶光刻工艺,针对工艺中的难点(大厚度和高深宽比)展开了深入分析。实验分析了基片处理、涂胶、前烘、曝光、后烘、显影等工艺过程对光刻的影响,通过优化工艺参数,解决了胶膜脱落、开裂,不同胶层间的结合,光栅沟槽间的光刻胶残留等问题,成功制备了厚度为700μm、深宽比为14的侧壁陡直、表面平整的双光栅结构胶膜。

As a key part of terahertz vacuum electronic device, metal grating can＇t be fabricated using traditional methods due to its tiny dimension. The photoetching process of metal bi-grating for radiation source at some terahertz band was presented. The influence of the procedure （including substrate preparation, spin-coating, pre-bake, exposure, post-bake and developing） on photoetching was analyzed experimentally. The problems such as film drop and crack, film＇s combination and the photoresist re- maining at gaps which were caused by thick film and high aspect ratio, were solved by the optimizing the process parameters. Fi- nally, a good film microstructure with steep side wall and smooth surface was achieved, with a thickness of 700/~m and an aspect ratio of 14. The work presented in this paper provides a technological guide to the similarly related project.