基于多掩膜光刻工艺的MEMS体硅加工

MEMS Bulk Silicon Process Based On Multi-mask Photolithograph

本文提出了一种新颖的MEMS多掩膜工艺,实现了带有大台阶和大深宽比窄槽的衬底上的体硅精细加工。通过薄胶多次光刻在衬底上制作出氧化硅(SiO2)、氮化硅(Si3N4)、光刻胶(photo-resist,PR)等材料的多层掩膜图形,每层掩膜可以进行一次衬底刻蚀或腐蚀,刻蚀或腐蚀完毕后去除该层掩膜。该工艺解决了MEMS工艺中的深坑涂胶和光刻问题,结合深反应离子刻蚀(Deep Re-active Ion Etching,DR IE)、湿法腐蚀等工艺可以用于多级台阶、深坑底部精细结构、微结构释放等MEMS工艺。

In this paper,a novel MEMS multi-mask process for precision bulk silicon process with big steps and big aspect trench was proposed.After repeated thin photoresist（PR） photolithograph on substrate,multi-mask layer included SiO2/ Si3N4/PR with different graph were created.Each layer can be used for substrate etching and can be removed after etching.This process solved the problem of PR coating and photolithograph on substrate with deep pits and trenches in MEMS device fabrication.Combined with Deep Reactive Ion Etching（DRIE）,wet etching and other process,it can be applied in some MEMS process such as multi-step,small structure in deep pits,micro-strcuture releasing.