MEMS芯片正面结构释放时的保护  

Protection of the Pad and the Structures on Chip During Front-Side Wet Etching in MEMS Post-Processing

作　　者：张筱朵[1] 秦明[1] 

机构地区：[1]东南大学MEMS教育部重点实验室,南京210096

出　　处：《纳米技术与精密工程》2007年第4期335-338,共4页Nanotechnology and Precision Engineering

基　　金：国家自然科学基金资助项目(60476019)

摘　　要：提出了一种MEMS后处理中正面结构释放的正面保护方法.尤其是针对在CMOS-MEMS工艺制造单片集成传感器时,MEMS后处理工艺中正面体硅湿法腐蚀时对已制作完成的CMOS电路部分的表面铝引线、铝焊盘和钝化层下多晶层的保护方法.将一种新型的复合膜结构和优化后的TMAH腐蚀液相结合,可以保证长时间高温腐蚀时腐蚀液不会渗透到钝化层下,同时完成正面MEMS结构释放.具有与CMOS工艺兼容、工艺实现简单等特点.A novel method was proposed to protect the pad and the structures on chip during front-side wet etching in MEMS post-processing. Especially when sensors are fabricated with CMOS-MEMS technology, wet etching is usually used in the bulk-silicon etching while the pad and the structures of the fabricated CMOS circuit on chip need protection. The novel method of such protection combines finding new kind of protecting films with enhancing the ability of etching solutions. Firstly, by using TMAH solution, doped with silicon and a certain oxidizing agent properly, which hardly etches aluminum, the pad and the structures on chip can be protected to some extent. Secondly, a new composite film was designed to prevent solution from seeping and undermining polysilicon. Therefore with the novel method, the front-side micro-structures of the chips were successfully released without etching the pad. The novel method is compatible with CMOS technology, and can be easily realized.

关 键 词：MEMS后处理 正面腐蚀 正面保护 正面结构释放 

分 类 号：TN405[电子电信—微电子学与固体电子学]