KOH和TMAH基腐蚀液中凸角补偿结构的研究  

Study on the convex corner compensation structures in the etching solutions based on KOH and TMAH

作　　者：孙卫华 韩建强 徐宇翔 张智超 施阁 SUN Weihua;HAN Jianqiang;XU Yuxiang;ZHANG Zhichao;SHI Ge(College of Mechanical and Electrical Engineering,China Jiliang University,Hangzhou 310018,China)

机构地区：[1]中国计量大学机电工程学院,浙江杭州310018

出　　处：《中国计量大学学报》2023年第3期421-428,共8页Journal of China University of Metrology

基　　金：浙江省自然科学基金重点项目(No.LZ22F040002)。

摘　　要：目的:在湿法各向异性腐蚀MEMS微结构过程中常出现凸角底切现象,需要设计凸角补偿图案以获得完整的凸角结构。方法:实验测量了不同电阻率的硅片在KOH和TMAH基腐蚀液中的底切率和八种凸角补偿图案的补偿深度,并与理论预测的补偿深度进行对比。结果:1)在KOH腐蚀液中加入IPA,底切率没有变化;但在TMAH腐蚀液中加入IPA,底切率显著降低;2)对KOH、KOH-IPA和TMAH溶液,硼掺杂浓度对底切率的影响不大。但在TMAH-IPA腐蚀液中,随着硼掺杂浓度增加,底切率减小;3)使用叠加正方形、<100>补偿条、<100>宽梁和窄梁作为凸角补偿图案,可以获得完整的凸角;其它补偿图案在凸角处出现了削角,但占用的补偿面积较小。结论:完善了凸角补偿理论体系。Aims:Convex corner undercutting often occurs in the process of wet anisotropic etching of MEMS microstructures.It is necessary to design convex compensation patterns to obtain holonomic convex corners.Methods:The undercutting ratio of silicon wafers with different resistivity in etching solution based on KOH and TMAH and the compensation depth of eight convex corner compensation patterns were measured experimentally and compared with the theoretical predicted compensation depth.Results:1)Adding IPA to KOH etching solution did not change the undercutting ratio;but adding IPA to TMAH etching solution decreased the undercutting ratio significantly.2)The boron doping concentration had little effect on the undercutting ratio in KOH,KOH-IPA and TMAH solutions.However,the undercutting ratio decreased with increasing boron doping concentration in TMAH-IPA etching solution.3)Using the superimposed square,<100>compensation bar,<100>wide beam and narrow beam as convex corner compensation patterns can obtain holonomic convex corners.The convex corner undercutting appeared by using other compensation patterns;but they occupied less compensation area.Conclusions:The experiment improves the theoretical system of convex compensation.

关 键 词：各向异性湿法腐蚀 凸角补偿 加速度计 底切率 补偿深度 

分 类 号：TN305.1[电子电信—物理电子学]