微机械陀螺DRIE刻蚀过程中的局域掩膜效应  

Local Mask Pattern Effect on the Si DRIE for Micro-Machined Gyroscope

作　　者：冷悦[1,2] 焦继伟[1] 张颖[1] 顾佳烨[1] 颜培力[1] 宓斌玮[1] 

机构地区：[1]中国科学院上海微系统与信息技术研究所传感技术联合国家重点实验室,上海200050 [2]中国科学院研究生院,北京100039

出　　处：《传感技术学报》2010年第8期1070-1074,共5页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金项目资助(60772030;60876079)

摘　　要：在微机电系统(MEMS)制造中,深反应离子刻蚀(DRIE)过程的精度是影响器件特性的重要因素之一。本文设计了一种完全对称弹性梁结构的模态匹配式陀螺的原型器件,以此为对象研究了局域掩膜图形对于DRIE刻蚀过程的影响。器件的测试结果表明驱动和检测模态有明显的失配,该失配的发生原因除了气体阻尼,更主要来源于驱动和检测结构弹性梁尺寸的工艺偏差。在分析了实验过程及结果的基础上可以认为,除了典型的DRIE滞后效应等因素外,器件结构的局域掩膜效应加剧了工艺偏差:对称弹性梁结构周边的非对称掩膜图形导致了刻蚀气体分布的局部不均匀,增加了DRIE刻蚀的侧蚀偏差。Deep reactive ion etching（DRIE） is an important issue in the field of the fabrication of Micro-Electro-Mechanical System（MEMS）.A mode-matched gyroscope with identical springs for both drive and sense structures was designed and fabricated,based on which we investigated the impact of local mask patterns on the Si DRIE.The measurement of frequency response gave a significant mismatch between drive and sense modes,which was mainly caused by the deviation between the widths of springs of both structures other than air damping.Based on the analysis and calculation,we believe that it is the impact of local mask patterns that contributes to this deviation besides the typical errors such as Lag Effect of DRIE.A hypothesis is proposed that a local non-uniformity of etchant distribution can be induced by the asymmetrical mask patterns close to the springs,which sequently strengthens the undercutting effect.

关 键 词：MEMS陀螺 深反应离子刻蚀 非对称结构 局域掩膜效应 模态失配 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]