Tolerance analysis for comb-drive actuator using DRIE fabrication
Tolerance analysis for comb-drive actuator using DRIE fabrication
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DOI：
10.1016/j.sna.2005.08.002
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发表时间：
2006-01-10
影响因子：
4.6
通讯作者：
Zhang, QX
中科院分区：
文献类型：
--
作者：
Li, J;Liu, AQ;Zhang, QX
深反应离子刻蚀(DRIE)工艺是专门为体微机械加工而发明的，目的是实现高深宽比微结构。然而，在制造过程中，各种公差是无法避免的，如倾斜的蚀刻轮廓、不均匀的深梁和根切。本文从静电力、机械刚度、稳定性和位移等方面讨论了各种制造公差的来源及其对横向梳齿驱动器性能的影响。结果表明，正斜率的梳指产生较大的静电力。当折梁向负倾斜时，横向力学刚度增大。如果将梳状指和折叠梁分别锥化到+1度和-1度，则位移将增加4.832倍。当运动距离达到初始重叠长度时，不均匀的深指产生突变力和位移。根切降低了横向梳齿驱动器的驱动力和机械刚度。制作的梳齿指形+1度、根切0.025微米、折梁斜度-1度、根切0.075微米的梳齿驱动器进行了测量，并与模型进行了比较，两者结果一致。这些分析结果可用于在设计阶段补偿制造公差，并允许执行器提供更可预测的性能。(C)2005 Elsevier B.V.保留所有权利。
Deep reactive ion etching (DRIE) process is specially invented for bulk micromachining fabrication with the objective of realizing high aspect ratio microstructures. However, various tolerances, such as slanted etched profile, uneven deep beams and undercut, cannot be avoided during the fabrication process. In this paper, the origins of various fabrication tolerances together with its effects on the performances of lateral comb-drive actuator, in terms of electrostatic force, mechanical stiffness, stability and displacement, are discussed. It shows that comb finger with positive slope generates larger electrostatic force. The mechanical stiffness along lateral direction increases when the folded beam slants negatively. The displacement is 4.832 times larger if the comb finger and folded beam are tapered to +1 degrees and -1 degrees, respectively. The uneven deep fingers generate an abrupt force and displacement when the motion distance reaches the initial overlap length. The undercut reduces both the driving force and the mechanical stiffness of the lateral comb-drive actuator. The fabricated comb-drive actuator, with comb finger of +1 degrees profile and 0.025 mu m undercut, and folded beam of -1 degrees slope and 0.075 mu m undercut, is measured and compared with the models where both show consistent results. These analytical results can be used to compensate the fabrication tolerances at design stage and allow the actuators to provide more predictable performance. (c) 2005 Elsevier B.V. All rights reserved.