KOH溶液无掩膜腐蚀加工硅对称梁技术研究

Study on Maskless Etching of Silicon Symmetric Beam-Mass Structure in Aqueous KOH

本文介绍了利用ＫＯＨ腐蚀液对硅台阶、台面等三维结构进行无掩膜腐蚀的新技术．应用该技术可以制作出仅用常规各向异性腐蚀所无法形成的微机械结构，从而使腐蚀工艺的灵活性大为增加．通过分析与计算，给出了无掩膜腐蚀过程中三维结构的变化规律，并通过大量实验证实了这些规律．利用该工艺已成功地制作了一种微机械硅电容加速度传感器用的对称梁－质量块结构．这种结构的特点是梁的中平面与质量块质心位于同一水平面上，从而能消除相关的横向寄生灵敏度效应．

Abstract A novel micromechanical technique by using maskless etching of three dimensional silicon structures is investigated. With the technique, some micro-structures which are hardly fabricated by conventional anisotropic etching can be formed. Therefore, the technique makes anisotropic etching processes more flexible. Analytical relations have been found to predict the evolution of the contours of the three dimensional structures.And the relations have been conformed by the experimental results. As an example of applications, a symmetric cantilever beam-mass structure which plays an important role in a miniature silicon capacitive accelerometer has been successfully fabricated by using the maskless etching technique. In the structure, the beams are located at the central plane of the mass,so that the lateral cross-sensitivity effect of the accelerometer can be eliminated.EEACC: 2550