An in-plane low-noise accelerometer fabricated with an improved process flow

作     者：Xu-dong ZHENG Zhong-he JIN Yue-lin WANG Wei-jun LIN Xiao-qi ZHOU 

作者机构：Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China 

出 版 物：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 (浙江大学学报（英文版）A辑（应用物理与工程）)

年 卷 期：2009年第10卷第10期

页      面：1413-1420页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：Project(No.NCET-06-0514)supported by the Program for New Century Excellent Talents in University China 

主　　题：MEMS accelerometer, Deeo reactive ion etchin (DRIE), Footin effect, Canacitive sensing 

摘      要：We present a bulk micromachined in-plane capacitive accelerometer fabricated with an improved process flow,by etching only one-fifth of the wafer thickness at the back of the silicon while forming the bar-structure electrode for the sensing *** improved flow greatly lowers the footing effect during deep reactive ion etching(DRIE),and increases the proof mass by 54% compared to the traditional way,resulting in both improved device quality and a higher yield *** in the X direction is sensed capacitively by varying the overlapped area of a differential capacitor pair,which eliminates the nonlinear behavior by fixing the parallel-plate *** damping coefficient of the sensing motion is low due to the slide-film damping.A large proof mass is made using DRIE,which also ensures that dimensions of the spring beams in the Y and Z directions can be made large to lower cross axis coupling and increase the pull-in *** theoretical Brownian noise floor is 0.47 μg/Hz1/2 at room temperature and atmospheric *** tested frequency response of a prototype complies with the low damping design *** data for input acceleration from ?1 g to 1 g are recorded by a digital multimeter and show very good *** tested random bias of the prototype is 130 μg at an averaging time of around 6 s.