Modeling the Microstructure Curvature of Boron-Doped Silicon in Bulk Micromachined Accelerometer

Materials

Wu Zhou²  Huijun Yu²  Bei Peng²  Huaqin Shen²  Xiaoping He¹ 

[1] Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900, China; E-Mails:;School of Mechatronics Engineering, University of Electronic Technology and Science of China, Chengdu 611731, China; E-Mails:

关键词: microstructure;    boron-doped silicon;    multilayer solid model;    curvature;   

DOI  :  10.3390/ma6010244

来源: mdpi

【 摘 要 】

Microstructure curvature, or buckling, is observed in the micromachining of silicon sensors because of the doping of impurities for realizing certain electrical and mechanical processes. This behavior can be a key source of error in inertial sensors. Therefore, identifying the factors that influence the buckling value is important in designing MEMS devices. In this study, the curvature in the proof mass of an accelerometer is modeled as a multilayered solid model. Modeling is performed according to the characteristics of the solid diffusion mechanism in the bulk-dissolved wafer process (BDWP) based on the self-stopped etch technique. Moreover, the proposed multilayered solid model is established as an equivalent composite structure formed by a group of thin layers that are glued together. Each layer has a different Young’s modulus value and each undergoes different volume shrinkage strain owing to boron doping in silicon. Observations of five groups of proof mass blocks of accelerometers suggest that the theoretical model is effective in determining the buckling value of a fabricated structure.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.