A Novel Method for Evaluating the Thickness of Silicon Membrane Using a Micromachined Acoustic Wave Sensor

Chi-Yuan Lee; Ying-Chou Cheng; Tsung-Tsong  Wu; Yung-Yu  Chen; Wen-Jong Chen; Shih-Yung Pao; Pei-Zen Chang; Ping-Hei  Chen; Kai-Hsiang Yen; Fu-Yuan  Xiao

doi:10.6180/jase.2004.7.2.01

A Novel Method for Evaluating the Thickness of Silicon Membrane Using a Micromachined Acoustic Wave Sensor

Chi-Yuan Lee This email address is being protected from spambots. You need JavaScript enabled to view it.¹, Ying-Chou Cheng¹ , Tsung-Tsong Wu² , Yung-Yu Chen² , Wen-Jong Chen² , Shih-Yung Pao² , Pei-Zen Chang² , Ping-Hei Chen¹ , Kai-Hsiang Yen² and Fu-Yuan Xiao²

¹Department of Mechanical Engineering National Taiwan University Taipei, Taiwan 106, R.O.C.
²Institute of Applied Mechanics National Taiwan University Taipei, Taiwan 106, R.O.C.

Received: December 25, 2003
Accepted: January 15, 2004
Publication Date: June 1, 2004

Download Citation: ||https://doi.org/10.6180/jase.2004.7.2.01

ABSTRACT

This work presents a novel method based on the micromachined acoustic wave sensor for evaluating silicon membrane thickness. Like pressure sensors, accelerometers, micro flow sensors and micropumps, many micro-electro-mechanical systems (MEMS) devices require that silicon membrane thickness be known exactly. Precisely controlling silicon membrane thickness during wet etching is important, because the thickness strongly affects device performance and post-processing. The proposed method for evaluating silicon membrane thickness is novel, simple to implement, and can be monitored in-situ and mass-produced. The spectral analysis of surface waves (SASW), detailed process flows, measurement set-up and the experimental results also are presented.

Keywords: MEMS, MicromachinedAcoustic Wave Sensor, SASW

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