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Journal of Engineering
Volume 2014, Article ID 715167, 8 pages
http://dx.doi.org/10.1155/2014/715167
Research Article

The Mechanical and Electrical Effects of MEMS Capacitive Pressure Sensor Based 3C-SiC for Extreme Temperature

1Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Malaysia
2Queensland Micro- and Nanotechnology Centre (QMNC), Griffith University, Brisbane, QLD 4111, Australia

Received 18 December 2013; Accepted 29 April 2014; Published 22 May 2014

Academic Editor: Sheng-Rui Jian

Copyright © 2014 N. Marsi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This paper discusses the mechanical and electrical effects on 3C-SiC and Si thin film as a diaphragm for MEMS capacitive pressure sensor operating for extreme temperature which is 1000 K. This work compares the design of a diaphragm based MEMS capacitive pressure sensor employing 3C-SiC and Si thin films. A 3C-SiC diaphragm was bonded with a thickness of 380 μm Si substrate, and a cavity gap of 2.2 μm is formed between the wafers. The MEMS capacitive pressure sensor designs were simulated using COMSOL ver 4.3 software to compare the diaphragm deflection, capacitive performance analysis, von Mises stress, and total electrical energy performance. Both materials are designed with the same layout dimensional with different thicknesses of the diaphragm which are 1.0 μm, 1.6 μm, and 2.2 μm. It is observed that the 3C-SiC thin film is far superior materials to Si thin film mechanically in withstanding higher applied pressures and temperatures. For 3C-SiC and Si, the maximum von Mises stress achieved is 148.32 MPa and 125.48 MPa corresponding to capacitance value which is 1.93 pF and 1.22 pF, respectively. In terms of electrical performance, the maximum output capacitance of 1.93 pF is obtained with less total energy of 5.87 × 10−13 J, thus having a 50% saving as compared to Si.