%0 Journal Article
%T The Mechanical and Electrical Effects of MEMS Capacitive Pressure Sensor Based 3C-SiC for Extreme Temperature
%A N. Marsi
%A B. Y. Majlis
%A A. A. Hamzah
%A F. Mohd-Yasin
%J Journal of Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/715167
%X 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£¿¦Ìm Si substrate, and a cavity gap of 2.2£¿¦Ìm 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£¿¦Ìm, 1.6£¿¦Ìm, and 2.2£¿¦Ìm. 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 ¡Á 10£¿13£¿J, thus having a 50% saving as compared to Si. 1. Introduction More recent developments in the field of robust micromechanical system (MEMS) for extreme environment such as MEMS pressure sensor have been widely used in airplanes, submarines, gas turbine engine, automobiles, and biomedical devices [1]. MEMS pressure sensor based silicon (Si) materials are not well suited, owing to its desirable and stable material properties under extreme environment due to this limited operating of mechanical and electrical properties that can degrade below temperature of 300¡ãC [2]. There are some significant challenges replacing the silicon with silicon carbide (3C-SiC) materials for MEMS application. The 3C-SiC is promising materials that have excellent mechanical and thermal stability for the fabrication MEMS capacitive pressure sensor operating for extreme environment [3]. In improving the performance of MEMS pressure sensor, the use of 3C-SiC materials is an alternative offering a new approach to overcome high temperature performance. The mechanical and electrical properties of 3C-SiC show great promise and effective materials that are highly wear resistant with good mechanical and electrical properties including high temperature strength, chemical stability, and excellent thermal shock resistance applications. In a previous study, Wijesundara
%U http://www.hindawi.com/journals/je/2014/715167/