Silicon carbide for microelectromechanical systems
Shuvo Roy2000, International Materials Reviews
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Abstract
Any discussion concerning SiC as a material for MEMS first requires a basic understanding of these Silicon carbide (SiC) has recently attracted micromachining processes. attention as a wide bandgap semiconductor with great potential for microelectromechanical Bulk micromachining was developed in the 1970s systems (MEMS). SiC exhibits excellent electrical, as an extension of IC technology for the fabrication mechanical, and chemical properties, making it of three-dimensional structures.1 Bulk micromachinwell suited for harsh environment applications ing of silicon uses wet and dry etching techniques in where traditional MEMS are constrained by the conjunction with etch masks and etch stops to sculpt physical limitations of silicon (Si). This paper micromechanical devices from the Si substrate. There reviews the material properties, deposition are two key capabilities that make bulk micromachintechniques, micromachining processes, and other ing of Si a viable technology. First, the availability of issues regarding the fabrication of SiC-based anisotropic etchants of Si such as ethylene-diamine sensors and actuators. Special emphasis is placed pyrocatecol (EDP) and potassium hydroxide (KOH), on the properties that make SiC attractive for MEMS, and the Si-based processing techniques which preferentially etch single crystal Si along select that have been adapted to realise SiC MEMS crystal planes. Second, the availability of etch masks structures and devices. An introduction to and etch-stop techniques which can be used in conmicromachining is provided for readers not junction with silicon anisotropic etchants to prevent familiar with MEMS fabrication techniques.
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