Title: Bulk micromachining for SOI based microsystems using double side XeF₂ etching

Authors: Avinash K. Bhaskar, Muthukumaran Packirisamy, Rama B. Bhat

Addresses: Optical Microsystems Laboratory, Department of Mechanical and Industrial Engineering, CONCAVE Research Centre, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal H3G 1M8, Canada. ' Optical Microsystems Laboratory, Department of Mechanical and Industrial Engineering, CONCAVE Research Centre, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal H3G 1M8, Canada. ' Optical Microsystems Laboratory, Department of Mechanical and Industrial Engineering, CONCAVE Research Centre, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal H3G 1M8, Canada.

Abstract: Microfabrication is pivotal in any microsystem synthesis. Even through silicon is the most common material used in the Micro Electro Mechanical System (MEMS) foundry, Silicon on Insulator (SOI) wafers are very promising for the fabrication of Micro Opto Electro Mechanical System (MOEMS) Devices such as micromirrors due to their better optical reflectivity, low residual stress and compatibility with silicon microfabrication processes. The present work explores the possibility of patterning and using controlled pulse etching method involving Xenon difluoride (XeF₂) to etch SOI wafers to realise micromirrors. Pulse-etching method is proposed due to its better control and etching uniformity. This paper also presents the process flow for the fabrication of SOI based micromirrors through double side XeF₂ micromachining which involves mask preparation, photolithography and pulse etching. The presented results also include etch characteristics obtained on SOI wafers.

Keywords: microelectromechanical systems; MEMS; microoptoelectromechanical systems; MOEMS; microfabrication; micromirrors; silicon on insulator; SOI wafers; pulse etching; bulk micromachining; lithography; microsystems; xenon difluoride; mask preparation; photolithography.

DOI: 10.1504/IJMTM.2008.016778

International Journal of Manufacturing Technology and Management, 2008 Vol.13 No.2/3/4, pp.297 - 307

Published online: 22 Jan 2008 *

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