Micromachining Techniques of Inertial Sensors

Robert M. Ostrom, Mahendra Singh

Abstract:	The techniques of silicon micromachining can be used to fabricate low cost sensors with the same batch processing methods used by the integrated circuit industry. This same technology makes possible the production of low cost inertial sensors that can be use with present GPS technology to create a low cost guidance system. The micromachining methods not only reduce the cost of the device but also the size and complexity, extending the range of applicability of inertial sensors. We will present results on methods developed to create closed loop rate sensors and accelerometers using bulk micromachining techniques with silicon wafers. The sensors have been fabricated from (110) silicon wafers. The design layout as dictated by sample orientation will be presented. This includes braces, springs, proof masses, electrostatic actuators and pick-offs as well as electrical isolation. The methods emphasize the use of the crystal properties to minimize the processing steps. The processing steps will also be presented emphasizing the problems specific to bulk micromachining, double-sided exposure and dealing with heavily etched wafers. We will also present techniques for packaging the devices.
Published in:	Proceedings of the 1998 National Technical Meeting of The Institute of Navigation January 21 - 23, 1998 Westin Long Beach Hotel Long Beach, CA
Pages:	153 - 160
Cite this article:	Ostrom, Robert M., Singh, Mahendra, "Micromachining Techniques of Inertial Sensors," Proceedings of the 1998 National Technical Meeting of The Institute of Navigation, Long Beach, CA, January 1998, pp. 153-160.
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