Material Properties: Measurement and Data

The performance of MEMS strongly depends on the properties of materials used not only as functional materials but also as structural materials. Therefore, the materials used for MEMS are required to possess many properties for applications with electrical, mechanical, thermal, magnetic, optical, and chemical requirements according to the specification of individual MEMS. Most of the MEMS use single-crystal silicon (SCS) as a substrate material because of its superior electrical and mechanical properties. The superiority of electrical properties of SCS has been widely accepted from the time they were first used as a substrate of large-scale integrations (LSIs). Furthermore, SCS has been used as a structural material for mechanical sensors such as piezoresistive pressure sensors and acceleration sensors since the early 1960s.[

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] The great success of silicon-based mechanical sensors is attributable to the excellent mechanical properties of SCS as well as its well-established piezoresistive effect. A detailed account of mechanical sensors and their applications is given in Chapter 10.