Material Aspects of Micro- and Nanoelectromechanical Systems

Abstract

One of the more significant technological achievements during the last 20 years has been the development of MEMS and its new offshoot, NEMS. These developments were made possible by significant advancements in the mater- ials and processing technologies used in the fabrication of MEMS and NEMS devices. While initial developments capitalized on a mature Si infrastructure built for the integrated cir- cuit (IC) industry, recent advances have come about using materials and processes not as- sociated with IC fabrication, a trend that is likely to continue as new application areas emerge. A well-rounded understanding of MEMS and NEMS technology requires a basic knowl- edge of the materials used to construct the devices, since material properties often gov- ern device performance and dictate fabrication approaches. An understanding of the materials used in MEMS and NEMS involves an under- standing of material systems, since such devices are rarely constructed of a single material but rather a collection of materials working in con- junction with each other to provide critical functions. It is from this perspective that the following chapter is constructed. A preview of thematerials selected for inclusion in this chap- ter is presented in Table 10.1. It should be clear from this table that this chapter is not a sum- mary of all materials used in MEMS and NEMS, as such a work would itself constitute a text of significant size. It does, however, present a se- lection of some of the more important material systems, and especially those that illustrate the importance of viewing MEMS and NEMS in terms of material systems.