Micromachined semiconductor gas

Abstract This chapter reviews micromachined semiconductor gas sensors. First, the chapter briefly discusses the history of this technology. 

It then addresses the micro-hotplates concept that has led to the development of different types of micromachined gas sensor devices. The different reahzations of micromachined semiconductor gas sensors are presented thin- and thick-film metal-oxide, field effect, and those using complementary metal-oxide semiconductors (CMOSs) and silicon-on-insulator (SOI) technologies. Finally, recent developments based on gas sensitive nanostructures, polymers, printing and foil-based technologies are highlighted. 

This chapter therefore focuses on silicon micromachined semiconductor gas sensors. After a brief history of silicon hotplates and metal-oxide... 

Silicon micromachined semiconductor gas sensors are mainly packaged using standard metallic transistor outline (TO) headers as support, and wire bonding is used for their electrical connection. Typically, a metallic cap with a grid is fixed to the TO header with a hydrophobic gas permeable membrane on top of it. A filtering agent can be also included in the package. 

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