Semiconductor industry applications processing/fabrication

First introduced for printing applications, bis-azide—mbber resists were soon adopted by the developing microelectronics industry and used extensively for device fabrication through the 1970s. However, as the semiconductor industry refined manufacturing processes to further miniaturize integrated circuits, the hmitations of this chemistry became apparent. 

Microfabrication is used in the semiconductor industry to make integrated circuits and has also been adapted to the fabrication of MEMS. It employs sequential film deposition and patterning steps on a planar surface MEMS structures are built layer-by-layer in such a way that they are assembled in place, and are partially freed from the surface so that they can move in a final release step [13, 14]. Two different processes sequences showing the steps for fabricating a metal/polymer bilayer actuator that can rotate a plate through 180° out of plane are illustrated in Figure 12.1. (The rotation is shown in Figure 12.2.) Applications of this structure are discussed in Section 12.4.1. 

Traditionally, thin-film deposition techniques have been related to the semiconductor industry and not to the biomedical sector. This is mainly due to the extreme conditions generally required for the material deposition process and their lack of compatibility with biological systems. However, the interdisciplinary characteristics of biosensors and POC devices has opened an entirely new range of applications for these techniques, mainly orientated towards the fabrication of platforms that can be employed as both the transducer for the sensing process and the support for the immobilization of the recognition molecule (Lin and Yan, 2012 Ceylan Koydemir et al., 2013). 

Chemical vapor deposition (CVD) has grown very rapidly in the last twenty years and applications of this fabrication process are now key elements in many industrial products, such as semiconductors, optoelectronics, optics, cutting tools, refractory fibers, filters and many others. CVD is no longer a laboratory curiosity but a maj or technology on par with other maj or technological disciplines such as electrodeposition, powder metallurgy, or conventional ceramic processing. 

In addition to drinking water and environmental applications, water purity is critical to many industries. Conductivity detectors are used in semiconductor and chip fabrication plants, to monitor cleanliness of pipelines in the food and beverage industry, to monitor incoming water for boilers to prevent scale buildup and corrosion. Any process stream with ions in it can be analyzed by conductometry. Conductivity detectors are part of commercial laboratory deionized water systems, to indicate the purity of the water produced and to alert the chemist when the ion-exchange cartridges are exhausted. The detector usually reads out in resistivity theoretically, completely pure water has a resistivity of 18 MO cm. 

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