Processing/fabrication techniques semiconductor industry

Fabrication of Base Sensors For fabrication of redundant sensor arrays on metal or flexible insulating substrates, processes used in the semiconductor industry can be utilized as shown in Figure 8.2.44,45 Photolithography, wet etch, dry etch, sputtering, and evaporation are a few processes that have been used.46,47 The techniques described in this section can be used many times on the same sample to lead to numerous metals (or different electrodes) being fabricated on the same substrate, which can then be implanted in vivo. 

As mentioned in Chapter 1, the present state of CMP is the result of the semiconductor industry s needs to fabricate multilevel interconnections for increasingly complex, dense, and miniaturized devices and circuits. This need is related to improving the performance while adding more devices, functions, etc. to a circuit and chip. This chapter, therefore, discusses the impact of advanced metallization schemes on the performance and cost issues of the ICs. Our discussions start with the impact of reducing feature sizes on performance and the need of various schemes to counter the adverse effect of device shrinkage on the performance of interconnections. An impact of continued device shrinkage on circuit delay is discussed. Then the need of low resistivity metal, low dielectric constant ILD, and planarized surfaces is established leading to the discussion of CMP. Finally various planarization techniques are compared to show why CMP is the process that will satisfy the planarity requirements of the future. 

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). 

Nanofabrication is the collection of techniques that generates reproducible patterns whose elements have sizes of 100 nm or less in at least one dimension. The majority of commercial nanofabrication takes place in the semiconductor industry. Essentially all integrated circuits are made hy a combination of electron-beam lithography (EBL), which generates nanoscale information in the form of features on photomasks, and photolithography, which replicates that information. We refer to these techniques as conventional methods of nano-fabrication. They are the workhorses of modem microelectronics, and are not likely to he replaced in the foreseeable future. Despite the ubiquity of scanning beam and photolithographic methods in commercial produaion, there are many circumstances outside of microelectronics where conventional techniques are prohihitively expensive, tm-available, or inapplicable. Further, processes developed for... 

The objective of this chapter is to illustrate the use of microradiology with coherent x-rays [ 1 ] to investigate open problems in electrodeposition. Metal electrodeposition is an old and widely exploited technique, one of the most frequently used for protective and decorative coating [2], semiconductor device fabrication processes, and other industrial tasks [3,4],... 

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