Capacitor fabrication

Barrier oxide film — When the surface of a metal is an-odically oxidized, a dense oxide film may grow that protects the metal underneath. Such barrier films are important for -> corrosion protection and also for fabricating -> capacitors. 

Capacitors. The outstandingly low dielectric loss of parylenes make them superior candidates for dielectrics in high quality capacitors. Furthermore, their dielectric constant and loss remain constant over a wide temperature range. In addition, they can be easily formed as thin, pinhole-free films. Kemet Flatkaps are fabricated by coating thin aluminum foil with Parylene N on both sides and winding the coated foils in pairs (62). 

Fig. 7. Fabrication process for MLC capacitors. Steps are (a) powder (b) slurry preparation (c) tape preparation (d) electroding (e) stacking (f) lamination (g) dicing (h) burnout and firing and (i) termination and lead attachment.

Equally important as tape casting in the fabrication of multilayer ceramics is thick film processing. Thick film technology is widely used in microelectronics for resistor networks, hybrid integrated circuitry, and discrete components, such as capacitors and inductors along with metallization of MLC capacitors and packages as mentioned above. 

T. L. Rutt andJ. A. Syne, "Fabrication of Multilayer Ceramic Capacitor by Metal Impregnation," IEEE Trans. Parts Hybrids Packag., PHP-9, 144-147 (1973). 

Electrical and Electronic Applications. Silver neodecanoate [62804-19-7] has been used in the preparation of a capacitor-end termination composition (110), lead and stannous neodecanoate have been used in circuit-board fabrication (111), and stannous neodecanoate has been used to form patterned semiconductive tin oxide films (112). The silver salt has also been used in the preparation of ceramic superconductors (113). Neodecanoate salts of barium, copper, yttrium, and europium have been used to prepare superconducting films and patterned thin-fHm superconductors. To prepare these materials, the metal salts are deposited on a substrate, then decomposed by heat to give the thin film (114—116) or by a focused beam (electron, ion, or laser) to give the patterned thin film (117,118). The resulting films exhibit superconductivity above Hquid nitrogen temperatures. 

Nawa, M., Nogami, T. and Mikawa, H., Application of activated carbon fiber fabrics to electrodes of rechargeable battery and organic electrolyte capacitor, J. Electrochem. Soc., 1984, 131(6), 1457 1459. 

A DEA is basically a compliant capacitor where an incompressible, yet highly deformable, dielectric elastomeric material is sandwiched between two complaint electrodes. The electrodes are designed to be able to comply with the deformations of the elastomer and are generally made of a conducting material such as a colloidal carbon in a polymer binder, graphite spray, thickened electrolyte solution, etc. Dielectric elastomer films can be fabricated by conventional... 

Brennecka, G. Tuttle, B. 2007. Deposition of ultrathin film capacitors fabricated by chemical solution deposition. /. Mat. Res. 22 2868-2874. 

Capacitor fabrication, 70 17 Capacitor-grade tantalum powder,... 

The measurement of changes of the surface potential Vo at the interface between an insulator and a solution is made possible by incorporating a thin film of that insulator in an electrolyte/insulator/silicon (EIS) structure. The surface potential of the silicon can be determined either by measuring the capacitance of the structure, or by fabricating a field effect transistor to measure the lateral current flow. In the latter case, the device is called an ion-sensitive field effect transistor (ISFET). Figure 1 shows a schematic representation of an ISFET structure. The first authors to suggest the application of ISFETs or EIS capacitors as a measurement tool to determine the surface potential of insulators were Schenck (15) and Cichos and Geidel (16). 

The material properties of PS offer new ways of making electronic devices. For the manufacture of cold cathodes, for example, oxidized microporous polysilicon has been found to be a promising material. The application of basic semiconductor processing steps such as doping, oxidation and CVD to a macroporous material enable us to fabricate silicon-based capacitors of high specific capacitance. Both devices will be discussed below. 

A macroporous silicon substrate with pores of about a micrometer and a pore depth of a few tenths of a millimeter offers a surface area enhancement of about two or three orders of magnitude compared to an unetched silicon surface. An example of such a macroporous substrate used for fabrication of a silicon capacitor (SIKO) is shown in Fig. 10.20 b. 

Surface layers of silicon oxide are important in semiconductor device fabrication as interlayer dielectrics for capacitors, isolation of conducting layers, or as masking materials. However, anodic oxides, due to their relatively poor electrical properties, breakdown voltage, and leakage current, have not yet found much use in device technology, and cannot compete with thermal oxides obtained at high temperatures of 700 to 900 °C. 

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