Photolithographic methods

OLEDs are obviously able to produce light with virtually every color in the CIE chromaticity diagram but the optimum inexpensive method to manufacture a pixeiatcd full color display is not yet established. The difficulty lies in patterning OLED materials with standard photolithographic methods. Five schemes to achieve color have been suggested, as illustrated schematically in Figure 13-19. 

Using a photolithographic method, etch a square opening on the Si02 film. 

Oligonucleotide and peptide microarrays can be prepared in situ with light-directed synthesis on a glass surface in conjunction with either a photolithographic method or using a micromirror device (2,11-15). However, these methods are not useful for most organic synthesis. Furthermore, such approaches require equipment that is not readily available. Spot synthesis on cellulose membrane is another in situ synthesis method, but the resulting microarrays are low density (16). 

Figure 8.2 An array of redundant gold electrodes fabricated by photolithographic methods, where the electrode diameters are 50 pm and the leads are 10 pm. Reprinted with permission from Ref. 2. Copyright 2000 Elsevier.

They can be handled outside of clean room facilities, and certain types of fabrication involving SAMs are relatively low in cost compared with conventional photolithographic methods. 

Photolithographic methods, which play a key part in the fabrication of semiconductors, are potential candidates for the photo-patterning of small enzyme-immobilized membranes on a FET at its wafer stage. Ion-sensing FET devices with neutral carrier membranes sensitive to alkaline and alkaline earth metal... 

The selective UV-inactivation method is effective for the deposition of a single enzyme-immobilized membrame on a FET, but it is not possible to deposit several different enzyme-immobilized membranes on one FET chip. Other photolithographic methods, outlined in Fig. 8, do not have this disadvantage. The methods are applicable to the simultaneous deposition of different membranes on a FET chip. In other words, these methods are usable for the preparation of a multifunctional enzymatically coupled FET. 

To date, a variety of lithographic techniques, including advanced soft- and photolithographic methods, have been extensively used for constructing molecular architectures at multiple length scales [100]. Thanks to their versatility, such approaches can be easily transferred to different substrates and molecular materials, including SMMs. For instance, solution-cast thin films of... 

Lu, Y. et al.. Growth of large crystals of monodispersed spherical colloids in fluidic cells fabricated using non-photolithographic methods, Langmuir, 17, 6344, 2001. 

Planar waveguides are also used for photometric transducers. Recently, there have been applications of photolithographic methods to create miniaturized waveguides, or other microfabrication techniques to produce thin films of organic materials for optical waveguides. For example, Hanken and Corn... 

Rogers. J. A., Z. Bao, M. Meier, A. Dodabalapur, O. J. A. Schueller, and G. M. Whitesides. 2000. Printing, molding, and near-field photolithographic methods for patterning organic lasers, smart pixels and simple circuits. Synth. Met. 115 5-11. 

Photolithographic methods rely on irradiation of the monolayer through a mask. The irradiated (or untreated) part of the monolayer is then selectively removed by the appropriate method and the free gold surface is exposed to the solution of another thiol. Irradiation of the monolayer by UV light in the presence of air results in the oxidation of the sulphur head group (Section VI). Rinsing the monolayer with the appropriate solvent achieves removal of the oxidized species in the irradiated area . Another example... 

F. A. Aguiar, A. J. Gallant, M. C. Rosamond, A. Rhodes, D. Wood, and R. Kataky, Conical recessed gold microelectrode arrays produced during photolithographic methods Characterisation and causes, Electrochem. 

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