Substrate computer-aided design

C. Tsai, S. Kang. Cell-level placement for improving substrate thermal distribution. IEEE Trans. Computer Aided Design Integrated Circuits System, 2000, Vol. 19, No. 2. pp. 253 - 266. 

The fabrication of a lithographic mask involves the transformation of computer-aided designs of an IC into a physical layout to create a geometrical pattern of the mask. Coordinates of the IC layout are digitized and stored in appropriate electronic storage media such as tapes. The pattern is then transferred onto the surface of chrome-quartz plates or appropriate substrates, depending on the mask type. ... 

In short, photolithography transfers the circuit patterns of photomasks (masks) on to the surface of the silicon dioxide coated silicon substrate. Masks are usually purchased from other specialist companies who manufacture them to correspond to the desired computer-aided designed circuit as mentioned earlier. 

De Rienzo, F., Fanelli, F., Menziani, M.C. and De Benedetti, P.G. (2000) Theoretical investigation of substrate specificity for cytochromes P450 IA2, P450 IID6 and P450 II IA4. Journal of Computer-Aided Molecular Design, 14, 93-116. 

Keseru, G. M. (2001) A virtual high throughput screen for high affinity cytochrome P450cam substrates. Implications for in silico prediction of drug metabolism. J. Comput. Aid. Molec. Design 15, 649-657. 

Considering the complex kinetic behavior of most enzymatically controlled reactions (41), the formal treatment of simple catalytic analogues should not pose additional problems. However, one consequence of the less perfect, but for most practical and mechanistical purposes sufficient performance of synthetic catalysts in comparison to enzymes is that in many kinetic studies, a large excess of substrate over the catalyst cannot be used, because then the uncatalyzed reaction will be too fast. Consequently, kinetic studies under catalyst saturation, or the steady-state methods that are most often used in the investigation of enzymes (18, 19, 41), are not suitable here. The formal treatment of the resulting, often quite complex, kinetics is greatly facilitated by computer-aided numerical simulations, which also help to design proper experimental conditions. 

Computer-aided optical film system design is to a large extent computer work and will therefore not be treated here in more detail. For practical application, a medium-sized or even small table model computer in which the system design refinement program - which may be commercially available - is recorded, is fed with the optical data of the substrate, the film and the adjoining medium as well as with the desired values of the spectral characteristics of, say, a reflection curve. 

The effect of supporting a thin film on a substrate can also lead to a variety of (potentially catalytically reactive) surfaces being exposed by the thin film. In particular. Fig. 5.8(c) shows a heavily corrugated CaO surface, which at a particular critical thickness transforms via dislocation evolution to CaO(lOO), Fig. 5.8(d). Accordingly, this paves the way for computer aided materials design in that various substrates and thin-film thicknesses can be explored computationally to determine systems with desirable (reactive) surfaces such predictions can then be tested experimentally. 

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