Deep etching

Figure A3.10.8 Depiction of etching on a Si(lOO) surface, (a) A surface exposed to Br2 as well as electrons, ions and photons. Following etching, the surface either becomes highly anisotropic with deep etch pits (b), or more regular (c), depending on the relative desorption energies for different surface sites [28].

Knoll G 1995 Time resolved analysis of rapid events Rapid Freezing, Freeze-fracture and Deep Etching ed N Sievers and D Shotton (New York Wiley-Lyss) p 105... 

As with any other fabrication process, masks are needed to define the features to be etched. It is common that the etch used for the semiconductor also etches the masking material. For this reason many different masks are used in etching, including photoresist, dielectric films, and metals. Masking can be a complex issue, especially when very deep etches (>5 fim) are performed with high aspect ratios (148). 

Tief, n. deep, depression minimum. -Mtz-probe, /. deep-etch test or sample, -atzimg, /. deep etching, -bau, m. underground construction or work, -blick, m. insight, penetration. 

In Proceedings of 21st SemiTherm Symposium, San Jose, 15-17 March 2005, pp 354—360 Mohr J, Ehrfeld W, Munchmeyer D (1988) Requirements on resist layers in deep-etch synchrotron radiation lithography. J Vac Sci Technol B6 2264-2267 Morini GL (2004) Single phase convective heat transfer in micro-channels overview of experimental results. Int J Thermal Sci 43 631-651... 

Fig 1. Electron micrograph of a platinum/carbon replica prepared by the fast-freeze, deep-etch, rotary-shadow replica technique printed in reverse contrast. Cell walls of onion parenchyma have an elaborate structure with many thin fibres bridging between thicker cellulosic microfibrils. Scale bar represents 200nm. 

Figure 5.25 AFM images of intermediate stmctures in self-assembly of peptide KFE8 in aqueous solution deposited on freshly cleaved mica surface (a) 8 min after preparation of solution. Inset electron micrograph of sample of peptide solution obtained using quick-freeze deep-etch technique (b) 35 min, (c) 2 h, and (d) 30 h after preparation. Reprinted with permission from Ref. 110. Copyright 2002 by the American Chemical Society.

Figure 5.26 TEM image of surfactant-like peptide A6D dissolved in water (4.3 mM at pH 7) obtained using quick-freeze deep-etch technique. Image shows dimensions, 30-50 nm in diameter with openings of nanotube ends (arrows). Inset Opening ends in more detail. Reprinted with permission from Ref. 112. Copyright 2002 by the National Academy of Sciences, U.S.A.

Somlyo AV, Franzini-Armstrong C 1985 New views of smooth muscle structure using freezing, deep-etching and rotary shadowing. Experientia 41 841-856 Somlyo AP, Somlyo AV 1994 Signal transduction and regulation in smooth muscle. Nature 372 231-236... 

Severs N.J. and Shotton D.M., eds.. Rapid Freezing, Freeze Fracture and Deep Etching, Wiley-Liss, New York, 1995. 

In tissues, microfibrils form loosely packed parallel bundles. X-ray fiber diffraction of hydrated zonular microfibril bundles identified one-third-staggered junctions that may modulate force transmission (Wess et al., 1998a), and quick-freeze deep-etch analysis of zonules has identified molecular links between microfibrils (Davis et al., 2002). 

Figure 9 Channel structure of a phase separator generated by ASE deep etching of silicon. (Source IMM.)...

Hanson PI, Roth R, Morisaki H, Jahn R, Heuser JE (1997) Structure and conformational changes in NSF and its membrane receptor complexes visualized by quick-freeze/deep-etch electron microscopy. Cell 90 523-35... 

Two-level glass etch was also performed first over photoresist for shallow etch (10 pm), and then over black lithographical masking tape for deep etch [117]. 

It was reported that double etch (shallow + deep etch) resulted in a cross section leading to less dispersion in chemical separations (by simulation) than the usual single deep-etched cross section [118,119]. 

It should be emphasised that the simplest way of avoiding the formation of deep etch patterns, namely, by reducing the time of the solid-with-liquid interaction, does not seem to be the best one because it only masks the phenomenon, not eliminating its cause. Therefore, it appears to be much more reasonable to increase the disc diameter and to reduce the volume of the liquid phase (within acceptable limits and taking account of other re-strictions 5 5 ), so that during dissolution of a solid from zero up to... 

Discrepancies between reactive and adsorption surface area may also be related to the presence of deep etch pits or pore outcrops which can constitute transport-limited micro-environments for dissolution (Jeschke and Dreybrodt, 2002). Much of the BET surface area for some alkali feldspars used for dissolution in the laboratory has been attributed to grinding-induced microporosity (Hodson et al, 1999), and such pore outcrops are candidates for transport limitation. If such induced surfaces react dilferently than surfaces of weathered samples, then the BET surface area may be an inappropriate parameter to use for extrapolating interface-limited kinetics from laboratory to field (Lee et al, 1998 Brantley and Mellott, 2000 Jeschke and Dreybrodt, 2002) and consideration may need to be given to length and extent of grinding for laboratory samples (Hodson, 1999). It may be more appropriate to use geometric rather than BET surface area to extrapolate kinetics for samples where etch pits or pore outcrops are important contributors to BET surface area (Gautier et al, 2001 Jeschke and Dreybrodt, 2002 Mellott et al, 2002). 

The Deep etch plates, on the other hand, are usually etched metal plates using a negatively working photoresist and an etching lacquer. In the Industry the Deep etch plates have found wider usage In view of their mechanical stability towards printing more copies. 

On the other hand. In the areas of Deep etch plates, the emphasis seems to be on the stability and etch resistance of the Images (to withstand chemical agents) necessitate the use of chemically stable compositions (such as cycllzed Isoprene, epoxldlsed esters). Additional factors such as adhesion of the photoresist... 

Dash several hours, yields deep etch pits on all orientations sensitive to oxygen impurity 3191. 020... 

---