Self-developed images

New Design for Self-Developing Imaging Systems Based on Thermally Labile Polyformals... 

FRECHET ET AL. New Design far Self-Developing Imaging Systems... 

Figure 7. Scanning Electron Micrograph of a self-developed image of polymer 9...

Fijgure 3.39. Optical micrographs of self-developed images of a polyphthal-aldehyde-onium salt resist. Reproduced with permission from reference 105. Copyright 1986 Electrochemical Society.)... 

Formation of monomeric phthalaldehyde due to acidolysis and depolymerization of polyphthalaldehyde initiated by the photolysis of onium salts is clearly demonstrated by IR spectroscopy (Figure 8). Figure 8c shows vaporization of the aldehyde monomer upon heating. The monomeric phthalaldehyde is crystalline at room temperature but sublimes under vacuum without heating. We have successfully delineated self-developed images in a 2.8 p thick film at a dose of 1.0 pC/cm2 of 20 keV e-beam radiation, which were subsequently transferred to silicon oxide by treatment with either buffered HF or CF4/02 plasma. 

Figure 7. Self-developed images in polyphthalaldehyde (a) 254 nm deep UV, Ph3SAsF6, (b) 20 keV e-beam, PhjAsFg, and (c) Al-Ko x-ray, Ph2IAsF6.

The excimer laser can function simply as an exposure source to effect a chemical change in the polymer film that subsequently can be developed out in a conventional manner. In addition, because of its high power, the laser can also be used to ablate the exposed areas directly and lead to self-developed images. The intensity of the excimer laser is such that almost any polymer can be made to undergo dramatic scission. The degraded fragments vaporize from the imaged area at the... 

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