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Plating and Etching Techniques to Provide Image Contrast

IP.com Disclosure Number: IPCOM000093491D
Original Publication Date: 1967-Oct-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Dyson, JJ: AUTHOR [+2]

Abstract

This process for the fabrication of optical masks, used in the fabrication of integrated circuits, eliminates the manual peeling of emulsion which other processes require. In one such process, a computer driven plotter generates a pattern on film. This pattern corresponds to the outline of the transparent areas in the desired mask. For example, in the case where a rectangular aperture defining a resistor is desired, the plotter traces a rectangular path corresponding to the outer edge of the aperture.

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Plating and Etching Techniques to Provide Image Contrast

This process for the fabrication of optical masks, used in the fabrication of integrated circuits, eliminates the manual peeling of emulsion which other processes require. In one such process, a computer driven plotter generates a pattern on film. This pattern corresponds to the outline of the transparent areas in the desired mask. For example, in the case where a rectangular aperture defining a resistor is desired, the plotter traces a rectangular path corresponding to the outer edge of the aperture.

The film is then processed so that the emulsion is removed in the area of the lines. The emulsion is manually peeled from the areas enclosed by the developed lines. From this point the mask can be reduced by conventional photographic techniques and used in the fabrication of integrated circuits.

This previous procedure has two major requirements. First, the substrates used to support the emulsion are sensitive to humidity and are, therefore, difficult to fabricate to close tolerances except in large sizes. Second, the manual peel operation requires a large mask so that the smaller peel areas can be manipulated.

This process utilizes the same plotter-generated pattern as a starting point. This is developed to give a generally transparent mask having a pattern of dark lines.

A glass plate, having a thin copper film over a material such as nickel to improve adhesion, is then coated with KPR* and exposed to light through the mask. The KPR...