Chemical and Plastic Factors in the Processing of Emulsions for Semiconductor Masks

Paper presented at a symposium on “Quantitative Applications of Photography” organized by the Science Committee of The Royal Photographic Society, December 1976 in London.

Abstract

Once they start to develop, it is generally believed that the exposed grains of a photographic emulsion are rapidly and completely converted to silver. While this is probably a close approximation to the truth, the corollary that development should stop when all the exposed grains arc developed is more questionable. In the case of high resolution emulsions, development does not appear to stop at this stage, but continues with far-reaching consequences for the control of line widths such as arc produced in semiconductor masks, for image structure and for the interaction between the optical and the photographic image.

In addition, high resolution emulsions swell during processing by an amount several limes the width of the finest lines they can reproduce. In spite of this, the plastic behaviour of the layer during processing produces good image positional accuracy so long as suitable handling conditions are used.

Notes

Paper presented at a symposium on “Quantitative Applications of Photography” organized by the Science Committee of The Royal Photographic Society, December 1976 in London.