Abstract: A specialized etching method for producing fine-geometry gold circuit structures. Production thereof is accomplished by maintaining a constant gold etching rate. Metal etching normally slows as the amount of dissolved gold (a reaction product of the etching process) increases. To remove the dissolved gold, one method involves cooling the etchant to precipitate a gold complex therefrom. The remaining, recovered etchant is then heated and made available for continued etching. Another method involves a cathode/anode assembly which is immersed in the etchant. Activation of the assembly recovers metallic gold and regenerates the etchant. These methods, when used continuously or periodically in a dip or spray etching system, maintain a constant etching rate. As a result, fine-geometry circuit structures may be accurately produced while minimizing material costs (e.g. etchant use) and minimizing the production of undesirable waste products and disposal expenses associated therewith.

Abstract: A structure for use in an X-ray membrane (pellicle) mask is provided in which anodic bonding of layers is employed. Anodic bonding as used here provides a permanent bond between the layers, has zero thickness and provides substantial improvements in the obtained flatness of the mask by eliminating conventional glue for attachment. By applying a voltage between a layer, such as silicon, and a glass plate, and simultaneously heating both elements a permanent bond is established which is extremely flat thus providing minimum misalignment of the mask during subsequent X-ray lithography fabrication.