Methods for forming thick self-supporting masks

Abstract From the Canadian patent

Abstract of the Disclosure, A method of constructing a relatively thick self-supporting, mask suitable for electron beam projection processes. Thickness is achieved by multiple steps of coating with resist exposure, and development. Either positive or negative resist may be used for second and subsequent coatings. Second and subsequent exposures are directed through the first relatively thin mask formed and through the substrate to eliminate critical alignment of subsequent masks. When desired thickness is achieved an even thicker frame may be fabricated for support purposes and the mask may then be lifted off the substrate on which it had rested during the fabrication steps. When positive …