Abstract: Well-defined metal lines of 0.5 micrometers and less in width are produced on a substrate by photolithography, using a two layer photoresist process. The first resist layer, adjacent the substrate, is poly(methylmethacrylate) from about 0.5 to about 1 micrometer thick, having a sufficient amount of an ultraviolet absorbing dye to prevent positive interference of light reflected from the surface of the substrate during exposure. The second resist layer is a polymer of naphthoquinone diazide, in a thickness of about 0.5 to about 1.1 micrometers. To achieve 0.5 micrometer resolution of the metal line, the total thickness of the two resist layers is about 1.5 micrometers; to achieve less than 0.5 micrometer resolution, the total thickness of the two resist layers is about 1.0 micrometer.