Integrated circuits (ICs) are often designed with active devices such as transistors, resistors and capacitors connected by conductive traces, such as metal lines and polysilicon lines, to form circuits. The active devices in ICs are formed by a photolithographic process that includes use of photoresists, photolithographic masks (masks), specialized light sources and various etchants. Increasingly dense ICs have numerous benefits in terms of speed, functionality and cost, but cause increasingly difficult design and fabrication problems.