Photolithographic Fine Patterning of Difficult-To-Etch Metals

A process that includes photolithography, liftoff, etching, and sputter deposition has been developed to enable the fabrication of thin, finely patterned layers of gold, platinum, and other difficultto- etch materials in advanced miniature sensors and associated electronic circuitry. Heretofore, photolithography has been used in conjunction with liftoff and etching to produce finely detailed structures in easy-to-etch materials. The present process is needed because conventional photolithography cannot be used to pattern difficult-to-etch materials and the alternative processes heretofore available for patterning difficult-to-etch materials are limited to spatial resolution of about 0.005 in. (≈0.13 mm) or coarser.