Pattern definition and formation on curved surfaces

This paper will discuss techniques used to delineate and form patterns on curved surfaces. Patterns were generated in AZ1350 photoresist using electron-beam writing and xenon–chloride excimer laser writing and ablation. Experiments were conducted on spherically concave surfaces which had a radius of curvature of 0.879 cm. Surface patterns 10 μm in width and varying in length from 40 μm to 0.6 cm were written. These beam-writing techniques show clear superiority over conventional ultraviolet photolithographic techniques for patterning nonflat surfaces. The resulting patterned photoresist can then be used as a mask for use with wet or dry etching techniques to form the desired surface features.