Increasing the Depth-of-Focus using an Axicon in Photolithography
Appl. Opt., Vol. 34, No. 20, pp. 4105-4110 (1995).
T. Tanaka and S. Kawata

Abstract
We propose a photolithography system that incorporates an axicon as a focusing lens. This system attains an extremely long depth of focus compared with a conventional photolithography system. We designed an axicon and developed a photolithography system with the axicon. Experimental results are shown to demonstrate that the developed system provides a super long depth of focus as well as high lateral resolution. The effects of spherical aberration for the three-dimensional imaging in high-refractive index material like as photoresist is theoretically analyzed to verify the advantage of the photolithography with an axicon.