Integrated evaluation of diffraction image quality in optical lithography using the rigorous diffraction solution for a slot

The method of integrated evaluation of quality of optical diffraction image is proposed. It uses several scalar parameters defined by integral comparison of two functions on the image surface. The first function represents real distribution of electric energy density on this surface, and can be simulated by the solution of corresponding exact or approximate diffraction problem of image formation. The second function describes required energy distribution on the given surface. The method is demonstrated by the example of evaluation of images formed by contactless printing from a mask in optical lithography, where the image function is computed by the known exact solution of plane wave diffraction by a slot in a conducting screen.