Method of designing and method of using a phase-shift mask

摘要

Method for utilizing halftoning structures (1704) to manipulate the relative magnitudes of diffraction orders to ultimately construct the desired projected-image. At the resolution limit of the mask maker, this is especially useful for converting strongly shifted, no-0-diffraction-order, equal-line-and-space chromeless phase edges to weak phase-shifters that have some 0 order. Halftoning creates an imbalance in the electric field between the shifted regions, and therefore results in the introduction of the 0 diffraction order.