Method of manufacturing binary phase shift mask

摘要

A method of manufacturing a binary phase shift photomask. A phase shift layer and a mask layer are sequentially formed over a transparent substrate. The mask layer and the phase shift layer are patterned to form a plurality of first openings and a plurality of second openings that expose a portion of the transparent substrate. The mask layer is patterned to form a layer of mask material around the edges of the first openings. All first openings occupy an area greater than a preset minimum area while all second openings occupy an area greater than the preset minimum area. The mask layer only surrounds the first openings while the phase shift layer surrounds both the first and the second openings.