| 摘要 |
A half-tone phase shift mask includes a transparent substrate, a phase shift pattern formed on the semiconductor substrate and having a stepped aperture which exposes the transparent substrate by a predetermined width, and an opaque film pattern formed on the upper surface of the phase shift pattern. The stepped aperture is defined by an interior side wall of the phase shift pattern. This side wall includes a horizontal surface which is parallel to the surface defining the bottom of the aperture. Light transmitted by the mask via the surface defining the bottom of the aperture has a phase difference of 180 degrees with respect to light transmitted by the mask via the horizontal surface, and light transmitted by the mask via the surface defining the bottom of the aperture has a phase difference of more than 180 degrees with respect to light transmitted by the mask via the upper surface of the phase shift pattern. Accordingly, the half-tone phase shift mask includes a first transmissive region for blocking light, a second transmissive region that sets the width of a pattern to be formed on photosensitive film, a third transmissive region for causing light transmitted thereby to be out of phase by 180 degrees with respect to the light transmitted by the second transmissive region, and a fourth transmissive region having a width greater than the width of the third transmissive region for causing light transmitted thereby to be out of phase by more than 180 degrees with respect to light transmitted by the second transmissive region.
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