A phase shift mask includes a first non-phase shift region, a first phase
shift region adjacent the first non-phase shift region, a second
non-phase shift region, a second phase shift region adjacent the second
non-phase shift region, and an opaque region interposed between said
second phase shift and non-phase shift regions. The first and second
non-phase shift regions transmit an exposure light at its original phase,
whereas the first and second phase shift regions invert the phase of the
exposure light. The phase shift mask is manufactured by first forming a
layer of opaque material on a transparent mask substrate. The first phase
shift region and the second phase and non-phase shift regions are formed
by selectively etching the opaque material and underlying portions of the
mask substrate to form recesses in the substrate. On the other hand, only
the opaque layer is etched from the mask substrate to form the first
non-phase shift region, and is left on the substrate between the second
phase shift and non-phase shift regions.