Phase shift masking for complex patterns with proximity adjustments

A method of designing masks for making integrated circuits with phase shifting, comprising:

• identifying a pattern for a layer to be formed using photolithography, the pattern including a plurality of intersecting line segments defining intersections with a plurality of inside corners;
• and
• laying out a phase shift mask, including:
• laying out phase shift regions for the identified pattern extending adjacent to line segments in the plurality of intersecting line segments, the phase shift regions stopping short of inside corners of the plurality of inside corners;
• and
• laying out an opaque field extending into the inside corners of the plurality of inside corners.

A method of designing masks for making integrated circuits with phase shifting, comprising:

• identifying a pattern for a layer to be formed using photolithography, the pattern including a plurality of intersecting line segments defining intersections with a plurality of inside corners;
• and
• laying out a phase shift mask, including:
• laying out, in an opaque field, phase shift regions for the identified pattern extending adjacent to line segments in the plurality of intersecting line segments and around the plurality of inside corners;
• and
• dividing the phase shift regions by extending the opaque field into portions of the phase shift regions at the plurality or inside corners;
• and
• laying out a complementary mask including a plurality of opaque features preventing exposure of the plurality of intersecting line segments to be exposed using the phase shift mask.

A method of designing masks for making integrated circuits with phase shifting, comprising:

• identifying a pattern for a layer to be formed using photolithography, the pattern including a plurality of intersecting line segments defining intersections with a plurality of inside corners;
• and
• laying out a phase shift mask, including:
• laying out, in an opaque field, phase shift regions for the identified pattern extending adjacent to line segments in the plurality of intersecting line segments and around the plurality of inside corners;
• and
• dividing the phase shift regions by extending the opaque field into portions of the phase shift regions at the plurality of inside corners.