Patent ID: 6901574

Claim:
A method of creating a file that describes a layer of an integrated circuit for use by a mask writing tool, comprising: receiving a hierarchical input file that defines a number of cells, each of which defines one or more polygons corresponding to patterns to be created on a mask, and may include references to other cells; selecting one or more cells from the hierarchical input file; modifying the selected cells to include the polygons or portions thereof found in overlapping placements of the non-selected cells and the placements of the selected cells; creating one or more remainder cells to include polygons or portions thereof defined in the placements of non-selected cells that are not within the modified, selected cells; and creating a file for use by a mask writing tool by eliminating the non-selected cells such that the description of the modified, selected cells and the one or more remainder cells with their placements describe the layer of the integrated circuit.