Method of performing design rule checking
AssigneeInternational Business Machines Corporation
InventorsHenry Bonges, David Reynolds, James Sundquist
Life of this patent
Estimating the term…
Abstract
A method of performing latch up check on an integrated circuit (IC) design that comprises rasterizing a conductor region shape and contact shapes and iteratively expanding the contact shapes within the conductor region shape using a cellular algorithm. Direction values for contact cells can be used to limit the number of neighboring cells which must be explored. In every fourth iteration of the expansion process, corner cells may not be expanded. Reachable areas outside of conductors can also be explored.
Claims20
A method of performing latch up check on an integrated circuit (IC) design comprising the steps of:
- computing a combined least enclosing rectangle enclosing a conductor region shape and contact shapes;
- rasterizing the conductor region shape and the contact shapes;
- iteratively expanding the contact shapes within the conductor region shape using a cellular algorithm;
- generating shapes representing an unreachable area of the conductor region shape;
- and
- checking the shapes representing the unreachable area of the conductor region shape against junction shapes in the design, and reporting to a designer any junction shapes which intersect the unreachable area as errors.
A method of performing latch up check on an integrated circuit (IC) design comprising the steps of:
- rasterizing vector domain images of a conductor region shape and well contact shapes;
- iteratively expanding the well contact shapes using a cellular algorithm;
- extracting unreachable areas of the conductor region shape by detecting chains of unreachable cells;
- converting unreachable areas into shapes, and returning these shapes as unreachable areas in the vector domain;
- checking the unreachable areas against junction shapes in the design;
- and
- flagging any junction shapes which intersect the unreachable areas as errors.
A computer program product comprising:
- a computer usable medium having computer readable program code means embodied therein for performing latch up check on an integrated circuit (IC) design;
- computer readable program code means for causing a computer to rasterize vector domain images of a conductor region shape and well contact shapes;
- computer readable program code means for causing the computer to iteratively expand the contact shapes using a cellular algorithm;
- computer readable program code means for causing the computer to extract unreachable areas of the conductor region shape by detecting chains of unreachable cells;
- computer readable program code means for causing the computer to convert unreachable areas into shapes, and returning these shapes as unreachable areas in the vector domain;
- and
- computer readable program code means for causing the computer to check the unreachable areas in the vector domain against junction shapes in the design, and to flag any junction shapes which intersect the unreachable areas as errors.
Dependencies are inferred from the claim text.