International Business Machines Corporation

William F DeCamp

Daniel J Nickel

John J Ellis-Monaghan

Peter Anton Habitz

Richard Quimby Williams

Edward W Seibert

Joseph J Oler, Jr

James Robert Montstream

Jason Steven Minahan

Laurice Thorsen Earl

A system, method and program product for performing density checking of an IC design. The invention establishes an evaluation array for the IC design including an array element for each evaluation window of the IC design. The number of evaluation windows is based on a smallest necessary granularity. A single pass through shape data for the IC design is then conducted to populate each array element with a shape area for a corresponding evaluation window. Density checking is performed by iterating over the evaluation array using a sub-array. The sub-array may have the size of the preferred density design rule window. The invention removes the need for repetitive calculations, and results in a more efficient approach to density checking.

IC design density checking method, system and program product

A method using a generate-and-verify computer program product to generate by repetitive passes a design rules checking computer program, wherein the design rules are described in a file called a runset. The design rules checking program is used for exhaustive testing of VLSI chips for compliance to the design rules of a given VLSI fabrication process. The runset is repeatedly iterated in loop fashion with respect to a testcase file containing groups of layout structures or shapes used for verifying the correctness of the runset. A general purpose shapes processing program creates an error shapes file for storing geometrical errors found in each said layout structure. Two additional shapes are used in the verification process: user boundary shapes for defining areas in which errors are not to be detected for a given design rule, and automated boundary shapes created to surround each said layout structure with a boundary that defines regions where error shapes can occur. An association table is created which is a compilation of the error shapes, user boundary shapes, and automated boundary shapes associated with each layout structure. The association table is processed to determine the correctness of the runset. The runset is modified to correct each valid error. The repetitive passes continue until a final runset is generated. This final runset becomes the input to design rules checking computer program product and customizes the program for a given VLSI fabrication process.

Method for verifying design rule checking software

According to the present embodiment, a method for calculating the parasitic capacitance in a semiconductor device is disclosed. According to the preferred method, a layout file containing the shapes of a semiconductor device is provided. The dimensions of the layout file are then adjusted to wafer dimensions so as reflect actual production devices. The shapes of the layout file are then partitioned into simpler shapes, typically abutted rectangles, called tiles. Each tile is then decomposed into overlap and fringe capacitance components, each component having a uniform capacitance environment with respect to its capacitance elements. The parasitic capacitance of the semiconductor device can thus be accurately computed, with an efficient use of resources. Additionally the preferred embodiment is easily adaptable to a wide range of technology types.

Method and apparatus for modeling capacitance in an integrated circuit

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Williston, VT, United States of America

William F DeCamp