International Business Machines Corporation

Susan Elizabeth Cellier

David J Widiger

Lewis William Dewey, Iii

Ronald Dennis Rose

Adam P Matheny

Anthony D Hagin

Robert J Allen

Steven Joseph Kurtz

Patrick M Williams

Ron D Rose

An effective spacing is calculated for each physical spacing between two or more neighbor nets of a target net. Segment boundaries are determined based on the calculated effective spacing to define segments for the target net and one of the segments is selected. A metal configuration for the selected segment is identified and a table of capacitance per-unit-length is accessed for the identified metal configuration to return an above capacitance value, a below capacitance value, a left-side capacitance value, and a right-side capacitance value for the corresponding segment, the table comprising at least a two-dimensional (2D) table. The capacitance values are scaled based on a corresponding segment length determined from the calculated effective spacing. The selecting, identifying, accessing and scaling operations are repeated for each remaining segment of the target net. Optionally, the above, below, left, and right capacitance values for all segments of the target net are summed.

Capacitance extraction

An integrated circuit includes a target wiring layer, a first adjacent wiring layer above the target wiring layer, and a second adjacent wiring layer below the target wiring layer. Each adjacent wiring layer including crossing wires orthogonal to the target wiring layer. Modify a putative design of the integrated circuit by selecting a target wire; identifying lateral neighbors of the target wire; defining regions of the target wire where the lateral neighbors are homogeneous in cross-section; for each region of the target wire, calculating a wire pattern for the crossing wires; identifying segments within above and below portions of the wire pattern; for each above and below segment pair, obtaining a per-unit-length capacitance from a reduced pattern database; extracting a total parasitic capacitance from the per-unit-length pattern capacitances; and in response to an assessment of the impact of the total parasitic capacitance on circuit performance, producing a modified design.

Extracting parasitic capacitance from circuit designs

A computer-implemented method for extracting a capacitance for a target wire of an integrated circuit includes receiving a design of the integrated circuit having a plurality of wiring layers and selecting a target wire to perform the capacitance extraction. The method further includes determining a first adjacent wiring layer and a second adjacent wiring layer and removing a first subset and a second subset of a plurality of non-adjacent wiring layers from the plurality of wiring layers. The method includes approximating a first plate to be used in the extraction based on the first subset of the plurality of non-adjacent wiring layers and approximating a second plate to be used in the extraction based on the second subset of the plurality of non-adjacent wiring layers and performing the extraction of the target wire based on the first and second adjacent wiring layers and the first and second plates.

Method for improving capacitance extraction performance by approximating the effect of distant shapes

Disclosed is a method for improving capacitance extraction performance in a circuit, the method including mapping, via a computing resource, a first layout including a plurality of wiring paths, selecting at least one target wire from the plurality of wiring paths, selecting at least one group of wires running orthogonally to the at least one target wire, identifying and selecting within the at least one group at least one set of two or more wires that are combinable for representation as a single merged wire, mapping a second layout, via the computing resource, and representing the at least one set of two or more wires as the single merged wire in said second layout, analyzing parasitic capacitance between the at least one target wire and the at least one group of wires using the second layout, and manufacturing the circuit using information from the analyzing of parasitic capacitance.

Process for improving capacitance extraction performance

Embodiments include methods, processing systems and computer program products for extracting via capacitance. Aspects include placing various shapes of target nets of an IC into a Cshapes collection and a CshapesVia collection, processing the shapes in these collections and placing the processed shapes into a Ctile collection and a CtilesVia collection, and extracting via capacitance of the target nets through each of Cshapes, CshapesVia, Ctiles, and CtilesVia collections. In exemplary embodiments, the processing operation includes: reducing the complexity of the shapes in the shape collections, removing all overhang shapes, and all overlapped shapes from the shape collections, and unioning the shapes in the Cshapes collection and the CshapesVia collection, respectively. Unioning operation includes: unioning shapes from Cshapes collection into a non-overlapping Ctiles collection, unioning shapes from CshapesVia collection into a non-overlapping CtileVia collection, computing the tile intersections of Cshapes collection and CshapesVia collection, and removing intersections from CshapesVia collection.

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Hopewell Junction, NY, United States of America

Susan Elizabeth Cellier