International Business Machines Corporation

Globalfoundries Inc.

David J Widiger

Lewis William Dewey, Iii

Ronald Dennis Rose

Susan Elizabeth Cellier

Ibrahim M Elfadel

Sharad Mehrotra

Adam P Matheny

Byron Lee Krauter

Anthony D Hagin

Sandy K Kao

Steven Joseph Kurtz

Tarek Ali El Moselhy

Gerald F Plumb

Bruce Martin Fleischer

Paul Gerard Villarrubia

Robert J Allen

Terry I Chappell

Barbara A Chappell

Howard Harold Smith

Gerard Vincent Kopcsay

Gregory M Schaeffer

Barry Jay Rubin

Alina Deutsch

Patrick M Williams

Chandramouli V Kashyap

Michael Alexander Bowen

Gary Stephen Ditlow

Michael P Beakes

Barry Lee Dorfman

Vinod Narayanan

Ghavam G Shahidi

Ying Liu

Debjit Sinha

Robert Alan Philhower

Parsotam Trikam Patel

Soroush Abbaspour

Mark Walz Wenning

Ayesha Akhter

Haihua Su

Harold E Reindel

Tarek A El-Moselhy

George Anthony Halasz

Ron D Rose

Jonathan Humphrey Saxman

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

The accuracy of electronic design automation is increased by determining whether fill wires in a putative integrated circuit design should be effectively grounded or floating. For each signal wire in the putative design adjacent to the fill wires, a signal sensitivity value, which represents sensitivity of a given one of the plurality of signal wires to noise and timing, is determined. For each one of the fill wires, a fill sensitivity value is determined by: identifying coupling of each one of the fill wires to the adjacent signal wires; and calculating the fill sensitivity value as a combination of the signal sensitivity values of each of the adjacent signal wires for which the coupling has been identified. At least a portion of the fill wires are selectively effectively grounded based on the fill sensitivity value, to obtain a modified design.

Selectively grounding fill wires

A system and method to perform capacitance extraction involves defining a location of signal wires and floating metal of an integrated circuit design. The method includes designating one of the signal wires as a target wire, defining a first area within which first capacitances between the target wire and the floating metal and other signal wires are determined, defining a second area, within which second capacitances between floating metal within the first area and the floating metal and the other signal wires not within the first area are determined, and generating an intermediate capacitive network. The intermediate capacitive network includes the target wire, the floating metal, and the other signal wires within the second area, the first capacitances and the second capacitances. A capacitive network is generated from the intermediate capacitive network. The first capacitances and the second capacitances are used to generate third capacitance values of the capacitive network.

Capacitance extraction for floating metal in integrated circuit

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.

Methods and computer program products for via capacitance extraction

A computer system selects a signal conductor from an electronic circuit design layout and assigns a first potential to the selected signal conductor. Next, the computer system assigns a second potential to other signal conductors included in the electronic circuit design layout. The computer system then selects a metal fill from the electronic circuit design layout, which is void from carrying an electrical signal, and generates a zero charge equation for the selected metal fill. The zero charge equation establishes that a total charge residing on the selected metal fill is equal to zero. The computer system includes the zero charge equation in a system of equations, which includes grid point potential equations, and solves the system of equations. In turn, the computer system computes capacitance values for the signal conductors based upon the system of equation solutions, and simulates the electronic circuit design layout using the computed capacitance values.

Generating capacitance look-up tables for wiring patterns in the presence of metal fills

The present disclosure is directed to a method for extracting information for a circuit design. The method may utilize an incremental extraction process for extracting information for a portion of the circuit design. Extracted results of this portion may be merged with a previously extracted result to obtain an integrated result that is equivalent to that of extracting the entire circuit design. The incremental extraction process may identify a set of changed shapes, a set of affected shapes, and a set of involved shapes for extraction. The method may also divide the circuit design into a plurality of regions, wherein two or more regions may be processed in parallel.

Method for extracting information for a circuit design

The present disclosure is directed to a method for extracting information for a circuit design. The method includes establishing a reflexive relationship between a plurality of design shapes corresponding to a plurality of circuit components in the circuit design. The method includes receiving a design change for at least one design shape of the plurality of design shapes. The method includes identifying a set of changed shapes, a set of affected shapes, and a set of involved shapes. The method includes extracting at least one of a capacitance, an inductance or a resistance for the updated circuit design based on at least one of the set of changed shapes, the set of affected shapes and the set of involved shapes. The method includes updating the plurality of circuit components in the circuit design based on at least one of the set of changed shapes and the set of affected shapes.

Computing the gradients of capacitances in an integrated circuit chip layout with respect to design and process parameters is described. Included is a shape processing engine in the form of a variational mapping engine and a capacitance calculation engine that includes a gradient calculation engine. The variational mapping engine translates physical parameter variations into variations on the edges of the elementary patterns to which the layout of the integrated circuit is decomposed. The gradient calculation engine computes capacitance gradients by combining information from two sources. The first source consists of pre-existing gradients in a capacitance lookup table. The second source consists of analytical expressions of capacitance correction factors.

Method for calculating capacitance gradients in VLSI layouts using a shape processing engine

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Pflugerville, TX, United States of America

David J Widiger