Patents by Inventor Lars Liebmann
Lars Liebmann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20070226674Abstract: System and Method for Semiconductor Device Fabrication Using Modeling System and method for using adjustment patterns as well as physical parameters as targets to control mask structure dimensions using optical proximity correction. A preferred embodiment includes defining targets based on definition rules and adjusting mask layer structures based on the targets. The targets comprise structures that are visible in the reproduced pattern as well as targets that affect geometric properties. The targets that affect geometric properties include target sacrificial structures that are selected from one or more of the following groups: actual sacrificial structures that are visible only in an intermediate exposure of the reproduced pattern, virtual sacrificial structures of a mask layer having at least one dimension smaller than a minimum dimension required for resolution, and virtual sacrificial structures not part of the reproduced pattern.Type: ApplicationFiled: March 27, 2006Publication date: September 27, 2007Inventors: Henning Haffner, Lars Liebmann, Donald Samuels, Steven Scheer
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Publication number: 20070220476Abstract: A method is provided for designing a mask layout for an integrated circuit that ensures proper functional interaction among circuit features by including functional inter-layer and intra-layer constraints on the wafer. The functional constraints used according to the present invention are applied among the simulated wafer images to ensure proper functional interaction, while relaxing or eliminating the EPE constraints on the location of the wafer images.Type: ApplicationFiled: January 10, 2006Publication date: September 20, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Maharaj Mukherjee, James Culp, Lars Liebmann, Scott Mansfield
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Publication number: 20070212863Abstract: A method of forming a planar CMOS transistor divides the step of forming the gate layer into a first step of patterning a resist layer with a first portion of the gate layer pattern and then etching the polysilicon with the pattern of the gates. A second step patterns a second resist layer with the image of the gate pads and local interconnect and then etching the polysilicon with the pattern of the gate pads and local interconnect, thereby reducing the number of diffraction and other cross-talk from different exposed areas.Type: ApplicationFiled: March 7, 2006Publication date: September 13, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Timothy Brunner, James Culp, Lars Liebmann
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Publication number: 20070106968Abstract: An iterative timing analysis is analytically performed before a chip is fabricated, based on a methodology using optical proximity correction techniques for shortening the gate lengths and adjusting metal line widths and proximity distances of critical time sensitive devices. The additional mask is used as a selective trim to form shortened gate lengths or wider metal lines for the selected, predetermined transistors, affecting the threshold voltages and the RC time constants of the selected devices. Marker shapes identify a predetermined subgroup of circuitry that constitutes the devices in the critical timing path. The analysis methodology is repeated as often as needed to improve the timing of the circuit with shortened designed gate lengths and modified RC timing constants until manufacturing limits are reached. A mask is made for the selected critical devices using OPC techniques.Type: ApplicationFiled: November 8, 2005Publication date: May 10, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: James Culp, Lars Liebmann, Rajeev Malik, K. Paul Muller, Shreesh Narasimha, Stephen Runyon, Patrick Williams
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Publication number: 20070106972Abstract: The present invention is directed to a method for conversion of an integrated circuit design into a set of masks for fabrication of an integrated circuit that optimizes use of an edge based image transfer mask process.Type: ApplicationFiled: November 9, 2005Publication date: May 10, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Lars Liebmann, Jochen Beintner
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Publication number: 20070083847Abstract: A method of conveying the designer's intended electrical characteristics for a semiconductor design is provided by forming tolerance bands for a design layer of interest that take into consideration constraints from design layers that interact with and influence the features on the design layer of interest. The method determines regions, i.e. tolerance bands, within which the printed edges of features of the layer of interest will print within a predetermined criterion, and satisfy a variety of constraints, including, but not limited to, electrical, overlay and manufacturability constraints arising from the influence of features on other layers. The method may be implemented in a computer program product for execution on a computer system. The resulting tolerance bands can be used to efficiently convey the designer's intent to a lithographer, an OPC engineer or a mask manufacturer or tool.Type: ApplicationFiled: October 12, 2005Publication date: April 12, 2007Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Scott Mansfield, Lars Liebmann, Azalia Krasnoperova, Ioana Graur
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Publication number: 20060166105Abstract: A method of designing a mask for projecting an image of an integrated circuit design in lithographic processing, wherein the integrated circuit layout has a plurality of segments of critical width. The method comprises creating a first mask design by aligning mask features used to assist in projecting critical width segments with the critical width segments of the integrated circuit design, such that the first mask design meets predetermined manufacturability design rules, and creating a second mask design by aligning mask features with the critical width segments of the integrated circuit design, such that the second mask design meets predetermined lithographic design rules in regions local to the critical width segments.Type: ApplicationFiled: January 21, 2005Publication date: July 27, 2006Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Lars Liebmann, Zachary Baum
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Publication number: 20060107248Abstract: A system, method and recording medium are provided for generating patterns of a paired set of a block mask and a phase shift mask from a data set defining a circuit layout to be provided on a substrate. A circuit layout is inputted and critical segments of the circuit layout are identified. Then, based on the identified critical segments, block mask patterns are generated and legalized for inclusion in a block mask. Thereafter, based on the identified critical segments and the block mask patterns, phase mask patterns are generated, legalized and colored to define a phase shift mask for use in a dual exposure method with the block mask for patterning the identified critical segments of the circuit layout.Type: ApplicationFiled: December 27, 2005Publication date: May 18, 2006Inventors: Lars Liebmann, Scott Bukofsky, Ioana Graur
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Publication number: 20060057475Abstract: A method of forming a photolithographic mask layout with Sub-Resolution Assist Feature (SRAF) elements on a mask for correcting for proximity effects for a pattern imaged comprising the steps of developing a layout of mask features for printing main pattern features. Provide a table of SRAF element data including spacing of main pattern features and SRAF elements, applying SRAF elements to the mask layout as a function of spacing of main pattern features and SRAF elements, legalizing the SRAF elements as a function of style options, and providing a target pattern comprising a modified layout for the mask, identifying problem edge segments of an SRAF element of the target pattern at risk of causing a printing defect, applying a selected bias to the problem edge segments to modify the pattern where there are areas of SRAF element loss, and providing an output of a modified pattern with modified SRAF elements removing the areas of SRAF element loss.Type: ApplicationFiled: October 17, 2005Publication date: March 16, 2006Inventors: Lars Liebmann, Richard Ferguson, Allen Gabor, Mark Lavin
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Publication number: 20060040188Abstract: A method of designing an alternating phase shifting mask for projecting an image of an integrated circuit design having a plurality of spaced segments of critical dimension. The method initially identifies a phase universe boundary, such that the phase universe comprises a contiguous region of the integrated circuit layout wherein critical dimension segments within the phase universe are beyond a maximum phase interaction distance from any critical dimension segments outside the phase universe in accordance with predetermined design rules. The method then divides the phase universe into phase regions separated by the integrated circuit layout and any extensions of the critical dimension segments so that the phase regions are binary colorable within the phase universe.Type: ApplicationFiled: August 18, 2004Publication date: February 23, 2006Applicant: International Business Machines CorporationInventors: Lars Liebmann, Carlos Fonseca
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Publication number: 20060036977Abstract: A design system for designing complex integrated circuits (ICs), a method of IC design and program product therefor. A layout unit receives a circuit description representing portions in a grid and glyph format. A checking unit checks grid and glyph portions of the design. An elaboration unit generates a target layout from the checked design. A data prep unit prepares the target layout for mask making. A pattern caching unit selectively replaces portions of the design with previously cached results for improved design efficiency.Type: ApplicationFiled: August 12, 2004Publication date: February 16, 2006Inventors: John Cohn, James Culp, Ulrich Finkler, Fook-Luen Heng, Mark Lavin, Jin Lee, Lars Liebmann, Gregory Northrop, Nakgeuon Seong, Rama Singh, Leon Stok, Pieter Woltgens
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Publication number: 20050287444Abstract: A method of designing an alternating phase shifting mask for projecting an image of an integrated circuit design. Phase units are binary colorable within each unit of the hierarchical circuit design, e.g., cell, an array, a net, or array of nets and/or cells, the phase shapes. The assignment of phases or colors within a hierarchical unit will be correctly binary colored to satisfy the lithographic, manufacturability and other design rules, referred to collectively as coloring rules. During assembly with other units, the coloring of phases in a hierarchical unit may change (e.g., be reversed or flipped), but the correct binary colorability of a hierarchical unit is preserved, which simplifies assembly of the integrated circuit layout.Type: ApplicationFiled: June 28, 2004Publication date: December 29, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Ioana Graur, Young Kim, Mark Lavin, Lars Liebmann
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Publication number: 20050202321Abstract: A method for increasing coverage of subresolution assist features (SRAFs) in a layout. A set of possible SRAF placement and sizing rules for a given pitch is provided, ranked according to some figure of merit. During SRAF placement, the fit of a plurality of different SRAF solutions is successively evaluated to find the SRAF solution, or combinations thereof, which most improves lithographic performance while avoiding manufacturability problems. In general, the method comprises: obtaining a plurality of SRAF configurations for the layout; ranking the SRAF configurations based on a figure of merit; applying a highest ranked SRAF configuration to the layout; applying a predetermined number of lower ranked SRAF configurations to the layout; and selecting SRAF features from at least one of the applied SRAF configurations to provide the optimal SRAF configuration for the layout.Type: ApplicationFiled: March 10, 2004Publication date: September 15, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Ronald Gordon, Ioana Graur, Lars Liebmann
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Publication number: 20050175906Abstract: A method of designing a layout of an alternating phase shifting mask for projecting an image of an integrated circuit design having a plurality of features to be projected using alternating phase shifting segments, including a gate-shrink region of a transistor having a critical width along a length thereof that extends beyond a diffusion region. The method also provides alternating phase shift design rules based on alternating phase shift design parameters comprising minimum phase width, minimum phase-to-phase spacing, and minimum extension of critical width beyond another feature. The method then includes identifying portions of the integrated circuit layout having a critical width feature that violate the alternating phase shift design rules, and reducing the length that the critical width gate-shrink region feature extends beyond the other diffusion region feature to the minimum extension.Type: ApplicationFiled: February 5, 2004Publication date: August 11, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Lars Liebmann, Ioana Graur
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Publication number: 20050166175Abstract: A method of designing an alternating phase shifting mask for projecting an image of an integrated circuit design having a plurality of essentially parallel segments of critical width comprises creating essentially parallel alternating phase shifting regions aligned with the critical width segments and extending beyond ends of at least some of the critical width segments, enclosing the integrated circuit layout and the alternating phase shifting regions within a boundary, extending the alternating phase shifting regions to an edge of the boundary, and thereafter creating an alternating phase shifting mask based on the alternating phase shifting regions.Type: ApplicationFiled: January 28, 2004Publication date: July 28, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Lars Liebmann, Zachary Baum
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Publication number: 20050153212Abstract: A method is disclosed for providing associated shapes of an optical lithography mask in relation to predetermined main shapes of the mask. The method includes generating simplified layout patterns from the predetermined main shapes of the mask. Such layout patterns are generated by eliminating detail of the main shapes which leads to unmanufacturable associated shapes while preserving geometrically relevant shape information. The associated shapes are then generated relative to the simplified mask patterns.Type: ApplicationFiled: January 12, 2004Publication date: July 14, 2005Applicant: International Business Machines CorporationInventors: Mark Lavin, Lars Liebmann, Scott Mansfield, Maharaj Mukherjee, Zengqin Zhao
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Publication number: 20050014074Abstract: A method of generating patterns of a pair of photomasks from a data set defining a circuit layout to be provided on a substrate includes identifying critical segments of the circuit layout to be provided on the substrate. Block mask patterns are generated and then legalized based on the identified critical segments. Thereafter, phase mask patterns are generated, legalized and colored. The legalized block mask patterns and the legalized phase mask patterns that have been colored define features of a block mask and an alternating phase shift mask, respectively, for use in a dual exposure method for patterning features in a resist layer of a substrate.Type: ApplicationFiled: July 15, 2003Publication date: January 20, 2005Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Lars Liebmann, Scott Bukofsky, Ioana Graur
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Patent number: 5899706Abstract: In preparation for etch processing a semiconductor chip having areas of little or no pattern and areas that are heavily patterned, adding non-operative patterns to the areas having little or no pattern so that the overall pattern density is about the same across the chip.Type: GrantFiled: June 30, 1997Date of Patent: May 4, 1999Assignees: Siemens Aktiengesellschaft, International Business Machines CorporationInventors: Andreas Kluwe, Lars Liebmann, Frank Prein, Thomas Zell