Patents by Inventor Christophe Pierrat

Christophe Pierrat 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).

  • Patent number: 7348108
    Abstract: A method for defining a full phase layout for defining a layer of material in an integrated circuit is described. The method can be used to define, arrange, and refine phase shifters to substantially define the layer using phase shifting. Through the process, computer readable definitions of an alternating aperture, dark field phase shift mask and of a complimentary mask are generated. Masks can be made from the definitions and then used to fabricate a layer of material in an integrated circuit. The separations between phase shifters, or cuts, are designed for easy mask manufacturability while also maximizing the amount of each feature defined by the phase shifting mask. Cost functions are used to describe the relative quality of phase assignments and to select higher quality phase assignments and reduce phase conflicts.
    Type: Grant
    Filed: September 10, 2004
    Date of Patent: March 25, 2008
    Assignee: Synopsys, Inc.
    Inventors: Michel L. Cote, Christophe Pierrat
  • Patent number: 7312003
    Abstract: A method for defining a full phase layout for defining a layer of material in an integrated circuit is described. The method can be used to define, arrange, and refine phase shifters to substantially define the layer using phase shifting. Through the process, computer readable definitions of an alternating aperture, dark field phase shift mask and of a complimentary mask are generated. Masks can be made from the definitions and then used to fabricate a layer of material in an integrated circuit. The separations between phase shifters, or cuts, are designed for easy mask manufacturability while also maximizing the amount of each feature defined by the phase shifting mask. Cost functions are used to describe the relative quality of phase assignments and to select higher quality phase assignments and reduce phase conflicts.
    Type: Grant
    Filed: March 12, 2004
    Date of Patent: December 25, 2007
    Assignee: Synopsys, Inc.
    Inventors: Michel L. Cote, Christophe Pierrat
  • Patent number: 7236916
    Abstract: A structure and method are provided for correcting the optical proximity effects on a tri-tone attenuated phase-shifting mask. An attenuated rim, formed by an opaque region and an attenuated phase-shifting region, can be kept at a predetermined width across the mask or for certain types of structures. Typically, the attenuated rim is made as large as possible to maximize the effect of the attenuated phase-shifting region while still preventing the printing of larger portions of the attenuated phase-shifting region during the development process.
    Type: Grant
    Filed: September 9, 2003
    Date of Patent: June 26, 2007
    Assignee: Synopsys, Inc.
    Inventors: Christophe Pierrat, Youping Zhang
  • Patent number: 7178128
    Abstract: Methods and apparatuses for preparing layouts and masks that use phase shifting to enable production of subwavelength features on an integrated circuit in close (optical) proximity to other structures are described. One embodiment selects from several strategies for resolving conflicts between phase shifters used to define features and (optically) proximate structures that are being defined other than by phase shifting. One embodiment adds additional phase shifters to define the conflicting structures. Another embodiment corrects the shape of the phase shifters in proximity to a conflicting structure. Resulting integrated circuits can include a greater number of subwavelength features even in areas that are in close proximity to structures that were not initially identified for production using a phase shifting mask.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: February 13, 2007
    Assignee: Synopsys Inc.
    Inventors: Hua-Yu Liu, Christophe Pierrat, Kent Richardson
  • Patent number: 7169515
    Abstract: A photolithographic mask used for defining a layer in an integrated circuit, or other work piece, where the layer comprises a pattern including a plurality of features to be implemented with phase shifting in phase shift regions is laid out including for patterns comprising high density, small dimension features, and for “full shift” patterns. The method includes identifying cutting areas for phase shift regions based on characteristics of the pattern. Next, the process cuts the phase shift regions in selected ones of the cutting areas to define phase shift windows, and assigns phase values to the phase shift windows. The phase shift values assigned comprise ? and ?, so that destructive interference is caused in transitions between adjacent phase shift windows having respective phase shift values of ? and ?. In the preferred embodiment, ? is equal to approximately ?+180 degrees.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: January 30, 2007
    Assignee: Synopsys, Inc.
    Inventors: Christophe Pierrat, Michel Luc Côté
  • Patent number: 7165234
    Abstract: Shifters on a phase shifting mask (PSM) can be intelligently assigned their corresponding phase. Specifically, the phase of a shifter can be assigned based on simulating the contrast provided by each phase for that shifter. The higher the contrast, the better the lithographic performance of the shifter. Therefore, the phase providing the higher contrast can be selected for that shifter. To facilitate this phase assignment, a pre-shifter can be placed relative to a feature on the layout. The pre-shifter can then be divided into a plurality of shifter tiles for contrast analysis. Model-based data conversion allows for a comprehensive solution including both phase assignment as well as optical proximity correction.
    Type: Grant
    Filed: May 12, 2004
    Date of Patent: January 16, 2007
    Assignee: Synopsys, Inc.
    Inventor: Christophe Pierrat
  • Publication number: 20070007615
    Abstract: Devices including multiple undercut profiles in a single material are disclosed. A resist pattern is applied over a work piece and a wet etch is performed to produce an undercut in the material. This first wet etch is followed by a polymerizing dry etch that produces a polymer film in the undercut created by the first wet etch. The polymer film prevents further etching of the undercut portion during a second wet etch. Thus, an undercut profile can be obtained having a larger undercut in an underlying portion of the work piece, utilizing only a single resist application step. The work piece may be a multi-layer work piece having different layers formed of the same material, or it may be a single layer of material.
    Type: Application
    Filed: May 17, 2006
    Publication date: January 11, 2007
    Inventors: Karen Huang, Christophe Pierrat
  • Publication number: 20070007238
    Abstract: A process for producing multiple undercut profiles in a single material. A resist pattern is applied over a work piece and a wet etch is performed to produce an undercut in the material. This first wet etch is followed by a polymerizing dry etch that produces a polymer film in the undercut created by the first wet etch. The polymer film prevents further etching of the undercut portion during a second wet etch. Thus, an undercut profile can be obtained having a larger undercut in an underlying portion of the work piece, utilizing only a single resist application step. The work piece may be a multi-layer work piece having different layers formed of the same material, or it may be a single layer of material.
    Type: Application
    Filed: May 17, 2006
    Publication date: January 11, 2007
    Inventors: Karen Huang, Christophe Pierrat
  • Publication number: 20070006118
    Abstract: Techniques for forming a mask fabrication layout for a physical integrated circuit design layout include correcting the fabrication layout for proximity effects using a proximity effects model. A proximity effects model is executed to produce an initial output. The initial output is based on a first position for a segment in a fabrication layout. The first position is displaced from a corresponding original edge in the original fabrication layout by a distance equal to an initial bias. The model is also executed to produce a second output based on a second position for the segment. The second position is displaced from the corresponding original edge by a distance equal to a second bias. An optimal bias for the segment is determined based on the initial output and the second output. The segment is displaced in the fabrication layout from the corresponding edge based on the optimal bias.
    Type: Application
    Filed: September 8, 2006
    Publication date: January 4, 2007
    Applicant: Synopsys Inc.
    Inventors: Christophe Pierrat, Youping Zhang
  • Patent number: 7155689
    Abstract: Subtleties of advanced fabrication processes and nano-scale phenomena associated with integrated circuit miniaturization have exposed the insufficiencies of design rules. Such inadequacies have adverse impact on all parts of the integrated circuit creation flow where design rules are used. In addition, segregation of the various layout data modification steps required for deep sub-micrometer manufacturing are resulting in slack and inefficiencies. This invention describes methods to improve integrated circuit creation via the use of a unified model of fabrication processes and circuit elements that can complement or replace design rules. By capturing the interdependence among fabrication processes and circuit elements, the unified model enables efficient layout generation, resulting in better integrated circuits.
    Type: Grant
    Filed: October 7, 2003
    Date of Patent: December 26, 2006
    Assignee: Magma Design Automation, Inc.
    Inventors: Christophe Pierrat, Alfred K. Wong
  • Patent number: 7132203
    Abstract: Techniques are provided for extending the use of phase shift techniques to implementation of masks used for complex layouts in the layers of integrated circuits, beyond selected critical dimension features. The method includes identifying features for which phase shifting can be applied, automatically mapping the phase shifting regions for implementation of such features, resolving phase conflicts which might occur according to a given design rule, and application of assist features and proximity correction features. The method includes applying an adjustment to a phase shift mask pattern including a first and a second phase shift window, and a control chrome with a control width, and/or to a trim mask pattern having a trim shape with a trim width based upon one or both of a rule based correction and a model based correction to improve a match between a resulting exposure pattern and a target feature.
    Type: Grant
    Filed: April 6, 2004
    Date of Patent: November 7, 2006
    Assignee: Synopsys, Inc.
    Inventor: Christophe Pierrat
  • Patent number: 7131101
    Abstract: Techniques for forming a mask fabrication layout for a physical integrated circuit design layout include correcting the fabrication layout for proximity effects using a proximity effects model. A proximity effects model is executed to produce an initial output. The initial output is based on a first position for a segment in a fabrication layout. The first position is displaced from a corresponding original edge in the original fabrication layout by a distance equal to an initial bias. The model is also executed to produce a second output based on a second position for the segment. The second position is displaced from the corresponding original edge by a distance equal to a second bias. An optimal bias for the segment is determined based on the initial output and the second output. The segment is displaced in the fabrication layout from the corresponding edge based on the optimal bias.
    Type: Grant
    Filed: October 16, 2003
    Date of Patent: October 31, 2006
    Assignee: Synopsys Inc.
    Inventors: Christophe Pierrat, Youping Zhang
  • Patent number: 7122281
    Abstract: To print sub-wavelength features on a wafer, a mask set including a full phase PSM (FPSM) and a corresponding trim mask can be used. Phase assignments on the FPSM can result in some feature definition with the trim mask, particularly in non-critical areas. Unfortunately, this limited feature definition can cause significant critical dimension (CD) variations in these non-critical areas. Undesirable critical dimension (CD) variations can be better controlled, even with substantial mask misalignment, by defining multiple feature edge portions with the trim mask in non-critical areas, such as T-intersections, elbows, and other types of intersecting lines.
    Type: Grant
    Filed: November 14, 2002
    Date of Patent: October 17, 2006
    Assignee: Synopsys, Inc.
    Inventor: Christophe Pierrat
  • Publication number: 20060218520
    Abstract: The manufacturing of integrated circuits relies on the use of optical proximity correction (OPC) to correct the printing of the features on the wafer. The data is subsequently fractured to accommodate the format of existing mask writer. The complexity of the correction after OPC can create some issues for vector-scan e-beam mask writing tools as very small slivers are created when the data is converted to the mask write tool format. Moreover the number of shapes created after fracturing is quite large and are not related to some important characteristics of the layout like for example critical areas. A new technique is proposed where the order of the OPC and fracturing steps is reversed. The fracturing step is done first in order to guarantee that no slivers are created and that the number of shapes is minimized. The shapes created can also follow the edges of critical zones so that critical and non-critical edges can be differentiated during the subsequent OPC step.
    Type: Application
    Filed: May 26, 2006
    Publication date: September 28, 2006
    Inventors: Christophe Pierrat, Alfred Wong
  • Publication number: 20060201539
    Abstract: A method and apparatus for cleaning and sealing components of a display utilizes continuous isolation of the components between the cleaning step and the sealing step. This limits exposure of the components to contaminants and isolates the components from oxidizing agents which can cause an oxide to form on the surface of one or more of the components. In one embodiment, a high vacuum transfer station couples a cleaning station and a sealing station to allow a component to be transferred from the cleaning station to the sealing station without leaving the high vacuum. In another embodiment, the apparatus includes a conveyor transferring the components from the cleaning station at a high vacuum to the sealing station at a similarly high vacuum without exposure to the atmosphere.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 14, 2006
    Inventors: Karen Huang, Christophe Pierrat
  • Publication number: 20060205100
    Abstract: A method and apparatus for cleaning and sealing components of a display utilizes continuous isolation of the components between the cleaning step and the sealing step. This limits exposure of the components to contaminants and isolates the components from oxidizing agents which can cause an oxide to form on the surface of one or more of the components. In one embodiment, a high vacuum transfer station couples a cleaning station and a sealing station to allow a component to be transferred from the cleaning station to the sealing station without leaving the high vacuum. In another embodiment, the apparatus includes a conveyor transferring the components from the cleaning station at a high vacuum to the sealing station at a similarly high vacuum without exposure to the atmosphere.
    Type: Application
    Filed: May 11, 2006
    Publication date: September 14, 2006
    Inventors: Karen Huang, Christophe Pierrat
  • Patent number: 7083879
    Abstract: A photolithographic mask used for defining a layer in an integrated circuit, or other work piece, where the layer comprises a pattern including a plurality of features to be implemented with phase shifting in phase shift regions is laid out including for patterns comprising high density, small dimension features, and for “full shift” patterns. The method includes identifying cutting areas for phase shift regions based on characteristics of the pattern. Next, the process cuts the phase shift regions in selected ones of the cutting areas to define phase shift windows, and assigns phase values to the phase shift windows. The phase shift values assigned comprise ? and ?, so that destructive interference is caused in transitions between adjacent phase shift windows having respective phase shift values of ? and ?. In the preferred embodiment, ? is equal to approximately ?+180 degrees.
    Type: Grant
    Filed: August 17, 2001
    Date of Patent: August 1, 2006
    Assignee: Synopsys, Inc.
    Inventors: Christophe Pierrat, Michel Luc Côté
  • Patent number: 7071058
    Abstract: Capacitors, DRAM circuitry, and methods of forming the same are described. In one embodiment, a capacitor comprises a first container which is joined with a substrate node location and has an opening defining a first interior area. A second container is joined with the node location and has an opening defining a second interior area. The areas are spaced apart from one another in a non-overlapping relationship. A dielectric layer and a conductive capacitor electrode layer are disposed operably proximate the first and second containers. In another embodiment, the first and second containers are generally elongate and extend away from the node location along respective first and second central axes. The axes are different and spaced apart from one another. In yet another embodiment, a conductive layer of material is disposed over and in electrical communication with a substrate node location. The layer of material has an outer surface with a first region and a second region spaced apart from the first region.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: July 4, 2006
    Assignee: Micron Technology, Inc.
    Inventors: Martin Ceredig Roberts, Christophe Pierrat
  • Publication number: 20060129968
    Abstract: Proximity effect correction has become a necessary step in the fabrication of integrated circuit in order to improve the pattern fidelity of current lithography processes. Current methodology is limited by data volume increase and correction inaccuracy due to extrapolation of the correction. The invention describes a methodology based on the interpolation of the correction between selected evaluation points of the target layout. By connecting the correction points this technique also provides a mean of reducing data volume and simplifying the mask writing, inspection and repair processes. The same methodology can be applied to layouts with non-printing assist features, where the correction of the assist features is based on the quality of the image of the main feature. For vector-scan mask write tool the segments interpolating the corrections can be fractured in segments with suitable angles.
    Type: Application
    Filed: February 9, 2006
    Publication date: June 15, 2006
    Inventor: Christophe Pierrat
  • Patent number: 7055127
    Abstract: The manufacturing of integrated circuits relies on the use of optical proximity correction (OPC) to correct the printing of the features on the wafer. The data is subsequently fractured to accommodate the format of existing mask writer. The complexity of the correction after OPC can create some issues for vector-scan e-beam mask writing tools as very small slivers are created when the data is converted to the mask write tool format. Moreover the number of shapes created after fracturing is quite large and are not related to some important characteristics of the layout like for example critical areas. A new technique is proposed where the order of the OPC and fracturing steps is reversed. The fracturing step is done first in order to guarantee that no slivers are created and that the number of shapes is minimized. The shapes created can also follow the edges of critical zones so that critical and non-critical edges can be differentiated during the subsequent OPC step.
    Type: Grant
    Filed: October 27, 2003
    Date of Patent: May 30, 2006
    Assignee: Takumi Technology Corp.
    Inventors: Christophe Pierrat, Alfred K. Wong