Patents Assigned to Numerical Technologies
  • Patent number: 6681376
    Abstract: A method for determining device yield of a semiconductor device design, comprises determining statistics of at least one device parameter from at least two device layer patterns; and calculating device yield from the statistics. At least one of the device layer patterns is neither a diffusion layer pattern nor a gate poly layer pattern.
    Type: Grant
    Filed: October 17, 2001
    Date of Patent: January 20, 2004
    Assignees: Cypress Semiconductor Corporation, Numerical Technologies, Inc., Sequoia Design Systems
    Inventors: Artur Balasinski, Linard Karklin, Valery Axelrad
  • Publication number: 20040006756
    Abstract: An approach to reducing the size of an output file generated by an optical proximity correction (OPC) process is described. An OPC output can be examined to identify identically sized segments with identical biases. Adjoining segments to those first identified to identify repeating basic shapes. Those basic shapes can be further refined and expanded as desired. Finally, the output is rewritten making use of the repeating shapes in a hierarchical output that places each shape once as a child cell of the original geometry and uses references to that shape in other locations thereby reducing data volume size. The data volume savings can be considerable.
    Type: Application
    Filed: July 3, 2002
    Publication date: January 8, 2004
    Applicant: Numerical Technologies, Inc.
    Inventor: Youping Zhang
  • Publication number: 20040006485
    Abstract: Techniques are provided for manufacturing phase-shifted masks. According to one technique, a facilitator provides, on behalf of a set of one or more parties that desire masks, subsidies for production of phase-shifted masks. The manufacture of the phase-shifted masks is paid using compensation that includes the subsidies from the facilitator. One or more mask makers manufacture the phase-shifted masks for the compensation. The facilitator receives, from the set of one or more parties, compensation for the subsidies based on one or more factors including a factor that reflects market success of integrated circuits produced using the phase-shifted masks. In addition to the subsidies, the facilitator may provide a variety of value-added services.
    Type: Application
    Filed: December 27, 2000
    Publication date: January 8, 2004
    Applicant: Numerical Technologies, Inc.
    Inventors: J. Tracy Weed, Christophe Pierrat, Yagyensh (Buno) Pati, Atul Sharan
  • Patent number: 6670082
    Abstract: An accurate, cost-effective system and method for correcting 3D effects on an alternating phase-shifting mask (PSM) is provided. To facilitate this correction, a library can be built to include a first group of 180 degree phase-shifting regions, wherein these regions have a common first size. Based on this first size, 3D simulation is performed. A transmission and a phase are altered in a 2D simulation based on this first size until a shape dependent transmission and a shape dependent phase allow the 2D simulation to substantially match the 3D simulation. Finally, a modified first size is chosen using the shape dependent transmission and the shape dependent phase such that a 2D simulation based on the modified first size substantially matches the 3D simulation based on the first size. The library associates the first size with the modified first size, the shape dependent transmission, and the shape dependent phase.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: December 30, 2003
    Assignee: Numerical Technologies, Inc.
    Inventors: Yong Liu, Hua-Yu Liu
  • Patent number: 6664009
    Abstract: Phase shifting layouts and masks with phase conflicts are described. The phase shifting layout defines light transmissive regions for use in defining selected features in a layer of material of an integrated circuit (IC). The phase shifting layout includes a phase conflict caused by two light transmissive regions that are out of phase with each other and which, without correction, would lead to the definition of an artifact in the layer of material. A corresponding mask adapted for use in conjunction with the phase shifting mask can ensure that the artifact is ultimately erased. The phase conflict is intentionally introduced into the phase shifting layout during phase assignment to permit all of the selected features to be defined using the phase shifting mask.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: December 16, 2003
    Assignee: Numerical Technologies, Inc.
    Inventor: Hua-Yu Liu
  • Patent number: 6665856
    Abstract: Techniques for forming a fabrication layout, such as a mask, for a physical design layout, such as a layout for an integrated circuit, 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: December 1, 2000
    Date of Patent: December 16, 2003
    Assignee: Numerical Technologies, Inc.
    Inventors: Christophe Pierrat, Youping Zhang
  • Publication number: 20030229879
    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: Application
    Filed: June 11, 2002
    Publication date: December 11, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Christophe Pierrat
  • Patent number: 6658640
    Abstract: A method of optimizing a wafer fabrication process for a given mask is provided. The method includes capturing an image of a mask and simulating a wafer image of the mask. A mask map of information can then be generated based on the simulated wafer image. The resulting mask map can be provided to any downstream wafer fabrication process when such process involves the mask. One or more one input parameters to the downstream wafer fabrication process can be changed based on the mask map, thereby optimizing the process for the given mask.
    Type: Grant
    Filed: December 26, 2001
    Date of Patent: December 2, 2003
    Assignee: Numerical Technologies, Inc.
    Inventor: J. Tracy Weed
  • Patent number: 6653026
    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: December 20, 2000
    Date of Patent: November 25, 2003
    Assignee: Numerical Technologies, Inc.
    Inventors: Christophe Pierrat, Youping Zhang
  • Publication number: 20030215616
    Abstract: One embodiment of the invention provides a system that uses pupil filtering to mitigate optical proximity effects that arise during an optical lithography process for manufacturing an integrated circuit. During operation, the system applies a photoresist layer to a wafer and then exposes the photoresist layer through a mask. During this exposure process, the system performs pupil filtering, wherein the pupil filtering corrects for optical proximity effects caused by an optical system used to expose the photoresist layer.
    Type: Application
    Filed: May 15, 2002
    Publication date: November 20, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Christophe Pierrat
  • Publication number: 20030211401
    Abstract: A method and system produce alternating phase shift masks using multiple phase shift mask resolution levels for multiple feature classes.
    Type: Application
    Filed: September 26, 2002
    Publication date: November 13, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Shao-Po Wu
  • Publication number: 20030208728
    Abstract: A method of modeling an edge profile for a layer of material is provided. The layer of material can include a resist and/or an etch. In this method, multiple models can be generated, wherein at least two models correspond to different elevations on the wafer. Each model includes an optical model, which has been calibrated using test measurements at the respective elevations. In this manner, an accurate edge profile can be quickly created using the multiple models. Based on the edge profile, layout, mask, and/or process conditions can be modified to improve wafer printing.
    Type: Application
    Filed: May 1, 2002
    Publication date: November 6, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Christophe Pierrat
  • Patent number: 6635393
    Abstract: A conductive blank enables election beam (e-beam) patterning rather than optical patterning for the phase level etch of a phase-shifting mask (PSM) photomask. The conductive blank includes a conductive layer between a chrome (pattern) layer and a quartz substrate. The chrome layer is patterned with in-phase and phased features, and then is recoated with a resist layer. An e-beam exposure tool exposes the resist layer over the phased features. The still intact conductive layer under the chrome layer dissipates any charge buildup in the resist layer during this process. A phase level etch then etches through the conductive layer and creates a pocket in the quartz. A subsequent isotropic etch through both the in-phase and phased features removes the conductive layer at the in-phase features and improves exposure radiation transmission intensity. Alternatively, a visually transparent conductive layer can be used, eliminating the need to etch through the in-phase features.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: October 21, 2003
    Assignee: Numerical Technologies, Inc.
    Inventor: Christophe Pierrat
  • Publication number: 20030192015
    Abstract: By using a test pattern that has been corrected according to an optical model to prepare test wafers, better data can be obtained for calibrating the optical model. As a result: fewer measurements need to be taken from the wafer to calibrate the model and the measurements that are taken are more valuable because they better assist in calibrating the model. Embodiments of the invention include data comprising the corrected test pattern, masks including the corrected test pattern, and methods and apparatuses for using the modified test pattern. Additionally, by taking more measurements closer to the target dimensions, more information is available for performing optical proximity correction of layouts. Another benefit includes increased ease of model accuracy determinations.
    Type: Application
    Filed: April 4, 2002
    Publication date: October 9, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Hua-yu Liu
  • Publication number: 20030192013
    Abstract: One embodiment of the invention provides a system that simulates effects of a manufacturing process on an integrated circuit to enhance process latitude and/or reduce layout size. During operation, the system receives a representation of a target layout for the integrated circuit, wherein the representation defines a plurality of shapes that comprise the target layout. Next, the system simulates effects of the manufacturing process on the target layout to produce a simulated printed image for the target layout. The system then identifies problem areas in the specification that no not meet a specification. Next, the system moves corresponding shapes in the target layout to produce a new target layout for the integrated circuit, so that a simulated printed image of the new target layout meets the specification.
    Type: Application
    Filed: April 5, 2002
    Publication date: October 9, 2003
    Applicant: Numerical Technologies, Inc.
    Inventors: Michel Luc Cote, Philippe Hurat, Christophe Pierrat
  • Publication number: 20030190762
    Abstract: One embodiment of the invention provides a system that facilitates exposing a wafer through at least two masks during an integrated circuit manufacturing process. The system includes a radiation source and two or more illuminators. Each of these illuminators receives radiation from the radiation source, and uses the radiation to illuminate a reticle holder. The radiation that passes through each reticle holder is then combined in an optical combiner, before passing through an imaging optics, which projects the combined radiation onto a semiconductor wafer.
    Type: Application
    Filed: April 8, 2002
    Publication date: October 9, 2003
    Applicant: Numerical Technologies, Inc.
    Inventors: Yao-Ting Wang, Christophe Pierrat, Fang-Cheng Chang
  • Publication number: 20030192025
    Abstract: An automated phase assignment method is described that allows multiple rules for defining phase shifters to be used within a single cell. The rules for defining phase shifters can be sequenced. Then for a cell, the rules can be recursively applied. At each stage if the number of phase conflicts is below a threshold, then portions of the cell having conflicts are masked and processed using the next less aggressive rule set. This in turn leads to phase shifting masks with greater variation in phase shifter shapes and sizes. When the mask is used to fabricate integrated circuits (ICs), the resulting IC may have a greater number of small transistors and other features than a mask defined using only a single rule set per cell. Additional benefits can include better process latitude during IC fabrication and improved yield.
    Type: Application
    Filed: April 3, 2002
    Publication date: October 9, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Hua-Yu Liu
  • Publication number: 20030192012
    Abstract: A critical dimension, or width, of a feature, or a semiconductor device, can be measured to provide direct and meaningful information regarding the impact of line end shortening, or length, on the function of the device. Specifically, a location on the feature where the width will have an impact on device performance can be selected. Using a simulation, the width at that location can be computed. Given the difficulties of direct measurement of line end shortening and the relationship between the width measurement and the impact on device performance, better layout checking is facilitated than by standard measurements of line end shortening.
    Type: Application
    Filed: April 3, 2002
    Publication date: October 9, 2003
    Applicant: Numerical Technologies, Inc.
    Inventor: Hua-Yu Liu
  • Publication number: 20030188283
    Abstract: One embodiment of the invention provides a system for speeding up processing of a layout of an integrated circuit that has been divided into cells. The system operates by determining if a target cell in the layout is identical to a preceding cell for which there exists a previously calculated solution by comparing an identifier created from the target cell with an identifier created from the preceding cell. If the target cell is identical to a preceding cell, the system uses the previously calculated solution as a solution for the target cell. Otherwise, if the target cell is not identical to the preceding cell, the system processes the target cell to produce the solution for the target cell. Note that this approach can also be used for a number of different processes, such as distributed fracturing or optical proximity correction.
    Type: Application
    Filed: March 15, 2002
    Publication date: October 2, 2003
    Applicant: Numerical Technologies, Inc.
    Inventors: Kevin D. MacLean, Roger W. Sturgeon
  • Patent number: 6625801
    Abstract: Techniques for fabricating a device include forming a fabrication layout, such as a mask layout, for a physical design layer, such as a design for an integrated circuit, and identifying evaluation points on an edge of a polygon corresponding to the design layer for correcting proximity effects. Techniques include correcting for proximity effects associated with an edge in a first fabrication layout by determining whether any portion of the edge corresponds to a target edge in a design layer. The first fabrication layout corresponds to the design layer that indicates target edges for a printed features layer. If any portion of the edge corresponds to the target edge, then it is determined whether to establish an evaluation point on the edge. Then it is determined how to correct the edge for proximity effects based on the evaluation point. In case it is determined that no portion of the edge corresponds to the target edge, then no evaluation point is selected on the edge.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: September 23, 2003
    Assignee: Numerical Technologies, Inc.
    Inventors: Christophe Pierrat, Youping Zhang