Patents by Inventor Lisheng Gao

Lisheng Gao 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).

  • Publication number: 20170307545
    Abstract: Disclosed are methods and apparatus for optimizing a mode of an inspection tool. A first image or signal for each of a plurality of first apertures of the inspection tool is obtained, and each first image or signal pertains to a defect area. For each of a plurality of combinations of the first apertures and their first images or signals, a composite image or signal is obtained. Each composite image or signal is analyzed to determine an optimum one of the combinations of the first apertures based on a defect detection characteristic of each composite image. In one aspect, determining an optimum one of the combinations of the first apertures includes selecting a set of one or more individual apertures that result in the highest signal to noise ratio for the defect area, and the method includes setting the optimum combination of the first apertures on the inspection tool and inspecting a sample using such optimum combination of the first apertures.
    Type: Application
    Filed: July 6, 2017
    Publication date: October 26, 2017
    Applicant: KLA-Tencor Corporation
    Inventors: Pavel Kolchin, Richard Wallingford, Lisheng Gao, Grace H. Chen, Markus B. Huber, Robert M. Danen
  • Publication number: 20170286589
    Abstract: A method includes identifying a first set of a first care area with a first sensitivity threshold, the first care area associated with a first design of interest within a block of repeating cells in design data; identifying an additional set of an additional care area with an additional sensitivity threshold, the additional care area associated with an additional design of interest within the block of repeating cells in design data; identifying one or more defects within the first set of the first care areas in one or more images of a selected region of a sample based on the first sensitivity threshold; and identifying one or more defects within the additional set of the additional care areas in the one or more images of the selected region of the sample based on the additional sensitivity threshold.
    Type: Application
    Filed: November 15, 2016
    Publication date: October 5, 2017
    Inventors: Junqing Huang, Soren Konecky, Hucheng Lee, Kenong Wu, Lisheng Gao
  • Publication number: 20170287128
    Abstract: Methods and systems for detecting defects on a wafer using adaptive local thresholding and color filtering are provided. One method includes determining local statistics of pixels in output for a wafer generated using an inspection system, determining which of the pixels are outliers based on the local statistics, and comparing the outliers to the pixels surrounding the outliers to identify the outliers that do not belong to a cluster of outliers as defect candidates, The method also includes determining a value for a difference in color between the pixels of the defect candidates and the pixels surrounding the defect candidates.
    Type: Application
    Filed: June 15, 2017
    Publication date: October 5, 2017
    Inventors: Junqing Huang, Hucheng Lee, Kenong Wu, Lisheng Gao
  • Patent number: 9727047
    Abstract: Systems and methods for detecting defects on a specimen based on structural information are provided. One system includes one or more computer subsystems configured for separating the output generated by a detector of an inspection subsystem in an array area on a specimen into at least first and second segments of the output based on characteristic(s) of structure(s) in the array area such that the output in different segments has been generated in different locations in the array area in which the structure(s) having different values of the characteristic(s) are formed. The computer subsystem(s) are also configured for detecting defects on the specimen by applying one or more defect detection methods to the output based on whether the output is in the first segment or the second segment.
    Type: Grant
    Filed: October 9, 2015
    Date of Patent: August 8, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Qing Luo, Kenong Wu, Hucheng Lee, Lisheng Gao, Eugene Shifrin, Yan Xiong, Shuo Sun
  • Patent number: 9726617
    Abstract: Disclosed are methods and apparatus for optimizing a mode of an inspection tool. A first image or signal for each of a plurality of first apertures of the inspection tool is obtained, and each first image or signal pertains to a defect area. For each of a plurality of combinations of the first apertures and their first images or signals, a composite image or signal is obtained. Each composite image or signal is analyzed to determine an optimum one of the combinations of the first apertures based on a defect detection characteristic of each composite image.
    Type: Grant
    Filed: November 8, 2013
    Date of Patent: August 8, 2017
    Assignee: KLA-Tencor Corporation
    Inventors: Pavel Kolchin, Richard Wallingford, Lisheng Gao, Grace H. Chen, Markus B. Huber, Robert M. Danen
  • Patent number: 9721337
    Abstract: Methods and systems for detecting defects on a wafer using defect-specific information are provided. One method includes acquiring information for a target on a wafer. The target includes a pattern of interest formed on the wafer and a known DOI occurring proximate to or in the pattern of interest. The information includes an image of the target on the wafer. The method also includes searching for target candidates on the wafer or another wafer. The target candidates include the pattern of interest. The target and target candidate locations are provided to defect detection. In addition, the method includes detecting the known DOI in the target candidates by identifying potential DOI locations in images of the target candidates and applying one or more detection parameters to images of the potential DOI locations.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: August 1, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Kenong Wu, Meng-Che Wu, Lisheng Gao
  • Patent number: 9715725
    Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes altering one or more design clips based on how the one or more design clips will appear in output generated by a wafer inspection process for a wafer. The method also includes aligning the one or more altered design clips to the output generated for the wafer during the wafer inspection process. In addition, the method includes detecting defects on the wafer based on the output aligned to the one or more altered design clips.
    Type: Grant
    Filed: December 8, 2014
    Date of Patent: July 25, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Yong Zhang, Tao Luo, Chaohong Wu, Stephanie Chen, Lisheng Gao
  • Publication number: 20170200264
    Abstract: Methods and systems for detecting anomalies in images of a specimen are provided. One system includes one or more computer subsystems configured for acquiring images generated of a specimen by an imaging subsystem. The computer subsystem(s) are also configured for determining one or more characteristics of the acquired images. In addition, the computer subsystem(s) are configured for identifying anomalies in the images based on the one or more determined characteristics without applying a defect detection algorithm to the images or the one or more characteristics of the images.
    Type: Application
    Filed: January 9, 2017
    Publication date: July 13, 2017
    Inventors: Allen Park, Lisheng Gao, Ashok Kulkarni, Saibal Banerjee, Ping Gu, Songnian Rong, Kris Bhaskar
  • Patent number: 9704234
    Abstract: Methods and systems for detecting defects on a wafer using adaptive local thresholding and color filtering are provided. One method includes determining local statistics of pixels in output for a wafer generated using an inspection system, determining which of the pixels are outliers based on the local statistics, and comparing the outliers to the pixels surrounding the outliers to identify the outliers that do not belong to a cluster of outliers as defect candidates. The method also includes determining a value for a difference in color between the pixels of the defect candidates and the pixels surrounding the defect candidates. The method further includes identifying the defect candidates that have a value for the difference in color greater than or equal to a predetermined value as nuisance defects and the defect candidates that have a value for the difference in color less than the predetermined value as real defects.
    Type: Grant
    Filed: August 1, 2014
    Date of Patent: July 11, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Junqing Huang, Hucheng Lee, Kenong Wu, Lisheng Gao
  • Publication number: 20170193680
    Abstract: Methods and systems for generating a high resolution image for a specimen from one or more low resolution images of the specimen are provided. One system includes one or more computer subsystems configured for acquiring one or more low resolution images of a specimen. The system also includes one or more components executed by the one or more computer subsystems. The one or more components include a model that includes one or more first layers configured for generating a representation of the one or more low resolution images. The model also includes one or more second layers configured for generating a high resolution image of the specimen from the representation of the one or more low resolution images.
    Type: Application
    Filed: January 2, 2017
    Publication date: July 6, 2017
    Inventors: Jing Zhang, Grace Hsiu-Ling Chen, Kris Bhaskar, Keith Wells, Nan Bai, Ping Gu, Lisheng Gao
  • Publication number: 20170191948
    Abstract: Methods and systems for detecting defects on a wafer are provided. One system includes one or more computer subsystems configured for generating a rendered image based on information for a design printed on the wafer. The rendered image is a simulation of an image generated by an optical inspection subsystem for the design printed on the wafer. Generating the rendered image includes one or more steps, and the computer subsystem(s) are configured for performing at least one of the one or more steps by executing a generative model. The computer subsystem(s)) are also configured for comparing the rendered image to an optical image of the wafer generated by the optical inspection subsystem. The design is printed on the wafer using a reticle. In addition, the computer subsystem(s) are configured for detecting defects on the wafer based on results of the comparing.
    Type: Application
    Filed: December 27, 2016
    Publication date: July 6, 2017
    Inventors: Lisheng Gao, Tao Luo, Keith Wells, Xiaochun Li
  • Publication number: 20170103517
    Abstract: Methods and systems for design based sampling and binning for yield critical defects are provided. One method includes aligning each image patch in each inspection image frame generated for a wafer by an optical subsystem of an inspection system to design information for the wafer. The method also includes deriving multiple layer design attributes at locations of defects detected in the image patches. In addition, the method includes building a decision tree with the multiple layer design attributes. The decision tree is used to separate the defects into bins with different yield impacts on a device being formed on the wafer. The method also includes binning the defects with the decision tree.
    Type: Application
    Filed: December 22, 2016
    Publication date: April 13, 2017
    Inventors: Satya Kurada, Raghav Babulnath, Kwok Ng, Lisheng Gao
  • Patent number: 9619876
    Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes determining difference values for pixels in first output for a wafer generated using a first optics mode of an inspection system and determining other values for pixels in second output for the wafer generated using a second optics mode of the inspection system. The first and second optics modes are different from each other. The method also includes generating a two-dimensional scatter plot of the difference values and the other values for the pixels in the first and second output corresponding to substantially the same locations on the wafer. The method further includes detecting defects on the wafer based on the two-dimensional scatter plot.
    Type: Grant
    Filed: March 12, 2013
    Date of Patent: April 11, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Junqing Huang, Lisheng Gao
  • Publication number: 20170091925
    Abstract: Methods and systems for detecting defects on a wafer using defect-specific and multi-channel information are provided. One method includes acquiring information for a target on a wafer. The target includes a pattern of interest (POI) formed on the wafer and a known defect of interest (DOI) occurring proximate to or in the POI. The method also includes detecting the known DOI in target candidates by identifying potential DOI locations based on images of the target candidates acquired by a first channel of an inspection system and applying one or more detection parameters to images of the potential DOI locations acquired by a second channel of the inspection system. Therefore, the image(s) used for locating potential DOI locations and the image(s) used for detecting defects can be different.
    Type: Application
    Filed: December 12, 2016
    Publication date: March 30, 2017
    Inventors: Kenong Wu, Lisheng Gao, Grace Hsiu-Ling Chen, David W. Shortt
  • Patent number: 9601393
    Abstract: Computer-implemented methods, computer-readable media, and systems for selecting one or more parameters for inspection of a wafer are provided.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: March 21, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Chris Lee, Lisheng Gao, Tao Luo, Kenong Wu, Tommaso Torelli, Michael J. Van Riet, Brian Duffy
  • Patent number: 9563943
    Abstract: Methods and systems for design based sampling and binning for yield critical defects are provided. One method includes aligning each image patch in each inspection image frame generated for a wafer by an optical subsystem of an inspection system to design information for the wafer. The method also includes deriving multiple layer design attributes at locations of defects detected in the image patches. In addition, the method includes building a decision tree with the multiple layer design attributes. The decision tree is used to separate the defects into bins with different yield impacts on a device being formed on the wafer. The method also includes binning the defects with the decision tree.
    Type: Grant
    Filed: April 6, 2016
    Date of Patent: February 7, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Satya Kurada, Raghav Babulnath, Kwok Ng, Lisheng Gao
  • Patent number: 9552636
    Abstract: Methods and systems for detecting defects on a wafer using defect-specific and multi-channel information are provided. One method includes acquiring information for a target on a wafer. The target includes a pattern of interest (POI) formed on the wafer and a known defect of interest (DOI) occurring proximate to or in the POI. The method also includes detecting the known DOI in target candidates by identifying potential DOI locations based on images of the target candidates acquired by a first channel of an inspection system and applying one or more detection parameters to images of the potential DOI locations acquired by a second channel of the inspection system. Therefore, the image(s) used for locating potential DOI locations and the image(s) used for detecting defects can be different.
    Type: Grant
    Filed: July 28, 2015
    Date of Patent: January 24, 2017
    Assignee: KLA-Tencor Corp.
    Inventors: Kenong Wu, Lisheng Gao, Grace Hsiu-Ling Chen, David W. Shortt
  • Patent number: 9523646
    Abstract: In an optical inspection tool, an illumination aperture is opened at each of a plurality of aperture positions of an illumination pupil area one at a time across the illumination pupil area. For each aperture opening position, an incident beam is directed towards the illumination pupil area so as to selectively pass a corresponding ray bundle of the illumination beam at a corresponding set of one or more incident angles towards the sample and an output beam, which is emitted from the sample in response to the corresponding ray bundle of the incident beam impinging on the sample at the corresponding set of one or more incident angles, is detected. A defect detection characteristic for each aperture position is determined based on the output beam detected for each aperture position. An optimum aperture configuration is determined based on the determined defect detection characteristic for each aperture position.
    Type: Grant
    Filed: May 18, 2016
    Date of Patent: December 20, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Grace H. Chen, Rudolf Brunner, Lisheng Gao, Robert M. Danen, Lu Chen
  • Publication number: 20160321800
    Abstract: Methods and systems for detecting defects on a specimen are provided. One system includes one or more computer subsystems configured for acquiring images generated by an imaging subsystem at multiple instances of a pattern of interest (POI) within a die formed on the specimen. The multiple instances include two or more instances that are located at aperiodic locations within the die. The computer subsystem(s) are also configured for generating a POI reference image from two or more of the images generated at the multiple instances of the POI within the die. The computer subsystem(s) are further configured for comparing the images generated at the multiple instances of the POI within the die to the POI reference image and detecting defects in the multiple instances of the POI based on results of the comparing.
    Type: Application
    Filed: April 27, 2016
    Publication date: November 3, 2016
    Inventors: Govindarajan Thattaisundaram, Hucheng Lee, Lisheng Gao
  • Publication number: 20160290934
    Abstract: Methods and systems for detecting defects on a wafer are provided. One system includes one or more computer subsystems configured for generating a rendered image based on information for a design printed on the wafer. The rendered image is a simulation of an image generated by the optical inspection subsystem for the design printed on the wafer. The computer subsystem(s) are also configured for comparing the rendered image to an optical image of the wafer generated by the optical inspection subsystem. The design is printed on the wafer using a reticle. In addition, the computer subsystem(s) are configured for detecting defects on the wafer based on results of the comparing.
    Type: Application
    Filed: March 31, 2016
    Publication date: October 6, 2016
    Inventors: Keith Wells, Xiaochun Li, Lisheng Gao, Tao Luo, Markus Huber