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: 20160275672
    Abstract: Methods and systems for determining a position of output generated by an inspection subsystem in design data space are provided. In general, some embodiments described herein are configured for substantially accurately aligning inspection subsystem output generated for a specimen to a design for the specimen despite deformation of the design in the inspection subsystem output. In addition, some embodiments are configured for generating and/or using alignment targets that can be shared across multiple specimens of the same layer and design rule for alignment of inspection subsystem output generated for a specimen to a design for the specimen.
    Type: Application
    Filed: March 17, 2016
    Publication date: September 22, 2016
    Inventors: Santosh Bhattacharyya, Pavan Kumar, Lisheng Gao, Thirupurasundari Jayaraman, Raghav Babulnath, Srikanth Kandukuri, Gangadharan Sivaraman, Karthikeyan Subramanian, Raghavan Konuru, Rahul Lakhawat
  • Publication number: 20160266047
    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: Application
    Filed: May 18, 2016
    Publication date: September 15, 2016
    Applicant: KLA-Tencor Corporation
    Inventors: Grace H. Chen, Rudolf Brunner, Lisheng Gao, Robert M. Danen, Lu Chen
  • Patent number: 9442077
    Abstract: Methods and systems for filtering scratches from wafer inspection results are provided. One method includes generating a defect candidate map that includes image data for potential defect candidates as a function of position on the wafer and removing noise from the defect candidate map to generate a filtered defect candidate map. The method also includes determining one or more characteristics of the potential defect candidates based on portions of the filtered defect candidate map corresponding to the potential defect candidates. In addition, the method includes determining if each of the potential defect candidates are scratches based on the one or more characteristics determined for each of the potential defect candidates and separating the potential defect candidates determined to be the scratches from other defects in inspection results for the wafer.
    Type: Grant
    Filed: August 25, 2014
    Date of Patent: September 13, 2016
    Assignee: KLA-Tencor Corp.
    Inventors: Junqing Huang, Huan Jin, Grace Hsiu-Ling Chen, Lisheng Gao
  • Publication number: 20160225138
    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: April 6, 2016
    Publication date: August 4, 2016
    Inventors: Satya Kurada, Raghav Babulnath, Kwok Ng, Lisheng Gao
  • Publication number: 20160188784
    Abstract: Methods and systems for determining a position of output generated by an inspection subsystem in design data space are provided. One method includes selecting one or more alignment targets from a design for a specimen. At least a portion of the one or more alignment targets include built in targets included in the design for a purpose other than alignment of inspection results to design data space. At least the portion of the one or more alignment targets does not include one or more individual device features. One or more images for the alignment target(s) and output generated by the inspection subsystem at the position(s) of the alignment target(s) may then be used to determine design data space positions of other output generated by the inspection subsystem in a variety of ways described herein.
    Type: Application
    Filed: December 29, 2015
    Publication date: June 30, 2016
    Inventors: Santosh Bhattacharyya, Bjoern Braeuer, Lisheng Gao
  • Patent number: 9347891
    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: March 1, 2013
    Date of Patent: May 24, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Grace H. Chen, Rudolf Brunner, Lisheng Gao, Robert M. Danen, Lu Chen
  • Publication number: 20160104600
    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: Application
    Filed: October 9, 2015
    Publication date: April 14, 2016
    Inventors: Qing Luo, Kenong Wu, Hucheng Lee, Lisheng Gao, Eugene Shifrin, Yan Xiong, Shuo Sun
  • Patent number: 9310320
    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 11, 2014
    Date of Patent: April 12, 2016
    Assignee: KLA-Tencor Corp.
    Inventors: Satya Kurada, Raghav Babulnath, Kwok Ng, Lisheng Gao
  • Publication number: 20160071256
    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: Application
    Filed: November 17, 2015
    Publication date: March 10, 2016
    Inventors: Kenong Wu, Meng-Che Wu, Lisheng Gao
  • Publication number: 20160027165
    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: July 28, 2015
    Publication date: January 28, 2016
    Inventors: Kenong Wu, Lisheng Gao, Grace Hsiu-Ling Chen, David W. Shortt
  • Patent number: 9224660
    Abstract: Systems and methods for determining one or more parameters of a wafer inspection process are provided. One method includes aligning optical image(s) of an alignment target to their corresponding electron beam images generated by an electron beam defect review system. The method also includes determining different local coordinate transformations for different subsets of alignment targets based on results of the aligning. In addition, the method includes determining positions of defects in wafer inspection system coordinates based on coordinates of the defects determined by the electron beam defect review system and the different local coordinate transformations corresponding to different groups of the defects into which the defects have been separated. The method further includes determining one or more parameters for an inspection process for the wafer based on defect images acquired at the determined positions by a wafer inspection system.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: December 29, 2015
    Assignee: KLA-Tencor Corp.
    Inventors: Ashok V. Kulkarni, Lisheng Gao, Junqing Huang
  • Publication number: 20150362908
    Abstract: Systems and methods for monitoring stability of a wafer inspection recipe over time are provided. One method includes collecting inspection results over time. The inspection results are generated by at least one wafer inspection tool while performing the wafer inspection recipe on wafers at different points in time. The method also includes identifying abnormal variation in the inspection results by comparing the inspection results generated at different times to each other. In addition, the method includes determining if the abnormal variation is attributable to the wafers, the wafer inspection recipe, or one or more of the at least one wafer inspection tool thereby determining if the wafer inspection recipe is stable over time.
    Type: Application
    Filed: June 10, 2015
    Publication date: December 17, 2015
    Inventors: Hucheng Lee, Lisheng Gao, Govindarajan Thattaisundaram
  • Patent number: 9189844
    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: October 15, 2012
    Date of Patent: November 17, 2015
    Assignee: KLA-Tencor Corp.
    Inventors: Kenong Wu, Meng-Che Wu, Lisheng Gao
  • Patent number: 9171364
    Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes determining characteristics of care areas for a wafer based on wafer patterns. Determining the characteristics includes determining locations of care areas, identifying at least one pattern of interest (POI) in the wafer patterns for each of the care areas, allowing any of the care areas to have a free-form shape, allowing the care areas to be larger than frame images and selecting two or more POIs for at least one of the care areas. The method also includes searching for POIs in images generated for the wafer using an inspection system. In addition, the method includes detecting defects on the wafer by determining positions of the care areas in the images and applying one or more defect detection methods to the images based on the positions of the care areas in the images.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: October 27, 2015
    Assignee: KLA-Tencor Corp.
    Inventors: Kenong Wu, Tao Luo, Lisheng Gao, Eugene Shifrin, Aravindh Balaji
  • Publication number: 20150221076
    Abstract: Systems and methods for classifying defects detected on a wafer are provided. One method includes detecting defects on a wafer based on output generated for the wafer by an inspection system. The method also includes determining one or more attributes for at least one of the defects based on portions of a standard reference image corresponding to the at least one of the defects. The method further includes classifying the at least one of the defects based at least in part on the one or more determined attributes.
    Type: Application
    Filed: February 2, 2015
    Publication date: August 6, 2015
    Inventors: Lisheng Gao, Avijit K. Ray-Chaudhuri, Raghav Babulnath, Kenong Wu
  • Patent number: 9092846
    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: January 31, 2014
    Date of Patent: July 28, 2015
    Assignee: KLA-Tencor Corp.
    Inventors: Kenong Wu, Lisheng Gao, Grace Hsiu-Ling Chen, David W. Shortt
  • Publication number: 20150178907
    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: Application
    Filed: December 8, 2014
    Publication date: June 25, 2015
    Inventors: Yong Zhang, Tao Luo, Chaohong Wu, Stephanie Chen, Lisheng Gao
  • Patent number: 9053527
    Abstract: Methods and systems for detecting defects on a wafer are provided. One method includes identifying one or more characteristics of first raw output generated for a wafer that correspond to one or more geometrical characteristics of patterned features formed on the wafer and assigning individual output in second raw output generated for the wafer to different segments based on the identified one or more characteristics of the first raw output and based on the individual output in the second raw output and individual output in the first raw output that were generated at substantially the same locations on the wafer such that the one or more geometrical characteristics of the patterned features that correspond to each of the different segments in the second raw output are different.
    Type: Grant
    Filed: January 2, 2013
    Date of Patent: June 9, 2015
    Assignee: KLA-Tencor Corp.
    Inventors: Jun Lang, Kan Chen, Lisheng Gao, Junqing Huang
  • Publication number: 20150125065
    Abstract: The correlation of optical images with SEM images includes acquiring a full optical image of a sample by scanning the sample with an optical inspection sub-system, storing the full optical image, identifying a location of a feature-of-interest present in the full optical image with an additional sources, acquiring an SEM image of a portion of the sample that includes the feature at the identified location with a SEM tool, acquiring an optical image portion at the location identified by the additional source, the image portions including a reference structure, correlating the image portion and the SEM image based on the presence of the feature-of-interest and the reference structure in both the image portions and the SEM image, and transferring a location of the feature-of-interest in the SEM image into the coordinate system of the image portion of the full optical image to form a corrected optical image.
    Type: Application
    Filed: October 3, 2014
    Publication date: May 7, 2015
    Inventors: Hucheng Lee, Lisheng Gao, Jan Lauber, Yong Zhang
  • Publication number: 20150120220
    Abstract: Methods and systems for detecting reliability defects on a wafer are provided. One method includes acquiring output for a wafer generated by an inspection system. The method also includes determining one or more geometric characteristics of one or more patterned features formed on the wafer based on the output. In addition, the method includes identifying which of the one or more patterned features will cause one or more reliability defects in a device being formed on the wafer based on the determined one or more characteristics.
    Type: Application
    Filed: October 12, 2014
    Publication date: April 30, 2015
    Inventors: Joanne Wu, Ellis Chang, Lisheng Gao, Satya Kurada, Allen Park, Raghav Babulnath