Patents by Inventor Zhongping Cai

Zhongping Cai 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: 20210325520
    Abstract: Systems and methods for calibrating a LiDAR device are disclosed. According to one embodiment, the system comprises a LiDAR device, a continuous curved target at a fixed distance from the LiDAR device, and a calibration controller operable to perform a reflectance over range calibration of the LiDAR device. The LiDAR device scans portions of the continuous curved target at different ranges during the calibration.
    Type: Application
    Filed: April 17, 2020
    Publication date: October 21, 2021
    Applicant: VELODYNE LIDAR, INC.
    Inventors: Zhongping Cai, Geovany Ramirez, Ayush Shah, Shing Leung Luk, Marcus Smith, David S. Hall
  • Patent number: 9810619
    Abstract: A system for substrate tilt and focus control in an inspection system includes a dynamically actuatable substrate stage assembly including a substrate stage for securing a substrate; a tilt-height detection system including: a height detection sub-system and a tilt detection sub-system. The system further includes a first actuator configured to selectably actuate the substrate along a direction perpendicular to the surface of the substrate at a location of the substrate stage assembly; and an additional actuator configured to selectably actuate the substrate along a direction substantially perpendicular to the surface of the substrate at an additional location of the substrate stage assembly; and a MIMO tilt-focus controller communicatively coupled to the height detection sub-system, the tilt detection sub-system, the first actuator and the additional actuator.
    Type: Grant
    Filed: September 10, 2013
    Date of Patent: November 7, 2017
    Assignee: KLA-Tencor Corporation
    Inventors: Zhongping Cai, Jingyi Xiong, Tyler Trytko, Alexander Slobodov, Paul Doyle, Anatoly Romanovsky
  • Patent number: 9097645
    Abstract: High speed height control of a surface of a substrate within a wafer inspection system includes positioning a substrate on a substrate stage of a dynamically adjustable substrate stage assembly, actuating the substrate perpendicular to the surface of the substrate, measuring a height error value of the surface of the substrate at a position of inspection of the surface, measuring a displacement value perpendicular to the surface of the substrate at the location of the substrate stage assembly, generating a displacement target from the height error value and the displacement value, and adjusting an actuation state of the actuator using the measured height error value and the generated displacement target in order to maintain the substrate surface at an imaging plane of a detector of the inspection system or a focus of illumination of the inspection system.
    Type: Grant
    Filed: August 19, 2014
    Date of Patent: August 4, 2015
    Assignee: KLA-Tencor Corporation
    Inventors: Zhongping Cai, Jingyi Xiong
  • Patent number: 9091666
    Abstract: Various embodiments for extended defect sizing range for wafer inspection are provided. One inspection system includes an illumination subsystem configured to direct light to the wafer. The system also includes an image sensor configured to detect light scattered from wafer defects and to generate output responsive to the scattered light. The image sensor is also configured to not have an anti-blooming feature such that when a pixel in the image sensor reaches full well capacity, excess charge flows from the pixel to one or more neighboring pixels in the image sensor. The system further includes a computer subsystem configured to detect the defects on the wafer using the output and to determine a size of the defects on the wafer using the output generated by a pixel and any neighboring pixels of the pixel to which the excess charge flows.
    Type: Grant
    Filed: February 9, 2012
    Date of Patent: July 28, 2015
    Assignee: KLA-Tencor Corp.
    Inventors: Zhongping Cai, Yury Yuditsky, Anatoly Romanovsky, Alexander Slobodov
  • Patent number: 9068952
    Abstract: A method and apparatus for producing high frequency dynamically focused oblique laser illumination for a spinning wafer inspection system. The focus is changed by changing the beam direction incidence angle so as to bring focal spot onto the wafer surface. Disclosed herein is a system and method for automatic beam shaping (i.e., spot size) and steering (i.e., position) for a spinning wafer inspection system, combined into a single module. Also disclosed is a method and system for measuring the beam position/size/shape and angle with sufficient resolution to make corrections using feedback from the monitor.
    Type: Grant
    Filed: September 2, 2009
    Date of Patent: June 30, 2015
    Assignee: KLA-Tencor Corporation
    Inventors: Aleksey Petrenko, Christian Wolters, Zhongping Cai, Anatoly Romanovsky, Bret Whiteside
  • Publication number: 20150055141
    Abstract: High speed height control of a surface of a substrate within a wafer inspection system includes positioning a substrate on a substrate stage of a dynamically adjustable substrate stage assembly, actuating the substrate perpendicular to the surface of the substrate, measuring a height error value of the surface of the substrate at a position of inspection of the surface, measuring a displacement value perpendicular to the surface of the substrate at the location of the substrate stage assembly, generating a displacement target from the height error value and the displacement value, and adjusting an actuation state of the actuator using the measured height error value and the generated displacement target in order to maintain the substrate surface at an imaging plane of a detector of the inspection system or a focus of illumination of the inspection system.
    Type: Application
    Filed: August 19, 2014
    Publication date: February 26, 2015
    Inventors: Zhongping Cai, Jingyi Xiong
  • Publication number: 20140071457
    Abstract: A system for substrate tilt and focus control in an inspection system includes a dynamically actuatable substrate stage assembly including a substrate stage for securing a substrate; a tilt-height detection system including: a height detection sub-system and a tilt detection sub-system. The system further includes a first actuator configured to selectably actuate the substrate along a direction perpendicular to the surface of the substrate at a location of the substrate stage assembly; and an additional actuator configured to selectably actuate the substrate along a direction substantially perpendicular to the surface of the substrate at an additional location of the substrate stage assembly; and a MIMO tilt-focus controller communicatively coupled to the height detection sub-system, the tilt detection sub-system, the first actuator and the additional actuator.
    Type: Application
    Filed: September 10, 2013
    Publication date: March 13, 2014
    Applicant: KLA-Tencor Corporation
    Inventors: Zhongping Cai, Jingyi Xiong, Tyler Trytko, Alexander Slobodov, Paul Doyle, Anatoly Romanovsky
  • Publication number: 20130208269
    Abstract: Various embodiments for extended defect sizing range for wafer inspection are provided.
    Type: Application
    Filed: February 9, 2012
    Publication date: August 15, 2013
    Applicant: KLA-TENCOR CORPORATION
    Inventors: Zhongping Cai, Yury Yuditsky, Anatoly Romanovsky, Alexander Slobodov
  • Publication number: 20110051132
    Abstract: A method and apparatus for producing high frequency dynamically focused oblique laser illumination for a spinning wafer inspection system. The focus is changed by changing the beam direction incidence angle so as to bring focal spot onto the wafer surface. Disclosed herein is a system and method for automatic beam shaping (i.e., spot size) and steering (i.e., position) for a spinning wafer inspection system, combined into a single module. Also disclosed is a method and system for measuring the beam position/size/shape and angle with sufficient resolution to make corrections using feedback from the monitor.
    Type: Application
    Filed: September 2, 2009
    Publication date: March 3, 2011
    Inventors: Aleksey Petrenko, Christian Wolters, Zhongping Cai, Anatoly Romanovsky, Bret Whiteside
  • Patent number: 7746462
    Abstract: An inspection system and method is provided herein for increasing the detection range of the inspection system. According to one embodiment, the inspection system may include a photodetector having a plurality of stages, which are adapted to convert light scattered from a specimen into an output signal, and a voltage divider network coupled for extending the detection range of the photodetector (and thus, the detection range of the inspection system) by saturating at least one of the stages. This forces the photodetector to operate in a non-linear manner. However, measurement inaccuracies are avoided by calibrating the photodetector output to remove any non-linear effects that may be created by intentionally saturating the at least one of the stages. In one example, a table of values may be generated during a calibration phase to convert the photodetector output into an actual amount of scattered light.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: June 29, 2010
    Assignee: KLA-Tencor Technologies Corporation
    Inventors: Zhongping Cai, Alexander Slobodov, Anatoly Romanovsky, Christian H. Wolters
  • Publication number: 20080291454
    Abstract: An inspection system and method is provided herein for increasing the detection range of the inspection system. According to one embodiment, the inspection system may include a photodetector having a plurality of stages, which are adapted to convert light scattered from a specimen into an output signal, and a voltage divider network coupled for extending the detection range of the photodetector (and thus, the detection range of the inspection system) by saturating at least one of the stages. This forces the photodetector to operate in a non-linear manner. However, measurement inaccuracies are avoided by calibrating the photodetector output to remove any non-linear effects that may be created by intentionally saturating the at least one of the stages. In one example, a table of values may be generated during a calibration phase to convert the photodetector output into an actual amount of scattered light.
    Type: Application
    Filed: May 21, 2007
    Publication date: November 27, 2008
    Applicant: KLA-TENCOR TECHNOLOGIES CORP.
    Inventors: Zhongping Cai, Alexander Slobodov, Anatoly Romanovsky, Christian H. Wolters