Patents by Inventor Andrei Shchegrov

Andrei Shchegrov 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: 20190252270
    Abstract: A method and system for measuring overlay in a semiconductor manufacturing process comprise capturing an image of a feature in an article at a predetermined manufacturing stage, deriving a quantity of an image parameter from the image and converting the quantity into an overlay measurement. The conversion is by reference to an image parameter quantity derived from a reference image of a feature at the same predetermined manufacturing stage with known overlay (“OVL”). There is also disclosed a method of determining a device inspection recipe for use by an inspection tool comprising identifying device patterns as candidate device care areas that may be sensitive to OVL, deriving an OVL response for each identified pattern, correlating the OVL response with measured OVL, and selecting some or all of the device patterns as device care areas based on the correlation.
    Type: Application
    Filed: June 24, 2018
    Publication date: August 15, 2019
    Inventors: Choon Hoong Hoo, Fangren Ji, Amnon Manassen, Liran Yerushalmi, Antonio Mani, Allen Park, Stilian Pandev, Andrei Shchegrov, Jon Madsen
  • Patent number: 9310290
    Abstract: An apparatus includes (i) a bright light source for providing an illumination beam at multiple wavelengths selectable with a range from a deep ultraviolet wavelength to an infrared wavelength, (ii) illumination optics for directing the illumination beam towards a sample at selectable sets of angles of incidence (AOI's) or azimuth angles (AZ's) and polarization states to provide spectroscopic ellipsometry, wherein the illumination optics include an apodizer for controlling a spot size of the illumination beam on the sample at each of the selectable AOI/AZ sets, (iii) collection optics for directing an output beam from the sample in response to the illumination beam at each of the selectable AOI/AZ sets and polarization states towards a detector that generates an output signal or image based on the output beam, and (v) a controller for characterizing a feature of the sample based on the output signal or image.
    Type: Grant
    Filed: June 19, 2015
    Date of Patent: April 12, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: David Y. Wang, Klaus Flock, Lawrence Rotter, Shankar Krishnan, Johannes D. de Veer, Catalin Filip, Gregory Brady, Muzammil Arain, Andrei Shchegrov
  • Patent number: 9291554
    Abstract: Electromagnetic modeling of finite structures and finite illumination for metrology and inspection are described herein. In one embodiment, a method for evaluating a diffracting structure involves providing a model of the diffracting structure. The method involves computing background electric or magnetic fields of an environment of the diffracting structure. The method involves computing scattered electric or magnetic fields from the diffracting structure using a scattered field formulation based on the computed background fields. The method further involves computing spectral information for the model of the diffracting structure based on the computed scattered fields, and comparing the computed spectral information for the model with measured spectral information for the diffracting structure. In response to a good model fit, the method involves determining a physical characteristic of the diffracting structure based on the model of the diffracting structure.
    Type: Grant
    Filed: January 31, 2014
    Date of Patent: March 22, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Alexander Kuznetsov, Kevin Peterlinz, Andrei Shchegrov, Leonid Poslavsky, Xuefeng Liu
  • Patent number: 9243886
    Abstract: One or more non-zero diffraction orders are selected, and these selected one or more zero or non-zero diffraction orders are selected for eliminating or obtaining corresponding zero or non-zero diffraction order terms or interference term from measurements from a periodic target using an optical metrology tool. The periodic target has a pitch, and the measurements contain a zero diffraction order and one or more non-zero diffraction order terms. Using the optical metrology tool, an incident beam is directed to positions on the target, and the measurements are obtained from the target in response to the incident beam. The measurements are processed to eliminate or obtain each zero or non-zero diffraction order term or interference term associated with each selected zero or non-zero diffraction order, resulting in a processed metrology signal.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: January 26, 2016
    Assignee: KLA-Tencor Corporation
    Inventors: Alexander Kuznetsov, Kevin Peterlinz, Andrei Shchegrov
  • Publication number: 20150285735
    Abstract: An apparatus includes (i) a bright light source for providing an illumination beam at multiple wavelengths selectable with a range from a deep ultraviolet wavelength to an infrared wavelength, (ii) illumination optics for directing the illumination beam towards a sample at selectable sets of angles of incidence (AOI's) or azimuth angles (AZ's) and polarization states to provide spectroscopic ellipsometry, wherein the illumination optics include an apodizer for controlling a spot size of the illumination beam on the sample at each of the selectable AOI/AZ sets, (iii) collection optics for directing an output beam from the sample in response to the illumination beam at each of the selectable AOI/AZ sets and polarization states towards a detector that generates an output signal or image based on the output beam, and (v) a controller for characterizing a feature of the sample based on the output signal or image.
    Type: Application
    Filed: June 19, 2015
    Publication date: October 8, 2015
    Applicant: KLA- Tencor Corporation
    Inventors: David Y. Wang, Klaus Flock, Lawrence Rotter, Shankar Krishnan, Johannes D. de Veer, Catalin Filip, Gregory Brady, Muzammil Arain, Andrei Shchegrov
  • Patent number: 9116103
    Abstract: An apparatus includes (i) a bright light source for providing an illumination beam at multiple wavelengths selectable with a range from a deep ultraviolet wavelength to an infrared wavelength, (ii) illumination optics for directing the illumination beam towards a sample at selectable sets of angles of incidence (AOI's) or azimuth angles (AZ's) and polarization states to provide spectroscopic ellipsometry, wherein the illumination optics include an apodizer for controlling a spot size of the illumination beam on the sample at each of the selectable AOI/AZ sets, (iii) collection optics for directing an output beam from the sample in response to the illumination beam at each of the selectable AOI/AZ sets and polarization states towards a detector that generates an output signal or image based on the output beam, and (v) a controller for characterizing a feature of the sample based on the output signal or image.
    Type: Grant
    Filed: October 1, 2013
    Date of Patent: August 25, 2015
    Assignee: KLA-Tencor Corporation
    Inventors: David Y. Wang, Klaus Flock, Lawrence Rotter, Shankar Krishnan, Johannes D. de Veer, Catalin Filip, Gregory Brady, Muzammil Arain, Andrei Shchegrov
  • Publication number: 20140375981
    Abstract: An apparatus includes (i) a bright light source for providing an illumination beam at multiple wavelengths selectable with a range from a deep ultraviolet wavelength to an infrared wavelength, (ii) illumination optics for directing the illumination beam towards a sample at selectable sets of angles of incidence (AOI's) or azimuth angles (AZ's) and polarization states to provide spectroscopic ellipsometry, wherein the illumination optics include an apodizer for controlling a spot size of the illumination beam on the sample at each of the selectable AOI/AZ sets, (iii) collection optics for directing an output beam from the sample in response to the illumination beam at each of the selectable AOI/AZ sets and polarization states towards a detector that generates an output signal or image based on the output beam, and (v) a controller for characterizing a feature of the sample based on the output signal or image.
    Type: Application
    Filed: October 1, 2013
    Publication date: December 25, 2014
    Applicant: KLA-Tencor Corporation
    Inventors: David Y. Wang, Klaus Flock, Lawrence Rotter, Shankar Krishnan, Johannes D. de Veer, Catalin Filip, Gregory Brady, Muzammil Arain, Andrei Shchegrov
  • Patent number: 8860937
    Abstract: Various metrology systems and methods for high aspect ratio and large lateral dimension structures are provided. One method includes directing light to one or more structures formed on a wafer. The light includes ultraviolet light, visible light, and infrared light. The one or more structures include at least one high aspect ratio structure or at least one large lateral dimension structure. The method also includes generating output responsive to light from the one or more structures due to the light directed to the one or more structures. In addition, the method includes determining one or more characteristics of the one or more structures using the output.
    Type: Grant
    Filed: January 16, 2013
    Date of Patent: October 14, 2014
    Assignee: KLA-Tencor Corp.
    Inventors: Thaddeus Gerard Dziura, Xuefeng Liu, David Y. Wang, Jonathan Madsen, Alexander Kuznetsov, Johannes D. de Veer, Shankar Krishnan, Derrick Shaughnessy, Andrei Shchegrov
  • Publication number: 20140222380
    Abstract: Electromagnetic modeling of finite structures and finite illumination for metrology and inspection are described herein. In one embodiment, a method for evaluating a diffracting structure involves providing a model of the diffracting structure. The method involves computing background electric or magnetic fields of an environment of the diffracting structure. The method involves computing scattered electric or magnetic fields from the diffracting structure using a scattered field formulation based on the computed background fields. The method further involves computing spectral information for the model of the diffracting structure based on the computed scattered fields, and comparing the computed spectral information for the model with measured spectral information for the diffracting structure. In response to a good model fit, the method involves determining a physical characteristic of the diffracting structure based on the model of the diffracting structure.
    Type: Application
    Filed: January 31, 2014
    Publication date: August 7, 2014
    Inventors: Alexander Kuznetsov, Kevin Peterlinz, Andrei Shchegrov, Leonid Poslavsky, Xuefeng Liu
  • Patent number: 8649404
    Abstract: A compact optically-pumped solid-state laser designed for efficient nonlinear intracavity frequency conversion into desired wavelengths using periodically poled nonlinear crystals. These crystals contain dopants such as MgO or ZnO and/or have a specified degree of stoichiometry that ensures high reliability. The laser includes a solid-state gain media chip, such as Nd:YVO4, which also provides polarization control of the laser; and a periodically poled nonlinear crystal chip such as PPMgOLN or PPZnOLT for efficient frequency doubling of the fundamental infrared laser beam into the visible wavelength range. The described designs are especially advantageous for obtaining low-cost green and blue laser sources. Also described design of the continuously operated laser with an electro-optic element for modulation of the intensity of the laser output at frequencies up to hundred of megahertz. Such modulation is desired for various applications, including compact projectors with high resolution.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: February 11, 2014
    Assignee: Spectralus Corporation
    Inventors: Stepan Essaian, Dzhakhangir Khaydarov, Andrei Shchegrov
  • Publication number: 20120163403
    Abstract: A compact optically-pumped solid-state laser designed for efficient nonlinear intracavity frequency conversion into desired wavelengths using periodically poled nonlinear crystals. These crystals contain dopants such as MgO or ZnO and/or have a specified degree of stoichiometry that ensures high reliability. The laser includes a solid-state gain media chip, such as Nd:YVO4, which also provides polarization control of the laser; and a periodically poled nonlinear crystal chip such as PPMgOLN or PPZnOLT for efficient frequency doubling of the fundamental infrared laser beam into the visible wavelength range. The described designs are especially advantageous for obtaining low-cost green and blue laser sources. Also described design of the continuously operated laser with an electro-optic element for modulation of the intensity of the laser output at frequencies up to hundred of megahertz. Such modulation is desired for various applications, including compact projectors with high resolution.
    Type: Application
    Filed: May 27, 2009
    Publication date: June 28, 2012
    Inventors: Stepan Essaian, Dzhakhangir Khaydarov, Andrei Shchegrov
  • Patent number: 8000357
    Abstract: A compact and efficient ultraviolet laser source based on a optically-pumped solid-state or fiber laser that produces near-infrared output light suitable for nonlinear frequency conversion. The infrared laser output is frequency tripled or quadrupled to produce light in the ultraviolet wavelength range (200 nm to 400 nm). The novel technology is the use of highly efficient periodically poled nonlinear crystals, such as stoichiometric and MgO-doped lithium tantalate and lithium niobate. As opposed to conventional frequency-converted UV laser sources, which have high power consumption, high cost, and low efficiency, the laser sources of this invention utilize high efficiency nonlinear conversion provided by periodically poled materials and allow lower-cost architectures without additional focusing lenses, high power pump diodes, etc.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: August 16, 2011
    Assignee: Spectralus Corporation
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Patent number: 7742510
    Abstract: A compact optically-pumped solid-state laser designed for efficient nonlinear intracavity frequency conversion into desired wavelengths using periodically poled nonlinear crystals. These crystals contain dopants such as MgO or ZnO and/or have a specified degree of stoichiometry that ensures high reliability. The laser includes a solid-state gain media chip, such as Nd:YVO4, which also provides polarization control of the laser; and a periodically poled nonlinear crystal chip such as PPMgOLN or PPZnOLT for efficient frequency doubling of the fundamental infrared laser beam into the visible wavelength range. The described designs are especially advantageous for obtaining low-cost green and blue laser sources.
    Type: Grant
    Filed: April 23, 2007
    Date of Patent: June 22, 2010
    Assignee: Spectralus Corporation
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Patent number: 7724797
    Abstract: A compact solid-state laser array for nonlinear intracavity frequency conversion into desired wavelengths using periodically poled nonlinear crystals. The crystals contain dopants such as MgO and/or have a specified stoichiometry. A preferred embodiment comprises a microchip laser cavity that includes a solid-state gain chip, such as Nd:YVO4, which also provides polarization control of the laser; and a periodically poled nonlinear crystal chip such as PPMgOLN, for efficient frequency doubling of a infrared laser pump beam into the visible wavelength range. The described designs are especially advantageous for obtaining low-cost green and blue laser sources. The use of such high-efficiency pumps and nonlinear materials allows scaling of a compact, low-cost architecture to provide high output power levels in the blue/green wavelength range.
    Type: Grant
    Filed: April 23, 2007
    Date of Patent: May 25, 2010
    Assignee: Spectralus Corporation
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Publication number: 20090290605
    Abstract: A compact and efficient ultraviolet laser source based on a optically-pumped solid-state or fiber laser that produces near-infrared output light suitable for nonlinear frequency conversion. The infrared laser output is frequency tripled or quadrupled to produce light in the ultraviolet wavelength range (200 nm to 400 nm). The novel technology is the use of highly efficient periodically poled nonlinear crystals, such as stoichiometric and MgO-doped lithium tantalate and lithium niobate. As opposed to conventional frequency-converted UV laser sources, which have high power consumption, high cost, and low efficiency, the laser sources of this invention utilize high efficiency nonlinear conversion provided by periodically poled materials and allow lower-cost architectures without additional focusing lenses, high power pump diodes, etc.
    Type: Application
    Filed: August 3, 2009
    Publication date: November 26, 2009
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Patent number: 7570676
    Abstract: A compact and efficient ultraviolet laser source based on a optically-pumped solid-state or fiber laser that produces near-infrared output light suitable for nonlinear frequency conversion. The infrared laser output is frequency tripled or quadrupled to produce light in the ultraviolet wavelength range (200 nm to 400 nm). The novel technology is the use of highly efficient periodically poled nonlinear crystals, such as stoichiometric and MgO-doped lithium tantalate and lithium niobate. As opposed to conventional frequency-converted UV laser sources, which have high power consumption, high cost, and low efficiency, the laser sources of this invention utilize high efficiency nonlinear conversion provided by periodically poled materials and allow lower-cost architectures without additional focusing lenses, high power pump diodes, etc.
    Type: Grant
    Filed: April 23, 2007
    Date of Patent: August 4, 2009
    Assignee: Spectralus Corporation
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Publication number: 20080317072
    Abstract: A compact optically-pumped solid-state laser designed for efficient nonlinear intracavity frequency conversion into desired wavelengths using periodically poled nonlinear crystals. These crystals contain dopants such as MgO or ZnO and/or have a specified degree of stoichiometry that ensures high reliability. The laser includes a solid-state gain media chip, such as Nd:YVO4, which also provides polarization control of the laser; and a periodically poled nonlinear crystal chip such as PPMgOLN or PPZnOLT for efficient frequency doubling of the fundamental infrared laser beam into the visible wavelength range. The described designs are especially advantageous for obtaining low-cost green and blue laser sources.
    Type: Application
    Filed: April 23, 2007
    Publication date: December 25, 2008
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Publication number: 20070263693
    Abstract: A compact and efficient ultraviolet laser source based on a optically-pumped solid-state or fiber laser that produces near-infrared output light suitable for nonlinear frequency conversion. The infrared laser output is frequency tripled or quadrupled to produce light in the ultraviolet wavelength range (200 nm to 400 nm). The novel technology is the use of highly efficient periodically poled nonlinear crystals, such as stoichiometric and MgO-doped lithium tantalate and lithium niobate. As opposed to conventional frequency-converted UV laser sources, which have high power consumption, high cost, and low efficiency, the laser sources of this invention utilize high efficiency nonlinear conversion provided by periodically poled materials and allow lower-cost architectures without additional focusing lenses, high power pump diodes, etc.
    Type: Application
    Filed: April 23, 2007
    Publication date: November 15, 2007
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Publication number: 20070253453
    Abstract: A compact solid-state laser array for nonlinear intracavity frequency conversion into desired wavelengths using periodically poled nonlinear crystals. The crystals contain dopants such as MgO and/or have a specified stoichiometry. A preferred embodiment comprises a microchip laser cavity that includes a solid-state gain chip, such as Nd:YVO4, which also provides polarization control of the laser; and a periodically poled nonlinear crystal chip such as PPMgOLN, for efficient frequency doubling of a infrared laser pump beam into the visible wavelength range. The described designs are especially advantageous for obtaining low-cost green and blue laser sources. The use of such high-efficiency pumps and nonlinear materials allows scaling of a compact, low-cost architecture to provide high output power levels in the blue/green wavelength range.
    Type: Application
    Filed: April 23, 2007
    Publication date: November 1, 2007
    Inventors: Stepan Essaian, Andrei Shchegrov
  • Publication number: 20070153866
    Abstract: Arrays of vertical extended cavity surface emitting lasers (VECSELs) are disclosed. The functionality of two or more conventional optical components are combined into an optical unit to reduce the number of components that must be aligned during packaging.
    Type: Application
    Filed: December 18, 2006
    Publication date: July 5, 2007
    Inventors: Andrei Shchegrov, Jason Watson, Dicky Lee, Arvydas Umbrasas, Rene Dato, John Green, Michael Jansen, Aram Mooradian