Patents by Inventor Duli Mao

Duli Mao 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: 20210051250
    Abstract: An image sensor includes a substrate. An array of photodiodes is disposed in the substrate. A plurality of spacers is arranged in a spacer pattern. At least one spacer of the plurality of spacers has an aspect ratio of 18:1 or greater. A buffer layer is disposed between the substrate and the spacer pattern. An array of color filters is disposed in the spacer pattern.
    Type: Application
    Filed: August 13, 2019
    Publication date: February 18, 2021
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Gang Chen, Yuanwei Zheng, Qin Wang, Cunyu Yang, Guannan Chen, Duli Mao, Dyson H. Tai, Lindsay Alexander Grant
  • Patent number: 10734434
    Abstract: An image sensor pixel includes a photodiode disposed in a semiconductor material to generate image charge in response to light incident on a backside of the semiconductor material, and a pinning layer disposed in the semiconducting material and coupled to the photodiode. The pixel also includes a vertical overflow drain disposed in the semiconductor material and coupled to the pinning layer such that the pinning layer is disposed between the vertical overflow drain and the photodiode. A floating diffusion disposed in the semiconductor material proximate to the photodiode, and a vertical transfer transistor is disposed in part in the semiconductor material and coupled to the photodiode to transfer the image charge from the photodiode to the floating diffusion in response to a transfer signal applied to the gate terminal of the vertical transfer transistor.
    Type: Grant
    Filed: May 18, 2018
    Date of Patent: August 4, 2020
    Assignee: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Yuanwei Zheng, Gang Chen, Duli Mao, Dyson Tai, Lindsay Grant
  • Publication number: 20200235158
    Abstract: A sensor includes a photodiode disposed in a semiconductor material to receive light and convert the light into charge, and a first floating diffusion coupled to the photodiode to receive the charge. A second floating diffusion is coupled to the photodiode to receive the charge, and a first transfer transistor is coupled to transfer the charge from the photodiode into the first floating diffusion. A second transfer transistor is coupled to transfer the charge from the photodiode into the second floating diffusion, and an inductor is coupled between a first gate terminal of the first transfer transistor and a second gate terminal of the second transfer transistor. The inductor, the first gate terminal, and the second gate terminal form a resonant circuit.
    Type: Application
    Filed: January 23, 2019
    Publication date: July 23, 2020
    Inventors: Xianmin Yi, Jingming Yao, Philip Cizdziel, Eric Webster, Duli Mao, Zhiqiang Lin, Jens Landgraf, Keiji Mabuchi, Kevin Johnson, Sohei Manabe, Dyson H. Tai, Lindsay Grant, Boyd Fowler
  • Patent number: 10687003
    Abstract: A pixel array for use in a high dynamic range image sensor includes a plurality of pixels arranged in a plurality of rows and columns in the pixel array. Each one of the pixels includes a linear subpixel and a log subpixel disposed in a semiconductor material. The linear subpixel is coupled to generate a linear output signal having a linear response, and the log subpixel is coupled to generate a log output signal having a logarithmic response in response to the incident light. A bitline is coupled to the linear subpixel and to the log subpixel to receive the linear output signal and the log output signal. The bitline is one of a plurality of bitlines coupled to the plurality of pixels. Each one of the plurality of bitlines is coupled to a corresponding grouping of the plurality of pixels.
    Type: Grant
    Filed: August 4, 2016
    Date of Patent: June 16, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Keiji Mabuchi, Dyson H. Tai, Oray Orkun Cellek, Duli Mao, Sohei Manabe
  • Patent number: 10644057
    Abstract: An image sensor includes a photodiode disposed in a first semiconductor material to absorb photons incident on the image sensor and generate image charge. A floating diffusion is disposed in the first semiconductor material and positioned to receive the image charge from the photodiode, and a transfer transistor is coupled between the photodiode and the floating diffusion to transfer the image charge out of the photodiode into floating diffusion in response to a transfer signal. A source follower transistor with a gate terminal is coupled to the floating diffusion to output an amplified signal of the image charge in the floating diffusion. The gate terminal includes a second semiconductor material in contact with the floating diffusion, and a gate oxide is partially disposed between the second semiconductor material and the first semiconductor material. The second semiconductor material extends beyond the lateral bounds of the floating diffusion.
    Type: Grant
    Filed: October 2, 2018
    Date of Patent: May 5, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Xin Wang, Dajiang Yang, Siguang Ma, Keiji Mabuchi, Bill Phan, Duli Mao, Dyson Tai
  • Publication number: 20200105807
    Abstract: An image sensor includes one or more photodiodes disposed in a semiconductor material to receive image light and generate image charge, and a floating diffusion to receive the image charge from the one or more photodiodes. One or more transfer transistors is coupled to transfer image charge in the one or more photodiodes to the floating diffusion, and a source follower transistor is coupled to amplify the image charge in the floating diffusion. The source follower includes a gate electrode (coupled to the floating diffusion), source and drain electrodes, and an active region disposed in the semiconductor material between the source and drain electrodes. A dielectric material is disposed between the gate electrode and the active region and has a first thickness and a second thickness. The second thickness is greater than the first thickness, and the second thickness is disposed closer to the drain electrode than the first thickness.
    Type: Application
    Filed: October 2, 2018
    Publication date: April 2, 2020
    Inventors: Gang Chen, Yuanwei Zheng, Qin Wang, Cunyu Yang, Guannan Chen, Duli Mao, Dyson Tai, Lindsay Grant, Eric Webster, Sing-Chung Hu
  • Publication number: 20200099878
    Abstract: An image sensor pixel comprises a first charge storage node configured to have a first charge storage electric potential; a second charge storage node configured to have a second charge storage electric potential and receive charge from the first charge storage node, wherein the second charge storage electric potential is greater than the first charge storage electric potential; and a transfer circuit coupled between the first and the second charge storage nodes, wherein the transfer circuit comprises at least three transfer regions, wherein: a first transfer region is proximate to the first charge storage node and configured to have a first transfer electric potential greater than the first charge storage electric potential and lower than the second charge storage electric potential; a second transfer region is coupled between the first and a third transfer region and configured to have a second transfer electric potential greater than the first charge storage electric potential and lower than the second cha
    Type: Application
    Filed: September 25, 2018
    Publication date: March 26, 2020
    Applicant: OmniVision Technologies, Inc.
    Inventors: Gang Chen, Duli Mao, Dyson Tai, Lindsay Grant
  • Patent number: 10586825
    Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material to convert image light into image charge, and a metal grid, including a metal shield that is coplanar with the metal grid, disposed proximate to a backside of the semiconductor material. The metal grid is optically aligned with the plurality of photodiodes to direct the image light into the plurality of photodiodes, and a contact pad is disposed in a trench in the semiconductor material. The contact pad is coupled to the metal shield to ground the metal shield.
    Type: Grant
    Filed: January 8, 2019
    Date of Patent: March 10, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Qin Wang, Gang Chen, Duli Mao
  • Patent number: 10582178
    Abstract: An active depth imaging system and method of operating the same captures illuminator-on and illuminator-off image data with each of a first and second imager. The illuminator-on image data includes information representing an imaged scene and light emitted from an illuminator and reflected off of objects within the imaged scene. The illuminator-off image data includes information representing the imaged scene without the light emitted from the illuminator. For each image set captured by the first and second imagers, illuminator-off image data is subtracted from the illuminator-on image data to identify the illuminated light within the scene. The depth of an object at which the light is incident on then is determined by the subtracted image data of the first and second imagers.
    Type: Grant
    Filed: November 2, 2016
    Date of Patent: March 3, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Zheng Yang, Eiichi Funatsu, Sohei Manabe, Keiji Mabuchi, Dajiang Yang, Duli Mao, Bowei Zhang
  • Patent number: 10566377
    Abstract: An image sensor includes a substrate, a plurality of light sensitive pixels, a first plurality of color filters, a plurality of reflective sidewalls, and a second plurality of color filters. The light sensitive pixels are formed on said substrate. The first plurality of color filters is disposed over a first group of the light sensitive pixels. The reflective sidewalls are formed on each side of each of the first plurality of color filters. The second plurality of color filters are disposed over a second group of light sensitive pixels and each color filter of the second plurality of color filters is separated from each adjacent filter of said first plurality of color filters by one of the reflective sidewalls. In a particular embodiment an etch-resistant layer is disposed over the first plurality of color filters and the second group of light sensitive pixels.
    Type: Grant
    Filed: September 13, 2018
    Date of Patent: February 18, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Xin Wang, Dajing Yang, Qin Wang, Duli Mao, Dyson Hsin-Chih Tai
  • Patent number: 10566364
    Abstract: A resonant-filter image sensor includes a pixel array including a plurality of pixels and a microresonator layer above the pixel array. The microresonator layer includes a plurality of microresonators formed of a first material with an extinction coefficient less than 0.02 at a free-space wavelength of five hundred nanometers. Each of the plurality of pixels may have at least one of the plurality of microresonators at least partially thereabove. The resonant-filter image sensor may further include a layer covering the microresonator layer that has a second refractive index less than a first refractive index, the first refractive index being the refractive index of the first material. Each microresonator may be one of a parallelepiped, a cylinder, a spheroid, and a sphere.
    Type: Grant
    Filed: February 14, 2019
    Date of Patent: February 18, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Yuanwei Zheng, Gang Chen, Duli Mao, Dyson H. Tai, Lequn Liu
  • Patent number: 10559615
    Abstract: A method for manufacturing a high-dynamic-range color image sensor includes (a) depositing a color filter layer on a silicon substrate having a photosensitive pixel array with a plurality of first pixels and a plurality of second pixels, to form (i) a plurality of first color filters above a first subset of each of the plurality of first pixels and the plurality of second pixels and (ii) a plurality of second color filters above a second subset of each of the plurality of first pixels and the plurality of second pixels, wherein thickness of the second color filters exceeds thickness of the first color filters, and (b) depositing, on the color filter layer, a dynamic-range extending layer including grey filters above the second pixels to attenuate light propagating toward the second pixels, combined thickness of the color filter layer and the dynamic-range extending layer being uniform across the photosensitive pixel array.
    Type: Grant
    Filed: April 2, 2018
    Date of Patent: February 11, 2020
    Assignee: OmniVision Technologies, Inc.
    Inventors: Chen-Wei Lu, Dajiang Yang, Oray Orkun Cellek, Duli Mao
  • Publication number: 20190355778
    Abstract: An image sensor pixel includes a photodiode disposed in a semiconductor material to generate image charge in response to light incident on a backside of the semiconductor material, and a pinning layer disposed in the semiconducting material and coupled to the photodiode. The pixel also includes a vertical overflow drain disposed in the semiconductor material and coupled to the pinning layer such that the pinning layer is disposed between the vertical overflow drain and the photodiode. A floating diffusion disposed in the semiconductor material proximate to the photodiode, and a vertical transfer transistor is disposed in part in the semiconductor material and coupled to the photodiode to transfer the image charge from the photodiode to the floating diffusion in response to a transfer signal applied to the gate terminal of the vertical transfer transistor.
    Type: Application
    Filed: May 18, 2018
    Publication date: November 21, 2019
    Inventors: Yuanwei Zheng, Gang Chen, Duli Mao, Dyson Tai, Lindsay Grant
  • Patent number: 10462433
    Abstract: An image sensor includes a substrate, a first set of sensor pixels formed on the substrate, and a second set of sensor pixels formed on the substrate. The sensor pixels of the first set are arranged in rows and columns and are configured to detect light within a first range of wavelengths (e.g., white light). The sensor pixels of the second set are arranged in rows and columns and are each configured to detect light within one of a set of ranges of wavelengths (e.g., red, green, and blue). Each range of wavelengths of the set of ranges of wavelengths is a subrange of said first range of wavelengths, and each pixel of the second set of pixels is smaller than each pixel of the first set of pixels.
    Type: Grant
    Filed: May 1, 2018
    Date of Patent: October 29, 2019
    Assignee: OmniVision Technologies, Inc.
    Inventors: Gang Chen, Duli Mao, Dyson Hsin-Chih Tai
  • Patent number: 10418408
    Abstract: An image sensor includes a plurality of photodiodes arranged in an array and disposed in a semiconductor material to receive light through a first surface of the semiconductor material. At least part of the semiconductor material is curved. A carrier wafer is attached to a second surface, opposite the first surface, of the semiconductor material, and a polymer layer is attached to the carrier wafer, so that the carrier wafer is disposed between the polymer layer and the semiconductor material.
    Type: Grant
    Filed: June 22, 2018
    Date of Patent: September 17, 2019
    Assignee: OmniVision Technologies, Inc.
    Inventors: Yuanwei Zheng, Chia-Chun Miao, Gang Chen, Yin Qian, Duli Mao, Dyson H. Tai, Lindsay Grant
  • Patent number: 10411063
    Abstract: A single-exposure high dynamic range (HDR) image sensor includes a first photodiode and a second photodiode, with a smaller full-well capacity than the first photodiode, disposed in a semiconductor material. The image sensor also includes a first floating diffusion disposed in the semiconductor material and a first transfer gate coupled to the first photodiode to transfer first image charge accumulated in the first photodiode into the first floating diffusion. A second floating diffusion is disposed in the semiconductor material and a second transfer gate is coupled to the second photodiode to transfer second image charge accumulated in the second photodiode into the second floating diffusion. An attenuation layer is disposed between the second photodiode and image light directed towards the single-exposure HDR image sensor to block a portion of the image light from reaching the second photodiode.
    Type: Grant
    Filed: June 20, 2017
    Date of Patent: September 10, 2019
    Assignee: OmniVision Technologies, Inc.
    Inventors: Dajiang Yang, Oray Orkun Cellek, Duli Mao, Xianfu Cheng, Xin Wang, Bill Phan, Dyson Tai
  • Patent number: 10334191
    Abstract: A pixel cell includes a second photodiode laterally surrounding a first photodiode in semiconductor material. The first and second photodiodes are adapted to photogenerate image charge in response to incident light. A floating diffusion is disposed in the semiconductor material proximate to an outer perimeter of the second photodiode. A first transfer gate is disposed proximate to the semiconductor material over a first channel region between the first and second photodiodes. The first transfer gate is coupled to transfer the image charge from the first photodiode to the second photodiode. A second transfer gate is disposed proximate to the semiconductor material over a second channel region between the second photodiode and the floating diffusion. The second transfer gate is coupled to transfer the image charge from the second photodiode to the floating diffusion.
    Type: Grant
    Filed: March 2, 2018
    Date of Patent: June 25, 2019
    Assignee: OmniVision Technologies, Inc.
    Inventors: Dajiang Yang, Zhiyong Zhan, Chen-wei Lu, Duli Mao, Xin Wang, Keiji Mabuchi
  • Publication number: 20190181173
    Abstract: A resonant-filter image sensor includes a pixel array including a plurality of pixels and a microresonator layer above the pixel array. The microresonator layer includes a plurality of microresonators formed of a first material with an extinction coefficient less than 0.02 at a free-space wavelength of five hundred nanometers. Each of the plurality of pixels may have at least one of the plurality of microresonators at least partially thereabove. The resonant-filter image sensor may further include a layer covering the microresonator layer that has a second refractive index less than a first refractive index, the first refractive index being the refractive index of the first material. Each microresonator may be one of a parallelepiped, a cylinder, a spheroid, and a sphere.
    Type: Application
    Filed: February 14, 2019
    Publication date: June 13, 2019
    Inventors: Yuanwei Zheng, Gang Chen, Duli Mao, Dyson H. Tai, Lequn Liu
  • Patent number: 10312391
    Abstract: An avalanche photodiode has a first diffused region of a first diffusion type overlying at least in part a second diffused region of a second diffusion type; and a first minority carrier sink region disposed within the first diffused region, the first minority carrier sink region of the second diffusion type and electrically connected to the first diffused region. In particular embodiments, the first diffusion type is N-type and the second diffusion type is P-type, and the device is biased so that a depletion zone having avalanche multiplication exists between the first and second diffused regions.
    Type: Grant
    Filed: October 4, 2016
    Date of Patent: June 4, 2019
    Assignee: OmniVision Technologies, Inc.
    Inventors: Gang Chen, Duli Mao, Vincent Venezia, Dyson H. Tai, Bowei Zhang
  • Publication number: 20190165033
    Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material to convert image light into image charge, and a metal grid, including a metal shield that is coplanar with the metal grid, disposed proximate to a backside of the semiconductor material. The metal grid is optically aligned with the plurality of photodiodes to direct the image light into the plurality of photodiodes, and a contact pad is disposed in a trench in the semiconductor material. The contact pad is coupled to the metal shield to ground the metal shield.
    Type: Application
    Filed: January 8, 2019
    Publication date: May 30, 2019
    Inventors: Qin Wang, Gang Chen, Duli Mao