Patents by Inventor Xianmin Yi

Xianmin Yi 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: 20250261460
    Abstract: An image sensor pixel array includes a source follower transistor configured with an asymmetric doping profile under its gate. In an example, a given pixel of a pixel array includes a photodetector coupled to a readout circuit, which includes a transfer gate between the photodetector and a source follower transistor. In an example, the source follower transistor includes doped source and drain regions with a lightly doped drain (LDD) region adjacent to the source region, but no corresponding LDD region adjacent to the drain region. Such a configuration allows for reduced parasitic capacitance across the gate-drain junction of the transistor, which provides a higher conversion gain for the pixel.
    Type: Application
    Filed: February 9, 2024
    Publication date: August 14, 2025
    Inventors: Xianmin Yi, Alexander Lu
  • Publication number: 20250261464
    Abstract: An image sensor includes a pixel array across a substrate, with at least one pixel of the array being defined by dielectric walls extending from both the top and bottom surfaces of the substrate. The dielectric walls contact each other within the substrate. The dielectric walls encircle around, or form a perimeter around, a volume of semiconductor material that defines the pixel. In this way, light entering through one end of the pixel is generally confined between the dielectric walls as it traverses through the height of the pixel. By using two different dielectric walls formed from the frontside and backside of the substrate, thicker substrates can be used which increases the quantum efficiency of the pixel.
    Type: Application
    Filed: February 12, 2024
    Publication date: August 14, 2025
    Applicant: Fairchild Imaging, Inc.
    Inventors: Xianmin Yi, Alexander Lu
  • Publication number: 20250184627
    Abstract: Structures are disclosed for a binned set of pixels (such as a 2×2 set of pixels) of a pixel array that shares a same readout circuit and can operate with a global shutter. The global shutter allows for greater charge storage from each pixel and for the charge from each of the binned pixels to be collected simultaneously. In an example, each of the binned pixels includes a photodetector, a transfer gate, and a storage gate. The storage gate of each binned pixel may be linked as part of a global shutter. The readout circuit can be coupled to the transfer gate of each of the binned pixels and includes its own second transfer gate that separates the pixels from a storage or sensing node. The photodetector signal on the sensing node can be amplified via a source follower component and ultimately read out to a column amplifier.
    Type: Application
    Filed: November 30, 2023
    Publication date: June 5, 2025
    Inventors: Xianmin Yi, Alexander Lu
  • Patent number: 12289549
    Abstract: Image sensor systems are disclosed that allow for charge transfer between pixels of a group included in a pixel array with a single digital readout of the accumulated charge from the group. Each of the pixels within a given group includes a photodetector. One or more pump gates are arranged between adjacent pixels of the given group to allow charge to be pumped from one pixel to the next in a serial fashion within the group. A readout circuit that includes at least a transfer gate and a capacitor may be coupled to a final pixel of the group to receive the accumulated charge and generate a photodetector signal (based on the accumulated charge) that can be amplified via a source follower component and ultimately read out to a column amplifier.
    Type: Grant
    Filed: November 9, 2022
    Date of Patent: April 29, 2025
    Assignee: FAIRCHILD IMAGING, INC
    Inventors: Xianmin Yi, Alexander Lu, Carol Zhao
  • Patent number: 12267605
    Abstract: Structures are disclosed for a binned set of two or more pixels of a pixel array that share a same readout circuit. The binned pixel design provides space-saving benefits on the chip and also improves the overall image quality. According to some embodiments, each of the binned pixels includes a photodetector and its own transfer gate. The readout circuit is coupled to the transfer gates of each of the binned pixels and includes its own second transfer gate that separates the pixels from a gain mode select block. The gain mode select block may include capacitors of different sizes and one or more switches to control which capacitors are to receive the charge from any one of the binned pixels. The readout circuit may also include a potential barrier (such as a diode), which allows for pumping charge onto the one or more capacitors of the gain mode select block.
    Type: Grant
    Filed: October 17, 2022
    Date of Patent: April 1, 2025
    Assignee: FAIRCHILD IMAGING, INC.
    Inventors: Xianmin Yi, Alexander Lu
  • Patent number: 12250478
    Abstract: Techniques to provide a low-power single-photon avalanche diode (SPAD) image. An example imaging device includes a SPAD array having a plurality of pixels configured to detect electromagnetic radiation, and a processing device configured to deactivate, based on an event count, a pixel of the SPAD array for a remaining duration of a first detection frame of the SPAD array. The pixel can remain deactivated for the remaining duration, and the remaining duration can span from a deactivation time until an end of the first SPAD frame. The processing device can be further configured to reactivate the pixel in a subsequent detection frame of the SPAD array.
    Type: Grant
    Filed: November 16, 2022
    Date of Patent: March 11, 2025
    Assignee: FAIRCHILD IMAGING, INC.
    Inventors: Xianmin Yi, Chien-Horn Lu, Shanli Hu, Edmond Tam, Angel Rogelio Lopez, William Tian
  • Patent number: 12250481
    Abstract: Image sensor systems are disclosed that include charge coupled device (CCD) pixels integrated with CMOS readout circuitry via separately bonded substrates. According to some embodiments, columns of image sensing pixels on a first substrate are arranged with overlapping gate structures to facilitate charge transfer between the pixels. At least one pixel is coupled to a first conductive pad that contacts (or is melded with) a second conductive pad from a second substrate bonded to the first substrate. The second substrate includes a readout circuit using one or more CMOS devices coupled to the second conductive pad to receive the accumulated charge from a given column of pixels. The resulting photodetector signal from the accumulated charge can be, for instance, amplified via a source follower component and ultimately read out to a column amplifier, and subjected to further processing and/or use in a given downstream system.
    Type: Grant
    Filed: February 7, 2023
    Date of Patent: March 11, 2025
    Assignee: FAIRCHILD IMAGING, INC.
    Inventors: Xianmin Yi, Alexander Lu
  • Publication number: 20240267652
    Abstract: Image sensor systems are disclosed that include charge coupled device (CCD) pixels integrated with CMOS readout circuitry via separately bonded substrates. According to some embodiments, columns of image sensing pixels on a first substrate are arranged with overlapping gate structures to facilitate charge transfer between the pixels. At least one pixel is coupled to a first conductive pad that contacts (or is melded with) a second conductive pad from a second substrate bonded to the first substrate. The second substrate includes a readout circuit using one or more CMOS devices coupled to the second conductive pad to receive the accumulated charge from a given column of pixels. The resulting photodetector signal from the accumulated charge can be, for instance, amplified via a source follower component and ultimately read out to a column amplifier, and subjected to further processing and/or use in a given downstream system.
    Type: Application
    Filed: February 7, 2023
    Publication date: August 8, 2024
    Applicant: BAE Systems Imaging Solutions Inc.
    Inventors: Xianmin Yi, Alexander Lu
  • Publication number: 20240163576
    Abstract: Techniques to provide a low-power single-photon avalanche diode (SPAD) image. An example imaging device includes a SPAD array having a plurality of pixels configured to detect electromagnetic radiation, and a processing device configured to deactivate, based on an event count, a pixel of the SPAD array for a remaining duration of a first detection frame of the SPAD array. The pixel can remain deactivated for the remaining duration, and the remaining duration can span from a deactivation time until an end of the first SPAD frame. The processing device can be further configured to reactivate the pixel in a subsequent detection frame of the SPAD array.
    Type: Application
    Filed: November 16, 2022
    Publication date: May 16, 2024
    Applicant: BAE Systems Imaging Solutions Inc.
    Inventors: Xianmin Yi, Chien-Horn Lu, Shanli Hu, Edmond Tam, Angel Rogelio Lopez, William Tian
  • Publication number: 20240155262
    Abstract: Image sensor systems are disclosed that allow for charge transfer between pixels of a group included in a pixel array with a single digital readout of the accumulated charge from the group. Each of the pixels within a given group includes a photodetector. One or more pump gates are arranged between adjacent pixels of the given group to allow charge to be pumped from one pixel to the next in a serial fashion within the group. A readout circuit that includes at least a transfer gate and a capacitor may be coupled to a final pixel of the group to receive the accumulated charge and generate a photodetector signal (based on the accumulated charge) that can be amplified via a source follower component and ultimately read out to a column amplifier.
    Type: Application
    Filed: November 9, 2022
    Publication date: May 9, 2024
    Applicant: BAE Systems Imaging Solutions Inc.
    Inventors: Xianmin Yi, Alexander Lu, Carol Zhao
  • Publication number: 20240129644
    Abstract: Structures are disclosed for a binned set of two or more pixels of a pixel array that share a same readout circuit. The binned pixel design provides space-saving benefits on the chip and also improves the overall image quality. According to some embodiments, each of the binned pixels includes a photodetector and its own transfer gate. The readout circuit is coupled to the transfer gates of each of the binned pixels and includes its own second transfer gate that separates the pixels from a gain mode select block. The gain mode select block may include capacitors of different sizes and one or more switches to control which capacitors are to receive the charge from any one of the binned pixels. The readout circuit may also include a potential barrier (such as a diode), which allows for pumping charge onto the one or more capacitors of the gain mode select block.
    Type: Application
    Filed: October 17, 2022
    Publication date: April 18, 2024
    Applicant: BAE Systems Imaging Solutions Inc.
    Inventors: Xianmin Yi, Alexander Lu
  • Publication number: 20240129647
    Abstract: A given pixel of a pixel array includes various operation modes with each of the operation modes having a different conversion gain for the charge received from the photodetector of the pixel. When the modes are used in conjunction with one another, the dynamic range of the pixel can be increased. A readout circuit coupled to a photodetector within a given pixel includes a transfer gate between the photodetector and a gain mode select block that includes capacitors of different sizes and one or more switches to control which capacitors are to receive the charge from the photodetector. Depending on the state(s) of the one or more switches, different operation modes with different conversion gains can be selected to increase the dynamic range of the pixel. The adaptability of the readout circuit can allow for a high dynamic range even in extreme temperature environments by lowering the dark current.
    Type: Application
    Filed: October 17, 2022
    Publication date: April 18, 2024
    Applicant: BAE Systems Imaging Solutions Inc.
    Inventors: Xianmin Yi, Alexander Lu
  • Patent number: 11956557
    Abstract: A given pixel of a pixel array includes various operation modes with each of the operation modes having a different conversion gain for the charge received from the photodetector of the pixel. When the modes are used in conjunction with one another, the dynamic range of the pixel can be increased. A readout circuit coupled to a photodetector within a given pixel includes a transfer gate between the photodetector and a gain mode select block that includes capacitors of different sizes and one or more switches to control which capacitors are to receive the charge from the photodetector. Depending on the state(s) of the one or more switches, different operation modes with different conversion gains can be selected to increase the dynamic range of the pixel. The adaptability of the readout circuit can allow for a high dynamic range even in extreme temperature environments by lowering the dark current.
    Type: Grant
    Filed: October 17, 2022
    Date of Patent: April 9, 2024
    Assignee: BAE Systems Imaging Solutions Inc.
    Inventors: Xianmin Yi, Alexander Lu
  • Patent number: 11211421
    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: Grant
    Filed: January 23, 2019
    Date of Patent: December 28, 2021
    Assignee: OMNIVISION TECHNOLOGIES, INC.
    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
  • 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: 9865642
    Abstract: A front-side-interconnect (FSI) red-green-blue-infrared (RGB-IR) photosensor array has photosensors of a first type with a diffused N-type region in a P-type well, the P-type well diffused into a high resistivity semiconductor layer; photosensors of a second type, with a deeper diffused N-type region in a P-type well, the P-type well; and photosensors of a third type with a diffused N-type region diffused into the high resistivity semiconductor layer underlying all of the other types of photosensors. In embodiments, photosensors of a fourth type have a diffused N-type region in a P-type well, the N-type region deeper than the N-type region of photosensors of the first and second types.
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: January 9, 2018
    Assignee: OmniVision Technologies, Inc.
    Inventors: Zhenhong Fu, Dajiang Yang, Xianmin Yi, Gang Chen, Sing-Chung Hu, Duli Mao
  • Publication number: 20170359545
    Abstract: An image sensor pixel having a hybrid transfer storage gate-storage diode storage node is disclosed herein. An example image sensor includes a photodiode, a storage diode, a transfer gate, and a buried storage well. The photodiode, storage diode, and buried storage well are all disposed in a semiconductor material. The transfer storage gate may be disposed on a surface of the semiconductor material between the photodiode and the storage diode. Further, the buried storage well may be disposed under the storage diode and partially under the transfer storage gate. Additionally, a length of the transfer storage gate and a length of the storage diode may be equal, and the storage diode may passivate a surface of the semiconductor material between the transfer storage gate and an output gate.
    Type: Application
    Filed: June 14, 2016
    Publication date: December 14, 2017
    Inventor: Xianmin Yi
  • Patent number: 9843754
    Abstract: An image sensor pixel having a hybrid transfer storage gate-storage diode storage node is disclosed herein. An example image sensor includes a photodiode, a storage diode, a transfer gate, and a buried storage well. The photodiode, storage diode, and buried storage well are all disposed in a semiconductor material. The transfer storage gate may be disposed on a surface of the semiconductor material between the photodiode and the storage diode. Further, the buried storage well may be disposed under the storage diode and partially under the transfer storage gate. Additionally, a length of the transfer storage gate and a length of the storage diode may be equal, and the storage diode may passivate a surface of the semiconductor material between the transfer storage gate and an output gate.
    Type: Grant
    Filed: June 14, 2016
    Date of Patent: December 12, 2017
    Assignee: OmniVision Technologies, Inc.
    Inventor: Xianmin Yi
  • Publication number: 20160358969
    Abstract: A front-side-interconnect (FSI) red-green-blue-infrared (RGB-IR) photosensor array has photosensors of a first type with a diffused N-type region in a P-type well, the P-type well diffused into a high resistivity semiconductor layer; photosensors of a second type, with a deeper diffused N-type region in a P-type well, the P-type well; and photosensors of a third type with a diffused N-type region diffused into the high resistivity semiconductor layer underlying all of the other types of photosensors. In embodiments, photosensors of a fourth type have a diffused N-type region in a P-type well, the N-type region deeper than the N-type region of photosensors of the first and second types.
    Type: Application
    Filed: June 5, 2015
    Publication date: December 8, 2016
    Inventors: Zhenhong Fu, Dajiang Yang, Xianmin Yi, Gang Chen, Sing-Chung Hu, Duli Mao
  • Patent number: 9472587
    Abstract: A storage transistor with a storage region is disposed in a semiconductor material. A gate electrode is disposed in a bottom side of an interlayer proximate to the storage region, and a dielectric layer is disposed between the storage region and the gate electrode. An optical isolation structure is disposed in the interlayer and the optical isolation structure extends from a top side of the interlayer to the gate electrode. The optical isolation structure is also adjoining a perimeter of the gate electrode and contacts the gate electrode. A capping layer is disposed proximate to the top side of the interlayer and the capping layer caps a volume encircled by the optical isolation structure.
    Type: Grant
    Filed: January 27, 2015
    Date of Patent: October 18, 2016
    Assignee: OmniVision Technologies, Inc.
    Inventors: Yuanwei Zheng, Xianmin Yi, Gang Chen, Duli Mao, Dyson H. Tai