Patents by Inventor Howard E. Rhodes

Howard E. Rhodes 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).

  • LIGHTLY-DOPED DRAINS (LDD) OF IMAGE SENSOR TRANSISTORS USING SELECTIVE EPITAXY
    Publication number: 20120295385
    Abstract: Embodiments of the present invention are directed to an image sensor having pixel transistors and peripheral transistors disposed in a silicon substrate. For some embodiments, a protective coating is disposed on the peripheral transistors and doped silicon is epitaxially grown on the substrate to form lightly-doped drain (LDD) areas for the pixel transistors. The protective oxide may be used to prevent epitaxial growth of silicon on the peripheral transistors during formation of the LDD areas of the pixel transistors.
    Type: Application
    Filed: July 26, 2012
    Publication date: November 22, 2012
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Duli Mao, Hsin-Chih Tai, Howard E. Rhodes, Vincent Venezia, Yin Qian
  • Image sensor with improved black level calibration
    Patent number: 8314869
    Abstract: An imaging system capable of black level calibration includes an imaging pixel array, at least one black reference pixel, and peripheral circuitry. The imaging pixel array includes a plurality of active pixels each coupled to capture image data. The black reference pixel is coupled to generate a black reference signal for calibrating the image data. Light transmitting layers are disposed on a first side of a pixel array die including the imaging system and cover at least the imaging pixel array and the black reference pixel. A light shielding layer is disposed on the first side of the pixel array die and covers a portion of the light transmitting layers and the black reference pixel without covering the imaging pixel array.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: November 20, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Wei Zheng, Hsin-Chih Tai, Yin Qian, Hongjun Li, Howard E. Rhodes
  • BACKSIDE ILLUMINATED IMAGING SENSOR WITH REINFORCED PAD STRUCTURE
    Publication number: 20120282728
    Abstract: A method of fabricating a backside illuminated imaging sensor that includes a device layer, a metal stack, and an opening is disclosed. The device layer has an imaging array formed in a front side of the device layer, where the imaging array is adapted to receive light from a back side of the device layer. The metal stack is coupled to the front side of the device layer and includes at least one metal interconnect layer having a metal pad. The opening extends from the back side of the device layer to the metal pad to expose the metal pad for wire bonding. The method includes depositing a film on the back side of the device layer and within the opening, then etching the film to form a frame within the opening to structurally reinforce the metal pad.
    Type: Application
    Filed: July 20, 2012
    Publication date: November 8, 2012
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Hsin-Chih Tai, Howard E. Rhodes, Duli Mao, Vincent Venezia, Yin Qian
  • Transparent conductor based pinned photodiode
    Patent number: 8298846
    Abstract: A pinned photodiode with improved short wavelength light response. In exemplary embodiments of the invention, a gate oxide is formed over a doped, buried region in a semiconductor substrate. A gate conductor is formed on top of the gate oxide. The gate conductor is transparent, and in one embodiment is a layer of indium-tin oxide. The transparent conductor can be biased to reduce the need for a surface dopant in creating a pinned photodiode region. The biasing of the transparent conductor produces a hole-rich accumulation region near the surface of the substrate. The gate conductor material permits a greater amount of charges from short wavelength light to be captured in the photo-sensing region in the substrate, and thereby increases the quantum efficiency of the photosensor.
    Type: Grant
    Filed: February 12, 2010
    Date of Patent: October 30, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Chandra Mouli, Howard E. Rhodes
  • Image sensor having supplemental capacitive coupling node
    Patent number: 8294077
    Abstract: An image sensor includes a pixel array, a bit line, supplemental capacitance node line, and a supplemental capacitance circuit. The pixel array includes a plurality of pixel cells each including a floating diffusion (“FD”) node and a photosensitive element coupled to selectively transfer image charge to the FD node. The bit line is coupled to selectively conduct image data output from a first group of the pixel cells. The supplemental capacitance node line is coupled to the FD node of a second group of the pixel cells to selectively couple a supplemental capacitance to the FD nodes of the second group in response to a control signal. In various embodiments, the first and second group of pixel cells may be the same group or a different group of the pixel cells and may add a capacitive boost feature or a multi conversion gain feature.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: October 23, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Duli Mao, Hsin-Chih Tai, Vincent Venezia, Howard E. Rhodes, Sohei Manabe
  • High full-well capacity pixel with graded photodetector implant
    Patent number: 8293629
    Abstract: Embodiments of a process for forming a photodetector region in a CMOS pixel by dopant implantation, the process comprising masking a photodetector area of a surface of a substrate for formation of the photodetector region, positioning the substrate at a plurality of twist angles, and at each of the plurality of twist angles, directing dopants at the photodetector area at a selected tilt angle. Embodiments of a CMOS pixel comprising a photodetector region formed in a substrate, the photodetector region comprising overlapping first and second dopant implants, wherein the overlap region has a different dopant concentration than the non-overlapping parts of the first and second implants, a floating diffusion formed in the substrate, and a transfer gate formed on the substrate between the photodetector and the transfer gate. Other embodiments are disclosed and claimed.
    Type: Grant
    Filed: April 6, 2010
    Date of Patent: October 23, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Duli Mao, Hsin-Chih Tai, Vincent Venezia, Yin Qian, Howard E. Rhodes
  • IMAGE SENSOR WITH IMPROVED BLACK LEVEL CALIBRATION
    Publication number: 20120249845
    Abstract: An imaging system capable of black level calibration includes an imaging pixel array, at least one black reference pixel, and peripheral circuitry. The imaging pixel array includes a plurality of active pixels each coupled to capture image data. The black reference pixel is coupled to generate a black reference signal for calibrating the image data. Light transmitting layers are disposed on a first side of a pixel array die including the imaging system and cover at least the imaging pixel array and the black reference pixel. A light shielding layer is disposed on the first side of the pixel array die and covers a portion of the light transmitting layers and the black reference pixel without covering the imaging pixel array.
    Type: Application
    Filed: June 13, 2012
    Publication date: October 4, 2012
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Wei Zheng, Hsin-Chih Tai, Yin Qian, Hongjun Li, Howard E. Rhodes
  • Laser anneal for image sensors
    Patent number: 8278690
    Abstract: A technique for fabricating an image sensor including a pixel circuitry region and a peripheral circuitry region includes fabricating front side components on a front side of the image sensor. A dopant layer is implanted on a backside of the image sensor. A anti-reflection layer is formed on the backside and covers a first portion of the dopant layer under the pixel circuitry region while exposing a second portion of the dopant layer under the peripheral circuitry region. The first portion of the dopant layer is laser annealed from the backside of the image sensor through the anti-reflection layer. The anti-reflection layer increases a temperature of the first portion of the dopant layer during the laser annealing.
    Type: Grant
    Filed: April 27, 2010
    Date of Patent: October 2, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Duli Mao, Hsin-Chih Tai, Vincent Venezia, Yin Qian, Howard E. Rhodes
  • Active pixel sensor with a diagonal active area
    Patent number: 8279313
    Abstract: An imaging device formed as a CMOS semiconductor integrated circuit having two adjacent pixels in a row connected to a common column line. By having adjacent pixels of a row share column lines, the CMOS imager circuit eliminates half the column lines of a traditional imager allowing the fabrication of a smaller imager. The imaging device also may be fabricated to have a diagonal active area to facilitate contact of two adjacent pixels with the single column line and allow linear row select lines, reset lines and column lines.
    Type: Grant
    Filed: February 25, 2010
    Date of Patent: October 2, 2012
    Assignee: Round Rock Research, LLC
    Inventor: Howard E. Rhodes
  • CMOS image sensor with heat management structures
    Patent number: 8274101
    Abstract: An image sensor includes a device wafer substrate of a device wafer, a device layer of the device wafer, and optionally a heat control structure and/or a heat sink. The device layer is disposed on a frontside of the device wafer substrate and includes a plurality of photosensitive elements disposed within a pixel array region and peripheral circuitry disposed within a peripheral circuits region. The photosensitive elements are sensitive to light incident on a backside of the device wafer substrate. The heat control structure is disposed within the device wafer substrate and thermally isolates the pixel array region from the peripheral circuits region to reduce heat transfer between the peripheral circuits region and the pixel array region. The heat sink conducts heat away from the device layer.
    Type: Grant
    Filed: August 9, 2010
    Date of Patent: September 25, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Vincent Venezia, Duli Mao, Hsin-Chih Tai, Yin Qian, Howard E. Rhodes
  • BACKSIDE-ILLUMINATED (BSI) IMAGE SENSOR WITH REDUCED BLOOMING AND ELECTRICAL SHUTTER
    Publication number: 20120235212
    Abstract: Embodiments of a pixel including a photosensitive region formed in a surface of a substrate and an overflow drain formed in the surface of the substrate at a distance from the photosensitive area, an electrical bias of the overflow drain being variable and controllable. Embodiments of a pixel including a photosensitive region formed in a surface of a substrate, a source-follower transistor coupled to the photosensitive region, the source-follower transistor including a drain, and a doped bridge coupling the photosensitive region to the drain of the source-follower transistor.
    Type: Application
    Filed: March 17, 2011
    Publication date: September 20, 2012
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Gang Chen, Sing-Chung Hu, Duli Mao, Hsin-Chih Tai, Yin Qian, Vincent Venezia, Rongsheng Yang, Howard E. Rhodes
  • RESONATOR FOR THERMO OPTIC DEVICE
    Publication number: 20120237165
    Abstract: A resonator for thermo optic devices is formed in the same process steps as a waveguide and is formed in a depression of a lower cladding while the waveguide is formed on a surface of the lower cladding. Since upper surfaces of the resonator and waveguide are substantially coplanar, the aspect ratio, as between the waveguide and resonator in an area where the waveguide and resonator front one another, decreases thereby increasing the bandwidth of the resonator. The depression is formed by photomasking and etching the lower cladding before forming the resonator and waveguide. Pluralities of resonators are also taught that are formed in a plurality of depressions of the lower cladding. To decrease resonator bandwidth, waveguide(s) are formed in the depression(s) of the lower cladding while the resonator is formed on the surface. Thermo optic devices formed with these resonators are also taught.
    Type: Application
    Filed: May 30, 2012
    Publication date: September 20, 2012
    Inventors: Gurtej Singh Sandhu, Guy T. Blalock, Howard E. Rhodes
  • Lightly-doped drains (LDD) of image sensor transistors using selective epitaxy
    Patent number: 8253200
    Abstract: Embodiments of the present invention are directed to an image sensor having pixel transistors and peripheral transistors disposed in a silicon substrate. For some embodiments, a protective coating is disposed on the peripheral transistors and doped silicon is epitaxially grown on the substrate to form lightly-doped drain (LDD) areas for the pixel transistors. The protective oxide may be used to prevent epitaxial growth of silicon on the peripheral transistors during formation of the LDD areas of the pixel transistors.
    Type: Grant
    Filed: November 19, 2008
    Date of Patent: August 28, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Duli Mao, Hsin-Chih Tai, Howard E. Rhodes, Vincent Venezia, Yin Qian
  • Backside illuminated imaging sensor with reinforced pad structure
    Patent number: 8247852
    Abstract: A backside illuminated imaging sensor with reinforced pad structure includes a device layer, a metal stack, an opening and a frame. The device layer has an imaging array formed in a front side of the device layer and the imaging array is adapted to receive light from a back side of the device layer. The metal stack is coupled to the front side of the device layer where the metal stack includes at least one metal interconnect layer having a metal pad. The opening extends from the back side of the device layer to the metal pad to expose the metal pad for wire bonding. The frame is disposed within the opening to structurally reinforce the metal pad.
    Type: Grant
    Filed: November 17, 2009
    Date of Patent: August 21, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Hsin-Chih Tai, Howard E. Rhodes, Duli Mao, Vincent Venezia, Yin Qian
  • Alternating row infrared filter for an image sensor
    Patent number: 8237121
    Abstract: An image sensor includes near-infrared cut filters formed over an array of photosensitive elements in a predetermined pattern. The near-infrared cut filters may be formed over one half of a photosensitive element in a split pixel arrangement, over one half the photosensitive elements in the array, over every other photosensitive element in the array, and/or in a checkerboard pattern.
    Type: Grant
    Filed: February 7, 2008
    Date of Patent: August 7, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Jeffrey L. Morin, Inayat Khajasha, Howard E. Rhodes
  • Image sensor with backside passivation and metal layer
    Patent number: 8232133
    Abstract: An image sensor includes a semiconductor layer that filters light of different wavelengths. For example, the semiconductor layer absorbs photons of shorter wavelengths and passes more photons of longer wavelengths such that the longer wavelength photons often pass through without being absorbed. An imaging pixel having a photodiode is formed near a front side of the semiconductor layer. A dopant layer is formed below the photodiode near a back side of the semiconductor layer. A mirror that primarily reflects photons of longer visible wavelengths is disposed on the back side of the semiconductor layer.
    Type: Grant
    Filed: July 26, 2011
    Date of Patent: July 31, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Howard E. Rhodes, Hidetoshi Nozaki
  • Image sensor with improved black level calibration
    Patent number: 8233066
    Abstract: An imaging system capable of black level calibration includes an imaging pixel array, at least one black reference pixel, and peripheral circuitry. The imaging pixel array includes a plurality of active pixels each coupled to capture image data. The black reference pixel is coupled to generate a black reference signal for calibrating the image data. Light transmitting layers are disposed on a first side of a pixel array die including the imaging system and cover at least the imaging pixel array and the black reference pixel. A light shielding layer is disposed on the first side of the pixel array die and covers a portion of the light transmitting layers and the black reference pixel without covering the imaging pixel array.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: July 31, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Wei Zheng, Hsin-Chih Tai, Yin Qian, Hongjun Li, Howard E. Rhodes
  • Circuit and photo sensor overlap for backside illumination image sensor
    Patent number: 8228411
    Abstract: A method of operation of a backside illuminated (BSI) pixel array includes acquiring an image signal with a first photosensitive region of a first pixel within the BSI pixel array. The image signal is generated in response to light incident upon a backside of the first pixel. The image signal acquired by the first photosensitive region is transferred to pixel circuitry of the first pixel disposed on a frontside of the first pixel opposite the backside. The pixel circuitry at least partially overlaps the first photosensitive region of the first pixel and extends over die real estate above a second photosensitive region of a second pixel adjacent to the first pixel such that the second pixel donates die real estate unused by the second pixel to the first pixel to accommodate larger pixel circuitry than would fit within the first pixel.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: July 24, 2012
    Assignee: OmniVision Technologies, Inc.
    Inventors: Tiejun Dai, Hsin-Chih Tai, Sohei Manabe, Hidetoshi Nozaki, Howard E. Rhodes
  • IMAGE SENSOR HAVING SUPPLEMENTAL CAPACITIVE COUPLING NODE
    Publication number: 20120153123
    Abstract: An image sensor includes a pixel array, a bit line, supplemental capacitance node line, and a supplemental capacitance circuit. The pixel array includes a plurality of pixel cells each including a floating diffusion (“FD”) node and a photosensitive element coupled to selectively transfer image charge to the FD node. The bit line is coupled to selectively conduct image data output from a first group of the pixel cells. The supplemental capacitance node line is coupled to the FD node of a second group of the pixel cells to selectively couple a supplemental capacitance to the FD nodes of the second group in response to a control signal. In various embodiments, the first and second group of pixel cells may be the same group or a different group of the pixel cells and may add a capacitive boost feature or a multi conversion gain feature.
    Type: Application
    Filed: December 17, 2010
    Publication date: June 21, 2012
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Duli Mao, Hsin-Chih Tai, Vincent Venezia, Howard E. Rhodes, Sohei Manabe
  • Resonator for thermo optic device
    Patent number: 8195020
    Abstract: A resonator for thermo optic devices is formed in the same process steps as a waveguide and is formed in a depression of a lower cladding while the waveguide is formed on a surface of the lower cladding. Since upper surfaces of the resonator and waveguide are substantially coplanar, the aspect ratio, as between the waveguide and resonator in an area where the waveguide and resonator front one another, decreases thereby increasing the bandwidth of the resonator. The depression is formed by photomasking and etching the lower cladding before forming the resonator and waveguide. Pluralities of resonators are also taught that are formed in a plurality of depressions of the lower cladding. To decrease resonator bandwidth, waveguide(s) are formed in the depression(s) of the lower cladding while the resonator is formed on the surface. Thermo optic devices formed with these resonators are also taught.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: June 5, 2012
    Assignee: Micron Technology, Inc.
    Inventors: Gurtej Singh Sandhu, Guy T. Blalock, Howard E. Rhodes