Omnivision Technologies, Inc.

Takayuki Goto

Sohei Manabe

Keiji Mabuchi

Dajiang Yang

Duli Mao

Gang Chen

Yin Qian

Vincent Venezia

Rui Wang

Hiroaki Ebihara

Boyd Fowler

Chen-Wei Lu

Eric A G Webster

Kazufumi Watanabe

Boyd Albert Fowler

Eric AG Webster

An image sensor comprising a semiconductor substrate and pixel cell circuitry is described. The semiconductor substrate includes a first side and a second side opposite the first side. The pixel cell circuitry is disposed proximate to the first side of the semiconductor substrate. The pixel cell circuitry includes an arrangement of individual groups of components, each including a reset gate, a source-follower gate, and a row select gate. The individual groups of components included in the pixel cell circuitry includes a first group and a second group adjacent to the first group, and wherein the source-follower gate of the first group is disposed adjacent to the source-follower gate of the second group.

Pixel cell circuitry for image sensors

A pixel array includes a plurality of pixel cells, each including a photodiode configured to photogenerate image charge in response to the incident light, a first floating diffusion (FD) coupled to receive the image charge from the photodiode, a reset transistor coupled between a voltage source and the first FD, a second FD coupled between the first FD and ground, a first dual FD transistor coupled between the first and second FDs. Second FDs of first and second pixel cells are coupled. Second FDs of third and fourth pixel cells are coupled.

Triple conversion gain pixel

A pixel cell for an image sensor including a first semiconductor substrate, a photodiode, and a transfer gate is described. The first semiconductor substrate includes a first side and a second side. The first side is opposite the second side. The photodiode is disposed within the first semiconductor substrate between the first and the second side. The transfer gate is disposed proximate to the first side of the first semiconductor substrate. The transfer gate includes a planar region. The first side of the semiconductor substrate is disposed between the planar region and the photodiode. A lateral area of the photodiode is less than or equal to a lateral area of the planar region of the transfer gate.

Image sensor structure for reduced pixel pitch and methods thereof

An image sensor includes a substrate and a plurality of infrared pixels formed in a front side of the substrate and configured to detect infrared light incident on the front side of the substrate. Each of the infrared pixels includes a photodiode, a region free of implants located above the photodiode, and a photogate formed over the substrate and above the photodiode. The image sensor also includes a plurality of color pixels dispersed among the infrared pixels, where each of the color pixels includes a pinned photodiode and is configured to detect visible light. The photodiode of each of the infrared pixels can include a deep charge-accumulation region underlying the pinned photodiode(s) of one or more neighboring color pixel(s). Methods of manufacturing also described and include forming the deep charge-accumulation regions and associated elements prior to forming any implant-blocking elements (e.g., polysilicon photogates) over the substrate.

Photogate for front-side-illuminated infrared image sensor and method of manufacturing the same

A method of backside illuminated image sensor fabrication includes forming a plurality of photodiodes in a semiconductor material, where the plurality of photodiodes are disposed to receive image light through a backside of the backside illuminated image sensor. The method further includes forming a transfer gate coupled to extract image charge from a photodiode in the plurality of photodiodes, and forming a storage gate coupled to the transfer gate to receive the image charge. Forming the storage gate includes forming an optical shield in the semiconductor material; depositing a gate electrode proximate to a frontside of the semiconductor material; and implanting a storage node in the semiconductor material, where the storage node is disposed in the semiconductor material between the optical shield and the gate electrode.

Storage gate protection

A pixel circuit for use in a high dynamic range (HDR) image sensor includes a photodiode and a floating diffusion is disposed in the first semiconductor wafer. A transfer transistor is disposed in the first semiconductor wafer and is adapted to be switched on to transfer the charge carriers photogenerated in the photodiode to the floating diffusion. An in-pixel capacitor is disposed in a second semiconductor wafer. The first semiconductor wafer is stacked with and coupled to the second semiconductor wafer. A dual floating diffusion (DFD) transistor is disposed in the first semiconductor wafer. The in-pixel capacitor is selectively coupled to the floating diffusion through the DFD transistor. The floating diffusion is set to low conversion gain in response to the in-pixel capacitor being coupled to the floating diffusion, and high conversion gain in response to the in-pixel capacitor being decoupled from the floating diffusion.

Low noise CMOS image sensor by stack architecture

An apparatus and method for a low dark current floating diffusion is discussed. An example method includes coupling a photodiode to a floating diffusion through a transfer gate where a gate terminal of the transfer gate is provided a first voltage, resetting the floating diffusion, repetitively sampling image charge on the photodiode a plurality of times, where the sampled image charge is coupled to the floating diffusion, and where the gate terminal of the transfer gate is provided a second voltage less than the first voltage during each sampling of the image charge, while repetitively sampling the image charge, coupling an additional capacitance to the floating diffusion, where a first capacitance voltage is applied to the additional capacitance during the sampling, and performing correlated double sampling of the sampled image charge.

Apparatus and method for low dark current floating diffusion

An image sensor includes a pixel array having plurality of pixel cells arranged into a plurality of rows and a plurality of columns of pixel cells in a first semiconductor die. A plurality of pixel support circuits are arranged in a second semiconductor die that is stacked and coupled together with the first semiconductor die. A plurality of interconnect lines are coupled between the first and second semiconductor dies, and each one of the plurality of pixel cells is coupled to a corresponding one of the plurality of pixel support circuits through a corresponding one plurality of interconnect lines. A plurality of shield bumps are disposed proximate to corners of the pixel cells in the pixel array and between the first and second semiconductor dies such that each one of the plurality of shield bumps is disposed between adjacent interconnect lines along a diagonal of the pixel array.

Stacked image sensor with shield bumps between interconnects

A pixel circuit for use in an image sensor includes an unpinned photodiode disposed in a semiconductor material. The unpinned photodiode adapted to photogenerate charge carriers in response to incident light. A floating diffusion is disposed in the semiconductor and coupled to receive the charge carriers photogenerated in the unpinned photodiode. A transfer transistor is disposed in the semiconductor material and coupled between the unpinned photodiode and the floating diffusion. The transfer transistor is adapted to be switched on to transfer the charge carriers photogenerated in the unpinned photodiode to the floating diffusion. A boost capacitor is disposed over a surface of the semiconductor material proximate to the unpinned photodiode. The boost capacitor is coupled to receive a photodiode boost signal while the transfer transistor is switched on to further drive the charge carriers photogenerated in the unpinned photodiode to the floating diffusion.

Imaging sensor with boosted photodiode drive

A backside illuminated image sensor includes a semiconductor material with a plurality of photodiodes disposed in the semiconductor material, and a transfer gate electrically coupled to a photodiode in the plurality of photodiodes to extract image charge from the photodiode. The image sensor also includes a storage gate electrically coupled to the transfer gate to receive the image charge from the transfer gate. The storage gate has a gate electrode disposed proximate to a frontside of the semiconductor material, an optical shield disposed in the semiconductor material, and a storage node disposed between the gate electrode and the optical shield. The optical shield is optically aligned with the storage node to prevent the image light incident on the backside illuminated image sensor from reaching the storage node.

A novel head mounted display includes a display/image sensor. In a particular embodiment the display/image sensor is formed on a single silicon die, which includes display pixels and light sensor pixels. The display pixels and light sensor pixels are each arranged in rows and columns, and the arrays of light sensor pixels and display pixels are interlaced. The center of each light sensor pixel is located between adjacent rows and adjacent columns of display pixels.

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Foster City, CA, United States of America

Takayuki Goto