Omnivision Technologies, Inc.

Chih-Wei Hsiung

Dyson Hsinchih Tai

Duli Mao

Gang Chen

Vincent Venezia

Kazufumi Watanabe

Chia-Ying Liu

Lindsay Alexander Grant

Yuanwei Zheng

Arvind Kumar

Wu-Zang Yang

Young Woo Jung

Chun-Yung Ai

Dominic Massetti

Chin-Poh Pang

Geunsook Park

Hsin-Chih Tai

Keiji Mabuchi

Chen-Wei Lu

Zhiqiang Lin

Oray Orkun Cellek

Wei Zheng

Boyang Zhang

Dyson Hsin-Chih Tai

Chao Niu

Sang Joo Lee

Hung Chih Chang

Electrical Phase Detection Auto Focus. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array disposed in a semiconductor material. Each pixel includes a plurality of photodiodes configured to receive incoming light through an illuminated surface of the semiconductor material. The plurality of pixels includes at least one autofocusing phase detection (PDAF) pixel having: a first subpixel without a light shielding, and a second subpixel without the light shielding. Autofocusing of the image sensor is at least in part determined based on different electrical outputs of the first subpixel and the second sub pixels.

Electrical phase detection auto focus

An image sensor includes an active pixel photodiode, a black pixel photodiode, a metal grid structure, and a light shield. Each of the active pixel photodiode and the black pixel photodiode are disposed in a semiconductor material having a first side and a second side opposite the first side. The first side of the semiconductor material is disposed between the light shield and the black pixel photodiode. The metal grid structure includes a first multi-layer metal stack including a first metal and a second metal different from the first metal. The light shield includes a second multi-layer stack including the first metal and the second metal. A first thickness of the first multi-layer metal stack is less than a second thickness of the second multi-layer metal stack.

Multi-layer metal stack for active pixel region and black pixel region of image sensor and methods thereof

A multi-pixel detector of an image sensor is described. The multi-pixel detector includes a first photodiode region disposed within a semiconductor substrate to form a first pixel, a second photodiode region disposed within the semiconductor substrate to form a second pixel adjacent to the first pixel, and a partial isolation structure extending from a first side of the semiconductor substrate towards a second side of the semiconductor substrate between the first photodiode region and the second photodiode region. A length of a lateral portion of the partial isolation structure between the first photodiode region and the second photodiode region is less than a lateral length of the first photodiode region.

Image sensor with multi-pixel detector and partial isolation structure

Backside illuminated sensor pixel structure. In one embodiment, and image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that are disposed in a semiconductor substrate. Individual photodiodes of the pixel array are configured to receive an incoming light through a backside of the semiconductor substrate. A front side of the semiconductor substrate is opposite from the backside. A plurality of transistors disposed proximate to the front side of the semiconductor substrate, are arranged in a row along an outer perimeter of the photodiodes of the respective pixel; and a plurality of isolation structures arranged to bracket the row of transistors along the outer perimeter of the photodiodes. A plurality of contacts electrically contacting the plurality of isolation structures, and the contacts are configured to voltage-bias the plurality of isolation structures.

Negatively biased isolation structures for pixel devices

An image sensor comprises a pixel array of pixel cells. A pixel cell comprises a photodiode, a reset transistor, a transfer transistor, at least one source follower transistor, a sample and hold circuit, an active reset transistor, and a readout transistor. A readout circuitry reads out image data from each columns of pixel cells. A column differential amplifier in the readout circuitry feeds back a column reset drive voltage to each pixel cells arranged in the same column. Signal data of each pixel cells in the same column are read out globally when all the active reset transistors are switched off. Determined by switching configurations of each active reset transistors of pixel cells in the same column, noise data of each pixel cells in the same column are read out either globally or row-by-row. Final image data is achieved by applying the method of correlated double sampling (CDS).

Data readout with active reset feedback amplifier for stacked image sensor

An image sensor pixel array comprises a center region and two parallel edge regions, wherein the center region is between the two parallel edge regions. The center region comprises a plurality of image pixels disposed along first sub-array of rows and columns, wherein each of the plurality of image pixels comprises a first micro-lens (ML) formed at an offset position above a first light receiving element as a countermeasure for shortening of exit pupil distance of the image pixel in the center region, and each of the two parallel edge regions comprises a plurality of phase detection auto-focus (PDAF) pixels disposed along second sub-array of rows and columns, wherein each of the plurality of PDAF pixels comprises a second micro-lens (ML) formed at an alignment position above a second light receiving element; and at least one of the PDAF pixels is located at a distance away from center of the edge region to receive incident light along an injection tilt angle.

Image sensors with phase detection auto focus pixels

An image sensor includes a photodiode disposed in a semiconductor material to generate image charge in response to incident light, and a floating diffusion disposed in the semiconductor material proximate to the photodiode. A transfer transistor is coupled to the photodiode to transfer the image charge from the photodiode into the floating diffusion in response to a transfer signal applied to a transfer gate of the transfer transistor. A source follower transistor is coupled to the floating diffusion to amplify a charge on the floating diffusion. The source follower transistor includes a gate electrode including a semiconductor material having a first dopant type; a source electrode, having a second dopant type, disposed in the semiconductor material; a drain electrode, having the second dopant type, disposed in the semiconductor material; and a channel, having the second dopant type, disposed between the source electrode and the drain electrode.

Source follower device for enhanced image sensor performance

A multi-color HDR image sensor includes at least a first combination color pixel with a first color filter and an adjacent second combination color pixel with a second color filter which is different from the first color filter, wherein each combination color pixel includes at least two sub-pixels having at least two adjacent photodiodes. Within each combination color pixel, there is a dielectric deep trench isolation (d-DTI) structure to isolate the two adjacent photodiodes of the two adjacent sub-pixels with same color filters in order to prevent the electrical cross talk. Between two adjacent combination color pixels with different color filters, there is a hybrid deep trench isolation (h-DTI) structure to isolate two adjacent photodiodes of two adjacent sub-pixels with different color filters in order to prevent both optical and electrical cross talk. Each combination color pixel is enclosed on all sides by the hybrid deep trench isolation (h-DTI) structure.

Cross talk reduction for high dynamic range image sensors

A backside-illuminated color image sensor with crosstalk-suppressing color filter array includes (a) a silicon layer including an array of photodiodes and (b) a color filter layer on the light-receiving surface of the silicon layer, wherein the color filter layer includes (i) an array of color filters cooperating with the array of photodiodes to form a respective array of color pixels and (ii) a light barrier grid disposed between the color filters to suppress transmission of light between adjacent ones of the color filters. The light barrier is spatially non-uniform across the color filter layer to account for variation of chief ray angle across the array of color filters.

Backside-illuminated color image sensors with crosstalk-suppressing color filter array

A phase detection autofocus image sensor includes a first photodiode in a plurality of photodiodes disposed in a semiconductor material and a second photodiode in the plurality of photodiodes. A first pinning well is disposed between the first photodiode and the second photodiode, and the first pinning well includes a first trench isolation structure that extends from a first surface of the semiconductor material into the semiconductor material a first depth. A second trench isolation structure is disposed in the semiconductor material and surrounds the first photodiode and the second photodiode. The second trench isolation structure extends from the first surface of the semiconductor material into the semiconductor material a second depth, and the second depth is greater than the first depth.

Dual photodiode for phase detection autofocus

An image sensor includes a semiconductor material including a photodiode disposed in the semiconductor material and an insulating material. A surface of the semiconductor material is disposed between the insulating material and the photodiode. The image sensor also includes isolation structures disposed in the semiconductor material and in the insulating material, and the isolation structures extend from within the semiconductor material through the surface and into the insulating material. The isolation structures include a core material and a liner material. The liner material is disposed between the core material and the semiconductor material, and is also disposed between the insulating material and the core material.

Through-semiconductor and through-dielectric isolation structure

An image sensor includes a plurality of photodiodes disposed in a semiconductor material between a first side and a second side of the semiconductor material. The image sensor also includes a plurality of hybrid deep trench isolation (DTI) structures disposed in the semiconductor material, where individual photodiodes in the plurality of photodiodes are separated by individual hybrid DTI structures. The individual hybrid DTI structures include a shallow portion that extends from the first side towards the second side of the semiconductor material, and the shallow portion includes a dielectric region and a metal region such that at least part of the dielectric region is disposed between the semiconductor material and the metal region. The hybrid DTI structures also include a deep portion that extends from the shallow portion and is disposed between the shallow portion and the second side of the semiconductor material.

Image sensor with hybrid deep trench isolation

A method of fabricating a pixel array includes forming a transistor network along a frontside of a semiconductor substrate. A contact element is formed for every pixel in the pixel array that is electrically coupled to a transistor within the transistor network. An interconnect layer is formed upon the frontside to control the transistor network with a dielectric that covers the contact element. A cavity is formed in the interconnect layer. A conductive layer is formed along cavity walls of the cavity and a dielectric layer is formed over the conductive layer within the cavity. A photosensitive semiconductor material is deposited over the dielectric layer within the cavity. An electrode cavity is formed that extends into the contact element. The electrode cavity is at least partially filled with a conductive material to form an electrode. The electrode, the conductive layer, and the photosensitive semiconductor material form a photosensitive capacitor.

Photosensitive capacitor pixel for image sensor

An image sensor includes a plurality of photodiodes arranged in an array and disposed in a semiconductor material with pinning wells disposed between individual photodiodes in the plurality of photodiodes. The image sensor also includes a microlens layer. The microlens layer is disposed proximate to the semiconductor material and is optically aligned with the plurality of photodiodes. A spacer layer disposed between the semiconductor material and the microlens layer. The spacer layer has a concave cross-sectional profile across the array, and the microlens layer is conformal with the concave cross-sectional profile of the spacer layer.

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San Jose, CA, United States of America

Chih-Wei Hsiung