Low noise CMOS image sensor by stack architecture

    公开(公告)号:US10218924B2

    公开(公告)日:2019-02-26

    申请号:US15485534

    申请日:2017-04-12

    Abstract: 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.

    Apparatus and method for low dark current floating diffusion

    公开(公告)号:US10103193B1

    公开(公告)日:2018-10-16

    申请号:US15668207

    申请日:2017-08-03

    Abstract: 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.

    Storage gate protection
    15.
    发明授权

    公开(公告)号:US09859311B1

    公开(公告)日:2018-01-02

    申请号:US15362391

    申请日:2016-11-28

    Abstract: 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.

    High speed rolling image sensor with ADM architecture and method of implementing thereof

    公开(公告)号:US09749569B2

    公开(公告)日:2017-08-29

    申请号:US14979058

    申请日:2015-12-22

    Abstract: High speed rolling image sensor includes pixel array disposed in first semiconductor die, readout circuits disposed in second semiconductor die and conductors. Pixel array is partitioned into pixel sub-arrays (PSAs). Each of the PSAs includes a plurality of pixels. Pixel groups include pixels that are non-contiguous, non-overlapping and distinct. Each pixel group includes pixels from different PSAs. Each pixel group is coupled to a corresponding analog-to-digital converter and memory unit tiles (ADMs) respectively included in readout circuits. ADMs respectively include (i) analog-to-digital (ADC) circuits that convert the image data from pixel groups from analog to digital to obtain ADC outputs, and (ii) memory units to store ADC outputs. Conductors are coupling pixel array to ADMs. Conductors include number of conductors per column of pixel array. Number of conductors per column of pixel array may be equal to number of pixels in PSA arranged in same column. Other embodiments are described.

    Photodiode and filter configuration for high dynamic range image sensor

    公开(公告)号:US09666631B2

    公开(公告)日:2017-05-30

    申请号:US14280880

    申请日:2014-05-19

    Abstract: An image sensor pixel includes a first photodiode, a second photodiode, a first microlens, a second microlens, and a filter. The first and second photodiode are disposed adjacent to each other in a semiconductor material. The first photodiode has a first full well capacity that is substantially equal to a second full well capacity of the second photodiode. The first microlens is disposed over the first photodiode and the second microlens is disposed over the second photodiode. The second microlens is substantially identical to the first microlens. The filter is disposed between the second microlens and the second photodiode to reduce an intensity of the image light incident upon the second photodiode. The filter does not substantially affect the image light directed toward the first photodiode.

    Wide dynamic range image sensor with global shutter

    公开(公告)号:US11272126B2

    公开(公告)日:2022-03-08

    申请号:US17204786

    申请日:2021-03-17

    Abstract: An image sensor includes a photodiode disposed in a semiconductor material to generate image charge in response to incident light, and a first transfer gate is coupled to the photodiode to extract image charge from the photodiode in response to a first transfer signal. A first storage gate is coupled to the first transfer gate to receive the image charge from the first transfer gate, and a first output gate is coupled to the first storage gate to receive the image charge from the first storage gate. A first capacitor is coupled to the first output gate to store the image charge.

    LOW NOISE SILICON GERMANIUM IMAGE SENSOR

    公开(公告)号:US20210343882A1

    公开(公告)日:2021-11-04

    申请号:US16863771

    申请日:2020-04-30

    Abstract: Low noise silicon-germanium (SiGe) image sensor. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array disposed in a semiconductor substrate. The photodiodes of an individual pixel are configured to receive an incoming light through an illuminated surface of the semiconductor substrate. The semiconductor substrate includes a first layer of semiconductor material having silicon (Si); and a second layer of semiconductor material having silicon germanium (Si1-xGex). A concentration x of Ge changes gradually through at least a portion of thickness of the second layer. Each photodiode includes a first doped region extending through the first layer of semiconductor material and the second layer of semiconductor material; and a second doped region extending through the first layer of semiconductor material and the second layer of semiconductor material.

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