Uneven-trench pixel cell and fabrication method

    公开(公告)号:US11948965B2

    公开(公告)日:2024-04-02

    申请号:US17220695

    申请日:2021-04-01

    发明人: Hui Zang Gang Chen

    摘要: An uneven-trench pixel cell includes a semiconductor substrate that includes a floating diffusion region, a photodiode region, and, between a front surface and a back surface: a first sidewall surface, a shallow bottom surface, a second sidewall surface, and a deep bottom surface. The first sidewall surface and a shallow bottom surface define a shallow trench, located between the floating diffusion region and the photodiode region, that extends into the semiconductor substrate from the front surface. A shallow depth of the shallow trench exceeds a junction depth of the floating diffusion region. The second sidewall surface and a deep bottom surface define a deep trench, located between the floating diffusion region and the photodiode region, that extends into the semiconductor substrate from the front surface. A distance between the deep bottom surface and the front surface defines a deep depth, of the deep trench, that exceeds the shallow depth.

    IMAGE SENSOR
    5.
    发明公开
    IMAGE SENSOR 审中-公开

    公开(公告)号:US20240072077A1

    公开(公告)日:2024-02-29

    申请号:US18156989

    申请日:2023-01-19

    发明人: Yuchao CHEN Kai CHENG

    IPC分类号: H01L27/146 H01L27/148

    CPC分类号: H01L27/14607 H01L27/14831

    摘要: Disclosed is an image sensor, comprising: at least one photosensitive unit, where the photosensitive unit includes a main photosensitive region and an auxiliary photosensitive region arranged at the periphery of the main photosensitive region, and a photosensitive component content of the main photosensitive region is different from a photosensitive component content of the auxiliary photosensitive region. The disclosure enlarges a wavelength range of sensible light of each the photosensitive unit by arranging the auxiliary photosensitive region at the periphery of the main photosensitive region of the photosensitive unit, where the photosensitive component content of the main photosensitive region is different from that of the auxiliary photosensitive region. Thereby more image details may be recorded to generate images with high dynamic range, which enables people to experience a visual effect close to a real environment.

    Back-illuminated sensor and a method of manufacturing a sensor using a silicon on insulator wafer

    公开(公告)号:US11848350B2

    公开(公告)日:2023-12-19

    申请号:US17197292

    申请日:2021-03-10

    申请人: KLA Corporation

    摘要: An image sensor is fabricated by first heavily p-type doping the thin top monocrystalline silicon substrate of an SOI wafer, then forming a relatively lightly p-doped epitaxial layer on a top surface of the top silicon substrate, where p-type doping levels during these two processes are controlled to produce a p-type dopant concentration gradient in the top silicon substrate. Sensing (circuit) elements and associated metal interconnects are fabricated on the epitaxial layer, then the handling substrate and oxide layer of the SOI wafer are at least partially removed to expose a lower surface of either the top silicon substrate or the epitaxial layer, and then a pure boron layer is formed on the exposed lower surface. The p-type dopant concentration gradient monotonically decreases from a maximum level near the top-silicon/epitaxial-layer interface to a minimum concentration level at the epitaxial layer's upper surface.

    VERTICALLY ARRANGED SEMICONDUCTOR PIXEL SENSOR

    公开(公告)号:US20230402488A1

    公开(公告)日:2023-12-14

    申请号:US18447529

    申请日:2023-08-10

    IPC分类号: H01L27/148 H01L27/146

    摘要: A pixel sensor may include a vertically arranged (or vertically stacked) photodiode region and floating diffusion region. The vertical arrangement permits the photodiode region to occupy a larger area of a pixel sensor of a given size relative to a horizontal arrangement, which increases the area in which the photodiode region can collect photons. This increases performance of the pixel sensor and permits the overall size of the pixel sensor to be reduced. Moreover, the transfer gate may surround at least a portion of the floating diffusion region and the photodiode region, which provides a larger gate switching area relative to a horizontal arrangement. The increased gate switching area may provide greater control over the transfer of the photocurrent and/or may reduce switching delay for the pixel sensor.