MULTIPLE DEEP TRENCH ISOLATION (MDTI) STRUCTURE FOR CMOS IMAGE SENSOR

    公开(公告)号:US20200343281A1

    公开(公告)日:2020-10-29

    申请号:US16924579

    申请日:2020-07-09

    Abstract: The present disclosure relates to a CMOS image sensor having a multiple deep trench isolation (MDTI) structure, and an associated method of formation. In some embodiments, the image sensor comprises a plurality of pixel regions disposed within a substrate and respectively comprising a photodiode configured to receive radiation that enters the substrate from a back-side. A boundary deep trench isolation (BDTI) structure is disposed at boundary regions of the pixel regions surrounding the photodiode. The BDTI structure extends from the back-side of the substrate to a first depth within the substrate. A multiple deep trench isolation (MDTI) structure is disposed at inner regions of the pixel regions overlying the photodiode. The MDTI structure extends from the back-side of the substrate to a second depth within the substrate smaller than the first depth. The MDTI structure is a continuous integral unit having a ring shape.

    BACK-SIDE DEEP TRENCH ISOLATION (BDTI) STRUCTURE FOR PINNED PHOTODIODE IMAGE SENSOR

    公开(公告)号:US20190096929A1

    公开(公告)日:2019-03-28

    申请号:US15795681

    申请日:2017-10-27

    Abstract: The present disclosure relates to a CMOS image sensor having a photodiode surrounded by a back-side deep trench isolation (BDTI) structure, and an associated method of formation. In some embodiments, a plurality of pixel regions is disposed within a substrate and respectively comprising a photodiode. A back-side deep trench isolation (BDTI) structure is disposed between adjacent pixel regions, extending from a back-side of the substrate to a position within the substrate. The BDTI structure comprises a doped layer lining a sidewall surface of a deep trench and a dielectric fill layer filling a remaining space of the deep trench. By forming the disclosed BDTI structure that functions as a doped well and an isolation structure, the implantation processes from a front-side of the substrate is simplified, and thus the exposure resolution, the full well capacity of the photodiode, and the pinned voltage is improved.

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