公开(公告)号：US11476290B2

公开(公告)日：2022-10-18

申请号：US16918929

申请日：2020-07-01

Applicant: OMNIVISION TECHNOLOGIES, INC.

Inventor： Hui Zang ,  Gang Chen ,  Kenny Geng

IPC: H01L27/146 ,  H04N5/378

Abstract: An image sensor includes photodiodes disposed in a pixel region and proximate to a front side of a semiconductor layer. A backside metal grating is formed in a backside oxide layer disposed proximate to a backside of the semiconductor layer. A deep trench isolation (DTI) structure with a plurality of pixel region portions and an edge region portion is formed in the semiconductor layer. The pixel region portions are disposed in the pixel region of the semiconductor layer such that incident light is directed through the backside metal grating, through the backside of the semiconductor layer, and between the pixel region portions of the DTI structure to the photodiodes. The edge region portion of the DTI structure is disposed in an edge region outside of the pixel region. The edge region portion of the DTI structure is biased with a DTI bias voltage.

公开(公告)号：US11462579B2

公开(公告)日：2022-10-04

申请号：US16804671

申请日：2020-02-28

Applicant: OmniVision Technologies, Inc.

Inventor： Hui Zang ,  Gang Chen

IPC: H01L27/146 ,  H01L29/423

Abstract: A method for forming a transfer gate includes (i) forming a dielectric pillar on a surface of a semiconductor substrate and (ii) growing an epitaxial layer on the semiconductor substrate and surrounding the dielectric pillar. The dielectric pillar has a pillar height that exceeds an epitaxial-layer height of the epitaxial layer relative to the surface. The method also includes removing the dielectric pillar to yield a trench in the epitaxial layer. A pixel includes a doped semiconductor substrate having a front surface opposite a back surface. The front surface forms a trench extending a depth zT with respect to the front surface within the doped semiconductor substrate along a direction z perpendicular to the front surface and the back surface. The pixel has a dopant concentration profile, a derivative thereof with respect to direction z being discontinuous at depth zT.