Image sensor with improved quantum efficiency surface structure
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYun-Wei Cheng, Chun-Hao Chou, Kuo-Cheng Lee, Hsun-Ying Huang, Shih-Hsun Hsu
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Abstract
The present disclosure relates to a semiconductor image sensor with improved quantum efficiency. The semiconductor image sensor can include a semiconductor layer having a first surface and a second surface opposite of the first surface. An interconnect structure is disposed on the first surface of the semiconductor layer, and radiation-sensing regions are formed in the semiconductor layer. The radiation-sensing regions are configured to sense radiation that enters the semiconductor layer from the second surface and groove structures are formed on the second surface of the semiconductor layer.
Claims20
An image sensor, comprising:
- a semiconductor layer;
- photodiodes in the semiconductor layer, wherein portions of the semiconductor layer over the photodiodes comprise triangular grooves;
- and
- an isolation structure in the semiconductor layer having a depth greater than half of a thickness of the semiconductor layer and positioned between adjacent photodiodes, wherein the isolation structure comprises:
- a first portion of a first dielectric disposed on sidewall and bottom surfaces of the isolation structure;
- and
- a first portion of a second dielectric disposed on the first portion of the first dielectric;
- and
- wherein a second portion of the first dielectric is disposed on surfaces of the triangular grooves and a second portion of the second dielectric is disposed on the second portion of the first dielectric.
An image sensor, comprising:
- a semiconductor layer having a first surface and a second surface opposite to the first surface;
- a groove extending from the first surface towards the second surface;
- a photodiode within the semiconductor layer disposed below the groove;
- and
- an isolation structure adjacent to the groove and the photodiode, wherein a portion of the first surface is between the groove and the isolation structure, and an angle formed between a sidewall of the groove and a direction parallel to the portion of the first surface is between 45 degrees and 60 degrees.
An image sensor, comprising:
- a semiconductor layer comprising:
- an upper surface comprising a plurality of triangular grooves, wherein a depth of the plurality of triangular grooves ranges from about 200 nm to about 500 nm;
- a plurality of photodiodes positioned below the plurality of triangular grooves;
- and
- a plurality of isolation structures extending from the upper surface within the semiconductor layer;
- a first dielectric layer disposed on sidewalls of the plurality of triangular grooves and sidewalls of the plurality of isolation structures;
- and
- a second dielectric layer disposed on the first dielectric layer, wherein a dielectric constant of the first dielectric layer is greater than that of the second dielectric layer.
Dependencies are inferred from the claim text.