Backside illuminated image sensor and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-12593522-B2
Application number	US-202318187171-A
Country	US
Kind code	B2
Filing date	Mar 21, 2023
Priority date	Oct 5, 2022
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

Disclosed are a backside illuminated image sensor and a method of manufacturing the same. More particularly, a backside illuminated image sensor and a method of manufacturing the backside illuminated image sensor include a light scattering portion in a substrate configured to converge a path of incident light to a photoelectric conversion structure, thereby preventing cross-talk between adjacent pixels and increasing light sensitivity.

First claim

What is claimed is:

1 . A backside illuminated image sensor comprising:
a substrate having a front surface and a back surface; a photoelectric conversion structure in the substrate, in a unit pixel of the backside illuminated image sensor; a wiring region comprising an interlayer insulation film on the front surface of the substrate and a metal wiring layer in the interlayer insulation film; an insulation film on the back surface of the substrate; a color filter on the insulation film; a planarization layer on the color filter; a lens on the planarization layer; and a light scattering portion having an upper surface at the back surface of the substrate, wherein the light scattering portion comprises: a center section having a first depth at a center of the unit pixel,
wherein the center section does not contact the photoelectric conversion structure;
and
a plurality of side sections spaced apart from the center section along a lateral direction in the unit pixel, each of the plurality of side sections having a second depth greater than the first depth and a lowermost surface that contacts the photoelectric conversion structure.

2 . The backside illuminated image sensor of claim 1 , wherein the light scattering portion comprises a first plurality of side sections along a first lateral direction from the center section and a second plurality of side sections along a second lateral direction from the center section, the second lateral direction being opposite from the first lateral direction.

3 . The backside illuminated image sensor of claim 1 , wherein the plurality of side sections comprises a first number of side sections along a first lateral direction from the center section, and a second number of side sections along a second lateral direction from the center section, the second number being different from the first number, and the second lateral direction being opposite from the first lateral direction.

4 . The backside illuminated image sensor of claim 1 , wherein each of the plurality of side sections has a width larger than a width of the center section.

5 . The backside illuminated image sensor of claim 1 , wherein the light scattering portion comprises silicon dioxide, silicon nitride, a single elemental metal, an alloy including at least two types of metals, polysilicon, or a refractory metal nitride.

6 . The backside illuminated image sensor of claim 5 , wherein a boundary region comprises a same material as the light scattering portion.

7 . The backside illuminated image sensor of claim 2 , wherein each of the first and second pluralities of side sections comprises a first, outermost side section and a second, inner side section between the first, outermost side section and the center section along a corresponding one of the first and second lateral directions.

8 . The backside illuminated image sensor of claim 7 , wherein each first, outermost side section is within an area of the photoelectric conversion structure.

9 . The backside illuminated image sensor of claim 7 , wherein the second, inner side section has a depth less than the first, outermost side section.

10 . The backside illuminated image sensor of claim 7 , wherein each of the first and second pluralities of side sections has a width larger than a width of the center section, and the second, inner side section has a width smaller than a width of the first, outermost side section.

11 . The backside illuminated image sensor of claim 8 , wherein each first, outermost side section is adjacent to an outermost peripheral border of the area of the photoelectric conversion structure.

12 . The backside illuminated image sensor of claim 7 , wherein each of the second, inner side sections has a lowermost surface that contacts the photoelectric conversion structure.

13 . The backside illuminated image sensor of claim 1 , wherein each of the plurality of side sections is within and adjacent to an outermost peripheral border of the photoelectric conversion structure.

Assignees

• Db Hitek Co Ltd

Inventors

• Yun Sang Won
• Jung Ju Hwan
• Kang Tae Wook

Classifications

• H10F39/8063

  Microlenses · CPC title

• H10F39/8057

  Optical shielding · CPC title

• H10F39/8053

  Colour filters · CPC title

• H10F39/811 Primary

  Interconnections · CPC title

• H10F39/199

  Back-illuminated image sensors · CPC title