Image sensor including fence structure disposed laterally of color filters

Patent metadata

Field	Value
Publication number	US-11670657-B2
Application number	US-202017003224-A
Country	US
Kind code	B2
Filing date	Aug 26, 2020
Priority date	Oct 23, 2019
Publication date	Jun 6, 2023
Grant date	Jun 6, 2023

Abstract

An image sensor includes; a photoelectric conversion element disposed on a substrate, a fence structure disposed on the substrate and including a low refractive index layer stacked on a barrier layer, wherein the barrier layer includes at least one metal, and a color filter disposed inwardly lateral with respect to a sidewall of the fence structure, wherein the barrier layer includes an inward lateral protrusion.

First claim

What is claimed is:

1. An image sensor comprising:
a photoelectric conversion element disposed in a substrate;
a fence structure disposed on the substrate and including a low refractive index layer stacked on a barrier layer, wherein the barrier layer includes at least one metal; and
a color filter disposed inwardly lateral with respect to a sidewall of the fence structure,
wherein the barrier layer includes an outward lateral stepped recess that underlays at least a portion of the fence structure.

2. The image sensor of claim 1 , wherein the fence structure includes a mask layer disposed on the low refractive index layer.

3. The image sensor of claim 2 , wherein the fence structure includes a penetration prevention layer disposed between the low refractive index layer and the mask layer, and
a thickness of the penetration prevention layer ranges from between 50 nm to 150 nm.

4. The image sensor of claim 1 , wherein a top surface of the fence structure is formed lower than a top surface of the color filter.

5. The image sensor of claim 1 , wherein a top surface of the fence structure is formed at a vertical plane lower than a top surface of the color filter.

6. The image sensor of claim 1 , wherein the barrier layer includes a first barrier layer formed from a first metal and disposed on the substrate, and a second barrier layer formed from a second metal different from the first metal and disposed on the first barrier layer.

7. The image sensor of claim 6 , wherein a first lateral width of a bottom surface of the first barrier layer is greater than a second lateral width of a top surface of the first barrier layer, and a sidewall of the first barrier layer has an angular profile,
a third lateral width of a bottom surface of the second barrier layer is the same as a lateral width of a top surface of the second barrier layer, and a sidewall of the second barrier layer has a vertical profile aligned with the sidewall of the fence structure, and
the sidewall of the first barrier layer provides an angular lateral recess as the outward lateral stepped recess underlying a portion of the second barrier layer.

8. The image sensor of claim 7 , further comprising:
a liner layer disposed on a top surface of the fence structure, the sidewall of the fence structure, and in the angular lateral recess to contact at least a portion of the bottom surface of the second barrier layer.

9. The image sensor of claim 6 , wherein a first lateral width of a bottom surface of the first barrier layer is greater than a second lateral width of a top surface of the first barrier layer, and a sidewall of the first barrier layer has an angular profile,
a third lateral width of a bottom surface of the second barrier layer is greater than the first lateral width of the bottom surface of the first barrier layer, is the same as a lateral width of a top surface of the second barrier layer, and a sidewall of the second barrier layer has a vertical profile, and
the sidewall of the first barrier layer provides an angular lateral recess as the outward lateral stepped recess underlying a portion of the second barrier layer.

10. The image sensor of claim 9 , further comprising:
a liner layer disposed on a top surface of the fence structure, the sidewall of the fence structure, on at least a portion of the top surface of the second barrier layer, and in the angular lateral recess to contact at least a portion of the bottom surface of the second barrier layer.

11. The image sensor of claim 10 , wherein an uppermost surface of the liner layer is formed at a same vertical plane as a top surface of the color filter.

12. An image sensor comprising:
a photoelectric conversion element disposed in a substrate;
a fence structure disposed on the substrate and including a low refractive index layer stacked on a barrier layer, wherein the barrier layer includes at least one metal; and
a color filter disposed inwardly lateral with respect to a sidewall of the fence structure,
wherein the barrier layer includes a composite lateral protrusion including a first lateral protrusion and a second lateral protrusion,
the barrier layer includes a first barrier layer formed from a first metal and disposed on the substrate, and a second barrier layer formed from a second metal different from the first metal and disposed on the first barrier layer,
a first lateral width of a bottom surface of the first barrier layer is greater than a second lateral width of a top surface of the first barrier layer, and a sidewall of the first barrier layer has an angular profile to form the first lateral protrusion, and
a third lateral width of a bottom surface of the second barrier layer is less than the second lateral width of the top surface of the first barrier layer and greater than a fourth lateral width of a top surface of the second barrier layer, and a sidewall of the second barrier layer has an angular profile to form the second lateral protrusion.

13. The image sensor of claim 12 , further comprising:
a liner layer disposed on a top surface of the fence structure, the sidewall of the fence structure, the sidewall of the first barrier layer, and the sidewall of the second barrier layer.

14. The image sensor of claim 12 , wherein a fifth lateral width of the fence structure is less than the fourth lateral width of the top surface of the second barrier layer.

15. The image sensor of claim 14 , further comprising:
a liner layer disposed on a top surface of the fence structure, the sidewall of the fence structure, a portion of the top surface of the second barrier layer, the sidewall of the second barrier layer, a portion of the surface of the first barrier layer, and the sidewall of the first barrier layer.

16. An image sensor comprising:
a photoelectric conversion element disposed in a substrate;
a fence structure disposed on the substrate and including a low refractive index layer stacked on a barrier layer, wherein the barrier layer includes a first barrier layer disposed on the substrate, and a second barrier layer disposed on the first barrier layer; and
a color filter disposed inwardly lateral with respect to a sidewall of the fence structure,
wherein the barrier layer includes an outward lateral stepped recess that underlays at least a portion of the fence structure.

17. The image sensor of claim 16 , wherein a bottom surface of the first barrier layer and a top surface of the first barrier layer have a first lateral width, and a sidewall of the first barrier layer has a vertical profile,
a bottom surface of the second barrier layer and a top surface of the second barrier layer have a second lateral width, and a sidewall of the second barrier layer has a vertical profile, and
the first lateral width is less than the second lateral width.

18. The image sensor of claim 17 , further comprising:
a liner layer disposed on a top surface of the fence structure, the sidewall of the fence structure, the sidewall of the first barrier layer, and the sidewall of the second barrier layer,
wherein the liner layer conformally fills at least a portion of the outward lateral stepped recess.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Jeon Min Hwan
• Kwon Doo Won
• Park Chan Ho
• Byun Kyung Rae
• Lee Dong-Chul
• Chang Chong Kwang

Classifications

• H04N23/10

  for generating image signals from different wavelengths · CPC title

• H10F39/807

  Pixel isolation structures · CPC title

• H10F39/806

  Optical elements or arrangements associated with the image sensors · CPC title

• H10F39/803 Primary

  Pixels having integrated switching, control, storage or amplification elements · CPC title

• H10F39/802

  Geometry or disposition of elements in pixels, e.g. address-lines or gate electrodes · CPC title