Image sensor and electronic device having the same

Patent metadata

Field	Value
Publication number	US-10115757-B2
Application number	US-201514743959-A
Country	US
Kind code	B2
Filing date	Jun 18, 2015
Priority date	Aug 22, 2014
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

An image sensor may include: a substrate including a substrate comprising a photoelectric conversion element; a pixel lens formed over the substrate and comprising a plurality of light condensing layers in which a lower layer has a larger area than an upper layer; a color filter layer covering the pixel lens; and an anti-reflection structure formed over the color filter layer.

First claim

What is claimed is:

1. An image sensor comprising:
a substrate comprising a photoelectric conversion element;
a pixel lens formed over the substrate and comprising a plurality of light condensing layers in which a lower layer has a larger area than an upper layer;
a color filter layer covering an entire surface of the pixel lens; and
an anti-reflection structure formed over the color filter layer, wherein the anti-reflection structure prevents reflection of incident light,
wherein each of the plurality of light condensing layers has a flat surface, and the lower layer exposed by the upper layer has a smaller width than the wavelength of the incident light, and
wherein the upper layer has a smaller effective refractive index than the lower layer, and the upper layer and the lower layer are formed of a same material.

2. The image sensor of claim 1 , further comprising:
a focusing layer provided between the photoelectric conversion element and the pixel lens.

3. The image sensor of claim 2 , wherein the focusing layer has a larger refractive index than the pixel lens.

4. The image sensor of claim 2 , wherein the focusing layer has the same area as or a larger area than the pixel lens.

5. The image sensor of claim 2 , wherein a focal distance between the pixel lens and the photoelectric conversion element is inversely proportional to the thickness of the focusing layer.

6. The image sensor of claim 1 , wherein the pixel lens has a multilayer stepped structure.

7. The image sensor of claim 1 , wherein the lower layer exposed by the upper layer has a smaller width than the wavelength of incident light which colors are separated through the color filter layer.

8. The image sensor of claim 1 , wherein the plurality of light condensing layers have the same shape and are arranged in parallel to each other.

9. The image sensor of claim 1 , wherein the upper layer has the same thickness as or a smaller thickness than the lower layer.

10. The image sensor of claim 1 , wherein the upper layer has the same refractive index as or a smaller refractive index than the lower layer.

11. The image sensor of claim 1 , further comprising:
an anti-reflection layer formed over the pixel lens.

12. The image sensor of claim 1 , wherein the color filter layer covers the entire surface of the pixel lens and has a flat top surface.

13. The image sensor of claim 1 , wherein the color filter layer has a smaller refractive index than the pixel lens.

14. The image sensor of claim 1 , wherein the anti-reflection structure comprises an anti-reflection layer or a hemispherical lens.

15. The image sensor of claim 1 , wherein the color filter layer is contacted with the pixel lens.

16. An electronic device comprising:
an optical system;
an image sensor suitable for receiving light from the optical system and comprising a pixel array in which a plurality of unit pixels are arranged in a matrix shape; and
a signal processing unit suitable for processing a signal outputted from the image sensor,
wherein each of the unit pixels comprises:
a substrate comprising a photoelectric conversion element;
a pixel lens formed over the substrate and comprising a plurality of light condensing layers in which a lower layer has a larger area than an upper layer;
a color filter layer covering an entire surface of the pixel lens; and
an anti-reflection structure formed over the color filter layer, wherein the anti-reflection structure prevents reflection of incident light,
wherein each of the plurality of light condensing layers has a flat surface, and the lower layer exposed by the upper layer has a smaller width than the wavelength of the incident light, and
wherein the upper layer has a smaller effective refractive index than the lower layer, and the upper layer and the lower layer are formed of a same material.

17. The electronic device of claim 16 , further comprising:
a focusing layer provided between the photoelectric conversion element and the pixel lens.

18. The electronic device of claim 17 , wherein the focusing layer has a larger refractive index than the pixel lens, and
wherein the color filter layer has a smaller refractive index than the pixel lens.

19. The electronic device of claim 17 , wherein a focal distance between the pixel lens and the photoelectric conversion element is inversely proportional to the thickness of the focusing layer.

20. The image sensor of claim 16 , wherein the color filter layer is contacted with the pixel lens.

Assignees

• Sk Hynix Inc

Inventors

• Lee Won-Jun
• Lee Kyoung-In

Classifications

• G02B1/11

  Anti-reflection coatings · CPC title

• G02B13/0085

  employing wafer level optics · CPC title

• H01L31/02327

  Electricity · mapped topic

• H01L27/14621

  Electricity · mapped topic

• H01L27/14645

  Electricity · mapped topic