Image sensors and methods of forming image sensors

1. A method of forming an image sensor, the method comprising:

forming an insulating layer on a color filter layer;

etching the insulating layer to form an opening that at least partially exposes a metal structure that is adjacent a sidewall of the color filter layer; and

forming a transparent electrode layer,

wherein forming the transparent electrode layer comprises simultaneously forming a transparent electrode material:

in the opening of the insulating layer; and

on a portion of the insulating layer that is outside of the opening.

2. The method of claim 1 , further comprising:

before forming the insulating layer, forming a transparent layer on the color filter layer.

3. The method of claim 2 , wherein forming the transparent electrode layer comprises forming the transparent electrode layer to contact a portion of the transparent layer through the opening.

4. The method of claim 2 , wherein:

forming the transparent layer on the color filter layer comprises forming the transparent layer on a red first color filter layer and a blue second color filter layer;

forming the insulating layer comprises forming an oxide layer on the transparent layer; and

forming the transparent electrode layer comprises forming an indium tin oxide (ITO) layer on the oxide layer and on the metal structure.

5. The method of claim 1 , further comprising:

forming a photoresist material on the insulating layer; and

performing an etch of the insulating layer while the photoresist material is on the insulating layer.

6. The method of claim 5 , wherein:

performing the etch of the insulating layer while the photoresist material is on the insulating layer comprises performing a first etch of the insulating layer;

the method further comprises performing a second etch of the insulating layer to form a recess that overlaps the metal structure, without exposing the metal structure; and

etching the insulating layer to form the opening that at least partially exposes the metal structure comprises performing a third etch of the insulating layer.

7. The method of claim 6 , wherein:

the photoresist material comprises a first photoresist layer;

the method further comprises removing the first photoresist layer and forming a second photoresist layer on the insulating layer, before performing the second etch of the insulating layer; and

the method further comprises removing the second photoresist layer, before performing the third etch that forms the opening that at least partially exposes the metal structure.

8. The method of claim 5 , wherein:

performing the etch comprises forming a protruding portion of the insulating layer; and

forming the transparent electrode layer comprises forming the transparent electrode layer on the protruding portion of the insulating layer.

9. The method of claim 1 , wherein forming the transparent electrode material comprises:

depositing the transparent electrode material on the insulating layer; and

performing a chemical mechanical polishing (CMP) process on the transparent electrode material until a protruding portion of the insulating layer is exposed.

10. The method of claim 9 ,

wherein the protruding portion of the insulating layer that is exposed by the CMP process overlaps the color filter layer, and

wherein the method further comprises forming an organic photoelectric layer on the transparent electrode layer and on the protruding portion of the insulating layer that is exposed by the CMP process.

11. A method of forming an image sensor, the method comprising:

forming a color filter layer on a semiconductor substrate;

forming a transparent layer on the color filter layer;

forming an insulating layer on the transparent layer;

etching the insulating layer to form an opening that exposes a portion of a metal structure that is adjacent a sidewall of the color filter layer;

forming an electrode layer on a first surface of the insulating layer, in the opening of a second surface of the insulating layer that is opposite the first surface and closer than the first surface to the semiconductor substrate; and

forming an organic photoelectric layer on the electrode layer.

12. The method of claim 11 , further comprising:

forming a photoresist material on a portion of the insulating layer; and

performing an etch of the insulating layer while the photoresist material is on the portion of the insulating layer, to form a protruding portion of the insulating layer,

wherein forming the electrode layer comprises forming the electrode layer on the protruding portion of the insulating layer.

13. The method of claim 11 , wherein:

forming the transparent layer on the color filter layer comprises forming the transparent layer on a red first color filter layer and a blue second color filter layer;

forming the insulating layer comprises forming an oxide layer on the transparent layer; and

forming the electrode layer comprises forming an indium tin oxide (ITO) layer on the oxide layer.

14. The method of claim 11 ,

wherein the metal structure comprises a tungsten portion and an aluminum portion on the tungsten portion, and

wherein the forming the electrode layer comprises forming the electrode layer to contact the aluminum portion.

15. The method of claim 14 , wherein sidewalls of the aluminum portion of the metal structure are tapered toward the electrode layer.

16. A method of forming an image sensor, the method comprising:

forming an insulating layer on a color filter layer;

forming a photoresist material on the insulating layer;

etching the insulating layer to form a recess that overlaps a metal structure that is adjacent a sidewall of the color filter layer while the photoresist material is on the insulating layer;

removing the photoresist material to expose a protruding portion of the insulating layer; and

forming an electrode layer in an opening of the insulating layer that at least partially exposes the metal structure and on a portion of the insulating layer that is outside of the opening.

17. The method of claim 16 , further comprising

performing a first etch of the insulating layer; and then

performing a second etch of the insulating layer to form the opening.

18. The method of claim 17 , wherein etching the insulating layer comprises performing a third etch of the insulating layer to form the recess that overlaps the metal structure, without exposing the metal structure, before performing the second etch of the insulating layer.

19. The method of claim 17 , wherein forming the electrode layer comprises forming the electrode layer on the protruding portion of the insulating layer.

20. The method of claim 19 , wherein:

the protruding portion of the insulating layer overlaps the color filter layer;

forming the electrode layer further comprises:

depositing an electrode material on the insulating layer; and

performing a chemical mechanical polishing (CMP) process on the electrode material until a surface of the protruding portion of the insulating layer is exposed; and

the method further comprises forming an organic photoelectric layer on the electrode layer and on the surface of the protruding portion of the insulating layer that is exposed by the CMP process.