Light block for pixel arrays
View Patent ↗Imager devices are formed with light block material between microlenses to enhance the characteristics of image acquisition. The light block material may be deposited over the lenses, and then partially removed to expose central portions of the lenses. The invention is applicable to, among other things, imager devices having pixel arrays formed with the light block material and integrated with one or more processing components in a semiconductor device.
1. A method of fabricating a pixel array in a CMOS imaging device, comprising:
forming a plurality of photosensors;
forming a plurality of lenses over said plurality of photosensors;
forming a material layer over and between said plurality of lenses; and
removing first portions of said material layer to expose at least an outer surface of each lens, wherein second portions of said material layer remain surrounding each lens in the completed pixel array, said second portions capable of either absorbing or reflecting substantially all light incident on said second portions.
2. The method of claim 1 , wherein the outer surface of each lens is a substantially curved outer surface.
3. The method of claim 1 , wherein said second portions comprise a material that absorbs light incident on said second portions.
4. The method of claim 1 , wherein said second portions comprise a material that absorbs substantially all light incident on said second portions.
5. The method of claim 1 , wherein said second portions comprise a material that reflects light incident on said second portions.
6. The method of claim 1 , wherein said second portions comprise a material that reflects substantially all light incident on said second portions.
7. The method of claim 1 , wherein said material layer comprises at least one layer of black photoresist.
8. The method of claim 1 , wherein said material layer comprises at least one metal layer.
9. The method of claim 8 , wherein said at least one metal layer comprises aluminum.
10. The method of claim 1 , wherein said second portions are below an upper level of each said lens.
11. The method of claim 10 , wherein said second portions have a generally planar upper surface.
12. The method of claim 1 , wherein said second portions extend above an upper level of each said lens to block light incident on said second portions.
13. The method of claim 12 , wherein said second portions have generally planar upper and sidewall surfaces.
14. A method of fabricating a pixel array in a CMOS imaging device, comprising:
forming a material layer over and between a plurality of lenses; and
removing first portions of said material layer to expose at least an outer surface of each lens, wherein second portions of said material layer partially cover each lens in the completed pixel array.
15. The method of claim 14 , wherein the outer surface of each lens is a substantially curved outer surface.
16. The method of claim 14 , wherein said second portions comprise a material that absorbs light incident on said second portions.
17. The method of claim 14 , wherein said second portions comprise a material that absorbs substantially all light incident on said second portions.
18. The method of claim 14 , wherein said second portions comprise a material that reflects light incident on said second portions.
19. The method of claim 14 , wherein said second portions comprise a material that reflects substantially all light incident on said second portions.
20. The method of claim 14 , wherein said material layer comprises at least one layer of black photoresist.
21. The method of claim 14 , wherein said material layer comprises at least one metal layer.
22. The method of claim 21 , wherein said at least one metal layer comprises aluminum.
23. The method of claim 14 , wherein said second portions are below an upper level of each said lens.
24. The method of claim 23 , wherein said second portions have a generally planar upper surface.
25. The method of claim 14 , wherein said second portions extend above an upper level of each said lens.
26. The method of claim 25 , wherein said second portions have generally planar upper and sidewall surfaces.
27. A method of enhancing light transmission to a photosensor in an imaging device, comprising:
exposing outer surfaces of lenses, wherein second portions of a material layer surround each lens; and
transmitting light through said lenses, such that said second portions of said material layer block light from entering said imaging device.
28. The method of claim 27 , wherein said second portions comprise a material that absorbs light incident on said second portions.
29. The method of claim 28 , wherein said second portions comprise a material that absorbs substantially all light incident on said second portions.
30. The method of claim 27 , wherein said second portions comprise a material that reflects light incident on said second portions.
31. The method of claim 30 , wherein said second portions comprise a material that reflects substantially all light incident on said second portions.
32. The method of claim 27 , wherein said material layer comprises at least one layer of black photoresist.
33. The method of claim 27 , wherein said at least one material comprises at least one metal layer.
34. The method of claim 33 , wherein said at least one metal layer comprises aluminum.
35. The method of claim 27 , wherein said second portions are below an upper level of each said lens.
36. The method of claim 35 , wherein said second portions have a generally planar upper surface.
37. The method of claim 27 , wherein said second portions extend above an upper level of each said lens.
38. The method of claim 37 , wherein said second portions have generally planar upper and sidewall surfaces.