Solid-state imaging device having improved light-collection, method of manufacturing the same, and electronic apparatus
A solid-state imaging device includes: a pixel region in which a plurality of pixels composed of a photoelectric conversion section and a pixel transistor is arranged; an on-chip color filter; an on-chip microlens; and a multilayer interconnection layer in which a plurality of layers of interconnections is formed through an interlayer insulating film. The solid-state imaging device further includes a light-shielding film formed through an insulating layer in a pixel boundary of a light receiving surface in which the photoelectric conversion section is arranged.
1. An imaging device, comprising:
a substrate having a first side as a light-incident side and a second side opposite to the first side;
a first photoelectric conversion region disposed in the substrate;
a second photoelectric conversion region disposed adjacent to the first photoelectric conversion region in the substrate;
a third photoelectric conversion region disposed adjacent to the second photoelectric conversion region in the substrate;
a silicon oxide film disposed over the first side of the substrate;
a hafnium oxide film disposed over the silicon oxide film;
a first light-shielding film disposed over the hafnium oxide film, the first light-shielding film disposed between the first photoelectric conversion region and the second photoelectric conversion region;
a second light-shielding film disposed over the hafnium oxide film, the second light-shielding film disposed between the second photoelectric conversion region and the third photoelectric conversion region;
a titanium nitride film disposed between the hafnium oxide film and the first light-shielding film;
a trench including a first trench portion and a second trench portion;
a plurality of photoelectric conversion portions, wherein a photoelectric conversion portion of the plurality of photoelectric conversion portions is disposed between the first trench portion and the second trench portion; and
a metallic oxide film including a first portion, a second portion and a third portion,
wherein,
the first portion is disposed in the first trench portion,
the second portion is disposed in the second trench portion, and
the third portion is overlapping with the photoelectric conversion portion.
2. The imaging device according to claim 1 , wherein the metallic oxide film is selected from the group consisting of hafnium oxide, tantalum pentoxide, zirconium dioxide, and combinations thereof.
3. The imaging device according to claim 1 , wherein the metallic oxide film is a high-dielectric material film.
4. The imaging device according to claim 1 , wherein the second light-shielding film includes a first portion disposed in the first trench portion and a second portion disposed in the second trench portion.
5. The imaging device according to claim 4 , wherein the second light-shielding film is made of tungsten or aluminum.
6. The imaging device according to claim 4 , further comprising:
a light-shielding portion including the trench, the metallic oxide film, and the second light-shielding film, wherein the light-shielding portion is lattice shaped in a plan view.
7. The imaging device according to claim 1 , wherein the first light-shielding film is disposed between a color filter and the first side of the substrate.
8. The imaging device according to claim 1 , wherein the first light-shielding film is coupled to a ground region of the substrate.
9. The imaging device according to claim 8 , wherein the ground region of the substrate is a p-type semiconductor region.
10. The imaging device according to claim 1 , wherein
the substrate includes the photoelectric conversion portion, the first trench portion and the second trench portion at an effective pixel region, and
the first light-shielding film is lattice shaped at the effective pixel region in a plan view.
11. The imaging device according to claim 10 , wherein the first light-shielding film covers the substrate at an optical black region adjacent to the effective pixel region.
12. The imaging device according to claim 11 , wherein the titanium nitride film is disposed with the first light-shielding film at the optical black region.
13. The imaging device according to claim 12 , wherein the silicon oxide film is disposed over the substrate at the effective pixel region and the optical black region.
14. The imaging device according to claim 13 , wherein the hafnium oxide film is disposed over the silicon oxide film at the effective pixel region and the optical black region.
15. The imaging device according to claim 1 , wherein the first light-shielding film is one of tungsten, aluminum or copper.
16. The imaging device according to claim 1 , further comprising:
an insulating film disposed between the hafnium oxide film and the titanium nitride film.
17. The imaging device according to claim 16 , further comprising:
a planarization film disposed between a color filter and the insulating film.
18. The imaging device according to claim 17 , wherein the color filter is disposed between a microlens and the planarization film.
19. The imaging device according to claim 18 , further comprising:
an antireflection film formed on a surface of the microlens.
20. The imaging device according to claim 18 , further comprising:
an interlayer lens disposed between the microlens and at least one photoelectric conversion portion of the plurality of photoelectric conversion portions.
21. The imaging device according to claim 17 , wherein the planarization film is made of an organic material.
22. The imaging device according to claim 1 , further comprising:
an element isolation region, wherein the trench is disposed in the element isolation region.
23. The imaging device according to claim 22 , wherein the element isolation region is a p-type impurity region.
24. The imaging device according to claim 1 , further comprising:
a plurality of wiring layers disposed at the second side of the substrate, wherein the plurality of wiring layers includes a plurality of wirings that drive a plurality of transistors.
25. The imaging device according to claim 24 , wherein the plurality of transistors includes a reset transistor, an amplifying transistor and a select transistor,
wherein the reset transistor, the amplifying transistor and the select transistor are shared by at least two photoelectric conversion portions of the plurality of photoelectric conversion portions.
26. The imaging device according to claim 25 , wherein the at least two photoelectric conversion portions share a floating diffusion.
27. The imaging device according to claim 26 , wherein the select transistor is coupled to a signal line that outputs an output signal from at least one photoelectric conversion portion of the plurality of photoelectric conversion portions.
28. The imaging device according to claim 1 , wherein each photoelectric conversion portion of the plurality of photoelectric conversion portions includes a p-type region and a n-type region.
29. The imaging device according to claim 28 , wherein each of the n-type regions does not contact the metallic oxide film.
30. The imaging device according to claim 1 , wherein the first portion, the second portion and the third portion of the metallic oxide film are continuously connected to each other.
31. The imaging device according to claim 1 , wherein the titanium nitride film is in direct contact with the hafnium oxide film.
32. The imaging device according to claim 1 , wherein the trench contacts the second side of the substrate.
33. The imaging device according to claim 1 , wherein a bottom surface of the titanium nitride film is in direct contact with an insulating film.