Solid-state imaging apparatus, method for manufacturing the same, and electronic device
The present technology relates to a solid-state imaging apparatus capable of suppressing occurrence of color mixing, a method for manufacturing the solid-state imaging apparatus, and an electronic device. The solid-state imaging apparatus includes a plurality of pixels arranged in a pixel region. Each of the pixels has: a first optical filter layer disposed on a photoelectric conversion unit; a second optical filter layer disposed on the first optical filter layer; and a separation wall separating at least a part of the first optical filter layer for each of the pixels. Either the first optical filter layer or the second optical filter layer in at least one of the pixels is formed by an infrared cut filter, while the other is formed by a color filter. The present technology can be applied to a CMOS image sensor including a visible light pixel.
1. A solid-state imaging apparatus comprising a plurality of pixels arranged in a pixel region, wherein
each of the pixels has:
a first optical filter layer disposed on a photoelectric conversion unit;
a second optical filter layer disposed on the first optical filter layer;
a separation wall separating at least a part of the first optical filter layer for each of the pixels without separating the photoelectric conversion units and without separating the second optical filter layer from each other for each of the pixels,
wherein the separation wall comprises a metal core with a height smaller than a height of an oxide film provided within the separation wall; and
either the first optical filter layer or the second optical filter layer in at least one of the pixels is formed by an infrared cut filter, while another is formed by a color filter.
2. The solid-state imaging apparatus according to claim 1 , wherein
the infrared cut filter includes an organic material to which an organic or inorganic color material is added.
3. The solid-state imaging apparatus according to claim 2 , wherein
the infrared cut filter has such spectral characteristics that a transmittance is 20% or less in a wavelength region of 700 nm or more.
4. The solid-state imaging apparatus according to claim 3 , wherein
the infrared cut filter has such spectral characteristics that an absorption maximum wavelength is present in a wavelength region of 700 nm or more.
5. The solid-state imaging apparatus according to claim 1 , wherein
the infrared cut filter is also formed in a region other than the pixel region.
6. The solid-state imaging apparatus according to claim wherein
the separation wall includes an organic resin having a refractive index equal to or lower than that of the color filter.
7. The solid-state imaging apparatus according to claim wherein
the separation wall includes an organic resin containing a filler.
8. The solid-state imaging apparatus according to claim wherein
a height of the separation wall is at least 100 nm or more.
9. The solid-state imaging apparatus according to claim 1 , comprising only visible light pixels as the plurality of pixels.
10. The solid-state imaging apparatus according to claim 1 , comprising a visible light pixel and an infrared light pixel as the plurality of pixels, wherein
either the first optical filter layer or the second optical filter layer in the visible light pixel is formed by an infrared cut filter, while the other is formed by a color filter.
11. The solid-state imaging apparatus according to claim 10 , wherein
each of the first optical filter layer and the second optical filter layer of the infrared light pixel is formed by a color filter that transmits infrared light.
12. The solid-state imaging apparatus according to claim 11 , wherein
the two color filters in the infrared light pixel have such spectral characteristics that a transmittance is 20% or less in a wavelength region of 400 to 700 nm, and a transmittance is 80% in a wavelength region of 700 nm or more.
13. The solid-state imaging apparatus according to claim 12 , wherein
the first optical filter layer and the second optical filter layer are color filters of a same type.
14. The solid-state imaging apparatus according to claim 12 , wherein
the first optical filter layer and the second optical filter layer are color filters of different types.
15. A method for manufacturing a solid-state imaging apparatus including a plurality of pixels arranged in a pixel region, each of the pixels having:
a first optical filter layer disposed on a photoelectric conversion unit;
a second optical filter layer disposed on the first optical filter layer; and
a separation wall separating at least a part of the first optical filter layer for each of the pixels without separating the photoelectric conversion units and without separating the second optical filter layer from each other for each of the pixels,
wherein the separation wall comprises a metal core with a height smaller than a height of an oxide film provided within the separation wall,
the method comprising:
forming the separation wall;
forming the first optical filter layer; and
forming the second optical filter layer, wherein
either the first optical filter layer or the second optical filter layer in at least one of the pixels is formed by an infrared cut filter, while another is formed by a color filter.
16. An electronic device comprising a solid-state imaging apparatus including a plurality of pixels arranged in a pixel region, wherein
each of the pixels has:
a first optical filter layer disposed on a photoelectric conversion unit;
a second optical filter layer disposed on the first optical filter layer;
a separation wall separating at least a part of the first optical filter layer for each of the pixels without separating the photoelectric conversion units and without separating the second optical filter layer from each other for each of the pixels,
wherein the separation wall comprises a metal core with a height smaller than a height of an oxide film provided within the separation wall; and
either the first optical filter layer or the second optical filter layer in at least one of the pixels is formed by an infrared cut filter, while another is formed by a color filter.
17. The electronic device according to claim 16 , wherein
the infrared cut filter includes an organic material to which an organic or inorganic color material is added.
18. The electronic device according to claim 17 , wherein
the infrared cut filter has such spectral characteristics that a transmittance is 20% or less in a wavelength region of 700 nm or more.
19. The electronic device according to claim 18 , wherein
the infrared cut filter has such spectral characteristics that an absorption maximum wavelength is present in a wavelength region of 700 nm or more.
20. The electronic device according to claim 17 , wherein the separation wall includes an organic resin containing a filler.