Solid state imaging device, method of manufacturing solid-state imaging device, and electronic apparatus
The present technique aims to provide a solid-state imaging device that reduces shading and color mixing between pixels. The present invention also provides a method of manufacturing the solid-state imaging device. The present technique further relates to a solid-state imaging device that enables provision of an electronic apparatus that uses the solid-state imaging device, a method of manufacturing the solid-state imaging device, and an electronic apparatus. The solid-state imaging device includes a substrate, pixels each including a photoelectric conversion unit formed in the substrate, and a color filter layer formed on the light incidence surface side of the substrate. The solid-state imaging device also includes a device isolating portion that is formed to divide the color filter layer and the substrate for the respective pixels, and has a lower refractive index than the refractive indexes of the color filter layer and the substrate.
1. An imaging device, comprising:
a semiconductor substrate;
a first photoelectric conversion region disposed in the semiconductor substrate;
a second photoelectric conversion region adjacent to the first photoelectric conversion region and disposed in the semiconductor substrate;
a first color filter disposed above the first photoelectric conversion region in a cross-sectional view;
a second color filter disposed above the second photoelectric conversion region in the cross-sectional view; and
an air gap, in the cross-sectional view, disposed between the first and second photoelectric conversion regions and disposed between the first and second color filters.
2. The imaging device of claim 1 , wherein the air gap is defined by a groove that extends into the semiconductor substrate.
3. The imaging device of claim 2 , further comprising:
a film disposed on inner wall surfaces of the groove.
4. The imaging device of claim 3 , wherein the film has a lower refractive index than the first color filter and the second color filter.
5. The imaging device of claim 3 , wherein the film is disposed on surfaces of the first color filter and surfaces of the second color filter.
6. The imaging device of claim 1 , further comprising:
an interconnect layer disposed on and electrically connected to the semiconductor substrate.
7. The imaging device of claim 6 , wherein the interconnect layer comprises a first transfer transistor to transfer charge collected by the first photoelectric conversion region, and a second transfer transistor to transfer charge collected by the second photoelectric conversion region.
8. The imaging device of claim 7 , wherein the interconnect layer further comprises a reset transistor, an amplification transistor, and a selection transistor.
9. The imaging device of claim 1 , further comprising:
a floating diffusion region disposed in the semiconductor substrate and that collects charge of the first photoelectric conversion region.
10. The imaging device of claim 9 , wherein, in the cross-sectional view, the floating diffusion region is below the air gap.
11. The imaging device of claim 10 , further comprising a first impurity region disposed in the semiconductor substrate and having a conductivity type opposite a conductivity type of the semiconductor substrate, wherein the floating diffusion region comprises the first impurity region.
12. The imaging device of claim 11 , further comprising:
a second impurity region disposed in the semiconductor substrate adjacent to the first impurity region and having a same conductivity type as the first impurity region with a higher concentration of impurities than the first impurity region.
13. The imaging device of claim 1 , further comprising:
an isolating portion disposed in the semiconductor substrate between the first photoelectric conversion region and the second photoelectric conversion region, wherein the isolating portion has a conductivity type opposite to a conductivity type of the semiconductor substrate.
14. An electronic apparatus, comprising:
a signal processing circuit; and
an imaging device, comprising:
a semiconductor substrate;
a first photoelectric conversion region disposed in the semiconductor substrate;
a second photoelectric conversion region adjacent to the first photoelectric conversion region and disposed in the semiconductor substrate;
a first color filter disposed above the first photoelectric conversion region in a cross-sectional view;
a second color filter disposed above the second photoelectric conversion region in the cross-sectional view; and
an air gap, in the cross-sectional view, disposed between the first and second photoelectric conversion regions and disposed between the first and second color filters.
15. The electronic apparatus of claim 14 , wherein the air gap is defined by a groove that extends into the semiconductor substrate.
16. The electronic apparatus of claim 15 , further comprising:
a film disposed on inner wall surfaces of the groove.
17. The electronic apparatus of claim 16 , wherein the film has a lower refractive index than the first color filter and the second color filter.
18. The electronic apparatus of claim 16 , wherein the film is disposed on surfaces of the first color filter and surfaces of the second color filter.
19. The electronic apparatus of claim 14 , further comprising:
an interconnect layer disposed on and electrically connected to the semiconductor substrate.
20. The electronic apparatus of claim 19 , wherein the interconnect layer comprises a first transfer transistor to transfer charge collected by the first photoelectric conversion region, and a second transfer transistor to transfer charge collected by the second photoelectric conversion region.