Solid-state imaging device and method for manufacturing electronic apparatus
The present disclosure relates to a solid-state imaging device, a method for manufacturing the same, and an electronic apparatus capable of improving sensitivity while suppressing degradation of color mixture. The solid-state imaging device includes an anti-reflection portion having a moth-eye structure provided on a boundary surface on a light-receiving surface side of a photoelectric conversion region of each pixel arranged two-dimensionally, and an inter-pixel light-blocking portion provided below the boundary surface of the anti-reflection portion to block incident light. In addition, the photoelectric conversion region is a semiconductor region, and the inter-pixel light-blocking portion has a trench structure obtained by digging the semiconductor region in a depth direction at a pixel boundary. The techniques according to the present disclosure can be applied to, for example, a solid-state imaging device of a rear surface irradiation type.
1. A solid-state imaging device, comprising:
a semiconductor substrate having a first surface that receives incident light and a second surface opposite to the first surface;
a first trench and a second trench disposed in the first surface of the semiconductor substrate; and
a first concave structure and a second concave structure disposed between the first trench and the second trench and in the first surface of the semiconductor substrate, depths of the first concave structure and the second concave structure being shallower than depths of the first trench and the second trench,
wherein a first flat part of the semiconductor substrate is disposed between the first trench and the first concave structure,
wherein a second flat part of the semiconductor substrate is disposed between the second trench and the second concave structure, and
wherein a third flat part of the semiconductor substrate is disposed between the first concave structure and the second concave structure, the third flat part being parallel to the first flat part and the second flat part in a cross-sectional view.
2. The solid-state imaging device of claim 1 , wherein a fourth flat part of the semiconductor substrate is disposed between the second flat part and the third flat part, and wherein the fourth flat part is parallel to the first flat part and the second flat part in the cross-sectional view.
3. The solid-state imaging device of claim 2 , further comprising:
a third concave structure disposed in the first surface and between the third flat part and the fourth flat part.
4. The solid-state imaging device of claim 1 , further comprising:
a photoelectric conversion region disposed in the semiconductor substrate between the first trench and the second trench in the substrate.
5. The solid-state imaging device of claim 4 , wherein the first concave structure and the second concave structure are disposed above the photoelectric conversion region.
6. The solid-state imaging device of claim 1 , further comprising:
a first insulation film disposed on first flat part and the second flat part.
7. The solid-state imaging device of claim 6 , wherein the first insulation film includes silicon.
8. The solid-state imaging device of claim 6 , wherein the first insulation film includes an oxide.
9. The solid-state imaging device of claim 6 , wherein the first insulation film includes silicon oxide.
10. The solid-state imaging device of claim 6 , further comprising:
a second insulation film disposed between the first insulation film and the first flat part and the second part.
11. The solid-state imaging device of claim 10 , wherein the second insulation film has a negative fixed charge.
12. The solid-state imaging device of claim 10 , wherein the second insulation film includes an oxide.
13. The solid-state imaging device of claim 12 , wherein the second insulation film includes hafnium oxide or tantalum oxide.
14. A method of manufacturing a solid-state imaging device comprising:
forming a first trench and a second trench in a surface of a substrate at a light incident side of the substrate; and
forming a first concave structure and a second concave structure in the surface of the substrate and between the first trench and the second trench, wherein depths of the first concave structure and the second concave structure are shallower than depths of the first trench and the second trench, and
wherein the forming the first concave structure and the second concave structure forms a first flat part, a second flat part, and a third flat part of the substrate, wherein the third flat part is parallel to the first flat part and second flat part, and wherein the first flat part is between the third flat part and the first trench.
15. The method of claim 14 , wherein the forming the first trench and the second trench and the forming the first concave structure and the second concave structure include dry etching.
16. The method of claim 14 , further comprising:
forming an anti-reflective film in the first and second trenches and in the first and second concave structures.
17. The method of claim 16 , further comprising:
forming an insulation film on the light shielding film such that the insulation film is in the first and second trenches and in the first and second concave structures.
18. The method of claim 17 , further comprising:
forming a light shielding film on the insulation film such that the light shielding film overlaps at least a portion of the first flat part in a cross-sectional view.