Semiconductor image sensor
A BSI image sensor includes a substrate including a front side and a back side opposite to the front side, a plurality of pixel sensors arranged in an array, an isolation grid disposed in the substrate and separating the plurality of pixel sensors from each other, and a reflective grid disposed over the isolation grid on the back side of the substrate. A depth of the reflective grid is less than a depth of the isolation grid.
1. A back side illumination (BSI) image sensor comprising:
a substrate comprising a front side and a back side opposite to the front side;
a plurality of pixel sensors arranged in an array,
an isolation grid disposed in the substrate and separating the plurality of pixel sensors from each other;
a reflective grid disposed over the isolation grid on the back side of the substrate, and a depth of the reflective grid being less than a depth of the isolation grid; and
a low-n grid disposed over the back side of the substrate and overlapping the reflective grid from a plan view,
wherein the isolation grid and the reflective grid comprise different materials, and a width of the low-n grid is greater than a width of the reflective grid.
2. The BSI image sensor of claim 1 , further comprising a plurality of color filters disposed over the substrate on the back side.
3. The BSI image sensor of claim 2 , wherein the low-n grid is disposed between and separating the color filters from each other.
4. The BSI image sensor of claim 1 , wherein the reflective grid is disposed between the low-n grid and the isolation grid.
5. The BSI image sensor of claim 1 , wherein the low-n grid comprises an insulating material.
6. The BSI image sensor of claim 1 , wherein the isolation grid comprises at least an insulating material.
7. The BSI image sensor of claim 1 , wherein the reflective grid comprises a conductive material.
8. The BSI image sensor of claim 1 , wherein the depth of the isolation grid is substantially equal to or less than a thickness of the substrate.
9. A back side illumination (BSI) image sensor comprising:
a substrate;
a pixel sensor; and
a hybrid isolation surrounding the pixel sensor in the substrate, and the hybrid isolation comprising:
a conductive structure;
a dielectric layer covering at least sidewalls of the conductive structure; and
a first insulating structure disposed in the substrate,
wherein the dielectric layer covers sidewalls and a bottom surface of the first insulating structure.
10. The BSI image sensor of claim 9 , wherein a thickness of the hybrid isolation is substantially equal to or less than a thickness of the substrate.
11. The BSI image sensor of claim 9 , further comprising a second insulating structure disposed over the substrate on the back side.
12. The BSI image sensor of claim 11 , wherein the conductive structure is disposed between the first insulating structure and the second insulating structure.
13. A back side illumination (BSI) image sensor comprising:
a substrate comprising a front side and a back side opposite to the front side;
a pixel sensor;
a color filter corresponding to the pixel sensor and disposed over the substrate on the back side;
a first hybrid isolation surrounding the pixel sensor in the substrate, and
a second hybrid isolation surrounding the color filter on the back side of the substrate and overlapping the first hybrid isolation from a plan view,
wherein the first hybrid isolation and the second hybrid isolation are separated from each other.
14. The BSI image sensor of claim 13 , wherein the first hybrid isolation comprises a first conductive structure and a first insulating structure, and the second hybrid isolation comprises a second conductive structure and a second insulating structure.
15. The BSI image sensor of claim 13 , wherein a depth of the first hybrid isolation is equal to or less than a thickness of the substrate.
16. The BSI image sensor of claim 1 , wherein the low-n grid is separated from the reflective grid.
17. The BSI image sensor of claim 1 , wherein the low-n grid is in contact with the reflective grid.
18. The BSI image sensor of claim 9 , wherein a thickness of the conductive structure is greater than a thickness of the first insulating structure.
19. The BSI image sensor of claim 13 , wherein the first hybrid isolation comprises a conductive structure and a dielectric layer covering at least sidewall of the conductive structure.
20. The BSI image sensor of claim 1 , further comprising a passivation layer disposed between the low-n grid and the reflective grid, wherein the low-n grid and the reflective grid are separated from each other by the passivation layer.