Image sensor

1. An image sensor including an infrared (IR) sensing region, the IR sensing region comprising:

a substrate having a top surface and a bottom surface;

a first boundary isolation trench having a first length from the top surface and disposed at a first boundary of the IR sensing region;

a first boundary isolation film filling the first boundary isolation trench;

a second boundary isolation trench having a second length from the top surface and disposed at a second boundary of the IR sensing region;

a second boundary isolation film filling the second boundary isolation trench;

an inner reflection pattern film having a third length from the top surface between the first boundary isolation trench and the second boundary isolation trench;

a planarizing film on the top surface;

an infrared filter on the inner reflection pattern film; and

a side anti-reflection film at the first boundary,

wherein the third length is shorter than the first length,

wherein the planarizing film includes a silicon nitride,

wherein the infrared filter and the side anti-reflection film are on the planarization film, and

wherein a bottom surface of the infrared filter is coplanar with a bottom surface of the side anti-reflection film.

2. The image sensor of claim 1 , wherein the first boundary isolation film includes hafnium oxide.

3. The image sensor of claim 2 , wherein the first boundary isolation trench does not connect the top surface and the bottom surface.

4. The image sensor of claim 2 , wherein the first boundary isolation trench connects the top surface and the bottom surface.

5. The image sensor of claim 1 , wherein the side anti-reflection film includes tungsten.

6. The image sensor of claim 1 , wherein the first boundary isolation film includes aluminum oxide.

7. The image sensor of claim 6 , wherein the first boundary isolation trench does not connect the top surface and the bottom surface.

8. The image sensor of claim 6 , wherein the first boundary isolation trench connects the top surface and the bottom surface.

9. An image sensor including an infrared (IR) sensing region, the IR sensing region comprising:

a substrate having a top surface and a bottom surface;

a first boundary isolation trench having a first length from the top surface and disposed at a first boundary of the IR sensing region a first boundary isolation film filling the first boundary isolation trench;

a second boundary isolation trench having a second length from the top surface and disposed at a second boundary of the IR sensing region;

a second boundary isolation film filling the second boundary isolation trench;

an inner reflection pattern film having a third length from the top surface between the first boundary isolation trench and the second boundary isolation trench;

a first planarizing film on the top surface; and

an infrared filter on the inner reflection pattern film, wherein infrared light transmitted through the infrared filter is incident on the substrate between the first boundary isolation film and second boundary isolation film,

wherein the third length is shorter than the first length, and

wherein the inner reflection pattern film includes a hafnium oxide.

10. The image sensor of claim 9 , further comprising a second planarizing film on the first planarizing film.

11. The image sensor of claim 10 , wherein the first boundary isolation trench does not connect the top surface and the bottom surface.

12. The image sensor of claim 10 , wherein the first boundary isolation trench connects the top surface and the bottom surface.

13. The image sensor of claim 10 , further comprising a micro-lens on the second planarizing film and a protection film on the micro-lens.

14. The image sensor of claim 13 , wherein the protection film is a silicon oxide film.

15. The image sensor of claim 9 , wherein the first planarizing film has a thickness from about 3,000 angstroms to about 8,000 angstroms.