Image sensors

1. An image sensor, comprising:

a plurality of photo detecting elements in an upper portion of a semiconductor substrate, the plurality of photo detecting elements being separate from each other; and

a backside protection pattern in a lower portion of the semiconductor substrate between the plurality of photo detecting elements,

wherein the backside protection pattern is doped with impurities which have the same conductivity type as a conductivity type of impurities in the semiconductor substrate, and

wherein a doping density of the backside protection pattern is higher than a doping density of the semiconductor substrate.

2. The image sensor of claim 1 , wherein

each photo detecting element of the plurality of photo detecting elements is disposed in one of a plurality of active areas of the semiconductor substrate, and

the backside protection pattern is disposed in a surrounding area of the semiconductor substrate, the plurality of active areas being surrounded by the surrounding area.

3. The image sensor of claim 2 , wherein the surrounding area corresponds to a grid pattern.

4. The image sensor of claim 2 , wherein each active area of the plurality of active areas corresponds to a circle or a polygon.

5. The image sensor of claim 4 , wherein each active area of the plurality of active areas is one of a same and different size as another active area of the plurality of active areas.

6. An image sensor, comprising:

a plurality of photo detecting elements in an upper portion of a semiconductor substrate, the plurality of photo detecting elements being separate from each other;

a backside protection pattern in a lower portion of the semiconductor substrate between the plurality of photo detecting elements; and

an isolation pattern on the backside protection pattern in the semiconductor substrate between the plurality of photo detecting elements, wherein a ground voltage is provided to the image sensor through the backside protection pattern and the isolation pattern.

7. The image sensor of claim 1 , further comprising:

an anti-reflection layer on a back surface of the semiconductor substrate.

8. The image sensor of claim 7 , wherein the anti-reflection layer includes negative fixed charges.

9. The image sensor of claim 7 , further comprising:

a plurality of color filters on the anti-reflection layer, each color filter of the plurality of color filters corresponding to one of the plurality of photo detecting elements, respectively; and

a plurality of micro lenses on the plurality of color filters, each micro lens of the plurality of micro lenses corresponding to one of the plurality of photo detecting elements, respectively.

10. The image sensor of claim 1 , wherein the semiconductor substrate includes a plurality of curved back surfaces, each of the plurality of curved back surfaces corresponding to one of the plurality of photo detecting elements, respectively.

11. The image sensor of claim 10 , wherein

the plurality of curved back surfaces are a plurality of convex surfaces, and

each photo detecting element of the plurality of photo detecting elements receives light through each convex surface of the plurality of convex surfaces.

12. An image sensor, comprising:

a plurality of photo detecting elements in an upper portion of a semiconductor substrate, the plurality of photo detecting elements being separate from each other;

a first backside protection pattern in a lower portion of the semiconductor substrate between the plurality of photo detecting elements; and

a plurality of second backside protection patterns in the lower portion of the semiconductor substrate under the plurality of photo detecting elements, each second backside protection pattern of the plurality of second backside protection patterns having a different thickness than the first backside protection pattern,

wherein the first backside protection pattern is doped with impurities which have the same conductivity type as a conductivity type of impurities in the semiconductor substrate, and

wherein a doping density of the first backside protection pattern is higher than a doping density of the semiconductor substrate.

13. The image sensor of claim 12 , wherein the thickness of each second backside protection pattern of the plurality of second backside protection patterns is smaller than the thickness of the first backside protection pattern.

14. The image sensor of claim 12 , wherein

each second backside protection pattern of the plurality of second backside protection patterns is in one of a plurality of active areas of the semiconductor substrate, and

the first backside protection pattern is in a surrounding area of the semiconductor substrate, the plurality of active areas being surrounded by the surrounding area.

15. An image sensor, comprising:

a photo detecting element in an active area of a semiconductor substrate; and

a backside protection pattern in a surrounding area of the semiconductor substrate, the active area surrounded by the surrounding area,

wherein the backside protection pattern is doped with impurities which have the same conductivity type as a conductivity type of impurities in the semiconductor substrate, and

wherein a doping density of the backside protection pattern is higher than a doping density of the semiconductor substrate.

16. The image sensor of claim 15 , wherein the active area is a plurality of active areas, and the surrounding area corresponds to a grid pattern.

17. The image sensor of claim 16 , wherein each active area of the plurality of active areas corresponds to one of a circle and a polygon.

18. The image sensor of claim 16 , wherein a size of each active area of the plurality of active areas is the same.

19. The image sensor of claim 16 , wherein a size of each active area of the plurality of active areas is different.