Image sensor and manufacturing method thereof

1. An image sensor comprising:

a circuit layer on a first surface of a semiconductor substrate;

a metal interconnection layer on the circuit layer;

trenches formed in a second surface of the semiconductor substrate along a boundary of a pixel;

a first light blocking layer in the trenches;

photodiodes in the first surface of the semiconductor; and

a second light blocking layer,

wherein the second light blocking layer includes an isolation layer extended from the first surface of the semiconductor substrate towards the second surface of the semiconductor substrate, wherein the second light blocking layer is formed between the photodiodes, and

wherein the second light blocking layer vertically overlaps with the first light blocking layer.

2. The image sensor of claim 1 , further comprising a color filter layer on the second surface having the first light blocking layer.

3. The image sensor of claim 2 , wherein the first light blocking layer is obtained by filling a portion of a first color filter of the color filter layer in the trenches.

4. The image sensor of claim 3 , wherein the first color filter includes blue color filter resin.

5. The image sensor of claim 1 , wherein the first light blocking layer includes blue color filter resin.

6. The image sensor of claim 1 , wherein the first light blocking layer includes at least one selected from the group consisting of Cu, W, Ti, Ta, Co, Al and Mo.

7. The image sensor of claim 1 , wherein the trenches have a depth of about 1˜2 μm.