CMOS image sensor having photodiode and method for manufacturing the same

1. A CMOS image sensor comprising:

a plurality of photodiodes in a semiconductor substrate;

an insulating interlayer over the semiconductor substrate, including the photodiodes;

a passivation layer pattern on the insulating interlayer corresponding to each of the photodiodes;

a first light-shielding layer pattern on the insulating interlayer between each passivation layer pattern;

a second light-shielding layer pattern on the first light-shielding layer pattern; and

at least one microlens on the passivation layer pattern.

2. The CMOS image sensor of claim 1 , wherein the second light-shielding layer pattern is narrower than the first light-shielding layer pattern.

3. The CMOS image sensor of claim 2 , wherein the at least one microlens is formed on the passivation layer pattern and on a predetermined portion of the first light-shielding layer pattern having no second light-shielding layer pattern thereon.

4. The CMOS image sensor of claim 1 , wherein the upper surface of the second light-shielding layer is higher than the upper surface of the at least one microlens.

5. The CMOS image sensor of claim 1 , wherein the passivation layer pattern is formed with a nitride layer.

6. A method for manufacturing a CMOS image sensor comprising:

forming an insulating interlayer over a semiconductor substrate, including a plurality of photodiodes;

forming a passivation layer pattern on the insulating interlayer corresponding to each photodiodes;

forming a first light-shielding layer pattern on the insulating interlayer between each passivation layer pattern;

forming a second light-shielding layer pattern on the first light-shielding layer pattern; and

forming at least one microlens on the passivation layer pattern.

7. The method of claim 6 , wherein the second light-shielding layer pattern is narrower than the first light-shielding layer pattern.

8. The method of claim 6 , wherein the process of forming the first light-shielding layer pattern includes:

forming a first light-shielding material layer on the insulating interlayer, including the passivation layer pattern; and

performing a planarization process to the first light-shielding material layer until an upper surface of the passivation layer pattern is exposed.

9. The method of claim 6 , wherein the process of forming the second light-shielding layer pattern includes:

forming a second light-shielding material layer on the passivation layer pattern and on the first light-shielding layer pattern; and

selectively etching the second light-shielding material layer so as to expose edge portions of the first light-shielding layer pattern and the passivation layer pattern.

10. The method of claim 6 , wherein the process of forming the at least one microlens includes:

forming a microlens material layer on the entire surface of the substrate, including the passivation layer pattern and the first and second light-shielding layer patterns;

forming a microlens pattern by planarizing the microlens material layer until exposing an upper surface of the second light-shielding layer pattern; and

forming the at least one microlens by performing a reflow process.

11. The method of claim 10 , wherein the reflow process is performed until an upper surface of the at least one microlens is lower than the upper surface of the second light-shielding layer pattern.

12. The method of claim 6 , wherein the passivation layer pattern is formed with a nitride layer.