CMOS image sensor structure

1. A method for manufacturing a semiconductor device, the method comprising:

providing a semiconductor layer, wherein the semiconductor layer has a first surface and a second surface opposite to the first surface;

forming a device layer including a plurality of light-sensing regions on the first surface of the semiconductor layer;

bonding the device layer to a surface of a substrate after forming the device layer on the first surface of the semiconductor layer;

performing a thinning process on the second surface of the semiconductor layer after bonding the device layer on the surface of the substrate;

forming a plurality of microstructures on the second surface of the semiconductor layer by removing a portion of the semiconductor layer after bonding the device layer on the surface of the substrate;

forming a dielectric layer to fill a gap between any two adjacent microstructures, wherein the dielectric layer has a planar surface opposite to the microstructures; and

forming a color filter layer on the planar surface of the dielectric layer.

2. The method of claim 1 , wherein providing the semiconductor layer comprises forming the semiconductor layer from silicon or germanium.

3. The method of claim 1 , wherein forming the microstructures is performed using a photolithography process and an etching process.

4. The method of claim 1 , wherein forming the microstructures is performed to form each of the microstructures with a cross-section in a shape of triangle, trapezoid, or arc.

5. The method of claim 1 , wherein forming the microstructures is performed to form any two adjacent ones of the microstructures adjoining to each other.

6. The method of claim 1 , wherein forming the microstructures is performed to form any two adjacent ones of the microstructures separated from each other.

7. The method of claim 1 , further comprising forming a plurality of micro-lenses on the color filter layer.

8. The method of claim 1 , wherein forming the microstructures is performed to form each of the microstructures having a height of greater than λ/2.5, λ representing a wavelength of an incident light.

9. The method of claim 1 , wherein forming the microstructures is performed to form any two adjacent ones of the microstructures between which a pitch is greater than λ/2, λ representing a wavelength of an incident light.

10. A method for manufacturing a semiconductor device, the method comprising:

providing a semiconductor layer, wherein the semiconductor layer has a first surface and a second surface opposite to the first surface;

forming a device layer including a plurality of light-sensing regions on the first surface of the semiconductor layer;

bonding the device layer to a surface of a substrate after forming the device layer on the first surface of the semiconductor layer;

performing a thinning process on the second surface of the semiconductor layer after bonding the device layer on the surface of the substrate;

forming a photomask above the second surface of the semiconductor layer after bonding the device layer on the surface of the substrate;

projecting light through the photomask toward the second surface of the semiconductor layer;

performing an etching process on the second surface of the semiconductor layer to remove a portion of the semiconductor layer after projecting the light, thereby forming a plurality of microstructures on the second surface;

forming a dielectric layer to fill a gap between any two adjacent microstructures; and

forming a color filter layer on the dielectric layer.

11. The method of claim 10 , wherein the etching process forms each of the microstructures with a cross-section in a shape of triangle, trapezoid, or arc.

12. The method of claim 10 , wherein the etching process forms any two adjacent ones of the microstructures adjoining to each other.

13. The method of claim 10 , wherein the etching process forms any two adjacent ones of the microstructures separated from each other.

14. The method of claim 10 , further comprising forming a plurality of micro-lenses on the color filter layer.

15. The method of claim 10 , wherein the etching process is performed to form each of the microstructures having a height of greater than λ/2.5, λ representing a wavelength of an incident light.

16. The method of claim 10 , wherein the etching process is performed to form any two adjacent ones of the microstructures between which a pitch is greater than λ/2, λ representing a wavelength of an incident light.

17. A method for manufacturing a semiconductor device, the method comprising:

providing a semiconductor layer, wherein the semiconductor layer has a first surface and a second surface opposite to the first surface;

forming a device layer including a plurality of light-sensing regions on the first surface of the semiconductor layer;

bonding the device layer to a surface of a substrate after forming the device layer on the first surface of the semiconductor layer;

performing a thinning process on the second surface of the semiconductor layer after bonding the device layer on the surface of the substrate;

forming a plurality of microstructures on the second surface of the semiconductor layer by using a laser removing technique to remove a portion of the semiconductor layer after bonding the device layer on the surface of the substrate;

forming a dielectric layer to fill a gap between any two adjacent microstructures;

performing a planarization process on the dielectric layer to form a planar surface of the dielectric layer; and

forming a color filter layer on the planar surface of the dielectric layer.

18. The method of claim 17 , wherein the thinning process is performed using a chemical mechanical polishing (CMP) technique.

19. The method of claim 17 , wherein the planarization process is performed using a CMP technique.

20. The method of claim 17 , further comprising forming a plurality of micro-lenses on the color filter layer.