Semiconductor device with nanostructures and methods of forming the same
A method of forming a semiconductor device includes forming a photo sensing region in a semiconductor substrate, wherein the semiconductor substrate is of a first type dopant and the photo sensing region is of a second type dopant that has a different conductivity type than the first type dopant; forming a nanostructure layer in contact with an interface between the photo sensing region and the semiconductor substrate; and etching the nanostructure layer until exposing the photo sensing region to form a plurality of nanostructures.
1. A method of forming a semiconductor device, comprising:
forming a photo sensing region in a semiconductor substrate, wherein the semiconductor substrate is of a first type dopant and the photo sensing region is of a second type dopant that has a different conductivity type than the first type dopant;
forming a nanostructure layer in contact with an interface between the photo sensing region and the semiconductor substrate; and
etching the nanostructure layer until exposing the photo sensing region to form a plurality of nanostructures.
2. The method of claim 1 , wherein forming the nanostructure layer is performed such that a material of the nanostructure layer is different from a material of the photo sensing region in the semiconductor substrate.
3. The method of claim 1 , wherein etching the nanostructure layer is performed to expose the semiconductor substrate.
4. The method of claim 1 , further comprising:
forming a dielectric layer over the nanostructures and in contact with the semiconductor substrate.
5. The method of claim 1 , further comprising:
forming a light filter layer over the nanostructures.
6. The method of claim 1 , wherein etching the nanostructure layer is performed such that the nanostructures are arranged in a hexagonal close packing arrangement.
7. The method of claim 1 , wherein etching the nanostructure layer is performed such that the nanostructures are in contact with each other.
8. The method of claim 1 , wherein the nanostructure layer comprises a silicon-containing material and the photo sensing region comprises a gallium-containing material.
9. A method of forming a semiconductor device, comprising:
forming a photo sensing region in a semiconductor substrate, wherein the semiconductor substrate is of a first type dopant and the photo sensing region is of a second type dopant that has a different conductivity type than the first type dopant;
removing portions of the photo sensing region to form a plurality of recesses;
filling a material into the recesses; and
planarizing the material until exposing the photo sensing region to form a plurality of nanostructures.
10. The method of claim 9 , wherein removing the portions of the photo sensing region comprising:
forming a photoresist layer over the photo sensing region;
patterning the photoresist layer; and
etching the photo sensing region using the patterned photoresist layer as an etch mask.
11. The method of claim 10 , wherein forming the photoresist layer is performed such that the photoresist layer is in contact with the semiconductor substrate.
12. The method of claim 9 , wherein removing portions of the photo sensing region is performed such that one of the recesses has a bottom surface, and a circle equivalent diameter of the bottom surface is about (4A/π)1/2, where A is an area of the bottom surface.
13. The method of claim 9 , wherein planarizing the material is performed such that top surfaces of the nanostructures are coplanar with a top surface of the photo sensing region.
14. The method of claim 9 , further comprising:
forming a dielectric layer over the nanostructures and in contact with the semiconductor substrate.
15. The method of claim 9 , wherein removing portions of the photo sensing region is performed such that the recesses are arranged in a hexagonal close packing arrangement.
16. A method of forming a semiconductor device, comprising:
forming a photo sensing region in a semiconductor substrate, wherein the semiconductor substrate is of a p-type dopant and the photo sensing region is of a n-type dopant;
forming a nanostructure layer above the photo sensing region, wherein a width of the nanostructure layer is wider than a width of the photo sensing region;
etching the nanostructure layer to form a plurality of nanostructures; and
forming a light filter layer over the nanostructures.
17. The method of claim 16 , further comprising:
forming a dielectric layer over the nanostructures prior to forming the light filter layer.
18. The method of claim 17 , wherein etching the nanostructure layer is performed until exposing the semiconductor substrate.
19. The method of claim 16 , further comprising:
forming a microlens layer over the light filter layer.
20. The method of claim 16 , wherein forming the nanostructure layer is performed such that a material of the nanostructure layer is different from a material of the photo sensing region in the semiconductor substrate.