Semiconductor structure and manufacturing method thereof
A semiconductor structure including a substrate, a light sensing device and a light-guiding structure is provided. The light sensing device is disposed in the substrate. The light-guiding structure is located above the light sensing device. The light-guiding structure has a top surface and a bottom surface opposite to each other, and the bottom surface is closer to the substrate than the top surface. A position of a minimum width of the light-guiding structure is located between the top surface and the bottom surface.
1. A semiconductor structure, comprising:
a substrate;
a light sensing device, disposed in the substrate; and
a light-guiding structure, located above the light sensing device, having a top surface and a bottom surface opposite to each other, wherein the bottom surface is closer to the substrate than the top surface and a position of a minimum width of the light-guiding structure is located between the top surface and the bottom surface.
2. The semiconductor structure as recited in claim 1 , wherein the light-guiding structure is aligned to the light sensing device.
3. The semiconductor structure as recited in claim 1 , wherein a material of the light-guiding structure comprises a negative photoresist.
4. The semiconductor structure as recited in claim 1 , wherein a width of the top surface and a width of the bottom surface are respectively larger the minimum width.
5. The semiconductor structure as recited in claim 1 , wherein a distance between the position of the minimum width and the bottom surface is ⅓ to ⅔ of a height of the light-guiding structure.
6. The semiconductor structure as recited in claim 1 , wherein a shape of the light-guiding structure comprises an hourglass shape.
7. The semiconductor structure as recited in claim 1 , wherein the light-guiding structure comprises a light-guiding pillar.
8. The semiconductor structure as recited in claim 1 , wherein a ratio of height to width of the light-guiding structure is 5 to 15.
9. The semiconductor structure as recited in claim 1 , wherein a height of the light-guiding structure is 90 microns to 135 microns.
10. The semiconductor structure as recited in claim 1 , wherein the minimum width of the light-guiding structure is 9 microns to 15 microns.
11. The semiconductor structure as recited in claim 1 , further comprising:
a dielectric layer, disposed on the substrate, wherein the light-guiding structure is disposed on the dielectric layer; and
a plurality of metal patterns, disposed in the dielectric layer, wherein the metal patterns have a gap therebetween and the gap is aligned to the light sensing device.
12. A manufacturing method for semiconductor structure, comprising:
providing a substrate;
forming a light sensing device in the substrate; and
forming a light-guiding structure above the light sensing device, wherein the light-guiding structure has a top surface and a bottom surface opposite to each other, the bottom surface is closer to the substrate than the top surface, and a position of a minimum width of the light-guiding structure is located between the top surface and the bottom surface.
13. The manufacturing method for semiconductor structure as recited in claim 12 , wherein the step of forming the light-guiding structure comprises performing a lithographic process and the lithographic process comprises a photoresist coating process, a light exposure process and an developing process.
14. The manufacturing method for semiconductor structure as recited in claim 13 , wherein a focusing position of the light exposure process is located between the top surface and the bottom surface.
15. The manufacturing method for semiconductor structure as recited in claim 14 , wherein the position of the minimum width is located at the focusing position.
16. The manufacturing method for semiconductor structure as recited in claim 14 , wherein a distance between the focusing position and the bottom surface is ⅓ to ⅔ of a height of the light-guiding structure.
17. The manufacturing method for semiconductor structure as recited in claim 13 , wherein a rotation speed of the developing process is 850 rpm to 2000 rpm.
18. The manufacturing method for semiconductor structure as recited in claim 13 , wherein a developing time of the developing process is 6 minutes to 15 minutes.
19. The manufacturing method for semiconductor structure as recited in claim 12 , wherein the light-guiding structure is aligned to the light sensing device.
20. The manufacturing method for semiconductor structure as recited in claim 12 , further comprising:
forming a dielectric layer on the substrate, wherein the light-guiding structure is disposed on the dielectric layer; and
forming a plurality of metal patterns in the dielectric layer, wherein the metal patterns have a gap therebetween and the gap is aligned to the light sensing device.