High density photodiodes
View Patent ↗The present invention is a front-side contact, back-side illuminated (FSC-BSL) photodiode arrays and front-side illuminated, back-side contact (FSL-BSC) photodiode arrays having improved characteristics, including high production throughput, low-cost manufacturing via implementation of batch processing techniques; uniform, as well as high, photocurrent density owing to presence of a large continuous homogeneous, heavily doped layer; and back to front intrachip connections via the homogenous, heavily doped layers on the front and back sides of the substrate.
1. A photodiode, having an incident light receiving side and a side opposing the incident light receiving side, comprising:
a substrate having a V-shaped groove positioned between the incident light receiving side and the side opposing the incident light receiving side, wherein the V-shaped groove is defined by a first inclined side and a second inclined side, wherein said first inclined side and said second inclined side intersect at a point;
a first doped region positioned at said point, wherein said first doped region is in electrical communication with a metal contact;
a second doped region positioned along the first inclined side and in physical communication with said first doped region; and
a third doped region positioned along the second inclined side and in physical communication with said first doped region, wherein each of said first, second and third doped region are of the same conductivity type and wherein the first, second, and third doped region form a continuous electrical connection between said incident light receiving side and said side opposing the incident light receiving side.
2. The photodiode of claim 1 wherein the conductivity type is p-type.
3. The photodiode of claim 1 wherein the second doped region is positioned along the first inclined side and further extends along a portion of the side opposing the incident light receiving side.
4. The photodiode of claim 1 wherein the third doped region is positioned along the second inclined side and further extends along a portion of the side opposing the incident light receiving side.
5. The photodiode of claim 1 wherein said V-shaped groove divides the photodiode into a first region and a second region.
6. The photodiode of claim 5 , wherein the first region comprises a fourth doped region of a second conductivity type proximate to said incident light receiving side.
7. The photodiode of claim 6 wherein said second conductivity type is a n-type.
8. The photodiode of claim 5 , wherein the second region comprises a fourth doped region of a second conductivity type proximate to said incident light receiving side.
9. The photodiode of claim 7 wherein said second conductivity type is a n-type.
10. A photodiode, having an incident light receiving side and a side opposing the incident light receiving side, comprising:
a substrate having a V shaped groove positioned between the incident light receiving side and the side opposing the incident light receiving side, wherein the V-shaped groove is defined by a first inclined side and a second inclined side, wherein said first inclined side and said second inclined side meet at a point;
a first doped region positioned at said point;
a second doped region positioned along the first inclined side and in physical communication with said first doped region; and
a third doped region positioned along the second inclined side and in physical communication with said first doped region, wherein each of said first, second and third doped region are of the same conductivity type and wherein the first, second, and third doped region form a continuous electrical connection between said incident light receiving side and said side opposing the incident light receiving side.
11. The photodiode of claim 10 further comprising at least one passivation layer on the incident light receiving side of the substrate.
12. The photodiode of claim 10 further comprising at least one passivation layer on the side opposing the incident light receiving side of the substrate.
13. The photodiode of claim 10 further comprising at least one anti-reflective layer on the incident light receiving side.
14. The photodiode of claim 10 further comprising at least one anti-reflective layer on the side opposing the incident light receiving side of the substrate.
15. The photodiode of claim 10 further comprising a plurality of contact electrodes in electrical communication with at least one of said doped regions.
16. The photodiode of claim 10 wherein the impurity of each of said first, second, and third doped regions is p-type.