Planar avalanche photodiode
View Patent ↗The present invention includes a planar avalanche photodiode having a first n-type semiconductor layer defining a planar contact area, and a second n-type semiconductor layer having a p-type diffusion region. Further features of the structure includes an n-type semiconductor multiplication layer, an n-type semiconductor absorption layer, and a p-type contact layer. Further embodiments include a planar avalanche photodiode having a first n-type semiconductor layer defining a planar contact area, an n-type semiconductor multiplication layer, an n-type semiconductor absorption layer and a p-type semiconductor layer electrically coupled to a p-type contact layer.
1. A planar avalanche photodiode comprising:
an n-type semiconductor layer defining a contact area;
a semiconductor layer having a p-type diffusion region, the p-type diffusion region having a smaller area than the semiconductor layer;
a semiconductor multiplication layer;
a semiconductor absorption layer;
a p-type contact layer;
wherein the p-type diffusion region is disposed directly adjacent to the p-type contact layer and the semiconductor absorption layer is disposed between the semiconductor multiplication layer and the semiconductor layer with the p-type diffusion region; and
at least one grading layer disposed adjacent to the semiconductor absorption layer.
2. The planar avalanche photodiode of claim 1 further comprising a p-type semiconductor charge control layer disposed adjacent to the semiconductor multiplication layer.
3. The planar avalanche photodiode of claim 1 a further comprising at least one n-type contact layer.
4. The planar avalanche photodiode of claim 1 wherein the n-type semiconductor layer is InAlAs.
5. The planar avalanche photodiode of claim 1 wherein the semiconductor layer with the p-type diffusion layer is InAlAs.
6. The planar avalanche photodiode of claim 1 wherein the semiconductor multiplication layer is InAlAs.
7. The planar avalanche photodiode of claim 1 wherein the semiconductor absorption layer is InGaAs.
8. A planar avalanche photodiode comprising:
an n-type semiconductor layer defining a contact area;
a semiconductor multiplication layer;
a semiconductor absorption layer, the semiconductor multiplication layer being disposed between the first n-type semiconductor layer and the semiconductor absorption layer;
a p-type semiconductor contact layer having a smaller area than the absorption layer, the semiconductor absorption layer being disposed between the semiconductor multiplication layer and the p-type semiconductor contact layer;
wherein the photodiode has a low field region near the p-type semiconductor contact layer and a low capacitance at least one grading layer disposed adjacent to the semiconductor absorption layer; and
at least one grading layer disposed adjacent to the semiconductor absorption layer.
9. The planar avalanche photodiode of claim 8 further comprising a p-type semiconductor charge control layer disposed adjacent to the semiconductor multiplication layer.
10. The planar avalanche photodiode of claim 8 wherein the n-type semiconductor layer is InAlAs.
11. The planar avalanche photodiode of claim 8 wherein the semiconductor multiplication layer is InAlAs.
12. The planar avalanche photodiode of claim 8 wherein the semiconductor absorption layer is InGaAs.
13. The planar avalanche photodiode of claim 8 wherein the p-type semiconductor contact layer is InAlAs.
14. A planar avalanche photodiode further comprising:
an n-type semiconductor layer defining a contact area;
a semiconductor multiplication layer;
a semiconductor absorption layer, the semiconductor multiplication layer being disposed between the first n-type semiconductor layer and the semiconductor absorption layer;
a p-type semiconductor contact layer having a smaller area than the absorption layer, the semiconductor absorption layer being disposed between the semiconductor multiplication layer and the p-type semiconductor contact layer;
wherein the photodiode has a low field region near the p-type semiconductor contact layer and a low capacitance at least one grading layer disposed adjacent to the semiconductor absorption layer; and
a passivated region including a semiconductor layer disposed between the p-type contact layer and the semiconductor absorption layer.
15. The planar avalanche photodiode of claim 14 wherein the passivated region includes a portion of a first grading layer and a portion of the semiconductor absorption and multiplication layers.