Photodiode structures
Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.
1. A structure, comprising:
a waveguide structure and metal wiring layers in a dielectric material;
a single crystalline Ge structure formed in the dielectric material and-separated from the waveguide structure in the dielectric material; and
at least one metal filled via in electrical contact with the single crystalline Ge structure; and
lined vias and trenches in the dielectric material, over the single crystalline Ge structure, wherein the lined vias and trenches is a nickel seed layer.
2. The structure of claim 1 , wherein at least one capping layer is between the at least one metal filled via and the single crystalline Ge structure.
3. The structure of claim 1 , wherein the single crystalline Ge structure is adjacent to the waveguide structure.
4. The structure of claim 1 , wherein the single crystalline Ge structure is a photodector above the waveguide structure.
5. The structure of claim 1 , wherein the single crystalline Ge structure is a photodector adjacent the waveguide structure.
6. The structure of claim 1 , wherein further comprising a barrier layer between the single crystalline Ge structure and the waveguide structure.
7. The structure of claim 6 , wherein the barrier layer is nitride.
8. The structure of claim 1 , wherein the single crystalline Ge structure includes nucleation sites.
9. The structure of claim 8 , wherein the nucleation sites include a capping layer which is in direct contact with both the single crystalline Ge structure and the at least one metal filled via.
10. The structure of claim 1 , wherein the lined vias and trenches are filled with metal material.
11. A structure, comprising:
a waveguide structure and metal wiring layers in a dielectric material;
a single crystalline Ge structure formed in the dielectric material and-separated from the waveguide structure in the dielectric material;
at least one metal filled via in electrical contact with the single crystalline Ge structure; and
lined vias and trenches in the dielectric material, over the single crystalline Ge structure, wherein:
the lined vias and trenches is germanides;
the single crystalline Ge structure includes nucleation sites;
the nucleation sites include a capping layer which is in direct contact with both the single crystalline Ge structure and the at least one metal filled via; and
the capping layer is NiGe, using Ni as a seed layer.
12. The structure of claim 1 , further comprising a boundary layer in the single crystalline Ge structure.
13. The structure of claim 6 , wherein:
the single crystalline Ge structure is laterally offset from a center of the waveguide structure; and
the barrier layer separates the single crystalline Ge structure and the waveguide structure from one another such that there is no contact.
14. The structure of claim 13 , wherein the waveguide structure is composed of Si.
15. The structure of claim 13 , further comprising a boundary layer in the single crystalline Ge structure and on a side of the waveguide structure.
16. A structure, comprising:
a waveguide structure and metal wiring layers in a dielectric material;
a single crystalline Ge structure formed in the dielectric material and-separated from the waveguide structure in the dielectric material;
at least one metal filled via in electrical contact with the single crystalline Ge structure; and
a barrier layer between the single crystalline Ge structure and the waveguide structure,
wherein:
the single crystalline Ge structure is laterally offset from a center of the waveguide structure;
the barrier layer separates the single crystalline Ge structure and the waveguide structure from one another such that there is no contact; and
the at least one metal filled via is two metal filled vias in electrical contact with a capping layer of the single crystalline Ge structure, the two metal filled vias being dual damascene structures offset from a center of the waveguide structure such that they do not interfere with light entering the waveguide structure.
17. The structure of claim 1 , wherein the waveguide structure is composed of nitride material.