Photodiode structures

Patent metadata

Field	Value
Publication number	US-10896992-B2
Application number	US-201916531649-A
Country	US
Kind code	B2
Filing date	Aug 5, 2019
Priority date	Sep 11, 2014
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

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.

First claim

What is claimed:

1. A method, comprising:
forming a waveguide structure in a dielectric material and which is located above metal wirings;
forming a single crystalline Ge structure formed in the dielectric material and separated from the waveguide structure in the dielectric material by a barrier layer directly in contact with both the single crystalline Ge structure and the waveguide structure and completely separating the single crystalline Ge structure from the waveguide structure; and
forming lined vias and trenches in the dielectric material, over the single crystalline Ge structure, wherein the lined vias and trenches includes a seed layer and filled with a metal material.

2. The method of claim 1 , further comprising forming at least one metal filled via in electrical contact with the single crystalline Ge structure, and at least one capping layer between the at least one metal filled via and the single crystalline Ge structure.

3. The method of claim 1 , wherein the single crystalline Ge structure is adjacent to the waveguide structure.

4. The method of claim 1 , wherein the single crystalline Ge structure is a photodetector above the waveguide structure.

5. The method of claim 1 , wherein the single crystalline Ge structure is a photodetector adjacent the waveguide structure.

6. The method of claim 1 , wherein the barrier layer is between the single crystalline Ge structure and the waveguide structure.

7. The method of claim 6 , wherein the barrier layer is nitride.

8. The method of claim 1 , wherein the single crystalline Ge structure includes nucleation sites.

9. The method of claim 8 , wherein the nucleation sites include a capping layer which is in direct contact with the single crystalline Ge structure.

10. The method of claim 1 , wherein the single crystalline Ge structure is laterally offset from a center of the waveguide structure.

11. The method of claim 10 , wherein the barrier layer separates the single crystalline Ge structure and the waveguide structure from one another such that there is no contact.

12. The method of claim 1 , further comprising forming a boundary layer within the single crystalline Ge structure.

13. The method of claim 12 , wherein the boundary layer within the single crystalline Ge structure is provided away from and not over the waveguide structure.

14. A method, comprising:
forming a waveguide structure in a dielectric material and which is located above metal wirings;
forming a single crystalline Ge structure formed in the dielectric material and separated from the waveguide structure in the dielectric material; and
forming a boundary layer within the single crystalline Ge structure which is provided away from and not over the waveguide structure;
wherein the single crystalline Ge structure includes nucleation sites which include a capping layer which is in direct contact with both the single crystalline Ge structure and at least one metal filled via.

15. The method of claim 14 , wherein the at least one metal filled via is two metal filled vias which are in electrical contact with the capping layer of the single crystalline Ge structure.

16. The method of claim 15 , wherein the two metal filled vias are 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 method of claim 14 , further comprising forming a barrier layer directly in contact with both the single crystalline Ge structure and the waveguide structure.

18. The method of claim 17 , wherein the barrier layer completely separates the single crystalline Ge structure from the waveguide structure such that there is no contact between the single crystalline Ge structure and the waveguide structure.

Assignees

• IBM

Inventors

• Ellis-Monaghan John J
• Gambino Jeffrey P
• Jaffe Mark D
• Peterson Kirk D

Classifications

• H10W44/216

  Waveguides, e.g. strip lines · CPC title

• H10F77/933

  for devices having potential barriers · CPC title

• H10F77/413

  directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42) · CPC title

• H10F77/122

  comprising only Group IV materials · CPC title

• H10F71/131

  Recrystallisation; Crystallization of amorphous or microcrystalline semiconductors · CPC title