Controlling oxygen concentration levels during processing of highly-reflective contacts
View Patent ↗Techniques for controlling oxygen concentration levels during annealing of highly-reflective contacts for LED devices together with lamps, LED device and method embodiments thereto are disclosed.
1. A method for controlling oxygen concentration levels of reflective and electrically conductive Ag-based contacts of an optoelectronic semiconductor device, the method comprising:
depositing a metallic stack on a semiconductor plane of the optoelectronic semiconductor device, the stack comprising at least one silver layer and at least one layer of an oxygen-gettering metal;
introducing a predetermined dose of oxygen into the metallic stack; and
annealing the optoelectronic semiconductor device to diffuse the oxygen-gettering metal to interfaces of the semiconductor plane and the metallic stack, wherein the oxygen is diffused to the interface.
2. The method of claim 1 , wherein the oxygen-gettering metal is nickel.
3. The method of claim 1 , wherein the dose of oxygen is introduced by flowing a controlled amount of oxygen into an annealing chamber during the annealing step.
4. The method of claim 1 , wherein the oxygen is introduced by applying an oxygen-containing chemical onto the metallic stack.
5. The method of claim 1 , wherein the oxygen is introduced by applying an oxygen-depositing treatment onto the metallic stack.
6. The method of claim 1 , wherein the oxygen is introduced during a metal stack deposition step.
7. The method of claim 1 , wherein the metallic stack comprises a first silver layer, and at least a nickel layer formed on top of the silver layer.
8. The method of claim 7 , further comprising a second silver layer formed on top of the at least one nickel layer.
9. The method of claim 1 , further comprising controlling a timing and a rate of release of a controlled amount of the dose of oxygen.
10. The method of claim 1 , further comprising depositing a layer of titanium on top of the metal stack.
11. The method of claim 1 , wherein the semiconductor comprises a gallium and nitrogen-containing semiconductor material.
12. The method of claim 1 , further comprising performing an electrical measurement on the optoelectronic semiconductor device to determine effects of the oxygen dose.
13. The method of claim 1 , wherein the fraction of the oxygen-gettering metal and of the oxygen form a metal oxide at the at least one interface.
14. A method for controlling oxygen concentration levels of reflective and electrically conductive Ag-based contacts of an optoelectronic semiconductor device, comprising:
providing a gallium and nitrogen-containing semiconductor device;
depositing a first silver layer on at least one surface of the semiconductor;
depositing a nickel layer on the first silver layer;
depositing a second silver layer on the nickel layer; and
annealing the device in an oxygen-containing ambient environment to introduce a predetermined dose of oxygen into the optoelectronic semiconductor device and to diffuse at least a portion of nickel in the nickel layer and the oxygen through the first silver layer to the at least one surface.
15. A method for forming a reflective and electrically conductive Ag-based electrical contact on an optoelectronic semiconductor device, the method comprising:
depositing an electrical contact metal stack on a semiconductor plane of the device for powering the device, the stack comprising at least one silver layer and at least one layer of an oxygen-gettering metal;
introducing a predetermined dose of oxygen into the stack; and
annealing the device to diffuse at least a portion of the oxygen-gettering metal and the oxygen to at least one interface of the semiconductor plane and the stack.
16. The method of claim 15 , wherein the optoelectronic device is a light-emitting diode.
17. The method of claim 15 , wherein the oxygen-gettering metal is nickel.
18. The method of claim 15 , wherein the oxygen is introduced by applying an oxygen-depositing treatment to the stack.
19. The method of claim 15 , wherein the metal stack comprises a first silver layer, a nickel layer formed on top of the silver layer, and a second silver layer formed on top of the nickel layer.
20. The method of claim 15 , further comprising controlling a timing and rate of release of a controlled dose of oxygen.
21. The method of claim 15 , wherein the semiconductor comprises a gallium and nitrogen-containing semiconductor material.
22. The method of claim 15 , wherein the fraction of the oxygen-gettering metal and of the oxygen form a metal oxide at the at least one interface.