Pretreatment of transparent conductive oxide (TCO) thin films for improved electrical contact
Certain embodiments relate to optical devices and methods of fabricating optical devices that pre-treat a sub-layer to enable selective removal of the pre-treated sub-layer and overlying layers. Other embodiments pertain to methods of fabricating an optical device that apply a sacrificial material layer.
1. A method of fabricating an optical device, the method comprising, in the following order:
(a) exposing a sub-layer of the optical device to an energy source, wherein exposing the sub-layer to the energy source increases absorptive properties of the sub-layer;
(b) depositing one or more material layers of the optical device on the sub-layer; and
(c) ablating the one or more material layers and the sub-layer with a laser to expose an underlying layer.
2. The method of claim 1 , wherein the underlying layer is a lower conductor layer.
3. The method of claim 1 , wherein exposing the sub-layer to the energy source in (a) also decreases absorptive properties of the underlying layer.
4. The method of claim 1 , wherein (a) is performed on a portion of the sub-layer and (c) is performed on substantially the same portion of the sub-layer.
5. The method of claim 1 , wherein the energy source used in (a) is one of the laser used in (c), another laser, or a plasma.
6. The method of claim 1 , wherein the sub-layer comprises a metal oxide, a metal nitride, a metal carbide, a metal oxynitride, or a metal oxycarbide.
7. The method of claim 1 , wherein the sub-layer comprises TiO 2 .
8. The method of claim 1 , wherein the sub-layer comprises a metal oxide selected from the group consisting of aluminum oxide, titanium oxide, TiO 2 , tantalum oxide, cerium oxide, zinc oxide, tin oxide, silicon aluminum oxide, tungsten oxide, nickel tungsten oxide, and oxidized indium tin oxide.
9. The method of claim 1 , wherein the sub-layer comprises a metal nitride selected from the group consisting of titanium nitride, aluminum nitride, silicon nitride, tantalum nitride, and tungsten nitride.
10. The method of claim 1 , wherein the sub-layer comprises a metal carbide selected from the group consisting of titanium carbide, aluminum carbide, silicon carbide, tantalum carbide, and tungsten carbide.
11. The method of claim 1 , wherein (b) comprises forming an electrochromic device stack on the sub-layer.
12. The method of claim 11 , wherein the electrochromic device stack comprises a WO 3 electrochromic layer and a nickel-based counter electrode layer.
13. The method of claim 12 , wherein the nickel-based counter electrode layer comprises NiWO or NiTaO.
14. The method of claim 1 , wherein the optical device is an electrochromic device.
15. The method of claim 14 , wherein the underlying layer is a lower conductor layer of the electrochromic device, and wherein the sub-layer is on top of and directly adjacent to the lower conductor layer of the electrochromic device.
16. The method of claim 15 , further comprising fabricating a bus bar on the lower conductor layer exposed in (c).
17. The method of claim 14 , wherein the underlying layer is a lower conductor layer of the electrochromic device, and wherein the lower conductor layer comprises tin oxide.
18. The method of claim 1 , wherein exposing the sub-layer to the energy source heats a portion of the sub-layer to more than 400° C.
19. The method of claim 1 , wherein the energy source is an atmospheric-pressure plasma comprising at least one of O 2 and N 2 /H 2 .
20. A method of fabricating an optical device, the method comprising, in the following order:
(a) exposing a sub-layer of the optical device to an energy source;
(b) depositing one or more material layers of the optical device on the sub-layer; and
(c) ablating the one or more material layers and the sub-layer with a laser to expose an underlying layer,
wherein exposing the sub-layer to the energy source in (a) changes properties of the sub-layer and the underlying layer so that the sub-layer has higher absorptive properties relative to the underlying layer.
21. The method of claim 20 , wherein the underlying layer is a lower conductor layer.
22. The method of claim 20 , wherein (a) is performed on a portion of the sub-layer and (c) is performed on substantially the same portion of the sub-layer.
23. The method of claim 20 , wherein the energy source used in (a) is one of the laser used in (c), another laser, or a plasma.
24. The method of claim 20 , wherein the sub-layer comprises a metal oxide, a metal nitride, a metal carbide, a metal oxynitride, or a metal oxycarbide.
25. The method of claim 20 , wherein the sub-layer comprises TiO 2 .
26. The method of claim 20 , wherein the sub-layer comprises a metal oxide selected from the group consisting of aluminum oxide, titanium oxide, TiO 2 , tantalum oxide, cerium oxide, zinc oxide, tin oxide, silicon aluminum oxide, tungsten oxide, nickel tungsten oxide, and oxidized indium tin oxide.
27. The method of claim 20 , wherein the sub-layer comprises a metal nitride selected from the group consisting of titanium nitride, aluminum nitride, silicon nitride, tantalum nitride, and tungsten nitride.
28. The method of claim 20 , wherein the sub-layer comprises a metal carbide selected from the group consisting of titanium carbide, aluminum carbide, silicon carbide, tantalum carbide, and tungsten carbide.
29. The method of claim 20 , wherein (b) comprises forming an electrochromic device stack on the sub-layer.
30. The method of claim 29 , wherein the electrochromic device stack comprises a WO 3 electrochromic layer and a nickel-based counter electrode layer.
31. The method of claim 30 , wherein the nickel-based counter electrode layer comprises NiWO or NiTaO.
32. The method of claim 20 , wherein the optical device is an electrochromic device.
33. The method of claim 32 , wherein the underlying layer is a lower conductor layer of the electrochromic device, and wherein the sub-layer is on top of and directly adjacent to the lower conductor layer of the electrochromic device.