Sputtering targets including excess cadmium for forming a cadmium stannate layer
View Patent ↗Methods are generally provided for forming a conductive oxide layer on a substrate. In one particular embodiment, the method can include sputtering a transparent conductive oxide layer (e.g., including cadmium stannate) on a substrate from a target in a sputtering atmosphere comprising cadmium. The transparent conductive oxide layer can be sputtered at a sputtering temperature greater of about 100° C. to about 600° C. Methods are also generally provided for manufacturing a cadmium telluride based thin film photovoltaic device.
1. A ceramic sputtering target for forming a conductive oxide layer on a substrate, the ceramic sputtering target comprising:
cadmium, tin, and oxygen, wherein cadmium is present in the ceramic target in a stoichiometric amount that is greater than a standard stoichiometric amount of cadmium stannate, wherein the ceramic target comprises:
Cd 2 SnO 4 +x CdO+ y CdS
where x is 0 to about 10, y is 0 to about 10, and (x+y) is greater than 0 to about 10.
2. The ceramic sputtering target as in claim 1 , wherein x is 0 to about 8, y is 0 to about 8, and (x+y) is about 2 to about 8.
3. The ceramic sputtering target as in claim 1 , comprising:
Cd 2 SnO 4 +x CdO
where x is greater than 0 to about 10.
4. The ceramic sputtering target as in claim 3 , wherein x is about 2 to about 8.
5. The ceramic sputtering target as in claim 3 , wherein y is 0.
6. The ceramic sputtering target as in claim 1 , comprising:
Cd 2 SnO 4 +y CdS
where y is greater than 0 to about 10.
7. The ceramic sputtering target as in claim 6 , wherein y is about 2 to about 8.
8. The ceramic sputtering target as in claim 6 , wherein x is 0.
9. The ceramic sputtering target as in claim 1 , consisting essentially of cadmium, tin, and oxygen.
10. The ceramic sputtering target as in claim 1 , consisting of cadmium, tin, and oxygen.
11. A metal sputtering target for forming a conductive oxide layer on a substrate, the metal target comprising:
cadmium and tin according to the formula CdxSn, where x is 4 to about 10.
12. The metal sputtering target as in claim 11 , wherein x is about 6 to about 10.
13. The metal sputtering target as in claim 11 , wherein x is about 8.
14. The metal sputtering target as in claim 11 , consisting essentially of cadmium and tin.
15. The metal sputtering target as in claim 11 , consisting of cadmium and tin.