Haloalkynyl dicobalt hexacarbonyl precursors for chemical vapor deposition of cobalt
The present disclosure relates to a bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursors, and ultra high purity versions thereof, methods of making, and methods of using these bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursors in a vapor deposition process. One aspect of the disclosure relates to an ultrahigh purity bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursor of the formula Co 2 (CO) 6 (R 3 C≡CR 4 ), where R 3 and R 4 are different organic moieties and R 4 is more electronegative or more electron withdrawing compared to R 3 .
1. A precursor or precursor composition for a vapor deposition process of a cobalt film, the precursor or precursor composition comprising:
a bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursor of formula Co 2 (CO) 6 (R 3 C≡CR 4 ), wherein R 3 is a hydrogen and R 4 is a —C 2 F 5 or —C 6 F 5 ,
where the precursor or precursor composition has a viscosity between about 1 centipoise to about 40 centipoise.
2. A precursor or precursor composition according to claim 1 , wherein R 4 is —C 2 F 5 .
3. A precursor or precursor composition according to claim 1 , wherein R 4 is —C 6 F 5 .
4. A precursor or precursor composition according to claim 1 , further comprising a solvent.
5. A precursor or precursor composition according to claim 4 , wherein the solvent is a hydrocarbon.
6. A precursor or precursor composition according to claim 1 , wherein the precursor has a boiling point in the range of from 50° C. to 100° C.
7. A precursor or precursor composition according to claim 1 having a molecular purity of the bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursor of 99% or greater.
8. A bubbler comprising the precursor or precursor composition of claim 1 .
9. A method of depositing a cobalt film comprising:
bubbling a carrier gas through the precursor or precursor composition of claim 1 ; and
depositing cobalt from the precursor or precursor composition onto a substrate.
10. The method of claim 9 , wherein the carrier gas is an inert gas.
11. The method of claim 9 , wherein the substrate is from 50° C. to 250° C.
12. The method of claim 9 , wherein the deposited cobalt contains less than 5 atomic % carbon and less than 3 atomic % oxygen.
13. The method of claim 9 , wherein depositing cobalt is performed at a reaction chamber pressure in the range of from 0.01 Torr to 100 Torr.
14. The method of claim 9 , wherein depositing cobalt is accompanied by a flow of reactant or reactive gas.