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 cobalt film deposition process comprising:
volatilizing a 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 H and R 4 is —CF 3 to form precursor vapor, wherein the precursor or precursor composition has a viscosity between 1 centipoise and 40 centipoise; and,
depositing the precursor vapor on a substrate in a chamber to form a deposited cobalt film,
wherein the substrate is at a temperature in a range of from 50° C. to 250° C. during deposition, the asymmetric haloalkynyl dicobalt hexacarbonyl precursor has a temperature in the range of from 18° C. to 35° C. during the volatization, the deposited cobalt film contains less than 5 atomic % carbon and less than 3 atomic % oxygen, and the precursor or precursor composition has a molecular purity of the bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursor of 99% or greater.
2. The process of claim 1 , wherein the precursor vapor is deposited at a pressure in a in range of from 0.01 Torr to 100 Torr in the chamber.
3. The process of claim 1 , wherein the asymmetric haloalkynyl dicobalt hexacarbonyl precursor has a temperature in the range of from 20° C. to 23° C. during the volatization.
4. The process of claim 1 , wherein the deposited cobalt film has a resistivity measured at room temperature of 100 μQ-cm or less and the film has a thickness of 100 angstroms or less.
5. The process of claim 1 , wherein the substrate is a semiconductor product.
6. The process of claim 1 , wherein the precursor or precursor composition further comprises a solvent to form a solvent solution of the bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursor, the solvent solution comprising in the range of from 0.05 M to 0.5 M bridging asymmetric haloalkynyl dicobalt hexacarbonyl precursor.
7. The process of claim 6 , wherein the solvent comprises a hydrocarbon solvent.
8. The process of claim 1 , wherein the precursor or precursor composition is packaged in a container for subsequent use in a vapor deposition process.
9. The process of claim 1 , wherein the precursor or precursor composition is sealed in an ampoule configured to maintain an inert atmosphere and having connections and valves to enable mounting to a gas manifold, vaporizer, or bubbler.
10. The process of claim 1 , wherein the precursor or precursor composition is volatilized at room temperature.