Group VI metal deposition process
Provided is a process for the vapor deposition of molybdenum or tungsten, and the use of molybdenum hexacarbonyl (Mo(CO) 6 ) or tungsten hexacarbonyl (W(CO) 6 ) for such deposition, e.g., in the manufacture of semiconductor devices in which molybdenum-containing or tungsten-containing films are desired. In accordance with one aspect of the invention, molybdenum hexacarbonyl (Mo(CO) 6 ) has been found in vapor deposition processes such as chemical vapor deposition (CVD) to provide low resistivity, high deposition rate films in conjunction with a pulsed deposition process in which a step involving a brief pulse of H 2 O is utilized. This pulsing with H 2 O vapor was found to be effective in reducing the carbon content of films produced from Mo(CO) 6 -based CVD processes.
1. A process for forming a molybdenum-containing material or a tungsten-containing material on a substrate, comprising contacting the substrate with Mo(CO) 6 or W(CO) 6 , respectively, under pulsed vapor deposition conditions, wherein the pulsed vapor deposition conditions comprise:
(i) exposure of the substrate to Mo(CO) 6 or W(CO) 6 ;
(ii) exposure of the substrate to an oxidizing gas; and
(iii) exposure of the substrate to a reducing gas, and
wherein the molybdenum-containing material or tungsten containing material has a lower resistivity than material deposited without exposure of the substrate to the oxidizing gas and wherein gases used during exposure of the substrate to the oxidizing gas consist essentially of one or more oxidizing gases and optionally one or more inert gases.
2. The process of claim 1 , wherein the substrate is chosen from titanium nitride, tantalum nitride, aluminum nitride, aluminum oxide, zirconium oxide, hafnium oxide, silicon dioxide, silicon nitride, lanthanum oxide, ruthenium oxide, iridium oxide, niobium oxide, and yttrium oxide.
3. The process of claim 1 , wherein the exposure of the substrate to Mo(CO) 6 is conducted at a temperature of from about 250° to about 750° C.
4. The process of claim 1 , wherein the exposure of the substrate to W(CO) 6 is conducted at a temperature of from about 250° to about 750° C.
5. The process of claim 1 , wherein the one or more oxidizing gases are selective from the group consisting of H 2 O vapor, H 2 O 2 , O 3 , and N 2 O.
6. The process of claim 1 , wherein the reducing gas is comprised of gases chosen from H 2 , hydrazine, methyl hydrazine, t-butyl hydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, and NH 3 .
7. The process of claim 1 , wherein the reducing gas is H 2 and the temperature is about 300 to about 600° C.
8. The process of claim 1 , wherein the reducing gas comprises H 2 .
9. The process of claim 1 , wherein the oxidizing gas comprises H 2 O vapor.
10. The process of claim 1 , wherein the duration of (i) is about 100 microseconds to about 1 second.
11. The process of claim 1 , wherein the duration of (i) is about 0.15 to about 0.35 seconds.
12. The process of claim 1 , wherein the duration of (ii) is about 0.5 to about 3 seconds.
13. The process of claim 1 , wherein the duration of (ii) is about 0.8 to about 1.2 seconds.
14. The process of claim 1 , wherein the duration of (iii) is about 50 to about 200 seconds.
15. A process for forming a molybdenum-containing material on a substrate, wherein the substrate is chosen from titanium nitride, tantalum nitride, aluminum nitride, aluminum oxide, zirconium oxide, hafnium oxide, silicon dioxide, silicon nitride, lanthanum oxide, ruthenium oxide, iridium oxide, niobium oxide, and yttrium oxide, comprising contacting the substrate with Mo(CO) 6 , under pulsed vapor deposition conditions, wherein the pulsed vapor deposition conditions comprise:
(i) exposure of the substrate to Mo(CO) 6 for a period of about 100 microseconds to about one second;
(ii) exposure of the substrate to H 2 O vapor for a period of about 0.8 to about 1.2 seconds; and
(iii) exposure of the substrate to hydrogen gas for a period of about 75 seconds to about 125 seconds, and
the molybdenum-containing material is molybdenum metal and wherein the water vapor is mixed only with one or more inert gases.
16. The process of claim 15 , wherein (i), (ii), and (iii) are repeated until a desired thickness of a molybdenum-containing material has been deposited on the substrate.