Method for the removal of airborne molecular contaminants using oxygen gas mixtures
View Patent ↗The present invention discloses a method for the removal of a number of molecular contaminants from surfaces within a device. A purge gas containing oxygen and/or water is introduced into the interior of the device, contacting at least a portion of the interior surfaces. A contaminated purge gas is produced by transferring a portion of the contamination from the interior surfaces into the purge gas. The contaminated purge gas is removed from the device and the process is continued until the contaminant concentration in the contaminated purge gas is below a predetermined level.
1. A method for the removal of airborne molecular contaminants (AMC) from a substrate comprising:
providing a purified purge gas, wherein the purified purge gas comprises oxygen, the purified purge gas having a contaminant concentration of less than about 1 part per billion (ppb) on a volume basis of at least one of the contaminants selected from the group consisting of sulfur oxides, nitrogen oxides, Si-containing organics, organophosphates, amines, volatile bases, volatile acids, refractory compounds, volatile metal compounds, and non- methane hydrocarbons;
contacting at least a portion of the substrate with the purified purge gas at a temperature of about 20° C. to 100° C. that does not change or chemically alter the AMC, the substrate contaminated with AMC before the substrate is contacted with purified purge gas;
producing a contaminated purge gas by transferring AMC from the substrate into the purified purge gas, the contaminated purge gas including AMC from the substrate; and
removing the contaminated purge gas from the substrate; thereby removing AMC from the substrate.
2. The method as in claim 1 , wherein the steps are repeated until the contaminated purge gas has an AMC concentration below about 1 ppb AMC on a volume basis.
3. The method as in claim 1 , wherein the concentration of at least one of the contaminants in the purified purge gas is less than about 100 parts per trillion (ppt) on a volume basis.
4. The method as in claim 1 , wherein the concentration of at least one of the contaminants in the purified purge gas is less than about 10 ppt on a volume basis.
5. The method as in claim 1 , wherein the concentration of at least one of the contaminants in the purified purge gas is less than about 1 ppt on a volume basis.
6. The method as in claim 1 , wherein the substrate is enclosed within a chamber.
7. The method as in claim 1 further comprising purging of the substrate with an inert gas after removing said contaminated purge gas from the substrate.
8. The method as in claim 1 , wherein the purified purge gas is inert with respect to the AMC.
9. The method as in claim 1 , wherein the portion of the substrate and the purified purge gas are contacted at a temperature of about 20° C. to about 50° C.
10. The method as in claim 1 , wherein the portion of the substrate and the purified purge gas are contacted at a temperature of 80° C. to 100° C.
11. The method in claim 6 , wherein the substrate includes at least one silicon substrate.
12. The method as in claim 6 , wherein the substrate includes a wafer.
13. The method as in claim 7 , wherein said inert gas is selected from the group consisting of nitrogen, argon, noble gases and methane.
14. A method for the removal of airborne molecular contaminants (AMC) from a substrate comprising:
providing a purified purge gas, wherein the purified purge gas comprises oxygen at a concentration between about 1% and 25% on a volume basis and the purified purge gas has a contaminant concentration of less than about 1 part per billion (ppb) on a volume basis of at least one of the contaminants selected from the group consisting of sulfur oxides, nitrogen oxides, Si-containing organics, organophosphates, amines, volatile bases, volatile acids, refractory compounds, volatile metal compounds, and non-methane hydrocarbons;
contacting at least a portion of the substrate with the purified purge gas at a temperature of about 20° C. to 100° C. that does not change or chemically alter the AMC, the substrate contaminated with AMC before the substrate is contacted with purified purge gas;
producing a contaminated purge gas by transferring AMC from the substrate into the purified purge gas, the contaminated purge gas including AMC from the substrate; and
removing the contaminated purge gas from the substrate; thereby removing AMC from the substrate.
15. The method as in claim 14 comprising continuing the steps until the contaminated purge gas has an AMC concentration below 100 parts per trillion (ppt) on a volume basis.
16. The method as in claim 14 , wherein the concentration of at least one of the contaminants in the purified purge gas is less than 10 ppt on a volume basis.
17. The method as in claim 14 , wherein the concentration of at least one of the contaminants in the purified purge gas is less than 1 ppt on a volume basis.
18. The method as in claim 14 , wherein the substrate is enclosed within a chamber.
19. The method as in claim 14 , wherein the purified purge gas comprises oxygen at a concentration between about 17% and about 21% on a volume basis.
20. The method as in claim 14 , wherein the purified purge gas comprises extra clean dry air.
21. The method as in claim 14 , wherein the purified purge gas is inert with respect to the AMC.
22. The method as in claim 14 , wherein the portion of the substrate and the purified purge gas are contacted at a temperature of about 20° C. to about 50° C.
23. The method as in claim 14 , wherein the portion of the substrate and the purified purge gas are contacted at a temperature of 80° C. to 100° C.
24. The method as in claim 18 , wherein the substrate includes at least one silicon substrate.
25. The method as in claim 18 , wherein the substrate includes a wafer.
26. A method for the removal of airborne molecular contaminants (AMC) from a wafer comprising:
providing a purified purge gas, wherein the purified purge gas comprises oxygen, the purified purge gas having a contaminant concentration of less than about 1 part per billion (ppb) on a volume basis of at least one of the contaminants selected from the group consisting of sulfur oxides, nitrogen oxides, Si-containing organics, organophosphates, amines, volatile bases, volatile acids, refractory compounds, volatile metal compounds, and non-methane hydrocarbons;
contacting at least a portion of the wafer with the purified purge gas under temperature conditions that do not change or chemically alter the AMC, the wafer contaminated with AMC before the wafer is contacted with purified purge gas;
producing a contaminated purge gas by transferring AMC from the wafer into the purified purge gas, the contaminated purge gas including AMC from the wafer; and
removing the contaminated purge gas from the wafer; thereby removing AMC from the wafer.
27. The method as in claim 26 , wherein contacting at least a portion of the wafer with the purified purge gas includes contacting the portion of the wafer with the purified purge gas at a temperature of about 20° C. to 100° C.
28. A method for the removal of airborne molecular contaminants (AMC) from a wafer processing or wafer storage chamber comprising:
providing a purified purge gas, wherein the purified purge gas comprises oxygen, the purified purge gas having a contaminant concentration of less than about 1 part per billion (ppb) on a volume basis of at least one of the contaminants selected from the group consisting of sulfur oxides, nitrogen oxides, Si-containing organics, organophosphates, amines, volatile bases, volatile acids, refractory compounds, volatile metal compounds, and non-methane hydrocarbons;
contacting at least a portion of the wafer processing or wafer storage chamber with the purified purge gas under temperature conditions that do not change or chemically alter the AMC, the wafer processing or wafer storage chamber contaminated with AMC before the wafer processing or wafer storage chamber is contacted with purified purge gas;
producing a contaminated purge gas by transferring AMC from the wafer processing or wafer storage chamber into the purified purge gas, the contaminated purge gas including AMC from the wafer processing or wafer storage chamber; and
removing the contaminated purge gas from the wafer processing or wafer storage chamber; thereby removing AMC from the wafer processing or wafer storage chamber.
29. The method as in claim 28 , wherein contacting at least a portion of the wafer processing or wafer storage chamber with the purified purge gas includes contacting the portion of the wafer processing or wafer storage chamber with the purified purge gas at a temperature of about 20° C. to 100°.