Method for the removal of airborne molecular contaminants using water gas mixtures
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 the steps of:
providing a purified purge gas, wherein the purified purge gas comprises water at a concentration of at least about 100 parts per million (ppm) on a volume basis, the purified purge gas having an AMC concentration less than about 1 part per billion (ppb) on a volume basis;
contacting at least a portion of the substrate with the purified purge gas;
producing a contaminated purge gas by transferring AMC from the substrate into the purified purge gas; 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 100 parts per trillion (ppt) on a volume basis.
3. The method as in claim 1 , wherein the AMC concentration of the purified purge gas is less than about 10 ppt AMC on a volume basis.
4. The method as in claim 1 , wherein the AMC concentration of the purified purge gas is less than about 1 ppt AMC on a volume basis.
5. The method as in claim 1 , wherein the water comprises 100 ppm to 2% by volume.
6. The method as in claim 1 further comprising purging of the substrate with an inert gas after removing said contaminated purge gas from said substrate.
7. The method as in claim 1 , wherein the substrate is enclosed within a chamber.
8. The method as in claim 1 , wherein said contacting of said substrate with said purified purge gas removes said AMC from said substrate at a faster rate than using a nitrogen purge gas.
9. The method as in claim 6 , wherein said inert gas is selected from the group consisting of nitrogen, argon, noble gases and methane.
10. The method as in claim 7 , wherein the substrate includes at least one silicon substrate.
11. The method as in claim 7 , wherein the substrate includes a wafer.