Storage and delivery vessels and related methods
Described are methods, systems, and apparatus for processing a gas mixture that contains at least two gases by contacting the gas mixture with a membrane that allows for preferential flow of one of the gases through the membrane, to separate one constituent gas from the mixture.
1 . A method of processing a stored gas mixture contained in a storage vessel, the stored gas mixture comprising reagent gas and diluent gas, the method comprising:
contacting the stored gas mixture with a separation membrane that allows preferential flow of the diluent gas through the separation membrane relative to the reagent gas;
allowing a portion of the diluent gas of the stored gas mixture to flow through the separation membrane to produce a concentrated reagent gas having an increased concentration of the reagent gas compared to the stored gas mixture; and
removing diluent gas from the storage vessel, through the separation membrane, to produce the concentrated reagent gas within the storage vessel.
2 . The method of claim 1 , the separation membrane having a permeate side and a retentate side, the method comprising:
contacting the stored gas mixture with the retentate side, at a retentate-side pressure, and
applying a permeate-side pressure to the permeate side, the permeate-side pressure being lower than the retentate-side pressure, to cause diluent gas to flow through the membrane and to produce the concentrated gas mixture on the retentate side.
3 . The method of claim 1 , wherein:
the stored gas mixture comprises less than 40 percent reagent gas, and
the concentrated gas mixture comprises at least 60 percent reagent gas.
4 . The method of claim 3 , wherein the concentrated gas mixture comprises at least 85 percent reagent gas.
5 . The method of claim 1 , wherein the reagent gas is a hydride and the diluent gas is hydrogen.
6 . The method of claim 1 , wherein the reagent gas is selected from: CH 4 , NH 3 , H 2 O, SiH 4 , PH 3 , H 2 S, GeH 4 , Ge 2 H 6 , AsH 3 , H 2 S, H 2 Se, H 2 Te, C 2 H 2 , P 2 H 4 , SbH 3 , and B 2 H 6 .
7 . The method of claim 1 , wherein the diluent gas is selected from: nitrogen, hydrogen, xenon, and helium.
8 . The method of claim 1 , wherein the separation membrane comprises polydimethyl siloxane, acetate cellulose, polytetrafluoroethylene, a perfluorinate sulfocationite, nanoparticle silica, zeolite, metal-organic framework, nanoporous carbon, or porovskite, a precious metal, polyimide, polysulfone, cellulose acetate, polyaramide, polyethylene, or polyphenylene oxide.
9 . The method of claim 1 , wherein the stored gas mixture is contained in a first storage vessel having a first volume, the method comprising:
removing a portion of the stored gas mixture from the first storage vessel and adding the portion to a second storage vessel having a volume that is smaller than the first, and
removing diluent gas from the second storage vessel, through the separation membrane, to produce the concentrated reagent gas within the second storage vessel.
10 . The method of claim 1 , wherein the stored gas mixture is contained in a storage vessel, the method comprising:
delivering a flow of the stored gas mixture from the storage vessel to a concentrator that comprises:
the separation membrane having a permeate side and a retentate side,
a flow channel on the retentate side, and
a permeate space on the permeate side,
the method comprising:
flowing the stored gas mixture through the flow channel,
reducing pressure in the permeate space to a pressure that is below a pressure in the flow channel to cause diluent gas to pass through the membrane and into the permeate space, to produce the concentrated reagent gas in the flow channel.
11 . The method of claim 1 , wherein the concentrated reagent gas comprises at least 90 percent reagent gas.
12 . The method of claim 1 , comprising delivering the concentrated gas mixture to a semiconductor manufacturing tool.
13 . The method of claim 1 , comprising delivering the concentrated gas mixture to a semiconductor manufacturing tool for use in a method selected from: chemical vapor deposition, atomic layer deposition, and epitaxial growth.