Method, system, and device for delivery of high purity hydrogen peroxide

Abstract

A method and chemical delivery system are provided. The method includes providing a non-aqueous hydrogen peroxide solution having a vapor phase separated from the substantially non-aqueous hydrogen peroxide solution by a membrane. The method further includes contacting a carrier gas or vacuum with the vapor phase and delivering a gas stream comprising hydrogen peroxide to a critical process or application. The chemical delivery system includes a non-aqueous hydrogen peroxide solution having a vapor phase separated from the substantially non-aqueous hydrogen peroxide solution by a membrane. The system further includes a carrier gas or vacuum in fluid contact with the vapor phase and an apparatus for delivering a gas stream comprising at least one component of the hydrogen peroxide solution to a critical process or application.

Claims

1. A method comprising: (a) providing a non-aqueous hydrogen peroxide solution having a vapor phase separated from the non-aqueous hydrogen peroxide solution by a membrane; (b) contacting a carrier gas or vacuum with the vapor phase; and (c) delivering a gas stream comprising at least 1000 parts per million (ppm) hydrogen peroxide to a critical process or application.

2. The method of claim 1, wherein hydrogen peroxide permeates the membrane at a faster rate than any other component of the non-aqueous hydrogen peroxide solution.

3. The method of claim 1, wherein the membrane is a substantially gas-impermeable membrane.

4. The method of claim 3, wherein the substantially gas-impermeable membrane comprises an ion exchange membrane.

5. The method of claim 1, wherein the hydrogen peroxide solution comprises at least one component selected from the group consisting of diethyl phthalate, propylene carbonate, triethylphosphate, polyvinylpyrroidone, polyvinylalcohol, polyvinylacetate-polyvinylpyrrolidone co-polymer, mellitic acid, benzenehexol, tetrahydobenzoquinone, 1,8-octanediol, 2,6-dichlorophenol, acridine, 8-hydroxyquinoline, benzylic acid, 1,4-dioxane, amyl acetate, DMF, DMSO, dimethylacetamide, 2-ethyl-l-hexanol, furfuryl alcohol, 2-octanol, 2-methyl-2-heptanol, and combinations thereof.

6. The method of claim 1, further comprising changing the concentration of at least one component of the vapor phase by changing at least one of the following parameters: (a) the temperature of the hydrogen peroxide solution, (b) the pressure of the hydrogen peroxide solution, (c) the concentration of the hydrogen peroxide solution, (d) the temperature of the carrier gas, (e) the pressure of the carrier gas or vacuum, (f) the surface area of the membrane, and (g) the flow rate of the carrier gas.

7. A chemical delivery system comprising: (a) a non-aqueous hydrogen peroxide solution having a vapor phase separated from the non-aqueous hydrogen peroxide solution by a membrane; (b) a carrier gas or vacuum in fluid contact with the vapor phase; and (c) an apparatus for delivering a gas stream comprising at least 1000 ppm hydrogen peroxide to a critical process or application.

8. The chemical delivery system of claim 7, wherein hydrogen peroxide permeates the membrane at a faster rate than any other component of the non-aqueous hydrogen peroxide solution.

9. The chemical delivery system of claim 7, wherein the membrane is a substantially gas-impermeable membrane.

10. The chemical delivery system of claim 9, wherein the substantially gas-impermeable membrane comprises an ion exchange membrane.

11. The chemical delivery system of claim 7, wherein the hydrogen peroxide solution comprises at least one component selected from the group consisting of diethyl phthalate, propylene carbonate, triethylphosphate, polyvinylpyrroidone, polyvinyalcohol, polyvinyl acetate-polyvinylpyrrolidone co-polymer, mellitic acid, benzenehexol, tetrahydobenzoquinone, 1,8-octanediol, 2,6-dichlorophenol, acridine, 8-hydroxyquinoline, benzylic acid, 1,4-dioxane, amyl acetate, DMF, DMSO, dimethylacetamide, 2-ethyl-1-hexanol, furfuryl alcohol, 2-octanol, 2-methyl-2-heptanol, and combinations thereof.

12. A hydrogen peroxide delivery device comprising: (a)A housing having within it at least one membrane; (b) A non-aqueous hydrogen peroxide liquid solution contained within the housing; and (c) A head space contained within the housing and separated from the non-aqueous hydrogen peroxide solution by the membrane, wherein the housing is configured to allow a carrier gas to flow through the head space to produce a gas stream comprising at least 1000ppm hydrogen peroxide to a critical process or application.

13. The device of claim 12, wherein hydrogen peroxide permeates the membrane at a faster rate than any other component of the non-aqueous hydrogen peroxide solution.

14. The device of claim 12, wherein the membrane is a substantially gas-impermeable membrane.

15. The device of claim 14, wherein the substantially gas-impermeable membrane comprises an ion exchange membrane.

16. The device of claim 12, wherein the hydrogen peroxide solution comprises at least one component selected from the group consisting of diethyl phthalate, propylene carbonate, triethylphosphate, polyvinylpyrroidone, polyvinylalcohol, polyvinylacetate-polyvinylpyrrolidone co-polymer, mellitic acid, benzenehexol, tetrahydobenzoquinone, 1,8-octanedial, 2,6-dichlorophenol, acridine, 8-hydroxyquinoline, benzylic acid, 1,4-dioxane, amyl acetate, DMF, DMSO, dimethylacetamide, 2-ethyl-1-hexanol, furfuryl alcohol, 2-octanol, 2-methyl-2-heptanol, and combinations thereof.

17. The device of claim 16, wherein the membrane is substantially impermeable to the component.

18. The device of claim 12, wherein the at least one membrane comprises a plurality of membrane lumens.

19. The method of claim 1, wherein the hydrogen peroxide solution comprises propylene carbonate.

20. The method of claim 1, wherein the hydrogen peroxide solution comprises diethyl phthalate.

21. The system of claim 7, wherein the hydrogen peroxide solution comprises propylene carbonate.

22. The system of claim 7, wherein the hydrogen peroxide solution comprises diethyl phthalate.

23. The device of claim 12, wherein the hydrogen peroxide liquid solution comprises propylene carbonate.

24. The device of claim 12, wherein the hydrogen peroxide liquid solution comprises diethyl phthalate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a diagram illustrating a part of a membrane assembly useful in certain embodiments of the present invention.

(2) FIG. 1B is a diagram illustrating an embodiment of a hydrogen peroxide delivery assembly (HPDA) according to certain embodiments of the present invention.

(3) FIG. 2A is a cross-sectional view of an embodiment of an HPDA according to certain embodiments of the present invention.

(4) FIG. 2B is a cross-sectional view of an embodiment of an HPDA according to certain embodiments of the present invention.

(5) FIG. 3 is a P&ID of a manifold that can be used to test methods, systems, and devices for H.sub.2O.sub.2 delivery according to certain embodiments of the present invention.

(6) FIG. 4 is a P&ID of a manifold that can be used to test methods, systems, and devices for H.sub.2O.sub.2 delivery according to certain embodiments of the present invention.

(7) FIG. 5 is a P&ID of a manifold that can be used to test methods, systems, and devices for H.sub.2O.sub.2 delivery according to certain embodiments of the present invention.

(8) FIG. 6 is a chart depicting the H.sub.2O.sub.2 concentration measured during a test of a non-aqueous H.sub.2O.sub.2 solution, according to certain embodiments of the present invention.

(9) FIG. 7 is a chart depicting the H.sub.2O.sub.2 concentration measured during a test of a non-aqueous H.sub.2O.sub.2 solution along with theoretical H.sub.2O.sub.2 concentrations for a 30% aqueous solution and a 74% aqueous solution, according to certain embodiments of the present invention.

(10) FIG. 8 is a chart depicting the H.sub.2O.sub.2 concentration measured during a test of a non-aqueous H.sub.2O.sub.2 solution, according to certain embodiments of the present invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

(11) The term process gas as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a gas that is used in an application or process, e.g., a step in the manufacturing or processing of micro-electronics and in other critical processes. Exemplary process gases are inorganic acids, organic acids, inorganic bases, organic bases, and inorganic and organic solvents. A preferred process gas is hydrogen peroxide.

(12) The term reactive process gas as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a process gas that chemically reacts in the particular application or process in which the gas is employed, e.g., by reacting with a surface, a liquid process chemical, or another process gas.

(13) The term non-reactive process gas as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a process gas that does not chemically react in the particular application or process in which the gas is employed, but the properties of the non-reactive process gas provide it with utility in the particular application or process.

(14) The term carrier gas as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a gas that is used to carry another gas through a process train, which is typically a train of piping. Exemplary carrier gases are nitrogen, argon, hydrogen, oxygen, CO.sub.2, clean dry air, helium, or other gases that are stable at room temperature and atmospheric pressure.

(15) The term head space as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a volume of gas in fluid contact with a hydrogen peroxide solution that provides at least a portion of the gas contained in the head space. There may be a permeable or selectively permeable barrier separating the head space, that is optionally in direct contact with the hydrogen peroxide solution. In those embodiments where the membrane is not in direct contact with the hydrogen peroxide solution, more than one head space may exist, i.e. a first head space directly above the solution that contains the vapor phase of the solution and a second head space separated from the first head space by a membrane that only contains the components of the first space that can permeate the membrane, e.g., hydrogen peroxide. In those embodiments with a hydrogen peroxide solution and a head space separated by a substantially gas-impermeable membrane, the head space may be located above, below, or on any side of the hydrogen peroxide solution, or the head space may surround or be surrounded by the hydrogen peroxide solution. For example, the head space may be the space inside a substantially gas-impermeable tube running through the hydrogen peroxide solution or the hydrogen peroxide solution may be located inside a substantially gas-impermeable tube with the head space surrounding the outside of the tube.

(16) The term substantially gas-impermeable membrane as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a membrane that is relatively permeable to other components that may be present in a gaseous or liquid phase, e.g., hydrogen peroxide, but relatively impermeable to other gases such as, but not limited to, hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide, hydrogen sulfide, hydrocarbons (e.g., ethylene), volatile acids and bases, refractory compounds, and volatile organic compounds.

(17) The term ion exchange membrane as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to a membrane comprising chemical groups capable of combining with ions or exchanging with ions between the membrane and an external substance. Such chemical groups include, but are not limited to, sulfonic acid, carboxylic acid, sulfonamide, sulfonyl imide, phosphoric acid, phosphinic acid, arsenic groups, selenic groups, phenol groups, and salts thereof.

(18) The term non-aqueous solution as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers to a solution comprising two or more components containing less than 10% water.

(19) The term solvent as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers to any compound that produces a liquid when mixed with a solute, such as hydrogen peroxide, in the applicable ratio under the applicable operating conditions.

(20) The advantageous hydrogen peroxide delivery provided by the present invention, and specifically the methods, systems, and devices of certain embodiments described herein, is preferably obtained using a membrane contactor. In a preferred embodiment, a non-porous membrane is employed to provide a barrier between the hydrogen peroxide solution and the head space that is in fluid contact with a carrier gas or vacuum. Preferably, hydrogen peroxide rapidly permeates across the membrane, while gases are excluded from permeating across the membrane into the solution. In some embodiments the membrane may be chemically treated with an acid, base, or salt to modify the properties of the membrane.

(21) In certain embodiments, the hydrogen peroxide is introduced into a carrier gas or vacuum through a substantially gas-impermeable ionic exchange membrane. Gas impermeability can be determined by the leak rate. The term leak rate as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a specialized or customized meaning), and refers without limitation to the volume of a particular gas that penetrates the membrane surface area per unit of time. For example, a substantially gas-impermeable membrane could have a low leak rate of gases (e.g., a carrier gas) other than a process gas (e.g., hydrogen peroxide), such as a leak rate of less than about 0.001 cm.sup.3/cm.sup.2/s under standard atmospheric temperature and pressure. Alternatively, a substantially gas-impermeable membrane can be identified by a ratio of the permeability of a process gas vapor compared to the permeability of other gases. Preferably, the substantially gas-impermeable membrane is more permeable to such process gases than to other gases by a ratio of at least 10,000:1, such as a ratio of at least about 20,000:1, 30,000:1, 40,000:1, 50,000:1, 60,000:1, 70,000:1, 80,000:1, 90,000:1 or a ratio of at least 100,000:1, 200,000:1, 300,000:1, 400,000:1, 500,000:1, 600,000:1, 700,000:1, 800,000:1, 900,000:1 or even a ratio of at least about 1,000,000:1. However, in other embodiments, other ratios that are less than 10,000:1 can be acceptable, for example 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1; 50:1, 100:1, 500:1, 1,000:1, or 5,000:1 or more.

(22) In certain embodiments, the membrane is an ion exchange membrane, such as a polymer resin containing exchangeable ions. Preferably, the ion exchange membrane is a fluorine-containing polymer, e.g., polyvinylidenefluoride, polytetrafluoroethylene (PTFE), ethylene tetrafluoride-propylene hexafluoride copolymers (FEP), ethylene tetrafluoride-perfluoroalkoxyethylene copolymers (PFE), polychlorotrifluoroethylene (PCTFE), ethylene tetrafluorideethylene copolymers (ETFE), polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-trifluorinated ethylene chloride copolymers, vinylidene fluoride-propylene hexafluoride copolymers, vinylidene fluoridepropylene hexafluoride-ethylene tetrafluoride terpolymers, ethylene tetrafluoride-propylene rubber, and fluorinated thermoplastic elastomers. Alternatively, the resin comprises a composite or a mixture of polymers, or a mixture of polymers and other components, to provide a contiguous membrane material. In certain embodiments, the membrane material can comprise two or more layers. The different layers can have the same or different properties, e.g., chemical composition, porosity, permeability, thickness, and the like. In certain embodiments, it can also be desirable to employ a layer (e.g., a membrane) that provides support to the filtration membrane, or possesses some other desirable property.

(23) The ion exchange membrane is preferably a perfluorinated ionomer comprising a copolymer of ethylene and a vinyl monomer containing an acid group or salts thereof. Exemplary perfluorinated ionomers include, but are not limited to, perfluorosulfonic acid/tetrafluoroethylene copolymers (PFSA-TFE copolymer) and perfluorocarboxylic acid/tetrafluoroethylene copolymer (PFCA-TFE copolymer). These membranes are commercially available under the tradenames NAFION (E.I. du Pont de Nemours & Company), 3M Ionomer (Minnesota Mining and Manufacturing Co.), FLEMION (Asashi Glass Company, Ltd.), and ACIPLEX (Asashi Chemical Industry Company).

(24) In preparing a hydrogen peroxide containing gas stream, a hydrogen peroxide solution can be passed through the membrane. The term passing a hydrogen peroxide solution through a membrane as used herein is a broad term, and is to be given its ordinary and customary meaning to a person of ordinary skill in the art (and is not to be limited to a special or customized meaning), and refers without limitation to contacting a first side of a membrane with the hydrogen peroxide solution, such that the hydrogen peroxide passes through the membrane, and obtaining a hydrogen peroxide containing gas stream on the opposite side of the membrane. The first and second sides can have the form of substantially flat, opposing planar areas, where the membrane is a sheet. Membranes can also be provided in tubular or cylindrical form where one surface forms the inner position of the tube and an opposing surface lies on the outer surface. The membrane can take any form, so long as the first surface and an opposing second surface sandwich a bulk of the membrane material. Depending on the processing conditions, nature of the hydrogen peroxide solution, volume of the hydrogen peroxide solution's vapor to be generated, and other factors, the properties of the membrane can be adjusted. Properties include, but are not limited to physical form (e.g., thickness, surface area, shape, length and width for sheet form, diameter if in fiber form), configuration (flat sheet(s), spiral or rolled sheet(s), folded or crimped sheet(s), fiber array(s)), fabrication method (e.g., extrusion, casting from solution), presence or absence of a support layer, presence or absence of an active layer (e.g., a porous prefilter to adsorb particles of a particular size, a reactive prefilter to remove impurities via chemical reaction or bonding), and the like. It is generally preferred that the membrane be from about 0.5 microns in thickness or less to 2000 microns in thickness or more, preferably from about 1, 5, 10, 25, 50, 100, 200, 300, 400, or 500 microns to about 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, or 1900 microns. When thinner membranes are employed, it can be desirable to provide mechanical support to the membrane (e.g., by employing a supporting membrane, a screen or mesh, or other supporting structure), whereas thicker membranes may be suitable for use without a support. The surface area can be selected based on the mass of vapor to be produced.

(25) Certain embodiments of the methods, systems, and devices provided herein, in which a carrier gas or vacuum can be used to deliver substantially water-free hydrogen peroxide, are shown by reference to FIGS. 1-8.

(26) According to certain embodiments of the present invention, a hydrogen peroxide delivery assembly (HPDA) is provided. An HPDA is a device for delivering hydrogen peroxide into a process gas stream, e.g., a carrier gas used in a critical process application, e.g., micro-electronics manufacturing or other critical process applications. An HPDA may also operate under vacuum conditions. An HPDA may have a variety of different configurations comprising at least one membrane and at least one vessel containing a non-aqueous hydrogen peroxide solution and a head space separated from the solution by membrane.

(27) FIGS. 1A and 1B depict different views of one embodiment of an HPDA 100 and a membrane assembly 110 that forms part of an HPDA that can be used as provided herein. FIG. 1A shows membrane assembly 110 comprising a plurality membranes 120, for example, 5R NAFION membrane, which can be configured as lumens. As depicted in FIG. 1A, membranes 120 configured into lumens are inserted into a collector plate 130 through a plurality of holes within collector plate 130. Membrane assembly 110 also comprises a plurality of polytetrafluoroethylenene (PTFE) rods 140 inserted into collector plate 130. As shown in FIG. 1B, as part of HPDA 100, membrane assembly 110 comprises membrane lumens 120 spanning collector plates 130, HPDA 100 further comprises endcaps 150 at each end of membrane assembly 110. Endcaps 150 further include branches 160, which can be fitted with tubing to provide access to the interior of HPDA 100, e.g., to fill, empty, clean, or refill the HPDA.

(28) FIG. 2A and FIG. 2B show a cross-sectional view of two embodiments of HPDAs according to certain embodiments of the present invention.

(29) HPDA 200A, as shown in FIG. 2A, comprises a membrane assembly 210A within a shell housing 220A and end caps 230A configured to couple to shell housing 220A. Membrane assembly 210A comprises of a plurality of membranes 240A, which can be configured as lumens. The number of lumens can vary depending on various factors, including the size of the lumens, the size of HPDA 200A, and the operating conditions of the HPDA. In certain embodiments, an HPDA may contain up to 1000 membrane lumens, up to 500 lumens, up to 200 lumens, up to 100 lumens, or up to 50 lumens. For example, HPDA 200A may have about 20-50 membrane lumens. The membrane lumens can be constructed from a perfluorinated sulfonic acid membrane, for example, 5R NAFION membrane. The end caps 230A and shell housing 220A can be formed from a variety of materials, for example, PTFE, stainless steel (such as 316 stainless steel), or other suitable materials. Each end cap 230A further comprises a gas connection 231A. Gas connection 231A can take the form of a variety of connection configurations and sizes, for example, VCR, NPT, or other suitable connectors.

(30) HPDA 200B, as shown in FIG. 2B, comprises a membrane assembly 210B within a shell housing 220B and end caps 230B configured to couple to shell housing 220B. Membrane assembly 210B can be comprised of a plurality of membrane lumens (not shown), The number of lumens can vary depending on various factors, including the size of the lumens, the size of HPDA 200B, and the operating conditions of the HPDA. In certain embodiments, an HPDA may contain up to 1000 membrane lumens, up to 500 lumens, up to 200 lumens, up to 100 lumens, or up to 50 lumens. For example, HPDA 200B may have about 20-50 membrane lumens. The membrane lumens can be constructed from a perfluorinated sulfonic acid membrane, for example, 5R NAFION membrane. The end caps 230B and shell housing 220B can be formed from a variety of materials, for example, PTFE, stainless steel (such as 316 stainless steel), or other suitable materials. Each end cap 230B can comprise a gas connection 231B. Gas connection 231B can take the form of a variety of connection configurations and sizes, for example, VCR, NPT, or other suitable connectors.

(31) According to the various embodiments, the HPDA can be filled with a non-aqueous hydrogen peroxide containing solution, while maintaining a head separated from the hydrogen peroxide containing solution by a membrane. Because the membrane is permeable to hydrogen peroxide and substantially impermeable to the other components of the solution, the head space will contain substantially pure hydrogen peroxide vapor in a carrier gas or vacuum, depending upon the operating conditions of the process.

(32) According to various embodiments, an HPDA can be constructed similarly to the devices described in commonly assigned U.S. Pat. No. 7,618,027, which is herein incorporated by reference.

(33) An embodiment according to an aspect of the methods, systems, and devices provided herein is described below by reference to a manifold 300, as shown by reference to FIG. 3. According to the embodiment shown by reference to FIG. 3, a carrier gas 310 flows through the head space of HPDA 320, which can be an HPDA as described above. A mass flow controller (MFC) 330, for example, Unit UFC-1260A 1 slm, can be used to control the flow rate of carrier gas 310, which can be typically set to 1 slm. Analysis of the amount of hydrogen peroxide in the gas stream typically requires dilution of the resultant gas stream, which can be accomplished with dilution gas 350. A mass flow controller (MFG) 340, for example, a Unit UFC-1260A 10 slm can be used to control the flow rate of dilution gas 350. Carrier gas 310 and dilution gas 350 can be supplied by a gas source 360, which can be typically nitrogen or other suitable carrier gas. A valve 370 can be used to isolate the dilution line when it is not required. Check valves 371, 372 can be placed downstream of both MFC 330 and MFC 340 to protect them from possible H.sub.2O.sub.2 exposure. A 60 psig pressure gauge 373 can be placed between MFC 330 and check valve 372 to insure that the manifold's pressure does not exceed the maximum pressure allowed by H.sub.2O.sub.2 analyzer 380, e.g., 5 psig.

(34) The nitrogen pressure can be maintained with a forward pressure regulator 374, typically set to 15 psig. A thermocouple 375 can measure the temperature of nitrogen carrier gas 310 before it enters HPDA 320 for H.sub.2O.sub.2 addition. A thermocouple 376 can measure the temperature of the 30% hydrogen peroxide solution in HPDA 100. A thermocouple 377 can measure the gas temperature before entering H.sub.2O.sub.2 analyzer 380. H.sub.2O.sub.2 analyzer 380 can pull in a 500 sccm sample of carrier gas 310 to measure the H.sub.2O.sub.2 concentration. Manifold 300 can further comprise a relative humidity/resistance temperature detector (RH/RTD) probe 378. A heater tape 390 can be placed on certain sections as indicated in FIG. 3. The manifold's temperature can be controlled in two separate zones, the membrane assemblies and the remaining tubing, with a Trilite Equipment & Technologies Controller and a Watlow 96 Controller, respectively. The entire manifold can be set up inside of a fume hood.

(35) The embodiment shown by reference to FIG. 3 is set up as a test apparatus to measure the amount of hydrogen peroxide introduced into a carrier gas stream under various operating conditions of an HPDA. It will be understood that a similar apparatus can be used to deliver hydrogen peroxide to a critical process application.

(36) FIG. 4 is a P&ID of a test manifold 400, according to another embodiment, used to demonstrate delivery of hydrogen peroxide under vacuum conditions, according to the methods, systems, and devices provided herein. According to the embodiment shown by reference to FIG. 4, a vacuum pump 410 removes gas from the hydrogen peroxide containing vapor side (i.e., head space) of HPDA 420, which can be an HPDA as described above. For example, vacuum pump 410 can be maintained at about 24 mmHg using a valve 480 and a pressure gauge 430. A gas source 440 can be maintained at a pressure of about 2 psig with a forward pressure regulator 450. A valve 460 can be used as a flow restrictor. A thermocouple 470 can be placed inside the filling tube of a HPDA 420 to measure the solution's temperature inside the shell of HPDA 420. The test involves contacting the vapor side, i.e., head space, of HPDA 420 to a vacuum produced by vacuum pump 410 while holding HPDA 420 at a constant temperature. A heat tape 490 can be placed around HPDA 420 to allow for constant temperature control of the hydrogen peroxide containing solution within HPDA 420. This vacuum-based method, system, and device is particularly preferred in numerous micro-electronics and other critical process applications that are operated at relatively reduced pressures (i.e., under vacuum).

(37) The embodiment shown by reference to FIG. 4 is set up as a test apparatus to measure the amount of hydrogen peroxide introduced into a carrier gas stream under various operating conditions of an HPDA. It will be understood that a similar apparatus can be used to deliver hydrogen peroxide to a critical process application.

(38) FIG. 5 is a P&ID of a test manifold 500, according to another embodiment, used to demonstrate delivery of hydrogen peroxide, according to an aspect of the methods, systems, and devices provided herein. As shown in FIG. 5, a nitrogen carrier gas 510 can flow through the head space of HPDA 520, which can be an HPDA as described above. A mass flow controller (MFC) 530, for example, a Brooks SLA5850S1EAB1B2A1 5 slm, can be used to control the flow rate of nitrogen carrier gas 510, which can be typically set to 1 slm. Analysis of the amount of hydrogen peroxide in the gas stream typically requires dilution of the resultant gas stream, which can be accomplished with dilution gas 350. A mass flow controller (MFC) 540, for example, a Brooks SLA5850S1EAB1B2A1 10 slm, can be used to control the flow rate of a nitrogen dilution gas 550. Nitrogen carrier gas 510 and nitrogen dilution gas 550 can be supplied by a nitrogen gas source 560. A valve 570 can be used to isolate the dilution line when desired. A pair of check valves 571, 572 can be placed downstream of both MFC 530 and MFC 540 to protect them from possible H.sub.2O and H.sub.2O.sub.2 exposure. A pressure gauge 573, for example, 100 psi gauge, can be placed between MFC 330 and HPDA 520 to insure that the manifold's pressure does not exceed the maximum pressure allowed by an analyzer 580, which is 5 psig.

(39) The nitrogen pressure can be maintained with a forward pressure regulator 574, typically set to 25 psig. A thermocouple 575 can measure the temperature of nitrogen carrier gas 510 before it enters HPDA 520 for H.sub.2O.sub.2 addition. Within HPDA 520, nitrogen carrier gas 510 can flow through the membrane tubes and peroxide vapor can permeate through the membrane from the solution contained within the shell housing and combined with carrier gas 510. A thermocouple 576 can measure the temperature of the hydrogen peroxide solution in HPDA 520. A thermocouple 577 can measure the gas temperature exiting HPDA 520. In this embodiment, an ozone analyzer 580 can be used to measure the H.sub.2O.sub.2 concentration in the gas stream. Ozone analyzer 580 can be, for example, a Teledyne 465L O.sub.3 Analyzer utilizing UV absorption technology. The reading of ozone analyzer 580 should be multiplied by a concentration factor (e.g., 150) to obtain the H.sub.2O.sub.2 concentration. Ozone analyzer 580 can pull a sample of the hydrogen peroxide containing gas stream to measure the H.sub.2O.sub.2 concentration. A thermocouple 578 can be used to measure the gas temperature before entering ozone analyzer 580. A thermocouple 581 can be used to measure the temperature of nitrogen dilution gas 550.

(40) Manifold 500 can further comprise a scrubber 585, for example, a Carulite 200 configured to remove the H.sub.2O.sub.2 by converting it into water and oxygen. Downstream of scrubber 585 can be a probe 579, for example, a E+E Elektronik EE371 humidity transmitter configured to measure the dew point (DP) and moisture concentration. Downstream of probe 579 can be a vent. A heater tape 590 can be placed on certain sections as indicated in FIG. 5. The manifold's temperature can be controlled in four separate zones, indicated by the dotted line boxes, with Watlow EZ-Zone 96 controllers, respectively. The entire manifold can be set up inside of a fume hood.

(41) The embodiment shown by reference to FIG. 5 is set up as a test apparatus to measure the amount of hydrogen peroxide introduced into a carrier gas stream under various operating conditions of an HPDA. It will be understood that a similar apparatus can be used to deliver hydrogen peroxide to a critical process application.

(42) Manifold 500 as described above was utilized for test procedures as described below. The test procedures involved obtaining stable H.sub.2O.sub.2 readings utilizing non-aqueous H.sub.2O.sub.2 solutions. The solutions can be prepared in a manner similar to that described in U.S. Pat. No. 4,564,514, incorporate herein by reference, which describes a process for the production of water-free organic hydrogen peroxide solutions.

EXAMPLE 1

(43) In one example, the non-aqueous solvent utilized was propylene carbonate (PC) having a molecular weight of 102.09 g/mol and a boiling point of about 240 C. at atmospheric pressure. The initial composition of the non-aqueous hydrogen peroxide solution for this test was about 28.5% H.sub.2O.sub.2/1.5% H.sub.2O/70% PC. For this example, an HPDA like HPDA 200B shown in FIG. 2B was utilized. The HPDA housing utilized in this test procedure was constructed of 316 stainless steel.

(44) Manifold 500, including the HPDA and hydrogen peroxide containing solution, was maintained at about 40 C. The carrier gas flow rate was 1 slm and the dilution gas flow rate was 8 slm. Dilution allowed for optimization of the concentration to the measurement range of ozone analyzer 580. In addition, dilution limited the possibility of sending high moisture concentrations to ozone analyzer 580, which can affect the accuracy of the readings.

(45) Regarding relative humidity probe 579, in addition to applying the correction factor for the dilution, the H.sub.2O.sub.2 concentration was subtracted from the H.sub.2O concentration to account for the conversion of hydrogen peroxide into water vapor by scrubber 585.

(46) The H.sub.2O.sub.2 concentration of the carrier gas reading from ozone analyzer 580 is depicted in FIG. 6. As shown in FIG. 6, after about 6 hours, the H.sub.2O.sub.2 concentration in the carrier gas output stabilized at about 3500-3900 ppm for about 17 hours.

(47) FIG. 7 depicts a portion of the H.sub.2O.sub.2 concentration data together with theoretical H.sub.2O.sub.2 concentrations that would be expected at 40 C., without a membrane, for a 30% H.sub.2O.sub.2 aqueous solution and a 74% H.sub.2O.sub.2 aqueous solution based on Raoult's Law (see, e.g., Hydrogen Peroxide, Schumb), As shown in FIG. 7, the H.sub.2O.sub.2 concentration in the carrier gas obtained using the non-aqueous PC solution was equivalent to what may be achieved from an about 74% H.sub.2O.sub.2 aqueous solution, which would be considered unsafe in many applications and processes.

(48) As shown in Table 1, non-aqueous H.sub.2O.sub.2 solutions, for example, 28.5% H.sub.2O.sub.2/1.5% H.sub.2O/70% PC, can provide stable readings of H.sub.2O.sub.2 as well as a low ratio of H.sub.2O to H.sub.2O.sub.2 in the process gas stream, which can be beneficial for many critical process applications. The initial concentration of the solution was 28.5% H.sub.2O.sub.2/2.4% H.sub.2O/69.1% PC by weight and the final concentration of the solution was 30.2% H.sub.2O.sub.2/1.25% H.sub.2O/68.55% PC by weight. Under the above operating conditions, this solution produced a consistent stream of H.sub.2O.sub.2 of about 3500-3900 ppm over a 17-hour period. Data from the humidity transmitters shows that some residual H.sub.2O is present, but this amount can decrease over time.

(49) TABLE-US-00001 TABLE 1 Concentration in HPDA (%) Concentration in Gas Stream (ppm) H.sub.2O.sub.2 H.sub.2O PC H.sub.2O.sub.2 H.sub.2O Ini- 28.5 2.4 69.1 3513 5836 tial Final 30.2 1.25 68.55 3833 3085

EXAMPLE 2

(50) In another example, the non-aqueous solvent utilized was diethyl phthalate (DEP) having a molecular weight of 224.25 g/mol and a boiling point of about 298.5 C. at atmospheric pressure. The initial composition of the non-aqueous hydrogen peroxide solution was about 19.0% H.sub.2O.sub.2/1.0% H.sub.2O/80.0% DEP. For this example, an HPDA like HPDA 200A shown in FIG. 2A was utilized. The HPDA housing utilized in this test procedure was constructed of PTFE.

(51) Manifold 500, including the HPDA and hydrogen peroxide containing solution, was maintained at about 40 C. The carrier gas flow rate was 1 slm and the dilution gas flow rate was 8 slm. As shown in FIG. 8, after about 2 hours, the H.sub.2O.sub.2 output stabilized at about 3900-4000 ppm for about 8 hours.

(52) As shown in Table 2, non-aqueous H.sub.2O.sub.2 solutions, for example, 19.0% H.sub.2O.sub.2/1.0% H.sub.2O/80.0% DEP, can provide stable readings of H.sub.2O.sub.2 as well as a low ratio of H.sub.2O to H.sub.2O.sub.2 in the process gas stream, which can be beneficial for many critical process applications. The initial concentration of the solution was 19.0% H.sub.2O.sub.2/1.0% H.sub.2O/80.0% DEP by weight and the final concentration of the solution was 17.0% H.sub.2O.sub.2/0.4% H.sub.2O/82.6% PC PC by weight. Under the above operating conditions, this solution produced a consistent stream of H.sub.2O.sub.2 of about 3900-4000 ppm over an 8-hour period. Data from the humidity transmitters shows that some residual H.sub.2O is present, but this amount can decrease over time.

(53) TABLE-US-00002 TABLE 2 Concentration in HPDA (%) Concentration in Gas Stream (ppm) H.sub.2O.sub.2 H.sub.2O DEP H.sub.2O.sub.2 H.sub.2O Ini- 19.0 1.0 80.0 4005 4205 tial Final 17.0 0.4 82.6 3914 1860

(54) By controlling the temperature of the hydrogen peroxide containing solution and, as applicable, the carrier gas or vacuum, particular hydrogen peroxide concentrations can be delivered. The selection of a particular hydrogen peroxide concentration will depend on the requirements of the application or process in which the hydrogen peroxide containing process gas will be used. In certain embodiments, the hydrogen peroxide containing gas stream may be diluted by adding additional carrier gas. In certain embodiments, the hydrogen peroxide containing gas stream may be combined with other process gas streams prior to or at the time of delivering hydrogen peroxide to an application or process. Alternatively or additionally, any residual solvent or stabilizers, or contaminants present in the hydrogen peroxide containing process gas may be removed in a purification (e.g., dehumidification) step using a purifier apparatus.

(55) Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.