CN109152990B

CN109152990B - Method, system and apparatus for delivering process gas

Info

Publication number: CN109152990B
Application number: CN201780029147.5A
Authority: CN
Inventors: 丹尼尔·小阿尔瓦雷斯; 拉塞尔·J·霍姆斯; 杰弗瑞·J·史派杰曼; 爱德华·海因莱因; 克里斯托弗·拉莫斯; 杰里迈亚·特拉梅尔
Original assignee: RASIRC Inc
Current assignee: RASIRC Inc
Priority date: 2016-04-16
Filing date: 2017-04-14
Publication date: 2021-11-09
Anticipated expiration: 2037-04-14
Also published as: KR102483803B1; DE17783234T1; JP2019521948A; EP3442691A4; EP3442691A1; KR20180135915A; WO2017181013A1; JP6918921B2; CN109152990A

Abstract

Methods, systems, and apparatuses for gas phase delivery of high purity process gases to critical processes or applications are provided herein.

Description

Method, system and apparatus for delivering process gas

Cross Reference to Related Applications

According to 35u.s.c. § 119(e), the present application also claims priority to U.S. serial No. 62/323,697 filed 2016, 4, 16. The entire contents of each of these applications are incorporated herein by reference.

Technical Field

Methods, systems, and apparatus for gas phase delivery of high purity process gases in microelectronic and other critical process applications.

Background

Various process gases are available for the fabrication and processing of microelectronics. In addition, various chemicals may be used in other environments requiring high purity gases, for example, critical processes or applications including, but not limited to, microelectronics applications, wafer cleaning, wafer bonding, photoresist stripping, silicon oxidation, surface passivation, photolithographic mask cleaning, atomic layer deposition, chemical vapor deposition, flat panel display, sterilization of surfaces contaminated with bacteria, viruses, and other biological agents, industrial component cleaning, pharmaceuticals, nanomaterial production, power generation and control devices, fuel cells, power transmission devices, and other applications where process control and purity are key considerations. In these processes and applications, it is necessary to deliver specific quantities of certain process gases under controlled operating conditions, e.g., temperature, pressure, and flow rate.

For various reasons, gas phase delivery of process chemicals is preferred over liquid phase delivery. For applications requiring a low mass flow of process chemicals, the liquid delivery of the process chemicals is not accurate or clean enough. Gas delivery is desirable from the standpoint of ease of delivery, accuracy and purity. Gas flow devices are more suitable for precise control than liquid delivery devices. Furthermore, microelectronic applications and other critical processes typically have a wide range of gas handling systems that make gas delivery much easier than liquid delivery. One approach is to directly evaporate the process chemistry at or near the point of use. Evaporating the liquid provides a process that leaves heavy contaminants and thereby purifies the process chemicals. However, many process gases are not suitable for direct vaporization for safety, handling, stability and/or purity reasons.

Numerous process gases are used in microelectronic applications and other critical processes or applications. Ozone is a gas commonly used to clean semiconductor surfaces (e.g., photoresist stripping) and as an oxidizing agent (e.g., to form an oxide or hydroxide layer). One advantage of using ozone gas in microelectronics applications and other critical processes is that the gas can access high aspect ratio features on the surface compared to existing liquid-based methods. For example, according to the international roadmap for semiconductor technology (ITRS), current semiconductor processes should be compatible with half pitches as small as 20-22 nm. The next technology node for semiconductors is expected to have a half pitch of 10nm, with ITRS requiring less than 7nm in the near future. At these dimensions, liquid-based chemical processing is not feasible because the surface tension of the process liquid prevents it from approaching the bottom of the deep hole or channel and the corners of the high aspect ratio feature. Thus, ozone gas is used in some cases to overcome some of the limitations of liquid-based processes because the gas is not subject to the same surface tension limitations. Plasma-based processes have also been used to overcome certain limitations of liquid-based processes. However, ozone and plasma based processes have their own limitations, including operating costs, inadequate process control, undesirable side reactions, and inefficient cleaning.

Other problems relate to the temperature required for successful deposition. For example, for silicon nitride (SiN), ammonia (NH)₃) It is currently common to use temperatures in excess of 500 c or even 600 c. Maintaining such high deposition temperatures is expensive and, preferably, deposits at lower temperatures. Furthermore, new semiconductor device technologies have a tight thermal budget, which inhibits the use of high temperatures above 400 ℃. Hydrazine (N)₂H₄) Offers the opportunity to explore lower temperatures, in part because the good thermodynamics of hydrazine leads to lower deposition temperatures and spontaneous reactions to form nitrides. Although reported in the literature (Burton et al, j. electrochem. soc.,155(7) D508-D516(2008)), the use of hydrazine has not been adopted commercially due to the serious safety issues with its use. Hydrazine replacements, which are generally safer than hydrazine, have the disadvantage of causing undesirable carbon contamination. Therefore, there is a need to develop a safer method for using hydrazine in deposition processes or for transport to other critical process applications.

The use of hydrazine in the gas phase is limited by safety, handling and purity issues. Hydrazine has been used in rocket fuels and can be very explosive. Anhydrous hydrazine has a low flash point of about 37 ℃. Semiconductor industry protocols for the secure handling of such materials are very limited. Accordingly, there is a need in the art to overcome these limitations, particularly to provide gaseous hydrazine that is substantially free of water suitable for use in microelectronics and other critical process applications.

Similarly, as explained in PCT publication No.2014014511 to Rasirc, inc. (which publication is incorporated herein by reference), the use of hydrogen peroxide in the gas phase in critical process applications is limited because high concentration hydrogen peroxide solutions present serious safety and handling problems and high concentrations of gas phase hydrogen peroxide are not possible using the prior art.

Disclosure of Invention

Methods, systems, and apparatus are provided for delivering a substantially anhydrous process gas stream, particularly a hydrazine-containing gas stream. The methods, systems, and apparatus are particularly useful in microelectronic applications and other critical processes. Generally, the method comprises (a) providing a non-aqueous hydrazine solution having a gas phase comprising an amount of hydrazine vapor; (b) contacting a carrier gas or vacuum with the gas phase; and (c) passing the gas stream comprising substantially anhydrous hydrazine to a critical process or application. In many embodiments, the amount of hydrazine in the gas phase is sufficient to provide hydrazine directly to a critical process or application without the need for further concentration or treatment of the hydrazine-containing gas stream. In many embodiments, the non-aqueous hydrazine solution includes a stabilizer. In certain embodiments, the method further comprises removing the one or more stabilizing agents from the gas stream. By adjusting the operating conditions of these processes, e.g., the temperature and pressure of the carrier gas or vacuum, the concentration of the hydrazine solution, and the temperature and pressure of the hydrazine solution, hydrazine can be delivered as a process gas with precision and safety. In certain embodiments, the amount of hydrazine delivered to a critical process or application in the gas phase can be controlled by adding energy, e.g., thermal, rotational or ultrasonic energy, to the hydrazine solution. In many embodiments of the invention, the non-aqueous hydrazine is pure hydrazine or hydrazine substantially free of water.

Systems and devices for delivering hydrazine using the methods described herein are also provided. In general, the systems and devices include: (a) a non-aqueous hydrazine solution having a gas phase containing an amount of hydrazine vapor; (b) a carrier gas or vacuum in contact with the gas phase fluid; and (c) means for conveying the hydrazine-containing gas stream to a critical process or application. In many embodiments, the non-aqueous hydrazine solution includes one or more stabilizers. In certain embodiments, the systems and apparatus further comprise a device for removing one or more stabilizing agents from the gas stream. In many embodiments, the amount of hydrazine in the gas phase is sufficient to provide hydrazine directly to a critical process or application without the need for further concentration or treatment of the hydrazine-containing gas stream. In certain embodiments, the apparatus for delivering a gas stream comprising hydrazine is an outlet from a headspace comprising a gas phase, the headspace being directly or indirectly connected to a microelectronic application or other critical process system, allowing the gas stream comprising hydrazine to flow from the headspace to the application or process in which it is used. The Hydrazine Delivery Assembly (HDA) described herein is one such device. By adjusting the operating conditions of the system and apparatus, e.g., the temperature and pressure of the carrier gas or vacuum, the concentration of the hydrazine solution, and the temperature and pressure of the hydrazine solution, hydrazine can be delivered as a process gas with precision and safety. In certain embodiments, the amount of hydrazine delivered to a critical process or application in the gas phase can be controlled by adding energy, e.g., thermal, rotational or ultrasonic energy, to the hydrazine solution.

Many embodiments of the methods, systems, and devices disclosed herein utilize a membrane in contact with a hydrazine-containing solution. The use of a membrane has safety advantages. In certain embodiments, the membrane completely or partially separates the hydrazine-containing solution from the hydrazine-containing gas phase. By eliminating contact between the gas phase and the liquid phase, the sudden decomposition of hydrazine in the gas phase will be limited and will not cause a corresponding decomposition in the liquid phase due to the presence of the membrane.

Also disclosed herein is an apparatus for containing a liquid comprising a volatile chemical or chemical composition (e.g., hydrazine, hydrogen peroxide, water, an alcohol, an amine, or ammonium hydroxide), wherein the apparatus comprises a headspace, wherein a vapor comprising the chemical or composition enters the headspace as a process gas to be incorporated into a process gas stream. The process gas stream containing the chemical or composition is typically delivered to a critical process application. In certain embodiments, the device comprises (a) a chamber containing a liquid comprising a volatile chemical or chemical composition; (b) a headspace comprising a gas phase comprising a volatile chemical or chemical composition in the gas phase; (c) an inlet through which a carrier gas stream may enter the chamber; and (d) a protected outlet through which a process gas stream comprising a carrier gas and a volatile chemical or chemical composition can exit the headspace. In certain embodiments, the headspace is a portion of the chamber. In certain alternative embodiments, the headspace is distinct from and in fluid communication with the chamber to allow volatile chemicals or chemical compositions in the gas phase to move from the chamber into the headspace. In many embodiments, the membrane facilitates the transfer of a volatile chemical or chemical composition from a liquid to a gas phase. The configuration of the membrane may vary depending on the particular application and process design. In some embodiments, the membrane completely or partially separates the liquid from the headspace. In certain embodiments, the membrane comprises a tube connected to the inlet such that all or a portion of the carrier gas passes through the membrane. In such an embodiment, the membrane tube may also pass through a portion of the liquid in the chamber and terminate in the headspace. The protected outlet includes means for ensuring that the volatile chemical or chemical composition entering the outlet is substantially in the gas phase, i.e. substantially free of liquid phase materials such as droplets, mist or fog.

The methods, systems, and apparatus described herein are generally applicable to a variety of process gas streams, particularly non-aqueous hydrazine solutions, wherein the hydrazine solution comprises a non-aqueous component.

In certain embodiments, the solution comprises substantially pure hydrazine, meaning that no other chemicals are intentionally included in the hydrazine, but incidental amounts of impurities are permitted. In certain embodiments, the solution comprises from about 5% to about 99% by weight hydrazine, or from about 90% to about 99%, from about 95% to about 99%, from about 96% to about 99%, from about 97% to about 99%, from about 98% to about 99%, or from about 99% to about 100% by weight hydrazine, with the remaining components comprising a solvent and/or a stabilizer. In some embodiments, the solution comprises hydrazine at a concentration greater than 99.9%, and in some embodiments, the solution comprises hydrazine at a concentration greater than 99.99%. The selection of a suitable non-aqueous hydrazine solution will be determined by the requirements of the particular application or process.

In certain embodiments, the non-aqueous hydrazine solution includes one or more suitable solvents in addition to hydrazine. In one example, the non-aqueous hydrazine solution includes ethylene glycol solvents, such as ethylene glycol, triethylene glycol, alpha propylene glycol, and beta propylene glycol. A particular non-aqueous hydrazine solution that can be used in the methods and systems described herein is 65% hydrazine/35% triethylene glycol. In other examples, the non-aqueous hydrazine solution comprises an alcohol amine, such as ethanolamine, diethanolamine, or triethanolamine. In other examples, the non-aqueous hydrazine solution comprises an aprotic amide solvent, such as hexamethyl phosphoramide, 1, 3-dimethyl-3, 4,5, 6-tetrahydro-2 (1H) -pyrimidinone (DMPU), 1, 3-dimethyl-2-imidazolidinone (DMEU), tetramethylurea, or other aprotic urea-based solvents. Another solvent is hexamethylenetetramine. The non-aqueous hydrazine solution may include a pegylation solvent, wherein the pegylation solvent is a liquid when the temperature is about 25 ℃. The term "pegylation solvent" refers to a solvent that contains covalently attached polyethylene glycol moieties. One exemplary pegylation solvent is poly (ethylene glycol) dimethyl ether. In some embodiments, suitable solvents are selected from low molecular weight polymers or oligomers of polyaniline, polypyrrole, polypyridine, or polyvinyl alcohol. The low molecular weight polymer is a polymer having a viscosity of about 35 centipoise (cp) or less when mixed with hydrazine. Other examples of solvents include glymes, such as monoglyme, diglyme, triglyme, diglyme, and tetraglyme. One skilled in the art will recognize that other solvents may be useful in the methods, systems, and apparatuses disclosed herein. Criteria for selecting an appropriate solvent include miscibility and solubility with hydrazine, chemical compatibility with hydrazine, compatibility with other components of the system (e.g., the membrane), boiling point of the solvent, flash point of the non-aqueous hydrazine solution, and other safety and handling issues.

Further examples include a range of pegylated dimethyl ethers, for example polyethylene glycol DME200, polyethylene glycol DME 250, polyethylene glycol DME500, polyethylene glycol DME1000 or polyethylene glycol DME 2000. In some embodiments, the non-aqueous hydrazine solution comprises hydrazine in a range of from about 30% to about 69% by weight, ranging from about 65% to about 69% by weight. The remainder of the solution may include, for example, one or more pegylated solvents, e.g., glyme. For example, the hydrazine solution may contain about 32% to 35% by weight of a pegylation solvent, e.g., dimethyl ether of polyethylene glycol or other suitable solvent. In other embodiments, less than about 65% hydrazine is used, and greater than about 35% of a pegylation solvent, e.g., polyethylene glycol dimethyl ether, e.g., polyethylene glycol DME 250, is used.

The methods, systems, and devices provided herein can employ various films. The membrane is typically a perm-selective membrane, particularly a substantially gas impermeable membrane, for example, a perfluorinated ion exchange membrane, for example,

and (3) a membrane. In certain embodiments, acid, base or salt pairs may be used, for example

The membrane is chemically treated to change its reactivity. For example, in certain embodiments, the treatment may be in a manner that forms an ammonium species

And (3) a membrane. By using certain perm-selective membranes, generally substantially gas impermeable membranes, in particular

Membranes and derivatives thereof, the concentration of hydrazine gas in the resulting gas stream can be varied relative to the hydrazine concentration obtained directly from the vapors of the hydrazine solution in the absence of the membrane. In certain embodiments, the hydrazine gas concentration is increased (i.e., higher) than the concentration expected for the vapors of the hydrazine solution without the membrane. Preferably, the concentration of hydrazine is increased using the methods, systems, and devices disclosed herein.

In another embodiment, the film is a copolymer of tetrafluoroethylene and sulfonyl fluoride vinyl ether. One such example of such a membrane may be made of

(Solvay s.a. by brussel belgium). A specific

The polymer is designated P98S and is provided in particulate form.

The methods, systems, and apparatuses provided herein can further include removing one or more components from the hydrazine-containing gas stream to produce a purified hydrazine-containing gas stream, e.g., using an apparatus that selectively or non-selectively removes components from the gas stream. Preferred apparatus are those which substantially remove non-reactive process gases from a hydrazine-containing gas stream, while the amount of hydrazine in the gas stream is relatively unaffected. For example, the apparatus may remove any non-aqueous solvent or stabilizer from the gas stream, including but not limited to any trace amounts of water or non-aqueous solvent. For example, the apparatus may further comprise a purifier located downstream of the head space. Particularly preferred purification units are membrane contactors, molecular sieves, activated charcoal and other adsorbents if they have the desired characteristics to meet the application or process requirements. A preferred feature of the gas removal means is the ability to remove certain components in a relatively selective manner whilst allowing the remaining components to remain relatively unaffected in the hydrazine gas stream.

The systems and devices provided herein can also include various components for containing and controlling the flow of gases and liquids used therein. For example, the systems and devices may also include mass flow controllers, valves, check valves, pressure gauges, regulators, rotameters, and pumps. The systems and devices provided herein can also include various heaters, thermocouples, and temperature controllers to control the temperature of the various components of the device and the steps of the method.

Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the description and claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.

Drawings

FIG. 1A is a diagram illustrating a portion of a membrane module useful in certain embodiments of the present invention;

fig. 1B is a diagram illustrating an embodiment of a Hydrazine Delivery Assembly (HDA) according to certain embodiments of the invention;

FIG. 2A is a cross-sectional view of an embodiment of an HDA according to some embodiments of the invention;

FIG. 2B is a cross-sectional view of an embodiment of an HDA according to some embodiments of the invention;

FIG. 3 is a P & ID of a manifold that may be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention;

FIG. 4 is a P & ID of a manifold that may be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention;

FIG. 5 is a P & ID of a manifold that may be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention;

FIG. 6 is a diagram showing a membrane module and HDA according to certain embodiments of the invention;

FIG. 7 is a P & ID of a manifold that may be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention;

FIG. 8 is a graph depicting hydrazine gas concentration and temperature as a function of time using substantially pure hydrazine as a liquid source in accordance with an embodiment of the invention;

FIG. 9 is a P & ID of a manifold that may be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention;

FIG. 10 is a graph depicting hydrazine gas concentration and temperature as a function of time using anhydrous 98% hydrazine as a liquid source in accordance with an embodiment of the invention;

FIG. 11 is a graph depicting hydrazine gas concentration and temperature as a function of time using 65% hydrazine in polyethylene glycol dimethyl ether as a liquid source in accordance with an embodiment of the present invention;

FIG. 12 is a diagram illustrating an HDA according to some embodiments of the invention;

FIG. 13 is a P & ID of a manifold that can be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention;

figure 14 is a picture of a tube containing four different non-aqueous hydrazine solutions that can be used as liquid sources according to certain embodiments of the invention;

fig. 15 is a graph depicting hydrazine gas concentration and time dependence using 65% hydrazine in triethylene glycol as the liquid source in accordance with an embodiment of the present invention.

Detailed Description

Various embodiments of the present invention will now be explained in more detail. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. Any discussion of certain embodiments or features is intended to illustrate certain exemplary aspects of the present invention. The present invention is not limited to the embodiments specifically discussed herein.

Unless otherwise indicated, all numbers used in the specification and claims (e.g., numbers expressing temperatures, weight percentages, concentrations, time periods, dimensions, and values for certain parameters or physical properties) are to be understood as being modified in all instances by the term "about". It should also be understood that the precise numerical values and ranges used in the specification and claims form additional embodiments of the invention. All measurements were subject to uncertainty and experimental variability.

The term "critical process or application" as used herein is a broad term that one of ordinary skill in the art would impart in its conventional and customary meaning (not limited to a specific or specified meaning) and refers, but is not limited to, processes or applications for which process control and purity are critical considerations. Examples of key processes and applications include, but are not limited to, microelectronic applications, wafer cleaning, wafer bonding, photoresist stripping, silicon oxidation, surface passivation, photolithographic mask cleaning, atomic layer deposition, chemical vapor deposition, flat panel displays, surface disinfection by bacteria, viruses, and other biological agents, industrial component cleaning, pharmaceuticals, nanomaterial production, power generation and control devices, fuel cells, and power transmission devices.

The term "process gas" as used herein is a broad term that one of ordinary skill in the art would impart conventional and customary meaning (not limited to a specific or designated meaning) and refers to, but is not limited to, gases used in applications or processes, such as, for example, those used in steps in microelectronic fabrication or processing and other critical processes. Exemplary process gases are reducing agents, oxidizing agents, inorganic acids, organic acids, inorganic bases, organic bases, and inorganic and organic solvents. The preferred process gas is hydrazine.

The term "reactive process gas" as used herein is a broad term that one of ordinary skill in the art would impart its conventional and customary meaning (without limitation to a particular or specified meaning) and refers, without limitation, to a process gas that chemically reacts in a particular application or process in which the gas is used, for example, by reacting with a surface, a liquid process chemical, or another process gas.

The term "non-reactive process gas" as used herein is a broad term that one of ordinary skill in the art would impart in its conventional and customary meaning (and not limited to a specific or designated meaning) and refers to, but is not limited to, process gases that do not chemically react in the particular application or process in which the gas is used, but the nature of the "non-reactive process gas" provides for its use in the particular application or process.

The term "carrier gas" as used herein is a broad term that one of ordinary skill in the art would impart in its conventional and customary meaning (and not limited to a specific or designated meaning) and refers to, but is not limited to, a gas used to carry another gas through a process flow, which is typically a pipeline transport flow. Exemplary carrier gases are nitrogen, argon, hydrogen, oxygen, CO2, clean dry air, helium, or other gases that are stable at room temperature and atmospheric pressure.

The term "headspace" as used herein is a broad term that one of ordinary skill in the art would impart its conventional and customary meaning (and not limited to a specific or designated meaning) and refers to, but is not limited to, the volume of gas in fluid contact with the hydrazine solution that provides at least a portion of the gas contained in the headspace. There may be a permeable or selectively permeable barrier that completely or partially separates the head space, which is optionally in direct contact with the hydrazine solution. In those embodiments where the membrane is not in direct contact with the hydrazine solution, there may be more than one headspace, i.e. a first headspace directly above the solution comprising the solution gas phase and a second headspace separated from the first headspace by a membrane comprising only the components of the first space that can permeate the membrane, e.g. hydrazine. In those embodiments where the hydrazine solution and the headspace are separated by a substantially gas-impermeable membrane, the headspace can be above, below, or on either side of the hydrazine solution, or the headspace can surround or be surrounded by the hydrazine solution. For example, the headspace can be a space within a substantially gas-impermeable tube through the hydrazine solution, or the hydrazine solution can be located within the substantially gas-impermeable tube with the headspace surrounding the exterior of the tube.

The term "substantially gas-impermeable membrane" as used herein is a broad term that one of ordinary skill in the art would impart its conventional and customary meaning (and is not limited to a particular or specified meaning) and refers to, but is not limited to, membranes that are relatively permeable to other components that may be present in a gas or liquid phase (e.g., hydrazine), but relatively impermeable to other gases (e.g., without limitation, hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide, hydrogen sulfide, hydrocarbons (e.g., ethylene), volatile acids and bases, refractory compounds, and volatile organic compounds).

The term "ion exchange membrane" as used herein is a broad term that one of ordinary skill in the art would impart its conventional and customary meaning (without being limited to a specific or designated meaning) and refers to, but is not limited to, membranes that include chemical groups capable of binding ions or exchanging ions with the membrane and external substances. These chemical groups include, but are not limited to, sulfonic acids, carboxylic acids, sulfonamides, sulfonimides, phosphoric acids, phosphinic acids, arseno, seleno, phenolic groups, and salts thereof.

The term "permeation rate" as used herein is a broad term that one of ordinary skill in the art would impart in its ordinary and customary meaning (and not limited to a specific or designated meaning) and refers to, but is not limited to, the rate at which a particular chemical (e.g., hydrazine or chemical composition) permeates a membrane. The permeation rate may be expressed as the amount of target chemical or composition that permeates a membrane of a particular surface area over a period of time, e.g., liters per minute per square inch (L/min/in)²)。

The term "non-aqueous solution" or "non-aqueous hydrazine solution" as used herein is a broad term which one of ordinary skill in the art will impart conventional and customary meanings (without being limited to specific or specified meanings) and refers to solutions comprising hydrazine and optional other components and comprising less than 10% by weight water. Exemplary non-aqueous solutions include those containing less than 2%, 0.5%, 0.1%, 0.01%, 0.001% or less water, which are referred to herein as "anhydrous hydrazine".

The term "stabilizer" as used herein is a broad term that one of ordinary skill in the art would impart conventional and customary meanings (not limited to specific or designated meanings) and refers to chemicals that prevent the decomposition or reaction of process chemicals (e.g., hydrazine or hydrogen peroxide). In certain embodiments, the stabilizer is non-volatile and is present in the gas phase in an amount no greater than an insubstantial amount. In certain embodiments, the stabilizer may be removed from the process gas stream by exposing the process gas stream to an adsorbent or passing the process gas stream through a cold trap. In certain embodiments including membranes that separate the non-aqueous hydrazine solution from the gas phase, the stabilizing agent may not penetrate the membrane.

The methods, systems, and apparatus disclosed herein provide for the advantageous delivery of volatile process components to critical process applications. In many embodiments, the methods, systems, and devices disclosed herein are particularly useful for hydrazine. Certain of the devices disclosed herein are also suitable for use with other volatile process components.

In certain embodiments, membrane contactors may be used to achieve the advantageous hydrazine transport provided by the methods, systems, and apparatus of the present invention, particularly certain embodiments described herein. In a preferred embodiment, a non-porous membrane is used to provide a barrier between the hydrazine solution and the headspace in contact with the carrier gas or vacuum fluid. Preferably, hydrazine rapidly permeates through the membrane while preventing gas permeation through the membrane into solution. In some embodiments, the membrane may be chemically treated with an acid, base, or salt to alter the properties of the membrane.

In certain embodiments, the hydrazine is introduced into the carrier gas or vacuum through a substantially gas impermeable ion exchange membrane. The gas impermeability can be determined by the "leak rate". The term "leak rate" as used herein is a broad term that one of ordinary skill in the art will impart to it a conventional and customary meaning (not limited to a specific or specified meaning) and refers to, but is not limited to, the volume of a particular gas that permeates the surface area of the membrane per unit time. For example, at standard atmospheric temperature and pressure, a substantially gas impermeable membrane may have a low leakage rate of a gas (e.g., a carrier gas) other than a process gas (e.g., hydrazine), e.g., a leakage rate of less than about 0.001cm3/cm 2/s. Alternatively, a substantially gas impermeable membrane may be identified by the ratio of the permeability of the process gas vapor to the permeability of the other gases. Preferably, the substantially gas impermeable membrane has a permeability to such process gases that is higher than the permeability of the other gases by a ratio of at least 10,000: 1, for example, 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 at least 1,000,000: 1. However, in other embodiments, other ratios less than 10,000: 1 are acceptable, e.g., 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.

In certain embodiments, the membrane is an ion exchange membrane, e.g., a polymer resin containing exchangeable ions. Preferably, the ion-exchange membrane is a fluoropolymer, for example, polyvinylidene fluoride, Polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFE), Polytrifluoroethylene (PCTFE), tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-chlorotrifluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene terpolymer, tetrafluoroethylene rubber, and fluorinated thermoplastic elastomer. Alternatively, the resin comprises a composite or mixture of polymers, or a mixture of polymers and other components, to provide a continuous film material. In certain embodiments, the film material may comprise two or more layers. The different layers may have the same properties or different properties, e.g., chemical composition, porosity, permeability, thickness, etc. In certain embodiments, it may also be desirable to use a layer (e.g., a membrane) that provides support for the filtration membrane, or has some other desired property.

The ion exchange membrane is preferably a perfluorinated ionomer comprising a copolymer of ethylene and a vinyl monomer containing acid groups or a salt thereof. Exemplary perfluorinated ionomers include, but are not limited to, perfluorosulfonic acid/tetrafluoroethylene copolymers ("PFSA-TFE copolymers") and perfluorocarboxylic acid/tetrafluoroethylene copolymers ("PFCA-TFE copolymers"). These films are under the trade name

(E.I.du Pont de Nemours&Company), 3M ionomers (Minnesota Mining and Manufacturing Co.), and,

(Asashi Glass Company, Ltd.) and

(Asashi Chemical Industry Company) and

(Solvay) is marketed.

In the preparation of the hydrazine-containing gas stream, the hydrazine solution can be passed through a membrane. The term "passing the hydrazine solution through the membrane" as used herein is a broad term and is given its ordinary and customary meaning (without being limited to a specific or specified meaning) by a person of ordinary skill in the art and refers, without limitation, to contacting a first side of the membrane with the hydrazine solution, allowing the hydrazine to pass through the membrane and obtaining a hydrazine-containing gas stream on the opposite side of the membrane. The first and second sides may have the form of substantially flat, relatively planar regions, wherein the membrane is a sheet. The membrane may also be provided in a tubular or cylindrical form, wherein one surface forms the inner position of the tube and the opposite surface is located on the outer surface. The membrane may take any form so long as the first surface and the opposing second surface sandwich a substantial portion of the membrane material. The properties of the film can be adjusted depending on the process conditions, the nature of the hydrazine solution, the volume of hydrazine solution vapor to be generated, and other factors. Properties include, but are not limited to, physical form (e.g., thickness, surface area, shape, length, and width of a sheet form, diameter if in fiber form), configuration (one or more flat sheets, one or more spiral or rolled sheets, one or more folded or rolled sheets, one or more arrays of fibers), manufacturing process (e.g., extrusion, casting from solution), presence or absence of a support layer, presence or absence of an active layer (e.g., a porous pre-filter that adsorbs particles of a particular size, a reactive pre-filter that removes impurities via chemical reaction or adhesion), and the like. It is generally preferred that the film has a thickness of from about 0.5 microns or less to 2000 microns 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 used, it may be desirable to provide mechanical support to the membrane (e.g., by using a support membrane, screen or mesh or other support structure), while thicker membranes may be suitable for use without support. The surface area may be selected based on the quality of the steam to be produced.

Certain embodiments of the methods, systems, and apparatus provided herein are illustrated with reference to the figures, wherein a carrier gas or vacuum can be used to transport substantially anhydrous hydrazine.

According to certain embodiments of the present invention, a Hydrazine Delivery Assembly (HDA) is provided. HDA is a device for delivering hydrazine into a process gas stream, for example, a carrier gas for use in critical process applications (e.g., microelectronics manufacturing or other critical process applications). The HDA may also be run under vacuum. The HDA can have a variety of different configurations, including at least one membrane and at least one vessel containing a non-aqueous hydrazine solution and a headspace separated from the solution by the membrane.

Fig. 1A and 1B depict different views of an embodiment of an HDA 100 and a membrane module 110, the membrane module 110 forming a portion of an HDA that may be used as provided herein. FIG. 1A shows a membrane module 110 comprising a plurality of membranes 120, e.g., 5R

A membrane, which may be configured as a lumen. As shown in fig. 1A, the membrane 120 configured as an inner cavity is inserted into the collector plate 130 through a plurality of holes in the collector plate 130. The membrane assembly 110 also includes a plurality of Polytetrafluoroethylene (PTFE) rods 140 inserted within the collector plates 130. As shown in fig. 1B, the membrane assembly 110 includes a membrane cavity 120 that spans a collector plate 130 as part of the HDA 100. HDA 100 also includes end caps 150 at each end of membrane module 110. The end cap 150 also includes a branch 160, and the branch 160 may be equipped with tubing to provide access to the interior of the HDA 100, e.g., to fill, empty, clean, or refill the HDA.

Fig. 2A and 2B illustrate cross-sectional views of two embodiments of an HDA according to some embodiments of the invention.

As shown in fig. 2A, HDA 200A includes a membrane assembly 210A located within a housing 220A and an end cap 230A configured to be coupled to housing 220A. The diaphragm assembly 210A includes a plurality of diaphragms 240A, which diaphragms 240A may be configured as lumens. The number of lumens may vary depending on various factors, including the size of the lumens, the size of the HDA 200A, and the operating conditions of the HDA. In certain embodiments, the HDA may contain up to 1000 membrane lumens, up to500 lumens, up to 200 lumens, up to 100 lumens, or up to 50 lumens. For example, the HDA 200A may have about 20 to 50 membrane lumens. The membrane lumen may be formed of a perfluorinated sulfonic acid membrane (e.g., 5R)

A film). The end cap 230A and the housing 220A may be formed from various materials, such as PTFE, stainless steel (e.g., 316 stainless steel), or other suitable materials. Each end cap 230A also includes a gas connection 231A. Gas coupling 231A may take the form of various coupling configurations and sizes, for example, an 1/4 inch VCR, a 1/4 inch NPT, or other suitable connector.

As shown in fig. 2B, HDA 200B includes a membrane assembly 210B within a housing 220B and an end cap 230B configured to be coupled to housing 220B. The diaphragm assembly 210B may include a plurality of diaphragm lumens (not shown). The number of lumens may vary depending on various factors, including the size of the lumens, the size of the HDA 200B, and the operating conditions of the HDA. In certain embodiments, the HDA may comprise up to 1000 lumens, up to 500 lumens, up to 200 lumens, up to 100 lumens, or up to 50 lumens. For example, the HDA 200B may have about 20-50 membrane lumens. The membrane lumen may be formed of a perfluorinated sulfonic acid membrane (e.g., 5R)

A film). End cap 230B and housing 220B may be formed from various materials, such as PTFE, stainless steel (e.g., 316 stainless steel), or other suitable materials. Each end cap 230B may include a gas connection 231B. Gas connection 231B may take the form of various connection configurations and sizes, for example, an 1/4 inch VCR, a 1/4 inch NPT, or other suitable connector.

According to various embodiments, the HDA may be filled with a non-aqueous hydrazine-containing solution while keeping the head separated from the hydrazine-containing solution by a membrane. Because the membrane is permeable to hydrazine and substantially impermeable to the other components of the solution, the headspace will contain substantially pure hydrazine vapor in a carrier gas or vacuum, depending on the operating conditions of the process.

According to various embodiments, the HDA may be constructed similar to the apparatus described in commonly assigned U.S. patent No.7,618,027, which is incorporated herein by reference.

According to certain embodiments, there is provided a device for containing a liquid and a gaseous phase comprising a volatile chemical or composition, which may be a non-aqueous hydrazine-containing solution, wherein the membrane is contacted with the volatile chemical or composition on one side of the membrane and a carrier gas stream on the other side of the membrane. Fig. 12 depicts one example of such a device 1200 that includes (a) a chamber containing a liquid containing a volatile chemical or chemical composition; (b) a headspace comprising a vapor phase comprising a volatile chemical or chemical composition in a vapor phase; (c) an inlet through which a carrier gas stream can enter the chamber, and (d) a protected outlet through which a process gas stream comprising the carrier gas stream and the volatile chemical or chemical composition can exit the headspace.

As shown in fig. 12, the carrier gas 1214 enters through inlet 1202. The carrier gas 1214 then moves through the membrane 1208, which is connected to the inlet 1202 by a seal 1216. In certain embodiments, the seal 1216 provides a leak-free connection between the

inlets

1202 and 1208. In certain embodiments, the seal 1216 may be non-leak proof or may be a partial seal to allow a portion of the carrier gas 1214 to flow into the headspace 1210. In certain embodiments, the membrane 1208 is a tubular membrane, but its geometry can be tailored according to the requirements of the particular application or process in which the device is used. One side of the membrane 1208 is configured to contact a liquid 1212, the liquid 1212 comprising a volatile chemical or composition capable of diffusing through the membrane 1208. The carrier gas 1214 flows through the membrane 1208 on the side opposite the side in contact with the liquid 1212. As the volatile chemical or composition diffuses through the membrane into the carrier gas stream, a process gas stream 1218 is formed that includes the volatile chemical or composition in a gas phase. The membrane 1208 allows certain components of the liquid 1212 to diffuse through the membrane into the carrier gas stream to provide a selected process gas stream 1218 while preventing other components of the liquid 1212 from diffusing into the process gas stream 1218 (e.g., water, metal ions, other ionic contaminants, and other contaminants). At the outlet 1222 of the membrane 1208, a process gas stream 1218 comprising a carrier gas 1214 and process chemicals from the liquid 1212 enters the headspace 1210. Thus, the pressure inside tubular membrane 1208 matches the pressure in headspace 1210, and thus matches the vapor pressure of liquid 1212, which prevents collapse of the membrane when the outlet pressure is lower than the inlet pressure. The process gas 1220 contained in the headspace 1210 exits the apparatus through the splash shield 1206 and outlet 1204 for delivery to the critical process 1224. In this embodiment, the splash guard 1206 holds the open end 1222 of the tubular membrane 1208 such that the process gas stream discharged through the outlet 1204 is substantially free of liquid contaminants, such as droplets, particles, mist, or fog.

In many embodiments, for example, the embodiment shown in fig. 12, the membrane is partially immersed in the liquid source. The submerged membrane increases the mass transfer surface area and the residence time for which the carrier gas must be fully saturated with the gas generated by the liquid source. The membrane may be long enough to reach the bottom of the tank and then return above the liquid level. The length of the membrane may range from about 3.0 inches or less to about 72 inches or more, including lengths between about 5, 10, 15, 20, 25, 30, or 35 inches to about 40, 45, 50, 55, 60, or 65 inches or more. The immersed portion of the membrane may be coiled to increase the surface area of the liquid to the membrane. Multiple membranes may be used and run in parallel to further increase the surface area of the liquid to the membrane. The film can be about 0.002 inches thick or less to about 0.010 inches thick or more, including about 0.003, 0.004, or 0.005 inches thick to about 0.006, 0.007, 0.008, or 0.009 inches thick or more. The membrane may have a diameter of about 0.062 inches or less to about 0.250 inches or more, including 0.070, 0.080, 0.090, 0.100, 0.110, 0.120, 0.130, 0.140, or 0.150 inches to about 0.160, 0.170, 0.180, 0.190, 0.200, 0.210, 0.220, 0.230, or 0.240 inches or more.

In many embodiments, for example, the embodiment shown in fig. 12, the device includes a splash shield. The splash shield limits the volume, velocity, or properties of the liquid flowing out through the device outlet. The splash shield is capable of maintaining the outlet of the tubular membrane above the liquid. In several embodiments, the splash shield has a long narrow slit in the conductive path leading to the outlet barb that prevents liquid droplets from entering the air stream exiting the outlet. The splash shield is made of a material that is compatible with the chemicals used in the liquid source and carrier gas. For example, a low reactivity material such as, but not limited to, stainless steel, aluminum, or plastic may be used. The splash shield may be connected to the container by fitting over the outlet barb. In some embodiments, the splash shield has a height of about 1.50 inches, a slit width of about 0.03 inches and a height of about 1.25 inches, and the slit length is the same as the splash shield diameter and is about 1.00 inches.

Although the primary purpose of the present disclosure is to vapor phase transport non-aqueous hydrazine in accordance with the methods, systems, and apparatus provided herein, other process chemicals capable of diffusing across the membrane may also be used in the liquid source, and thus may also be part of the process gas stream 1218 exiting the outlet, including hydrogen peroxide, water, alcohols (e.g., ethanol, methanol, ethylene glycol, pentanol, glycerol, xylitol, or isopropanol), amines (e.g., hydrazine, methylamine, ethanolamine, dimethylamine, aniline, trimethylamine, triphenylamine, aziridine, or methylethanolamine), or ammonium hydroxide. These process chemicals, whether in liquid sources or process gases, can be used alone or in combination. In certain embodiments, the liquid source may comprise a polar solvent, while in certain other embodiments, the liquid source may comprise a non-polar solvent.

The apparatus disclosed herein (e.g., the apparatus shown in fig. 12) capable of containing a liquid source containing at least one process chemical and delivering the at least one process chemical in a gas phase to a critical process application can be used in conjunction with the methods, systems, and other apparatus of the present invention or can be used as a stand-alone apparatus for delivering a process gas stream to a critical process application.

Embodiments in accordance with one aspect of the methods, systems, and apparatus provided herein are described below with reference to a manifold 300, as shown with reference to fig. 3. According to the embodiment illustrated with reference to fig. 3, the carrier gas 310 flows through the headspace of the HDA 320, which HDA 320 may be an HDA as described above. A Mass Flow Controller (MFC)330 (e.g., unit UFC-1260 A1 slm) may be used to control the flow rate of the carrier gas 310, e.g., the carrier gas 310 may be set to 1 slm. Analysis of the amount of hydrazine in the gas stream may require dilution of the resulting gas stream, which may be accomplished with a diluent gas 350. A Mass Flow Controller (MFC)340 (e.g., unit UFC-1260a 10slm) may be used to control the flow rate of the dilution gas 350. The carrier gas 310 and the diluent gas 350 may be supplied by a gas source 360, and the gas source 360 may typically be nitrogen or other suitable carrier gas. Valve 370 may be used to isolate the dilution line when not needed. Check valves 371, 372 may be placed downstream of MFC 330 and MFC 340 to protect them from possible hydrazine exposure. A 60psig pressure gauge 373 can be placed between the MFC 330 and the check valve 372 to ensure that the manifold pressure does not exceed the maximum pressure allowed by the hydrazine analyzer 380, e.g., 5 psig.

The nitrogen pressure can be maintained with a forward pressure regulator 374, typically set at 15 psig. Thermocouple 375 can measure the temperature of the nitrogen-bearing gas 310 before it enters HDA 320 to add hydrazine. Thermocouple 376 can measure the temperature of the hydrazine solution in HDA 100. The thermocouple 377 may measure the temperature of the gas before entering the hydrazine analyzer 380. The hydrazine analyzer 380 can aspirate a sample of the carrier gas 310 to measure the hydrazine concentration. The manifold 300 may also include a relative humidity/resistance temperature detector (RH/RTD) probe 378. As shown in fig. 3, a heating band 390 may be placed on some portion. The temperature of the manifold can be controlled in two separate zones (i.e., the membrane module and the remaining piping) using a Trilite Equipment & Technologies controller and a Watlow 96 controller, respectively. The entire manifold may be disposed inside the fumehood.

The embodiment shown with reference to fig. 3 was configured as a test apparatus to measure the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar equipment can be used to deliver hydrazine to critical process applications.

Fig. 4 is a P & ID of a test manifold 400 according to another embodiment, the test manifold 400 being used to illustrate the delivery of hydrazine under vacuum conditions according to the methods, systems, and apparatus provided herein. According to the embodiment illustrated with reference to fig. 4, vacuum pump 410 removes gas from the hydrazine-containing vapor side (i.e., headspace) of HDA 420, which HDA 420 may be an HDA as described above. For example, the vacuum pump 410 may be maintained at about 24mmHg using the valve 480 and the pressure gauge 430. The gas source 440 may be maintained at a pressure of about 2psig with a forward pressure regulator 450. Valve 460 may function as a flow restrictor. A thermocouple 470 may be placed within the fill tube of the HDA 420 to measure the temperature of the solution within the HDA 420 enclosure. The test involves contacting the vapor side (i.e., headspace) of the HDA 420 with the vacuum generated by the vacuum pump 410 while maintaining the HDA 420 at a constant temperature. A heating belt 490 may be placed around the HDA 420 to allow for isothermal control of the hydrazine-containing solution within the HDA 420. Such vacuum-based methods, systems and apparatus are particularly preferred in many microelectronic and other critical process applications that operate at relatively reduced pressures (i.e., under vacuum).

The embodiment shown with reference to fig. 4 was configured as a test apparatus to measure the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar equipment can be used to deliver hydrazine to critical process applications.

Fig. 5 is a P & ID of a test manifold 500 according to another embodiment, the test manifold 500 for illustrating hydrazine delivery according to one aspect of the methods, systems, and apparatus provided herein. As shown in FIG. 5, the nitrogen-laden gas 510 may flow through the headspace of the HDA 520, and the HDA 520 may be an HDA as described above. A Mass Flow Controller (MFC)530 (e.g., Brooks SLA5850S1EAB1B2A 15 slm) may be used to control the flow rate of the nitrogen carrier gas 510, which may be set to 1slm, for example. Analysis of the amount of hydrazine in the gas stream may require dilution of the resulting gas stream, which may be accomplished with a dilution gas 550. Mass Flow Controllers (MFCs) 540 (e.g., Brooks SLA5850S1EAB1B2a 110 slm) may be used to control the flow rate of nitrogen dilution gas 550. The nitrogen carrier gas 510 and the nitrogen diluent gas 550 may be supplied by a nitrogen source 560. Valve 570 may be used to isolate the dilution line when desired. A pair of

check valves

571, 572 can be placed downstream of MFC 530 and MFC 540 to protect MFC 530 and MFC 540 from possible hydrazine exposure. A pressure gauge 573 (e.g., 100psi gauge) may be placed between the MFC 530 and the HDA 520 to ensure that the manifold pressure does not exceed any maximum pressure allowed by the analyzer 580.

Nitrogen pressure can be maintained with forward pressure regulator 574, set, for example, to 25 psig. The thermocouple 575 may measure the temperature of the nitrogen carrier gas 510 before it enters the HDA 520 to add hydrazine. Within the HDA 520, a nitrogen-bearing gas 510 can flow through the membrane tube, and hydrazine vapor can permeate through the membrane from a solution contained within the housing and combined with the carrier gas 510. Thermocouple 576 can measure the temperature of the hydrazine solution in HDA 520. The thermocouple 577 may measure the temperature of the gas exiting the HDA 520. In this embodiment, the analyzer 580 can be used to measure the concentration of hydrazine in the gas stream. The analyzer 580 may be, for example, a MiniRAE3000 having a photoionization detector with an 11.7ev gas discharge lamp. For example, the analyzer 580 can sample the hydrazine-containing gas stream to measure the hydrazine concentration. The thermocouple 578 may be used to measure the gas temperature before the gas enters the analyzer 580. Thermocouple 581 may be used to measure the temperature of nitrogen dilution gas 550.

The manifold 500 may also include a catalytic converter 585, which catalytic converter 585 is configured to remove hydrazine by converting the hydrazine to nitrogen and hydrogen. Downstream of the catalytic converter 585 may be a detector 579, e.g., an E + E Elektronik EE371 humidity transmitter, configured to measure Dew Point (DP) and humidity concentration. Downstream of the probe 579 may be an exhaust port. As shown in fig. 5, heating strips 590 may be placed on certain sections. Watlow can be used in four separate areas, respectively

The controller 96 controls the temperature of the manifold, represented by the dashed box. The entire manifold may be disposed inside the fumehood.

The embodiment shown with reference to fig. 5 was configured as a test apparatus to measure the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar equipment can be used to deliver hydrazine to critical process applications.

FIG. 6 is a diagram illustrating side and cross-sectional views of membrane assemblies useful in certain embodiments of the invention when a single membrane is used. The membrane module may be incorporated into, for example, an HDA, e.g., as shown in fig. 1B. In one embodiment of the invention, as shown in fig. 6, the membrane may be a single membrane lumen that is sleeved over a stainless steel tube containing a calibrated number of holes to provide a specific membrane surface area available for permeation. The nested stainless steel tube was wrapped inside an outer tube to form a Hydrazine Delivery Assembly (HDA). Liquid hydrazine is filled in the space between the inner tube and the outer tube. A carrier gas is directed to flow through the inner tube to carry the hydrazine vapor that has permeated the membrane to the desired process.

Figure 7 is a P & ID of a manifold that may be used to test methods, systems, and apparatus for hydrazine delivery, according to certain embodiments of the invention. According to this embodiment, a Carrier Gas (CG) flows through the headspace of the HDA, labeled "vaporizer," which may be the HDA as described above. A mass flow controller (MFC 1) (e.g., a 5slm Brooks SLA5850S1EAB1B2a1 mass flow controller) may be used to control the flow rate of the carrier gas into the HDA. Analysis of the amount of hydrazine in the gas stream leaving the evaporator may comprise first diluting the resulting gas stream, which may be done with a diluent gas (DG-1). A mass flow controller (MFC2) (e.g., a 10slm Brooks SLA5850S1EAB1B2A1 mass flow controller) can be used to control the flow rate of diluent gas DG-1. A separate line for diluent gas DG-2 may be supplied to a portion of the manifold located within the glove bag.

Carrier gas CG and diluent gases DG-1 and DG-2 may be supplied from a gas source, which may typically be nitrogen or other suitable carrier gas. In some embodiments, such as the embodiment shown in fig. 7, the carrier gas and the dilution gas share the same gas source. In other embodiments, the carrier gas and the diluent gas may have separate gas sources. Valves V-1 and V-2 can be used to control the flow of gas into the HDA/DG-1 dilution line or DG-2 dilution line/glove bag, respectively. Check valves CV-1 and CV-2 may be placed downstream of MFC2 and MFC 1, respectively, to protect MFC2 and MFC 1 from possible hydrazine exposure. Pressure gauge PG-2 may be placed between CV-2 and the evaporator to measure the pressure upstream of the evaporator.

The carrier gas pressure may be maintained with a forward pressure regulator PR1 and measured with pressure gauge PG-1. A forward pressure regulator PR2 can be used to control the flow of diluent gas DG-2 through the airbag. Thermocouple T-1 can measure the temperature of the hydrazine solution in the evaporator. Thermocouple T-2 can measure the temperature of the gas after the mixing loop and before entering the hydrazine analyzer. MiniRAE3000 is an example of a hydrazine analyzer. The heating zone HT may be placed on some sections, for example on the evaporator, a portion of the line of dilution gas DG-1 and on the line downstream of the evaporator, as shown in fig. 7. The manifold may also include an evaporator and a catalytic converter downstream of the glove bag to decompose hydrazine into nitrogen and hydrogen. The entire manifold may be disposed inside the fumehood.

The embodiment shown with reference to fig. 7 was configured as a test apparatus to measure the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar equipment can be used to deliver hydrazine to critical process applications.

Example 1

Experiment of

In embodiments of the present disclosure, a film is prepared by: the sulfonyl fluoride perfluorinated polymer is purchased, extruded, and then hydrolyzed using methods known in the art to form a film. Such films are also referred to herein as

In this example, the manifold shown in FIG. 7 was used for the test procedure. The test procedure included the use of a non-aqueous, substantially pure hydrazine solvent as the liquid source to obtain stable gas phase hydrazine readings.

Use of

The evaporator (P/N #200801-01) performs this experiment. The evaporator included a single 5R tube fitted over an 1/8 inch SS (stainless steel) tube

And (3) a membrane. The SS tube had 20 holes with a diameter of 0.06 inches, allowing a total permeate area of 0.06 square inches. The tubing was surrounded by an 3/8 inch SS tube with two 1/4 inch fill ports on the shell side. The volume of the shell side was about 8 ml.

The manifold is disposed in the fumehood. Nitrogen pressure was maintained at 25psig with a forward pressure regulator (PR-1) and measured with a pressure gauge (PG-1). Two valves (V-1 and V-2) are used to terminate the gas flow through the evaporator and/or dilution line. The carrier gas flow rate was controlled using a 5slm Brooks SLA5850S1EAB1B2A1 mass flow controller (MFC-1). The dilution gas flow rate was controlled using a 10slm Brooks SLA5850S1EAB1B2A1 mass flow controller (MFC-2). Check valves (CV-1 and CV-2) are placed downstream of the two MFCs to prevent exposure of the two MFCs to hydrazine. A forward pressure regulator (PR-2) with a pressure gauge was used to control the flow of nitrogen through the balloon. The pressure upstream of the evaporator was measured with a pressure gauge (PG-2). A type J thermocouple (TC-1) was attached to the evaporator as a control point for the heating zone. The carrier gas is mixed with nitrogen from the dilution line downstream of the evaporator. Type J thermocouple (TC-2) was used to monitor the mixed gas temperature. The concentration of hydrazine in the gas stream was measured using a MiniRAE3000 with a Photo Ionization Detector (PID) with an 11.7ev gas discharge lamp. The test manifold and glove bag exhaust lines have catalytic converters that decompose hydrazine into nitrogen and hydrogen. The evaporator, a portion of the dilution line, and a test manifold downstream of the evaporator were heat traced with a heating tape.

For this experiment, the carrier gas flow was set at 1 slm. The flow rate of the dilution gas was initially set to 1slm, and if the concentration is higher than 2000ppm (upper limit of detection of MiniRae 3000), the flow rate of the dilution gas would increase. The manifold was heated to maintain the gas temperature at 30 ℃ of TC-2.

FIG. 8 shows the experimental results of carrier gas flow and dilution gas flow at 1 slm. As shown, once the system is stable, the hydrazine output is directly affected by the gas temperature. This effect is shown when the temperature set point for the test is increased from 30 ℃ to 31 ℃ 78 minutes after the start of the test. The average hydrazine concentration at the last 26 minutes of the test was 2426 ppm. The result was a permeation rate of 0.04043L/min/in under these conditions²。

Example 2

In this example, the manifold shown in FIG. 9 was used for the test procedure. The test procedure included using anhydrous 98% hydrazine solvent as the liquid source, or a solution of 65% hydrazine in a dimethyl ether of polyethylene glycol solvent (Mn-250) as the liquid source, to obtain stable gas phase hydrazine readings.

Use of

The evaporator (P/N #200846-A) performed these experiments. The evaporator consists of a 5R tube fitted over an 1/8 inch SS tube

And (3) film composition. The SS tube had ten holes with a diameter of 0.06 inches, allowing a total permeate area of 0.03 square inches. The tubing was surrounded by an 3/8 inch SS tube with two 1/4 inch fill ports on the shell side. The volume of the shell side was about 8 ml.

The manifold is disposed in the fumehood. An Entegris 500KF Gatekeeper purifier is used to remove oxygen, water and hydrocarbons from the gas stream. Two valves (V-1 and V-2) are used to terminate the flow of gas through the glove box and test manifold, respectively. The flow rate of nitrogen gas in the glove box was maintained by a forward pressure regulator, and the pressure was measured by a pressure gauge (PG-1). A check valve (CV-1) was placed upstream of the glove box to prevent the hydrazine from flowing back. A forward pressure regulator with a pressure gauge was used to maintain a gas pressure of 25psig upstream of the MFC. The carrier gas flow was controlled using a 5slm Brooks SLA5850S1EAB1B2A1 mass flow controller (MFC-1). A 10slm unit mass flow controller (MFC-2) was used to control the dilution gas flow. Check valves (CV-2 and CV-3) are placed downstream of the two MFCs to prevent exposure of the two MFCs to hydrazine.

A single chamber evaporator was used to add hydrazine vapor to the gas stream. The mixing loop was used to mix the nitrogen from the dilution line with the hydrazine vapor in the carrier gas downstream of the vaporizer. A type J thermocouple (TC-1) was used to monitor the mixed gas temperature. The concentration of hydrazine in the gas stream was measured using a MiniRAE3000 with a Photo Ionization Detector (PID) with an 11.7ev gas discharge lamp. The test manifold and glove box vent lines had scrubbers that catalytically decomposed hydrazine into nitrogen and hydrogen. A valve (V-3) was used to create a back pressure in the glovebox and for isolation.

For this example, two solutions were tested at room temperature. One solution was anhydrous 98% hydrazine (Sigma Aldrich). The second solution was 65% w/w hydrazine (ρ ═ 1.029g/ml) in polyethylene glycol dimethyl ether (ρ ═ 1.03 g/ml). An 8ml solution was made with 5.2ml of anhydrous 98% hydrazine and 2.8ml of polyglycol dimethyl ether.

Prior to each test run, the MiniRAE3000 was calibrated with a 100ppm isobutylene gas standard. Once the analyzer was connected to the test manifold, the solution was added to the evaporator with no gas flowing through the test manifold. Once filled, the carrier gas flow is set to 1slm and the dilution gas flow is set to 1 slm. If the concentration is higher than 2000ppm (upper limit of detection for MiniRAE 3000), the diluent gas flow will increase. Readings of gas temperature and hydrazine concentration were recorded. Stability will be determined when the evaporator output changes by less than 5 pm/min.

Figure 10 shows the results for 98% hydrazine anhydrous, where the carrier gas and diluent gas flows were at 1slm for 330 minutes. After reaching a plateau within 10 minutes, the mean concentration was 1482.7 ppm. + -. 102.2ppm at a mean temperature of 23.6 ℃. + -. 0.4 ℃. Therefore, the concentration is stabilized within 10% of the average concentration. The result was an average permeation rate of 0.04942L/min/in under these conditions². The hydrazine permeation rate was close to 0.04043L/min/in measured in the previous test performed in example 1²The permeation rate.

Figure 11 shows the results for 65% hydrazine in dimethyl ether of polyethylene glycol, where the carrier and diluent gas streams were at 1slm for 320 minutes. After stabilization within 30 minutes, the average concentration was 1190.6 ppm. + -. 27.6ppm and the average temperature was 24.5 ℃ 0.3 ℃. Under these conditions, the result was an average permeation rate of 0.03969L/min/in². The peak hydrazine concentration shown near time zero in fig. 10 and 11 reflects artifacts in the measurement instrument and is not considered accurate or relevant.

Compared with 98% hydrazine solution, the permeability of 65% hydrazine/polyethylene glycol dimethyl ether solution is reduced by 19.7%. An encouraging property shown by 65% hydrazine/solvent is that the output is more stable over time than a 98% hydrazine hydrate solution. The concentration output of the 98% hydrazine solution decreased by 263ppm in 290 minutes. However, the 65% hydrazine/dimethyl glycol ether solution concentration output dropped only 23ppm within 290 minutes. The overall results for polyglycol dimethyl ether indicate that this is a viable solvent for safe transport of hydrazine vapor.

By controlling the temperature of the hydrazine-containing solution, and if applicable, the carrier gas or vacuum, a specific hydrazine concentration can be delivered. The stability of the hydrazine concentration in the process gas stream can be controlled to be less than about 20%, for example, less than about 18%, less than about 16%, less than about 14%, or less than about 12%, or less than about 10%. In a preferred embodiment, the stability of the hydrazine concentration in the process gas stream can be controlled within one standard deviation to be less than about 10%, e.g., less than about 9%, less than about 8%, less than about 7%, less than about 6%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, or even less than about 1% of the average concentration. The average concentration does not include measurements of the instrument before equilibrium is reached. For example, the measurement of hydrazine concentration in fig. 11 includes a peak that appears to be as high as about 1900 ppm. This peak is an instrumental factor rather than an actual measurement because the instrument takes about 10 minutes or more to stabilize and all the following average concentration readings take this stabilization into account. The selection of a particular hydrazine concentration will depend on the application or process requirements for which the hydrazine-containing process gas will be used. In certain embodiments, the hydrazine-containing gas stream can be diluted by adding additional carrier gas. In certain embodiments, the hydrazine-containing gas stream can be combined with other process gas streams prior to or while the hydrazine is being delivered to the application or process. Alternatively or additionally, any residual solvent or stabilizer or contaminant present in the hydrazine-containing process gas may be removed during the purification (e.g., dehumidification) step using the purifier apparatus.

Example 3

In this example, the manifold shown in FIG. 13 was used for the test procedure. Burte^TMThe evaporator 1306 was fitted with a PTFE splash guard over the outlet barb and a new inner chamber assembly. Burte^TMVaporizer 1306 is filled with 200ml of a liquid source solution containing hydrogen peroxide and a cap is assembled. As shown in fig. 13, a test system 1300 is assembled. The pressure gauge 1310 is connected to a reading display device. All

valves

1302, 1304, 1308, and 1312 are closed, and the

vacuum pumps

1318, 1320, and 1322 are turned off. Cold trap bath 1316 is filled with liquid nitrogen. The outlet Back Pressure Valve (BPV)1304 is closed and valve 1312 is opened.

Vacuum pumps

1318, 1320 and 1322 were turned on, cold trap bath 1316 was turned on, and the equilibrium pressure was recorded. The outlet BPV 1304 opens rapidly to impinge the evaporator 1306 at a low pressure.Monitoring observes Perfluoroalkoxy (PFA) tube 1324 for liquid source solution droplet indications. The evaporator 1306 is exposed to vacuum until the pressure is constant. The valve 1312 is closed and the rate of rise is recorded at minute intervals. This test was repeated several times. The splash guard prevents liquid solution from entering the outlet of the evaporator 1306 at pressures below 1 torr.

Example 4

The compatibility of the additional solvents used in the methods and systems disclosed herein was investigated. Four solutions were prepared containing 65% hydrazine in diethylene glycol (solvent 1), triethylene glycol (solvent 2), hexamethylenetetramine (solvent 3) and DMPU (solvent 4). The components of each test solution are listed in table 1.

Table 1: 65% hydrazine solution

Figure 14 shows a picture of each 65% hydrazine solution after 30 minutes of monitoring.

Solvents

1, 2 and 4 all immediately formed homogeneous 65% by weight hydrazine solutions without stirring. However, solvent 3 cannot be dissolved in hydrazine even after vigorous shaking.

Considering the boiling point, flash point and NFPRA ratings of the three solvents that are readily miscible with hydrazine, as described in example 3, in reference to Burte^TMSolvent 2 was tested in the evaporator application. From Burte containing 65% by weight hydrazine/35% by weight triethylene glycol solution as a liquid source over time^TMThe evaporator measures the hydrazine concentration. The results of this test are shown in fig. 15, fig. 15 plotting the measured hydrazine concentration and temperature as a function of time. The test lasted 120 minutes and the average hydrazine output at 500SCCM was approximately 24,600 PPM.

A65% hydrazine/35% triethylene glycol solution shows a flash point of 90.0 ℃. In contrast, the flash point of anhydrous hydrazine is about 37 ℃.

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.

Claims

1. A method for delivering a process gas stream, comprising:

(a) providing a non-aqueous solution comprising a process chemical and a solvent in an apparatus configured to contain a liquid and a gas phase, wherein the non-aqueous solution has a gas phase comprising an amount of anhydrous vapor of the process chemical;

(b) contacting a carrier gas or vacuum with the gas phase to form a gas stream; and

(c) the gas stream containing anhydrous steam is sent to a critical process or application,

wherein the process chemical is hydrazine, and wherein the solvent is at least one of diethylene glycol, triethylene glycol, 1, 3-dimethyl-3, 4,5, 6-tetrahydro-2 (1H) -pyrimidinone (DMPU), and polyethylene glycol dimethyl ether.

2. The method of claim 1, further comprising varying the concentration of at least one component of the gas phase by varying at least one of the following parameters: (a) temperature of the non-aqueous solution, (b) pressure of the non-aqueous solution, (c) concentration of the non-aqueous solution, (d) temperature of the carrier gas, (e) pressure of the carrier gas or vacuum, and (f) flow rate of the carrier gas.

3. The method of claim 1, wherein at least one membrane is disposed in the device, the membrane configured to at least partially separate a gas phase from a non-aqueous solution.

4. The method of claim 3, wherein the anhydrous vapor permeates the membrane at a faster rate than any other component in the non-aqueous solution.

5. The method of claim 3, wherein the membrane is an ion exchange membrane.

6. The method of claim 1, further comprising removing contaminants from the gas stream.

7. The method of claim 1, wherein the carrier gas is selected from the group consisting of nitrogen, argon, hydrogen, clean dry air, helium, ammonia, and other gases that are stable at room temperature and atmospheric pressure.

8. The method of claim 1, further comprising altering a concentration of at least one component of the gas phase by adding energy to the non-aqueous solution.

9. The method of claim 1, wherein the non-aqueous solution is a non-aqueous hydrazine solution comprising 25% to 69% hydrazine by weight.

10. The method of claim 9, wherein the non-aqueous hydrazine solution comprises 65% to 69% hydrazine by weight.

11. The method of claim 1, wherein the non-aqueous solution comprises less than 0.1% water.

12. The method of claim 1, wherein the non-aqueous solution comprises less than 0.01% water.

13. The method of claim 1, wherein the non-aqueous solution comprises less than 0.001% water.

14. The method of claim 1, wherein the concentration of anhydrous steam delivered in the gas stream stabilizes within 5% of the average concentration delivered.

15. The method of claim 1, wherein the concentration of anhydrous steam delivered in the gas stream stabilizes within 3% of the average concentration delivered.

16. A chemical delivery system, comprising:

(a) a device comprising a liquid and a gas phase;

(b) a non-aqueous solution provided in an apparatus comprising a process chemical and a solvent, wherein the non-aqueous solution has the gas phase comprising an amount of anhydrous vapor of the process chemical; and

(c) a carrier gas or vacuum in contact with the vapor phase fluid and configured to form a gas stream containing anhydrous vapor,

wherein the process chemical is hydrazine, wherein the apparatus has an outlet configured to deliver a gas stream to a key process or application, and wherein the solvent is at least one of diethylene glycol, triethylene glycol, 1, 3-dimethyl-3, 4,5, 6-tetrahydro-2 (1H) -pyrimidinone (DMPU), and polyethylene glycol dimethyl ether.

17. The chemical delivery system of claim 16, further comprising one or more components configured to change the concentration of at least one component of the gas phase by changing at least one of the following parameters: (a) temperature of the non-aqueous solution, (b) pressure of the non-aqueous solution, (c) concentration of the non-aqueous solution, (d) temperature of the carrier gas, (e) pressure of the carrier gas or vacuum, and (f) flow rate of the carrier gas.

18. The chemical delivery system of claim 16, wherein the device comprises at least one membrane configured to at least partially separate a gas phase from a non-aqueous solution.

19. The chemical delivery system of claim 18, wherein the membrane is an ion exchange membrane.

20. The chemical delivery system of claim 16, wherein the carrier gas is selected from the group consisting of nitrogen, argon, hydrogen, clean dry air, helium, ammonia, and other gases that are stable at room temperature and atmospheric pressure.

21. The chemical delivery system of claim 16, wherein the device further comprises a component configured to add energy to the non-aqueous solution.

22. The chemical delivery system of claim 16, wherein the non-aqueous solution is a non-aqueous hydrazine solution comprising 25% to 69% hydrazine by weight.