KR20180135915A - Method, system and apparatus for transferring process gas - Google Patents

Abstract

SUMMARY OF THE INVENTION In the present application, a method, system, and apparatus are provided for vapor phase transfer of a high purity process gas to a critical process or application.

Description

Method, system and apparatus for transferring process gas

Cross-reference to related application (s)

This application also claims priority from U.S. Patent Application 62 / 323,697, filed April 16, 2016, under 35 USC § 119 (e). The entire contents of such applications are incorporated herein by reference.

Technical field

To a method, system and apparatus for vapor phase transfer of high purity process gas in microelectronic devices and other critical process applications.

Various process gases may be used in the fabrication and processing of microelectronic devices. In addition, various chemicals may be used in other environments where high purity gases are required, such as, but not limited to, microelectronic device applications, wafer cleaning, wafer bonding, photoresist stripping, silicon oxidation, surface passivation, photolithography Disinfection of surfaces contaminated with bacteria, viruses and other biological agents, cleaning of industrial parts, manufacturing of medicines, production of nanomaterials, production of electric power, May be used in critical processes or applications, including control devices, fuel cells, power delivery devices, and other applications where process control and purity are critical considerations. In these processes and applications, a certain amount of specific process gas delivery is required under controlled operating conditions, e.g., temperature, pressure, and flow rate.

For various reasons, gas phase transfer of process chemicals is preferable to liquid phase transfer. For applications where low mass flow of process chemicals is required, liquid transfer of process chemicals is not sufficiently accurate or clean. Gas delivery will be desirable in terms of ease of delivery, accuracy and purity. The gas flow device is superior in aligning the liquid delivery device with more precise control. In addition, microelectronic device applications and other critical processes typically have a wide range of gas handling systems that make gas delivery considerably easier than liquid delivery. One approach is to vaporize the process chemical components directly at or near the point of use. Vaporizing the liquid provides a process for purifying process chemicals by leaving heavy contaminants. However, for reasons of safety, handling, stability and / or purity, many process gases are not directly vaporizable.

There are a number of process gases used in microelectronic device applications, and other critical processes or applications. Ozone is typically a gas used in cleaning semiconductor surfaces (e.g., photoresist stripping) and as an oxidizing agent (e.g., forming an oxide or hydroxide layer). One advantage of using ozone gas in microelectronic device applications and other critical processes, unlike the previous liquid-based approach, is that the gas can approach the surface with high aspect ratio features. For example, according to the International Technology Roadmap for Semiconductors (ITRS), current semiconductor processes must be compatible with half-pitch as small as 20-22 nm. The next technology node of the semiconductors is expected to have a half-pitch of 10 nm, and the ITRS will require <7 nm half-pitch in the near future. In this dimension, liquid-based chemical processing is not feasible because the surface tension of the process liquid prevents approaching the corners of the deep holes or channels, and high aspect ratio features. Thus, ozone gas has been used in some cases to overcome certain limitations of liquid-based processes, since the gas is not subject to such surface tension constraints. Plasma-based processes have also been used to overcome certain limitations of liquid-based processes. However, ozone- and plasma-based processes exhibit their own limitations, including in particular operating costs, insufficient process control, undesirable side reactions and inefficient cleaning.

Another problem is the temperature required for successful deposition. With respect to silicon nitride (SiN), for example, ammonia (NH ₃ ) is often used at temperatures of 500 ° C or even above 600 ° C at present. Keeping such a high temperature for deposition is costly and it may be desirable to deposit at lower temperatures. In addition, the new semiconductor device technology has a strict thermal budget that prohibits the use of elevated temperatures above 400 [deg.] C. Hydrazine (N ₂ H ₄ ) provides an opportunity to exploit lower temperatures in part because of the advantageous thermodynamics of hydrazine, which leads to lower deposition temperatures and the formation of nitrides in spontaneous reactions. Although reported in Burton et al. J. Electrochem. Soc. , 155 (7) D508-D516 (2008), hydrazine use has not been commercially adopted due to serious safety concerns associated with the use of hydrazine . Substituted hydrazines, generally safer than hydrazine, have the drawback of inducing undesirable carbon contamination. Thus, there is a need to develop a safer method of use of hydrazine for delivery to deposition processes or other critical process applications.

The use of gas phase hydrazine has been limited due to safety, handling and purity issues. Hydrazine has been used in rocket fuel and can be very explosive. Anhydrous hydrazine has a low flash point of about 37 캜. Semiconductor industry protocols for the safe handling of these materials are very limited. Therefore, there is a need for a technique to overcome these limitations and provide a substantially water-free gas hydrazine suitable for use in microelectronic devices and other critical process applications.

Similarly, Rasirc, Inc. As described in PCT Publication No. 2014014511 (which is hereby incorporated by reference), highly concentrated hydrogen peroxide solutions exhibit serious safety and handling problems and can be used to obtain high concentrations of hydrogen peroxide on the gas using existing techniques Because it is not possible, the gas phase use of hydrogen peroxide in critical process applications has limited usefulness.

Summary of Specific Implementations

A method, system and apparatus for delivering a substantially anhydrous process gas stream, in particular a hydrazine-containing gas stream, is provided. The methods, systems, and apparatus are particularly useful in microelectronic device applications and other critical processes. Generally, the method comprises the steps of: (a) providing a non-aqueous hydrazine solution having a vapor phase comprising an amount of hydrazine vapor; (b) contacting a carrier gas or vacuum with the vapor phase; And (c) delivering a gas stream comprising a substantially anhydrous hydrazine to a critical process or application. In many embodiments, the amount of hydrazine in the vapor phase is sufficient to provide hydrazine directly to a critical process or application, without additional concentration or processing of the hydrazine-containing gas stream. In many embodiments, the non-aqueous hydrazine solution comprises a stabilizer. In certain embodiments, the method further comprises removing one or more stabilizers from the gas stream. By adjusting the operating conditions of the process, for example, 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 accurately and safely delivered as the process gas. In certain embodiments, the amount of hydrazine present on the vapor and delivered to the critical process or application may be controlled by adding energy, e. G., Thermal energy, rotational energy, or ultrasonic energy to the hydrazine solution. In many embodiments of the present invention, the non-aqueous hydrazine is neat hydrazine or substantially anhydrous hydrazine.

Systems and apparatus for delivering hydrazine using the methods described herein are also provided. Generally, the system and apparatus comprise: (a) a non-aqueous hydrazine solution having a vapor phase comprising an amount of hydrazine vapor; (b) a carrier gas or vacuum in fluid contact with the vapor phase; And (c) a mechanism for transferring a gas stream comprising hydrazine to a critical process or application. In many embodiments, the non-aqueous hydrazine solution comprises one or more stabilizers. In certain embodiments, the system and apparatus further include a mechanism for removing one or more stabilizers from the gas stream. In many embodiments, the amount of hydrazine in the vapor phase is sufficient to provide hydrazine directly to a critical process or application, without additional concentration or processing of the hydrazine-containing gas stream. In certain embodiments, a mechanism for delivering a gas stream comprising hydrazine may be a micro-electronic device that enables the hydrazine-containing gas stream to flow from the head space to an application or process in which the hydrazine- The outlet of the headspace, including the vapor phase, directly or indirectly connected to the device application or other critical process system. The hydrazine transfer assembly (HDA) described herein is one such device. By adjusting the operating conditions of the system and the apparatus, for example, 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 accurately and safely delivered as a process gas. In certain embodiments, the amount of hydrazine present on the vapor and delivered to the critical process or application may be controlled by adding energy, e. G., Thermal energy, rotational energy, or ultrasonic energy to the hydrazine solution.

Many of the embodiments of the methods, systems, and apparatus described herein utilize a membrane that is in contact with a hydrazine-containing solution. The use of membranes has safety advantages. In certain embodiments, the membrane separates the hydrazine-containing solution in whole or in part from the hydrazine-containing vapor phase. By eliminating the access between the vapor phase and the liquid phase, sudden decomposition of the hydrazine in the vapor phase can be limited and the presence of the membrane may not cause a corresponding decomposition in the liquid phase.

Also contemplated herein is an apparatus for containing a liquid comprising volatile chemicals or chemical compositions (e.g., hydrazine, hydrogen peroxide, water, alcohol, amine or ammonium hydroxide), wherein a vapor, An apparatus comprising a headspace accessible as a process gas incorporated in a stream is disclosed. The process gas stream comprising the chemical or composition is typically delivered to a critical process application. In certain embodiments, the apparatus comprises: (a) a chamber comprising a liquid comprising a volatile chemical or chemical composition; (b) a headspace comprising a vapor phase comprising a volatile chemical or chemical composition on the gas; (c) an inlet port through which a carrier gas stream can enter the chamber, and (d) a protected outlet port through which a process gas stream comprising a carrier gas and a volatile chemical or chemical composition is introduced to the head Lt; RTI ID = 0.0 &gt; outlet ports &lt; / RTI &gt; In certain embodiments, the headspace is part of the chamber. In certain alternative embodiments, the headspace is distinct from the chamber and is in fluid communication with the chamber to enable gas-phase volatile chemical or chemical composition to move from the chamber to the headspace. In many embodiments, the membrane facilitates the transfer of volatile chemicals or chemical compositions from liquid to gaseous phase. The configuration of the membrane may vary depending on the particular application and process design. In some embodiments, the membrane separates the liquid in whole or in part from the headspace. In certain embodiments, the membrane comprises a tube connected to the inlet port such that all or a portion of the carrier gas travels through the membrane. In such an embodiment, the membrane tube may also move through the liquid portion in the chamber and terminate in the headspace. The protected outlet port includes a mechanism that ensures that the volatile chemical or chemical composition entering the outlet port is substantially in the gas phase, i.e., substantially free of liquid phase material such as droplets, mist, or mist.

The methods, systems, and apparatus described herein are generally applicable to a wide variety of process gas streams, especially non-aqueous hydrazine solutions in which the hydrazine solution contains a non-aqueous component.

In certain embodiments, the solution comprises substantially pure hydrazine, which means hydrazine, which does not intentionally contain other chemicals but allows incidental amounts of impurities. In certain embodiments, the solution comprises from about 5 wt% to about 99 wt% hydrazine, or from about 90 wt% to about 99 wt%, from about 95 wt% to about 99 wt%, from about 96 wt% to about 99 wt% , From about 97 wt% to about 99 wt%, from about 98 wt% to about 99 wt%, or from about 99 wt% to about 100 wt% of hydrazine, and a solvent and / or stabilizer. In some embodiments, the solution comprises hydrazine at a concentration of greater than 99.9% purity, and in some embodiments, the solution comprises hydrazine at a concentration of 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 comprises, in addition to the hydrazine, one or more suitable solvents. In one example, the non-aqueous hydrazine solution comprises a glycol solvent, such as ethylene glycol, triethylene glycol, alpha -propylene glycol, and beta -propylene glycol. A particular non-aqueous hydrazine solution useful in the methods and systems described herein is 65% hydrazine / 35% triethylene glycol. In another example, the non-aqueous hydrazine solution comprises an alcohol amine, such as ethanolamine, diethanolamine or triethanolamine. In another example, the non-aqueous hydrazine solution is a non-protic amide solvent such as hexamethylphosphoramide, 1,3-dimethyl-3,4,5,6-tetrahydro-2 (1H) (DMPU), 1,3-dimethyl-2-imidazolidinone (DMEU), tetramethylurea, or another aprotic urea-based solvent. Another solvent is hexamethylenetetramine. The non-aqueous hydrazine solution may comprise a PEGylated solvent, wherein the PEGylated solvent is a liquid at a temperature of about 25 占 폚. The term " pegylated solvent " refers to a solvent containing a poly (ethylene glycol) moiety attached as a covalent bond. 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, polypyrrolidine, or polyvinyl alcohol. Low molecular weight polymers, when combined with hydrazine, are polymers in which the combined solution has a viscosity of about 35 centipoise (cp) or less. Other examples of solvents include glymes such as monoglyme, diglyme, triglyme, higlyme and tetraglyme. Those skilled in the art will recognize that other solvents may be useful in the methods, systems, and apparatus described herein. Criteria for proper solvent selection include miscibility and solubility with hydrazine, chemical compatibility with hydrazine, compatibility with other components of the system (e.g., membrane), boiling point of solvent, flash point of non-aqueous hydrazine solution, and other safety and handling Sex problems.

Further examples include various PEGylated dimethyl ethers such as Polyglycol DME 200, Polyglycol DME 250, Polyglycol DME 500, Polyglycol DME 1000 or Polyglycol DME 2000. In some embodiments, the non-aqueous hydrazine solution comprises from about 30 wt% to about 69 wt% of hydrazine, and from about 65% to about 69 wt% of hydrazine. The remainder of the solution may contain one or more pegylation solvents such as, for example, poly (ethylene glycol) dimethyl ether. For example, the hydrazine solution may comprise from about 32% to 35% by weight of a pegylated solvent such as poly (ethylene glycol) dimethyl ether or other suitable solvent. In other embodiments, less than about 65% of hydrazine is used, and more than about 35% of a PEGylating solvent such as poly (ethylene glycol) dimethyl ether, such as Polyglycol DME 250, is used.

The methods, systems, and apparatus provided herein may utilize a variety of membranes. The membrane is typically a selectively permeable membrane, particularly a perfluorinated ion exchange membrane, such as a substantially gas-impermeable membrane, such as a NAFION® membrane. In certain embodiments, the NAFION 占 membrane can be chemically treated with an acid, base or salt, for example, to modify its reactivity. For example, in certain embodiments, NAFION® membranes can be treated in a manner that forms ammonium species. By using a specific, selectively permeable membrane, which is typically a gas-impermeable membrane, and in particular a NAFION® membrane and derivatives thereof, the concentration of hydrazine gas in the resulting gas stream is reduced from the vapor of the hydrazine solution in the absence of the membrane Can be varied with respect to the concentration of hydrazine that can be obtained directly. In certain embodiments, the hydrazine gas concentration is an amplification (i.e., higher) of the expected concentration from the vapor of the hydrazine solution in the absence of the membrane. Preferably, the concentration of hydrazine is amplified using the methods, systems and apparatuses disclosed herein.

In another embodiment, the membrane is a copolymer of tetrafluoroethylene and sulfonyl fluoride vinyl ethers. One example of such a membrane can be prepared from Aquivon (Solvay SA, Brussels, Belgium). Certain Aquivon (R) polymers are known as P98S and are provided as pellets.

The methods, systems, and apparatus provided herein may be used to remove one or more components from a hydrazine-containing gas stream to produce a purified hydrazine-containing gas stream, for example, to remove components selectively or non-selectively from a gas stream Removal of the &lt; / RTI &gt; A preferred apparatus may be a device that substantially removes the non-reactive process gas from the 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 solvents. For example, the device may further comprise a purification device disposed downstream of the headspace. Particularly preferred purification devices are membrane contactors, molecular sieves, activated carbon, and other adsorbents having features that are intended to meet application or process requirements. A desirable feature of the degassing device is the ability to allow the remaining component (s) to remain relatively unaffected by the hydrazine gas stream while removing the specific component (s) in a relatively selective manner.

The systems and apparatus provided herein may further include various components for controlling and including the flow of gas and liquid used therein. For example, the system and apparatus may further include a mass flow controller, a valve, a check valve, a pressure gauge, a regulator, a rotameter, and a pump. The systems and apparatus provided herein may further include various heaters, thermocouples, and temperature controllers for controlling the temperature of the components and methods of the various devices.

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 present invention will be realized and attained by means of the elements and combinations particularly pointed out in the examples and the 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.

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

1A is a diagram illustrating a portion of a membrane assembly useful in certain embodiments of the present invention.
1B is a diagram illustrating one embodiment of a hydrazine transfer assembly (HDA) in accordance with certain embodiments of the present invention.
Figure 2a is a cross-sectional view of one embodiment of an HDA in accordance with certain embodiments of the present invention.
Figure 2B is a cross-sectional view of one embodiment of an HDA in accordance with certain embodiments of the present invention.
Figure 3 is a P & ID of a manifold that can be used to test methods, systems, and devices for hydrazine delivery in accordance with certain embodiments of the present invention.
Figure 4 is a P & ID of a manifold that can be used to test methods, systems, and devices for hydrazine delivery in accordance with certain embodiments of the present invention.
Figure 5 is P &lt; RTI ID = 0.0 &gt; ID &lt; / RTI &gt; of a manifold that can be used to test methods, systems, and devices for hydrazine delivery in accordance with certain embodiments of the present invention.
Figure 6 is a diagram illustrating a membrane assembly and an HDA in accordance with certain embodiments of the present invention.
Figure 7 is P &lt; RTI ID = 0.0 &gt; ID &lt; / RTI &gt; of a manifold that can be used to test methods, systems, and devices for hydrazine delivery in accordance with certain embodiments of the present invention.
Figure 8 is a chart showing hydrazine gas concentration and temperature over time using substantially pure hydrazine as a liquid source, in accordance with an embodiment of the present invention.
Figure 9 is P &lt; RTI ID = 0.0 &gt; ID &lt; / RTI &gt; of a manifold that can be used to test methods, systems, and devices for hydrazine delivery in accordance with certain embodiments of the present invention.
Figure 10 is a chart showing hydrazine gas concentration and temperature over time using anhydrous 98% hydrazine as a liquid source, in accordance with an embodiment of the present invention.
Figure 11 is a chart showing hydrazine gas concentration and temperature over time using 65% hydrazine in poly (ethylene glycol) dimethyl ether as a liquid source, in accordance with an embodiment of the present invention.
Figure 12 is a diagram illustrating an HDA in accordance with certain embodiments of the present invention.
13 is P &lt; RTI ID = 0.0 &gt; ID &lt; / RTI &gt; of a manifold that can be used to test methods, systems and apparatus for hydrazine delivery according to certain embodiments of the present invention.
14 is a photograph of a tube containing four different non-aqueous hydrazine solutions useful as a liquid source in accordance with certain embodiments of the present invention.
15 is a chart showing hydrazine gas concentration and temperature over time using 65% hydrazine in triethylene glycol as a liquid source, in accordance with an embodiment of the present invention.

Various embodiments of the present invention will now be described 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 particular implementations or features serves to illustrate certain exemplary aspects of the present invention. The present invention is not particularly limited to the embodiments discussed herein.

Unless otherwise indicated, all numbers expressing the values of temperature, weight percent (weight%), concentration, duration, dimensions, and specific parameters or physical properties used in the description and the claims are used in all instances by the term " &Quot; as &lt; / RTI &gt; It should also be understood that the exact numerical values and ranges used in the specification and the claims form an additional embodiment of the invention. All measurements are subject to uncertainty and experimental variability.

As used herein, the term " critical process or application " is a broad term and is presented in its ordinary and customary sense to those skilled in the art (not limited to a specific or customized meaning) Purity represents a process or application that is a critical consideration. Examples of critical processes and applications include, but are not limited to, microelectronic device applications, wafer cleaning, wafer bonding, photoresist stripping, silicon oxidation, surface passivation, photolithographic mask cleaning, atomic layer deposition, chemical vapor deposition, Disinfection of surfaces contaminated with bacteria, viruses and other biological agents, cleaning of industrial parts, manufacturing of pharmaceuticals, production of nanomaterials, production and control of power, control devices, fuel cells and power transmission devices.

As used herein, the term " process gas " is a broad term and is presented in its ordinary and customary meaning to those skilled in the art (not limited to a particular or customized meaning) For example, the manufacturing or processing of microelectronic devices, and the gases used in other critical processes. Exemplary process gases are reducing agents, oxidizing agents, inorganic acids, organic acids, inorganic bases, organic bases, and inorganic and organic solvents. A preferred process gas is hydrazine.

As used herein, the term " reactive process gas " is a broad term and is presented to the person skilled in the art in its normal and customary sense (and is not limited to a specific or customized meaning) Refers to a process gas that reacts chemically with an application or process, e.g., with a surface, a liquid process chemical, or another process gas.

As used herein, the term " non-reactive process gas " is a broad term and is presented to the person skilled in the art in its normal and customary sense (and is not limited to a particular or customized meaning) Refers to a process gas that does not chemically react in a particular application or process, but the nature of the " non-reactive process gas " provides utility to a particular application or process.

As used herein, the term " carrier gas " is a broad term and is presented in its ordinary and customary sense to those of ordinary skill in the art (not limited to a particular or customized meaning), including but not limited to process trains, Typically refers to a gas used to transport another gas through a piping train. Exemplary carrier gases are nitrogen, argon, hydrogen, oxygen, CO ₂ , clean dry air, helium, or other gases that are stable at room temperature and atmospheric pressure.

As used herein, the term " headspace " is a broad term and is presented to those skilled in the art in its ordinary and customary sense (and not limited to any particular or customized meaning) Lt; RTI ID = 0.0 &gt; hydrazine &lt; / RTI &gt; There may be a permeable or selectively permeable barrier, which entirely or partly separates the headspace, optionally in direct contact with the hydrazine solution. In embodiments in which the membrane is not in direct contact with the hydrazine solution, it is desirable to have more than one headspace, i.e., a first headspace directly above the solution containing the vapor phase of the solution, and a first headspace capable of permeating the membrane, There may be a second headspace separated from the first headspace by, for example, a membrane containing only hydrazine. In embodiments having a headspace and a hydrazine solution separated by a substantially gas-impermeable membrane, the headspace may be located above, below or at any side of the hydrazine solution, or the headspace may surround the hydrazine solution Or it may be surrounded by it. For example, the headspace may be a space within a substantially gas-impermeable tube that penetrates the hydrazine solution, or the hydrazine solution may be a substantially gas-impermeable tube having a headspace surrounding the outside of the tube Lt; / RTI &gt;

As used herein, the term " substantially gas-impermeable membrane " is a broad term and is presented to the person skilled in the art in its normal and customary sense (and is not limited to a particular or customized meaning) But not limited to, hydrogen, nitrogen, oxygen, carbon monoxide, carbon dioxide, hydrogen sulfide, hydrocarbons (e.g., ethylene), volatile acids and bases, which are relatively permeable to other components that may be present in the gas or liquid, , A membrane that is relatively impermeable to other gases such as refractory compounds and volatile organic compounds.

As used herein, the term " ion exchange membrane " is a broad term and is presented in its ordinary and customary sense to those of ordinary skill in the art (not limited to a particular or customized meaning), including but not limited to, Lt; RTI ID = 0.0 &gt; ion-exchangeable &lt; / RTI &gt; Such chemical groups include, but are not limited to, sulfonic acid, carboxylic acid, sulfonamide, sulfonylimide, phosphoric acid, phosphinic acid, arylene, selenylene, phenol groups and salts thereof.

As used herein, the term " permeation rate " is a broad term and is presented in its ordinary and customary sense to those skilled in the art (not limited to a particular or customized meaning), including but not limited to, Hydrazine, or the rate at which the chemical composition permeates the membrane. The permeation rate can be expressed as the amount of chemical or composition discussed that permeates the specific surface area of the membrane for a period of time, for example, liters per minute per square inch (L / min / in ² ).

As used herein, the term " non-aqueous solution " or " non-aqueous hydrazine solution " is a broad term and is presented to the person skilled in the art in its ordinary and customary sense (not limited to any particular or customized meaning) Optionally containing other ingredients, and containing less than 10% by weight of water. Exemplary non-aqueous solutions include solutions containing less than 2%, 0.5%, 0.1%, 0.01%, 0.001% water and such solutions are referred to as "anhydrous hydrazine".

As used herein, the term " stabilizer " is a broad term and is presented in its ordinary and customary sense to those of ordinary skill in the art (not limited to any particular or customized meaning), and includes decomposition of process chemicals such as hydrazine or hydrogen peroxide Or a chemical that prevents the reaction. In certain embodiments, the stabilizing agent is non-volatile and is not present in the vapor phase above a non-substantial amount. In certain embodiments, the stabilizer may be removed from the process gas stream by exposing the process gas stream to the adsorbent or by passing the process gas stream through the cold trap. In certain embodiments involving a membrane that separates the non-aqueous hydrazine solution from the vapor phase, the stabilizer will not be permeable to the membrane.

The methods, systems, and apparatus described herein provide advantageous delivery of volatile process components to critical process applications. In many embodiments, the methods, systems and apparatuses disclosed herein are particularly applicable to hydrazine. The specific devices disclosed herein are also applicable to other volatile process components.

In certain embodiments, advantageous hydrazine delivery provided by the present invention, and in particular by the methods, systems and devices of the particular embodiments described herein, can be achieved using membrane contactors. In a preferred embodiment, the non-porous membrane is used to provide a barrier between the hydrazine solution and the headspace in fluid contact with the carrier gas or vacuum. Preferably, the hydrazine is rapidly permeated across the membrane while the gas is excluded from being permeated into the solution across the membrane. 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 &quot;. As used herein, the term " leak rate " is a broad term and is presented in its ordinary and customary sense to those of ordinary skill in the art (not limited to any particular or customized meaning), including but not limited to, It represents the volume of the specific gas that penetrates. For example, a substantially gas-impermeable membrane may have a low leakage rate of a gas (e.g., a carrier gas) other than the process gas (e.g., hydrazine), such as about 0.001 cm ³ / cm &lt; ² &gt; / s. Alternatively, a substantially gas-impermeable membrane can be identified as a ratio of the permeability of the process gas vapor relative to the permeability of the other gas. Preferably, the substantially gas-impermeable membrane has a ratio of at least 10,000: 1 such as at least about 20,000: 1, 30,000: 1, 40,000: 1, 50,000: 1, 60,000: 1, 70,000: 1, 900,000: 1, or 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: At least about 1,000,000: 1, and is more permeable to the process gas than to other gases. However, in other embodiments it is preferred to have a molecular weight of less than 10,000: 1, such as 1.5: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1, 7: 1, 8: , 10: 1; Other ratios of 50: 1, 100: 1, 500: 1, 1,000: 1, or 5,000: 1 or more may be acceptable.

In certain embodiments, the membrane is an ion exchange membrane, such as a polymer resin containing exchangeable ions. Preferably, the ion exchange membrane comprises a fluorine-containing polymer such as polyvinylidene fluoride, polytetrafluoroethylene (PTFE), ethylene tetrafluoride-propylene hexafluoride copolymer (FEP), ethylene tetrafluoro (PFE), polychlorotrifluoroethylene (PCTFE), ethylene tetrafluoride ethylene copolymer (ETFE), polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride- Vinylidene fluoride-propylene hexafluoride copolymer, vinylidene fluoride propylene hexafluoride-ethylene tetrafluoride terpolymer, ethylene tetrafluoride propylene rubber, and fluorinated thermoplastic elastomer. Alternatively, the resin comprises a complex or mixture of polymers, or a mixture of polymers and other components, to provide a close-up membrane material. In certain embodiments, the membrane material may comprise two or more layers. The different layers may have the same or different properties, for example, chemical composition, porosity, permeability, thickness, and the like. In certain embodiments, it may also be desirable to provide a support for the filtration membrane, or to use a layer (e. G., A membrane) that retains some other desired properties.

The ion exchange membrane is preferably a perfluorinated ionomer comprising a vinyl monomer containing an acid group or salt thereof and a copolymer of ethylene. Exemplary perfluorinated ionomers include, but are not limited to, perfluorosulfonic acid / tetrafluoroethylene copolymer ("PFSA-TFE copolymer") and perfluorocarboxylic acid / tetrafluoroethylene copolymer ("PFCA -TFE copolymer "). These membranes are commercially available under the tradenames NAFION® (EI du Pont de Nemours & Company), 3M ionomer (Minnesota Mining and Manufacturing Co.), FLEMION (Asashi Glass Company, Ltd.), and ACIPLEX (Asashi Chemical Industry Company) &Lt; RTI ID = 0.0 &gt; (Solvay). &Lt; / RTI &gt;

In the preparation of the hydrazine containing gas stream, the hydrazine solution may be passed through the membrane. As used herein, the term " passing a hydrazine solution through a membrane " is a broad term and is presented to the person skilled in the art in its ordinary and customary sense (not limited to a particular or customized meaning) Contacting the first side of the membrane with the hydrazine solution to pass through the membrane to obtain a hydrazine containing gas stream on the opposite side of the membrane. The first and second sides may have the form of a substantially flat, opposing planar area in which the membrane is a sheet. The membrane may also be provided in the form of a tube or cylinder, with one surface forming the internal location of the tube and an opposing surface on the exterior surface. The membrane may take any form as long as the first surface and the opposing second surface sandwich the bulk of the membrane material. Depending on the processing conditions, the nature of the hydrazine solution, the volume of hydrazine solution vapor produced, and other factors, the properties of the membrane can be tailored. The properties include, but are not limited to, physical form (e.g., thickness, surface area, shape, length and width (in the case of a sheet), diameter in the case of a fiber), configuration (flat sheet (s), spiral or rolled (E.g., sheet (s), folded or crimped sheet (s), fiber array (s)), method of fabrication (e.g. extrusion, casting from solution), presence or absence of a support layer, For example, a porous prefilter that absorbs particles of a particular size, a reactive prefilter that removes impurities through chemical reactions or bonds). The membrane may have a thickness of from about 0.5 microns or less to about 2000 microns or thicker and preferably about 1, 5, 10, 25, 50, 100, 200, 300, 400 or 500 microns to about 600, 700, 800, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800 or 1900 microns. Where a thinner membrane is used, it may be desirable to provide a mechanical support for the membrane (e.g., by using a support membrane, screen or mesh, or other support structure), but a thicker membrane may be used without a support Lt; / RTI &gt; The surface area can be selected based on the mass of the vapor being produced.

Certain embodiments of the methods, systems, and apparatus provided herein, which can be used to deliver hydrazine, wherein the carrier gas or vacuum is substantially anhydrous, is set forth with reference to the figures.

According to certain embodiments of the present invention, a hydrazine transfer assembly (HDA) is provided. HDA is a device for delivering hydrazine to a process gas stream, for example a carrier gas used in a critical process application, for example in the manufacture of microelectronic products or other critical process applications. HDA can also operate under vacuum conditions. The HDA may have a variety of different configurations, including at least one vessel, including at least one vessel containing a headspace and a non-aqueous hydrazine solution separated from the solution by the membrane.

1A and 1B illustrate different views of one embodiment of HDA 100 and membrane assembly 110 forming part of an HDA that can be used as provided herein. FIG. 1A shows a membrane assembly 110 comprising a plurality of membranes 120 , for example, a 5R NAFION® membrane, which may be comprised of lumens. As shown in Figure 1a, the membrane 120 is composed of the lumen through the collector plate (collector plate) 130 within the plurality of holes is inserted into the current collector plate 130. The membrane assembly 110 also includes a plurality of polytetrafluoroethylene (PTFE) rods 140 inserted into the collecting plate 130 . As shown in Figure 1B as part of the HDA 100 , the membrane assembly 110 includes a membrane lumen 120 extending across the current collector plate 130 . The HDA 100 further includes an endcap 150 at each end of the membrane assembly 110 . End cap 150 may include a branch 160 that may be secured by tubing to provide access to the interior of HDA 100 , for example, to charge, empty, clean, or refill HDA. .

2A and 2B show a cross-sectional view of two embodiments of an HDA in accordance with certain embodiments of the present invention.

As shown in FIG. 2A , the HDA 200A includes a shell housing 220A and a membrane assembly 210A within the end cap 230A configured to engage the shell housing 220A . Membrane assembly 210A is comprised of a plurality of membranes 240A that can be constructed as lumens. The number of lumens may vary depending on various factors including the size of the lumen, the size of the HDA 200A , and the operating conditions of the HDA. In certain embodiments, the HDA may contain no more than 1000 membrane lumens, no more than 500 lumens, no more than 200 lumens, no more than 100 lumens, or no more than 50 lumens. For example, the HDA 200A may have about 20-50 membrane lumens. The membrane lumen may consist of a perfluorinated sulfonic acid membrane, for example a 5R NAFION® membrane. The end cap 230A and the shell housing 220A may be formed from a variety of materials, such as PTFE, stainless steel (e.g., 316 stainless steel) or other suitable materials. Each end cap 230A further includes a gas connection 231A . The gas connection 231A may take the form of various connection configurations and sizes, for example, a 1/4 "VCR, a 1/4" NPT, or other suitable connector.

As shown in FIG. 2B , the HDA 200B includes a shell housing 220B and a membrane assembly 210B within the end cap 230B configured to engage the shell housing 220B . Membrane assembly 210B may be composed of a plurality of membrane lumens (not shown). The number of lumens may vary depending on various factors, including the size of the lumen, the size of the HDA 200B , and the operating conditions of the HDA. In certain embodiments, the HDA may contain no more than 1000 membrane lumens, no more than 500 lumens, no more than 200 lumens, no more than 100 lumens, or no more than 50 lumens. For example, the HDA 200B may have about 20-50 membrane lumens. The membrane lumen may consist of a perfluorinated sulfonic acid membrane, for example a 5R NAFION® membrane. End cap 230B and shell housing 220B may be formed from a variety of materials, such as PTFE, stainless steel (e.g., 316 stainless steel) or other suitable materials. Each end cap 230B may further include a gas connection 231B . The gas connection 231B may take the form of various connection configurations and sizes, e.g., a 1/4 "VCR, a 1/4" NPT, or other suitable connector.

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

In various implementations, the HDA can be structured similarly to the device described in commonly assigned U.S. Patent No. 7,618,027, which is incorporated herein by reference.

In certain embodiments, there is provided an apparatus for containing a vapor phase and a liquid comprising a volatile chemical or composition which may be a non-aqueous hydrazine containing solution, wherein the membrane comprises a volatile chemical or composition on one side of the membrane, In another aspect of the apparatus, an apparatus for contacting a carrier gas stream is provided. 12 is a diagrammatic view of a chamber comprising (a) a chamber containing a liquid comprising volatile chemicals or chemical compositions, (b) a headspace comprising a vapor phase containing volatile chemicals or chemical compositions on the gas, (c) (D) a protected outlet port through which a process gas stream comprising a carrier gas and a volatile chemical or chemical composition can escape from the headspace, through which the carrier gas stream can enter the chamber, and Lt; RTI ID = 0.0 &gt; 1200 &lt; / RTI &gt;

As shown in FIG. 12 , carrier gas 1214 enters through inlet port 1202 . The carrier gas 1214 then moves through the membrane 1208 attached to the injection port 1202 by a seal 1216 . In certain embodiments, the seal 1216 provides a leak tight connection between the inlet ports 1202 and 1208 . In certain embodiments, the seal 1216 may not be leak-tight, or it may be a partial seal that allows 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 may be tailored 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 with the liquid 1212 comprising a volatile chemical or composition capable of diffusion across the membrane 1208. Carrier gas 1214 And flows through the membrane 1208 on the opposite side of the side in contact with the liquid 1212 . A process gas stream 1218 comprising a volatile chemical or composition in a gas phase is formed as volatile chemical or composition is diffused across the membrane into the carrier gas stream. Membrane 1208 includes a liquid 1212 Is a particular component across the membrane diffusing into the carrier gas stream, while making it possible to provide a selected process gas stream 1218, and the other components of the liquid 1212, this 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 containing process chemistry and carrier gas 1214 from the liquid 1212 enters the headspace 1210 . Thus, the internal pressure of the tubular membrane 1208 coincides with the pressure at the headspace 1210 , and thus the vapor pressure of the liquid 1212 , which prevents membrane collapse if the outlet pressure is lower than the inlet pressure. Process gas 1220 contained in headspace 1210 exits through splash guard 1206 and outlet port 1204 for delivery to critical process 1224 . In this embodiment, since the splash guard 1206 retains the open distal end 1222 of the tubular membrane 1208, the process gas stream exiting through the outlet port 1204 is substantially free of liquid contaminants, such as droplets, particles, mist, or fog .

In many implementations, e. G., The implementation shown in FIG. 12 , the membrane is partially immersed in a liquid source. Immersing the membrane increases the residence time and mass transfer surface area by which the carrier gas must be completely saturated with the gas generated from the liquid source. The membrane can be long enough to reach the bottom of the canister and then back onto the liquid surface. The membrane may have a length of from about 3.0 inches or less to about 72 inches or more in length, including, for example, about 5, 10, 15, 20, 25, 30 or 35 inches to about 40, 45, 50, 55, Lt; / RTI &gt; The immersed portion of the membrane may be wound to increase the liquid to the membrane surface area. In order to further increase the liquid to the membrane surface area, multiple membranes can be used and run in parallel. The membrane may be from about 0.002, 0.004 or 0.005 inches thick to about 0.006, 0.007, 0.008 or 0.009 inches thick or thicker, from about 0.002 inch thick or thinner to about 0.010 inch thick or thicker. The diameter of the membrane is about 0.062 inches, 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 less to about 0.250 inches or more.

In many implementations, for example the implementation shown in FIG. 12 , the device includes a splash guard. The splash guard limits the volume, velocity or nature of the liquid exiting through the outlet of the device. The splash guard can hold the outlet of the tubular membrane above the liquid. In some embodiments, the splash guard has a long, narrow slit in the conductive path to the outlet barb, which prevents the droplet from entering the gas stream leaving the outlet port. The splash guard is made of a material compatible with the chemical used for the liquid source and the carrier gas. For example, a low-reactivity material such as, but not limited to, stainless steel, aluminum or plastic may be used. The splash guard can be attached to the container by being installed on the outlet bar. In some embodiments, the splash guard is about 1.50 inches in height, the slit is about 0.03 inches wide and about 1.25 inches high, and the length of the slit is equal to about 1.00 inches in diameter of the splash guard.

Although the primary purpose of this disclosure is the gas phase transfer of non-aqueous hydrazine in accordance with the methods, systems and devices provided herein, other process chemicals that can diffuse across the membrane can be used in the liquid source, the outgoing and the process can be a part of the gas stream 1218, thus the hydrogen peroxide, water, alcohols (e.g. ethanol, methanol, ethylene glycol, butanol, glycerol, xylitol or isopropyl alcohol), amines (for example, hydrazine, methylamine, ethanolamine, Dimethylamine, aniline, trimethylamine, triphenylamine, aziridine or methylethanolamine) or ammonium hydroxide. These process chemicals in the liquid source or process gas may be used alone or in combination. In certain embodiments, the liquid source may comprise a polar solvent, but in certain other embodiments, the liquid source may comprise a non-polar solvent.

The apparatus disclosed herein, e.g., the apparatus shown in Figure 12 , which may contain a liquid source comprising at least one process chemistry and which can transfer process chemistries on at least one gas to a critical process application, System, and other devices, or it may be used as a stand-alone device for delivery of a process gas stream to a critical process application.

Methods provided herein, one implementation according to one aspect of the system and device examples is described below as shown in Figure 3, as a reference, with reference to the manifold 300. 3 , carrier gas 310 flows through the headspace of HDA 320 , which may be HDA as described above. A mass flow controller (MFC) 330 , such as Unit UFC-1260A 1 slm, may be used to control the flow rate of the carrier gas 310 , which may be set, for example, to 1 slm. Dilution of the obtained gas stream, which can be achieved using a diluting gas 350 , may be required for the analysis of the amount of hydrazine in the gas stream. A mass flow controller (MFC) 340 , for example Unit UFC-1260A 10 slm, may be used to control the flow rate of the diluent gas 350 . Carrier gas 310 and diluent gas 350 may be supplied by a gas source 360 , which may typically be nitrogen or other suitable carrier gas. Valve 370 may be used to separate the dilution line if desired. Check valves 371, 372 may be to protect the MFC 330 and MFC 340 from a possible exposure to hydrazine, it disposed downstream of both the MFC 330 and MFC 340 both. The 60 psig pressure gauge 373 may be disposed between the MFC 330 and the check valve 372 to ensure that the pressure of the manifold does not exceed the maximum pressure allowed by the hydrazine analyzer 380 , for example, 5 psig.

Nitrogen pressure can be maintained by a forward pressure regulator 374 , which is typically set at 15 psig. The thermocouple 375 can measure the temperature of the nitrogen carrier gas 310 before entering the HDA 320 for hydrazine addition. The thermocouple 376 can measure the temperature of the hydrazine solution in the HDA 100 . The thermocouple 377 can measure the gas temperature before entering the hydrazine analyzer 380 . The hydrazine analyzer 380 can measure the concentration of hydrazine by drawing a sample of the carrier gas 310 . The manifold 300 may further include a relative humidity / resistance temperature detector (RH / RTD) probe 378 . Heating tape 390 can be disposed on the specific section, as shown in FIG. The temperature of the manifold can be controlled using Trilite Equipment & Technologies Controller and Watlow 96 Controller in two separate zones, the membrane assembly and the remaining tubing, respectively. The entire manifold may be installed inside the fume hood.

The embodiment shown with reference to Figure 3 is set as a test mechanism for measuring the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar mechanisms may be used to deliver hydrazine to critical process applications.

FIG. 4 illustrates an alternative embodiment of a test manifold 400 according to another embodiment, which is used to describe the delivery of hydrazine under vacuum conditions, in accordance with the methods, systems, P & ID. 4 , vacuum pump 410 may be an HDA 420 , which may be HDA as described above, The gas is removed from the hydrazine containing vapor side (i.e., the head space). For example, vacuum pump 410 may be maintained at about 24 mm Hg using valve 480 and pressure gauge 430 . The gas source 440 may be maintained at a pressure of about 2 psig using a forward pressure regulator 450 . Valve 460 may be used as a flow restrictor. The thermocouple 470 may be disposed within the fill tube of the HDA 420 to measure the temperature of the solution in the shell of the HDA 420 . The test involves contacting the headspace of the vapor side, i. E. The HDA 420 , with the vacuum produced by the vacuum pump 410 , while maintaining the HDA 420 at a constant temperature. Heat tape (heat tape) 490 may be disposed around the HDA 420 to enable a constant temperature control of the solution contained hydrazine in HDA 420. These vacuum-based methods, systems and devices are particularly desirable in a number of microelectronic devices and other critical process applications that operate at relatively reduced pressure (i.e., under vacuum).

The embodiment shown with reference to Figure 4 is set as a test mechanism for measuring the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar mechanisms may be used to deliver hydrazine to critical process applications.

5 is P &lt; RTI ID = 0.0 &gt; ID &lt; / RTI &gt; of a test manifold 500 according to another embodiment used to describe the delivery of hydrazine, according to one aspect of the methods, systems and apparatus provided herein. As shown in FIG. 5 , the nitrogen carrier gas 510 may flow through the headspace of the HDA 520 , which may be an HDA as described above. A mass flow controller (MFC) 530 , such as Brooks SLA5850S1EAB1B2A1 5 slm, may be used to control the flow rate of the carrier gas 510 , which may be set, for example, to 1 slm. Dilution of the obtained gas stream, which can be achieved using a diluting gas 550 , may be required for the analysis of the amount of hydrazine in the gas stream. A mass flow controller (MFC) 540 , such as Brooks SLA5850S1EAB1B2A1 10 slm, may be used to control the flow rate of the nitrogen dilution gas 550 . Nitrogen carrier gas 510 and nitrogen dilution gas 550 may be supplied by a nitrogen gas source 560 . Valve 570 can be used to separate the dilution line when not needed. A pair of check valves 571 and 572 may be placed downstream of both to protect the MFC 530 and MFC 540 from a possible exposure to hydrazine, MFC 530 and MFC 540 both. A pressure gauge 573 , for example a 100 psi gauge, may be placed between the MFC 530 and the HDA 520 to ensure that the pressure of the manifold does not exceed any maximum pressure allowed by the analyzer 580 .

The nitrogen pressure may be maintained by a forward pressure regulator 574 , for example set at 25 psig. The thermocouple 575 can measure the temperature of the nitrogen carrier gas 510 before entering the HDA 520 for hydrazine addition. Within the HDA 520 , the nitrogen carrier gas 510 may flow through the membrane tube, and the hydrazine vapor may be combined with the carrier gas 510 and permeate through the membrane from the solution contained in the shell housing. The thermocouple 576 is located within the HDA 520 The temperature of the hydrazine solution can be measured. The thermocouple 577 can measure the gas temperature exiting the HDA 520 . In this embodiment, analyzer 580 may be used to measure the concentration of hydrazine in the gas stream. The analyzer 580 may be, for example, a MiniRAE 3000 having a photoionization detector with a 11.7 eV gas discharge lamp. Analyzer 580 can measure the concentration of hydrazine, for example, by pulling a sample of the hydrazine containing gas stream. The thermocouple 578 can be used to measure the gas temperature before entering the analyzer 580 . The thermocouple 581 can be used to measure the temperature of the nitrogen dilution gas 550 .

The manifold 500 may further include a catalytic converter 585 configured to remove hydrazine by converting the hydrazine to nitrogen and hydrogen. The downstream of the catalytic converter 585 may be a probe 579 , for example a dew point (DP) and an E + E Elektronik EE371 humidity transmitter configured to measure the moisture concentration. The downstream of the probe 579 may be a vent. Heating tape 590 may be disposed on a section as shown in Fig. The temperature of the manifold can be controlled using the Watlow EZZone® 96 controller in each of the four individual zones marked with a dotted box. The entire manifold may be installed inside the fume hood.

The embodiment shown with reference to Figure 5 is set as a test mechanism for measuring the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar mechanisms may be used to deliver hydrazine to critical process applications.

Figure 6 is a diagram illustrating a side view and a cross-sectional view of a membrane assembly useful in certain embodiments of the present invention when a single membrane is used. The membrane assembly can be incorporated into HDA, for example, as shown in Figure 1B . As shown in Figure 6 , in one embodiment of the present invention, the membrane is a single, sleeved, on a stainless steel tube containing a calibrated number of holes, to provide a specific membrane surface area available for permeation Membrane lumen. The sleeve of the stainless steel tube is embedded inside the outer tube to form a hydrazine transfer assembly (HDA). The liquid hydrazine is charged in the space between the inner tube and the outer tube. The carrier gas flows through the inner tube to transport the hydrazine vapor that has permeated the membrane to the desired process.

Figure 7 is P &lt; RTI ID = 0.0 &gt; ID &lt; / RTI &gt; of a manifold that can be used to test methods, systems, and devices for hydrazine delivery in accordance with certain embodiments of the present invention. According to this embodiment, the carrier gas CG flows through the headspace of the HDA labeled &quot; vaporizer &quot; which can be HDA as described herein. A mass flow controller ( MFC 1 ), for example a 5 slm Brooks SLA5850S1EAB1B2A1 mass flow controller, can be used to control the flow rate of the carrier gas to the HDA . Analysis of the amount of hydrazine in the gas stream exiting the vaporizer may include dilution of the obtained gas stream, which may be accomplished first with diluent gas ( DG-1 ). A mass flow controller ( MFC 2 ), for example a 10 slm Brooks SLA5850S1EAB1B2A1 mass flow controller, is equipped with a dilution gas DG-1 Can be used to control the flow rate. The dilution gas DG-2 in a separate line can be supplied to a part of the manifold disposed in the glove bag.

Carrier gas CG , and diluent gases DG-1 and DG-2 may be supplied by a gas source, which may typically be nitrogen or other suitable carrier gas. In some embodiments, such as the one shown in Figure 7 , the carrier gas and the diluent gas share the same gas source. In other embodiments, the carrier gas and the diluent gas may have independent sources of gas. Valves V-1 and V-2 may be used to control gas flow to the HDA / DG-1 dilution line or the DG-2 dilution line / globe bag, respectively. Check Valves CV-1 and CV-2 are MFC 2 and MFC 1 May be placed downstream of MFC 2 and MFC 1 , respectively, to protect against possible hydrazine exposure. The pressure gauge PG-2 can be placed between the CV-2 and the vaporizer to measure the upstream pressure of the vaporizer.

The carrier gas pressure is maintained by the front pressure regulator PR1 and can be measured with a pressure gauge PG-1 . The front pressure regulator PR2 can be used to control the flow of diluent gas DG-2 through a gas bag. Thermocouple T-1 can measure the temperature of the hydrazine solution in the vaporizer. Thermocouple T-2 can measure the gas temperature after mixing loop and before entering the hydrazine analyzer. The MiniRAE 3000 is an example of a hydrazine analyzer. HT heater tape may be, as shown in certain sections, for example, Figure 7, disposed on the downstream line of the portion of the vaporizer and the vaporizer, a dilution gas line DG-1. The manifold may also include a catalytic converter downstream of the vaporizer and glove bag to decompose the hydrazine to nitrogen and hydrogen. The entire manifold may be installed inside the fume hood.

The embodiment shown with reference to Figure 7 is set as a test mechanism for measuring the amount of hydrazine introduced into the carrier gas stream under various operating conditions of the HDA. It will be appreciated that similar mechanisms may be used to deliver hydrazine to critical process applications.

Example 1

Experiment

In the examples of this disclosure, membranes were prepared by purchasing a sulfonyl fluoride perfluorinated polymer, extruding it, and hydrolyzing it by methods known in the art to form a membrane. Such membranes are also referred to herein as NAFION (R).

The manifold illustrated in Fig. 7 was used in the test procedure of this embodiment. The test procedure involved obtaining a stable gas phase hydrazine readout using a non-aqueous, substantially pure hydrazine solvent as the liquid source.

NAFION® vaporizer (P / N # 200801-01) was used for these experiments. These carburettors included a single 5R NAFION® membrane that was sleeved on 1/8 "SS (stainless steel) tubing.There were 20 0.06" diameter holes in the SS tubing, with a total transmissible area of 0.06 in ² . The tubing was surrounded by 3/8 "SS tubing with two ¼" charging ports on the shell side. The shell side volume was about 8 ml.

The manifold was installed in the fume hood. Nitrogen pressure was maintained at 25 psig using a forward pressure regulator ( PR -1 ) and measured with a pressure gauge ( PG-1 ). Two valves ( V-1 and V-2 ) were used to terminate gas flow through the vaporizer and / or dilution line. 5 slm Brooks SLA5850S1EAB1B2A1 mass flow controller ( MFC-1 ) was used to control the carrier gas flow rate. 10 slm Brooks SLA5850S1EAB1B2A1 mass flow controller ( MFC-2 ) was used to control the dilution gas flow rate. To protect the MFC from exposure to hydrazine, check valves ( CV-1 and CV-2 ) were placed downstream of the two MFCs. A front pressure regulator with gauge ( PR-2 ) was used to control the flow of nitrogen through the gas bag. The upstream pressure of the vaporizer was measured using a pressure gauge ( PG-2 ). The J-type thermocouple ( TC-1 ) was attached to the vaporizer as a control point for the heater tape. The carrier gas was mixed with nitrogen from a dilution line downstream of the vaporizer. The J-type thermocouple ( TC-2 ) was used to monitor the gas temperature after mixing. A MiniRAE 3000 with photoionization detector ( PID ) with a 11.7 eV gas discharge lamp was used to measure the concentration of hydrazine in the gas stream. In the test manifold and glove back vent lines, there was a catalytic converter that decomposes hydrazine to nitrogen and hydrogen. The vaporizer, a portion of the dilution line, and the vaporization downstream test manifold were heat-traced using a heater tape.

In this experiment, the carrier gas flow was set to 1 slm. The dilution gas flow was initially set at 1 slm and could be increased if the concentration exceeded 2000 ppm (upper limit of detection of MiniRae 3000). The manifold was heated to maintain the gas temperature at 30 [deg.] C at TC-2 .

Figure 8 shows the results from this experiment using a carrier gas flow to 1 slm and a dilute gas flow. As suggested, hydrazine yields were directly affected by the gas temperature once the system was stabilized. This effect was demonstrated when the temperature set point in this experiment was increased from 30 캜 to 31 캜 and tested for 78 minutes. The average concentration of hydrazine was 2426 ppm during the last 26 minutes of the test. The result was a permeation rate of 0.04043 L / min / in ² under these conditions.

Example 2

The manifold illustrated in Fig. 9 was used in the test procedure of this embodiment. The test procedure involved obtaining a stable gas phase hydrazine readout using a 98% hydrazine anhydrous solvent as the liquid source or a 65% hydrazine solution in the poly (ethylene glycol) dimethyl ether solvent (Mn = 250) as the liquid source .

NAFION® vaporizer (P / N # 200846-A) was used for these experiments. The vaporizer consisted of a single 5R NAFION® membrane that was sleeved on a 1/8 "SS tubing. There were 10 0.06" diameter holes in the SS tubing, resulting in a total permeable area of 0.03 in ² . The tubing was surrounded by 3/8 "SS tubing with two ¼" charging ports on the shell side. The shell side volume was about 8 ml.

The manifold was installed in the fume hood. An Entegris 500KF Gatekeeper refinery was used to remove oxygen, water and hydrocarbons from the gas stream. Two valves ( V-1 and V-2 ) were used to terminate the gas flow through the glove box and test manifold, respectively. The nitrogen flow inside the glove box was maintained using a forward pressure regulator and the pressure was measured with a pressure gauge ( PG-1 ). To prevent reverse streaming of hydrazine, a check valve ( CV-1 ) was placed upstream of the glove box. A front pressure regulator with a gauge was used to maintain the gas pressure upstream of the MFC at 25 psig. 5 slm Brooks SLA5850S1EAB1B2A1 mass flow controller ( MFC-1 ) was used to control the carrier gas flow rate. 10 slm Unit mass flow controller ( MFC-2 ) was used to control the dilution gas flow rate. To prevent the MFC from exposure to hydrazine, check valves ( CV-2 and CV-3 ) were placed downstream of both MFCs.

A single-lumen vaporizer was used to add the hydrazine vapor to the gas stream. A mixed loop was used to mix the nitrogen from the dilution line and the hydrazine vapor in the carrier gas downstream of the vaporizer. The J-type thermocouple ( TC-1 ) was used to monitor the gas temperature after mixing. A MiniRAE 3000 with photoionization detector ( PID ) with a 11.7 eV gas discharge lamp was used to measure the concentration of hydrazine in the gas stream. The test manifold and glovebox vent lines had scrubbers that catalyzed the catalytic decomposition of hydrazine to nitrogen and hydrogen. Valve V-3 was used to form and separate backpressure in the glove box.

In this example, the two solutions were tested at room temperature. One solution was anhydrous 98% hydrazine (Sigma Aldrich). The second solution was 65% w / w hydrazine (p = 1.029 g / ml) in poly (ethylene glycol) dimethyl ether (p = 1.03 g / ml). 8 ml of a solution was prepared with 5.2 ml of anhydrous 98% hydrazine and 2.8 ml of poly (ethylene glycol) dimethyl ether.

Before each test run, the MiniRAE 3000 was calibrated to 100 ppm isobutane gas standards. Once the analyzer was attached to the test manifold, the solution was added to the vaporizer, without the gas flow through the test manifold. Once charged, the carrier gas flow was set to 1 slm and the diluent gas flow was set to 1 slm. The dilution gas flow could be increased if the concentration exceeded 2000 ppm (upper limit of detection of MiniRae 3000). Gas temperature and hydrazine concentration readings were recorded. When the change in the vaporizer output was less than 5 ppm / min, stabilization could be determined.

Figure 10 shows the results from anhydrous 98% hydrazine using a carrier gas flow to 1 slm and a dilution gas flow for 330 minutes. After stabilization for 10 minutes, the average concentration was 1482.7 ppm ± 102.2 ppm at an average temperature of 23.6 ° C ± 0.4 ° C. Thus, the concentration was stable within less than 10% of the mean concentration. The result was an average permeation rate of 0.04942 L / min / in ² under these conditions. This hydrazine permeation rate was close to 0.04043 L / min / in ² , the permeation rate measured during the previous test performed in Example 1.

Figure 11 shows the results from 65% hydrazine in poly (ethylene glycol) dimethyl ether using a carrier gas flow to 1 slm and a dilution gas flow for 320 minutes. After stabilization for 30 minutes, the average concentration was 1190.6 ppm 占 .6 ppm and the average temperature was 24.5 占 폚 占 0.3 占 폚. The result was an average permeation rate of 0.03969 L / min / in ² under these conditions. In Figures 10 and 11 , the spikes of the hydrazine concentration seen at near zero time reflect the artifacts in the instrument and are not considered to be accurate or relevant.

In comparison with the 98% hydrazine solution, the permeation using a 65% hydrazine / poly (ethylene glycol) dimethyl ether solution was 19.7% lower. The promising property of using 65% hydrazine / solvent was that the yield was more stable over time than the 98% hydrazine hydrate solution. During 290 minutes, the yield of 98% hydrazine solution concentration was reduced by 263 ppm. However, the yield of the 65% hydrazine / poly (ethylene glycol) dimethyl ether solution was only reduced by 23 ppm for 290 minutes. The overall result in the case of using poly (ethylene glycol) dimethyl ether indicates that this is a practical solvent for safe hydrazine vapor transfer.

The temperature of the hydrazine containing solution and, if applicable, the carrier gas or vacuum can be controlled to deliver a particular hydrazine concentration. The stability of the hydrazine concentration in the process gas stream can be controlled to be less than about 20%, such as 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 is measured within a single standard deviation of less than about 10%, such as 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%. The average concentration does not include measurements by the instrument before reaching equilibrium. For example, the hydrazine concentration measurement of Figure 11 includes what appears to be spikes below about 1900 ppm. This spike is an instrument factor and is not an actual measurement because it takes about 10 minutes or more to stabilize the instrument, so that all average concentration readings take into account the stabilization described above. The selection of a particular hydrazine concentration will depend on the requirements of the application or process in which the hydrazine containing process gas is used. In certain embodiments, the hydrazine containing gas stream may be diluted by the addition of an additional carrier gas. In certain embodiments, the hydrazine containing gas stream may be combined with another process gas stream prior to or during delivery of the hydrazine 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 in a purification (e.g., dehumidification) step using a purification apparatus.

Example 3

The manifold illustrated in Fig. 13 was used in the test procedure of this embodiment. The Brute ™ vaporizer 1306 was assembled with a PTFE splash guard on the outlet barb and a new lumen assembly. Brute ™ vaporizer 1306 was charged with 200 mL of a liquid source solution containing hydrogen peroxide and the lid was assembled. A test system 1300 was assembled as shown in Fig. A manometer 1310 was connected to the display reader. All the valves 1302 , 1304 , 1308 and 1312 were closed and the vacuum pumps 1318 , 1320 and 1322 were turned off. The cold trap bath 1316 was filled with liquid nitrogen. The outlet back pressure valve (BPV) 1304 was closed, and the valve 1312 was opened. Vacuum pumps 1318 , 1320 and 1322 were turned on, cold trap bath 1316 was opened, and parallel pressure was recorded. The outlet BPV 1304 was opened quickly to shock the vaporizer 1306 at low pressure. An observational perfluoroalkoxy (PFA) tube 1324 was monitored for droplet traces in the liquid source solution. The vaporizer 1306 was exposed to vacuum until the pressure was constant. The valve 1312 was turned off, and the rising speed was recorded at intervals of minutes. The test was repeated several times. The splash guard prevented liquid solution from entering the outlet of vaporizer 1306 at pressures less than one torr.

Example 4

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

Figure 14 shows a photograph of each 65% hydrazine solution after monitoring for 30 minutes. Solvents 1, 2, and 4 all did not need to be stirred and immediately formed a homogeneous 65 wt% hydrazine solution. However, Solvent 3 did not dissolve in the hydrazine even after vigorous shaking.

Solvent 2 was tested in an application comprising a Brute ™ vaporizer as described in Example 3, taking into account the boiling point, flash point and NFPRA rating of the three solvents that were compatible with the hydrazine. The hydrazine concentration was measured over time from a Brute ™ vaporizer containing 65 wt% hydrazine / 35 wt% triethylene glycol solution as the liquid source. The results of this test are shown in FIG. 15, which graphs the hydrazine concentration and temperature measured over time. The test lasted for 120 minutes and the average hydrazine yield at 500 SCCM was about 24,600 PPM.

The 65% hydrazine / 35% triethylene glycol solution showed a flash point of 90.0 ° C. In contrast, the flash point of anhydrous hydrazine was about 37 ° C.

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 meaning of the invention being indicated by the following claims.

Claims (19)

(a) providing a non-aqueous solution comprising a process chemical and a solvent in an apparatus configured to include a liquid and a vapor phase, wherein the non-aqueous solution comprises an anhydrous vapor of the process chemical Providing a non-aqueous solution having a vapor phase comprising an amount of an organic solvent;
(b) contacting the carrier gas or vacuum with the vapor phase to form a gas stream; And
(c) delivering the gas stream comprising the anhydrous vapor to a critical process or application
The method comprising:
Wherein the process chemical is hydrazine or hydrogen peroxide and the solvent is selected from the group consisting of ethylene glycol, triethylene glycol, alpha -propylene glycol, beta -propylene glycol, 1,3-dimethyl-3,4,5,6-tetrahydro- ) -Pyrimidinone (DMPU), 1,3-dimethyl-2-imidazolidinone (DMEU) and tetramethylurea. The method of claim 1, further comprising the steps of: (a) determining the temperature of the non-aqueous solution, (b) the pressure of the non-aqueous solution, (c) ) Changing the concentration of at least one component of the vapor phase by changing at least one of the pressure of the carrier gas or vacuum and the flow rate of the carrier gas. The method of claim 1, wherein at least one membrane is disposed within the apparatus, and wherein the membrane is configured to at least partially separate the vapor phase from the non-aqueous solution. 4. The method of claim 3, wherein the anhydrous vapor permeates the membrane at a higher rate than any other component of the non-aqueous solution. 4. The method of claim 3, wherein the membrane is an ion exchange membrane. 2. The method of claim 1, further comprising removing contaminants from the gas stream. 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 stable at room temperature and atmospheric pressure. The method of claim 1, further comprising the step of varying the concentration of at least one component of the vapor phase by adding energy to the non-aqueous solution. 3. The method of claim 1, wherein the non-aqueous solution is a non-aqueous hydrazine solution comprising from about 25% to about 69% hydrazine by weight. 10. The method of claim 9, wherein the non-aqueous hydrazine solution comprises from about 65% to about 69% hydrazine. The method of claim 1, wherein the non-aqueous solution contains less than 0.1%, 0.01%, or 0.001% water. The method of claim 1, wherein the concentration of anhydrous vapor delivered in the gas stream is within about 5% of the delivered concentration or within about 3% of the delivered concentration. (a) an apparatus configured to include a liquid and a vapor phase;
(b) a non-aqueous solution comprising a process chemistry and a solvent provided in the apparatus, the non-aqueous solution having a vapor phase comprising an amount of anhydrous vapor of the process chemistry;
(c) a carrier gas in fluid communication with the vapor phase and configured to form a gas stream containing the anhydrous vapor,
A chemical delivery system comprising:
Wherein the process chemistry is hydrazine or hydrogen peroxide and the apparatus has an outlet configured to deliver a gas stream to a critical process or application, wherein the solvent is selected from the group consisting of ethylene glycol, triethylene glycol, alpha -propylene glycol, beta -propylene glycol, From the group consisting of 3-dimethyl-3,4,5,6-tetrahydro-2 (1H) -pyrimidinone (DMPU), 1,3-dimethyl-2-imidazolidinone (DMEU) and tetramethylurea The chemical delivery system is selected. 14. The method of claim 13, further comprising the steps of: (a) determining the temperature of the non-aqueous solution, (b) the pressure of the non-aqueous solution, (c) ) Of the at least one component of the vapor phase by changing at least one of the pressure of the carrier gas or the pressure of the carrier gas or the pressure of the carrier gas, and (f) the flow rate of the carrier gas. Delivery system. 14. The chemical delivery system of claim 13, wherein the apparatus comprises at least one membrane configured to at least partially separate the vapor phase from the non-aqueous solution. 16. The chemical delivery system of claim 15, wherein the membrane is an ion exchange membrane. 14. The chemical delivery system of claim 13, wherein the carrier gas is selected from the group consisting of nitrogen, argon, hydrogen, clean dry air, helium, ammonia, and other gases stable at room temperature and atmospheric pressure. 14. The chemical delivery system of claim 13, wherein the apparatus further comprises a component configured to add energy to the non-aqueous hydrazine solution. 14. The chemical delivery system of claim 13, wherein the non-aqueous solution is a non-aqueous hydrazine solution comprising from about 25% to about 69% hydrazine by weight.

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