WO2007140406A2

WO2007140406A2 - Storage and transport container for materials susceptible to physical state change under variable ambient temperature conditions

Info

Publication number: WO2007140406A2
Application number: PCT/US2007/069973
Authority: WO
Inventors: Jeffrey F. Roeder; Thomas H. Baum
Original assignee: Advanced Technology Materials, Inc.
Priority date: 2006-05-30
Filing date: 2007-05-30
Publication date: 2007-12-06
Also published as: WO2007140406A3; WO2007140406A8; TW200815253A

Abstract

A storage and transport container for chemical reagent that is susceptible to physical state change under variable ambient temperature conditions. In one implementation, the container includes a monitor for determining phase state of the chemical reagent contained in the container, and a heater arranged to heat the chemical reagent in response to phase state monitored by the phase state monitor, so as to maintain the chemical reagent in a liquid state. The container is particularly suited for chemical reagents having high freezing point, such as octamethylcyclotetrasiloxane (OMCTS).

Description

STORAGE AND TRANSPORT CONTAINER FOR MATERIALS

SUSCEPTIBLE TO PHYSICAL STATE CHANGE UNDER VARIABLE

AMBIENT TEMPERATURE CONDITIONS

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] This invention relates to packaging, systems and methods for storage and transport of materials that are susceptible to physical state change under variable ambient temperature, pressure and environmental conditions.

Description of the Related Art

[0002] In semiconductor manufacturing and numerous other industrial processing operations, chemical reagents are supplied for use in a wide variety of containers. The container may for example be pressurized to contain a chemical reagent in a liquid form or the container can be constructed to hold the chemical reagent at atmospheric or sub-atmospheric pressure conditions in a vapor phase, or in an adsorbed state on a physical sorbent medium, or the container may be otherwise fabricated and accessorized to dispense the chemical reagent in a predetermined condition for use.

[0003] In many applications, the chemical reagent must be supplied in a specific condition that is subject to stringent requirements of purity, form and character of the material. [0004] The art continues to seek new and innovative packaging approaches for chemical reagents, particularly in the microelectronic device manufacturing industry, where out-of- specification chemical reagents can result in wafers and/or microelectronic devices being deficient or even useless for their intended function. SUMMARY OF THE INVENTION

[0005] The present invention relates to packaging, systems and methods for storage and transport of materials such as OMCTS that are susceptible to freezing under some ambient conditions.

[0006] In one aspect, the present invention relates to a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is freeze-susceptible under variable ambient conditions, and a heater adapted to heat the chemical reagent in the vessel to maintain same in a liquid state when temperature of an ambient environment of the container is below the freezing point of the contained material.

[0007] Another aspect of the invention relates to a semiconductor manufacturing system including a semiconductor manufacturing tool and a container as described in the preceding paragraph, arranged in chemical reagent-supplying relationship to the semiconductor manufacturing tool.

[0008] A further aspect of the invention relates to a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent, and a physical state sensor arranged to produce an output indicative of physical state of chemical reagent in the container.

[0009] Yet another aspect of the invention relates to a semiconductor manufacturing system including a semiconductor manufacturing tool and a container as described in the preceding paragraph, arranged in chemical reagent-supplying relationship to the semiconductor manufacturing tool.

[0010] A still further aspect of the invention relates to a method of supplying a chemical reagent in liquid form, when the chemical reagent is freeze-susceptible under variable ambient conditions. The method comprises providing the chemical reagent in a storage and transport container, and inputting heat to the chemical reagent in the container in an amount as necessary to maintain the chemical reagent in a liquid state. [0011] Another aspect of the invention relates to a method of supplying a chemical reagent in liquid form, when the chemical reagent is freeze-susceptible under variable ambient conditions. The method comprises providing the chemical reagent in a storage and transport container, monitoring the chemical reagent in the container with a physical state sensor, and generating an output indicative of physical state of the chemical reagent in the container. [0012] A still further aspect of the invention relates to a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is susceptible to change of state under variable ambient conditions, and a heat transfer unit adapted to heat or cool the chemical reagent in the vessel to maintain same in a predetermined physical state when variable ambient conditions in the environment of the container would produce a change of physical state of the chemical reagent from such predetermined physical state.

[0013] Yet another aspect of the invention relates to a method of supplying a chemical reagent in a predetermined physical state, said chemical reagent being susceptible to change of state under variable ambient conditions, said method comprising providing said chemical reagent in a storage and transport container, and transferring heat to or from the chemical reagent in the container to maintain same in a predetermined physical state when variable ambient conditions in the environment of the container would produce a change of physical state of the chemical reagent from such predetermined physical state.

[0014] A still further aspect of the invention relates to a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is susceptible to deleterious change under variable ambient conditions, and a heat transfer unit adapted to heat or cool the chemical reagent in the vessel to maintain same in a non-deleterious state when variable ambient conditions in the environment of the container would produce a deleterious change in the chemical reagent.

[0015] Another aspect of the invention relates to a method of supplying a chemical reagent, said chemical reagent being susceptible to a deleterious change under variable ambient conditions, said method comprising providing said chemical reagent in a storage and transport container, and transferring heat to or from the chemical reagent in the container to maintain same in a non-deleterious state when variable ambient conditions in the environment of the container would produce a deleterious change in the chemical reagent.

[0016] Additional aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a sectional elevation view of a storage and transport container according to one embodiment of the present invention, in a production facility.

[0018] Figure 2 is a sectional elevation view of a storage and transport container according to another embodiment of the invention.

[0019] Figure 3 is a schematic elevation view of a storage and transport container according to a further embodiment of the invention.

[0020] Figure 4 is a sectional elevation view of yet another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION. AND PREFERRED EMBODIMENTS THEREOF

[0021] The present invention provides packaging, systems and methods for storage and transportof materials susceptible to physical state change in variable ambient temperature environments, e.g., materials having a freezing point in a range of from 10°C-35°C.

[0022] One issue with numerous chemical reagents is that such materials are susceptible to physical state or phase changes under variable ambient temperature, pressure and environmental conditions. Such physical state changes may be problematic for a variety of reasons, with respect to containers that may be employed for the transport and delivery of such reagents.

[0023] For example, if a chemical reagent is to be dispensed in liquid form and it has a freezing point that is in the vicinity of ambient temperatures or pressures, particularly in colder climates, winter conditions and/or during air transport, a drop in temperature may result in freezing of such material, thereby preventing dispensing of the material. Further, to the extent that the liquid expands upon freezing, such physical state change may result in unwanted stresses and even damage to the container in which the material is stored. [0024] Octamethylcyclotetrasiloxane (OMCTS) is one example of a material that can freeze under ambient temperature conditions. This chemical reagent freezes in the vicinity of 63°F-66°F, a temperature level that is not infrequently experienced in various warehousing, transport and semiconductor fab environments.

[0025] OMCTS is a widely used precursor for deposition of low dielectric constant (k) films, and its phase stability during dispensing operations therefore is a matter of significant concern, since freezing of such reagent can cause flow instability, clogging of delivery lines and equipment, reduced system performance, process tool down time, and interference with normal processing cycles.

[0026] The present invention enables freeze-susceptible chemical reagents such as OMCTS to be maintained in a liquid state during storage and transport, so that they are delivered in liquid form under dispensing conditions.

[0027] In one embodiment, the invention provides a storage and transport container for materials such as OMCTS that are freeze-susceptible in variable ambient conditions, in which the container is adapted to maintain the contained material in liquid form for dispensing. [0028] Preferably, the interior of the container is very clean, so as to ensure the purity and character of the chemical reagent that is contained. The interior surfaces of the container therefore may be steam- or chemically-sterilized prior to use, or the surfaces may be passivated or otherwise chemically treated to prevent chemical reaction with the contents of the container. The container preferably is sealed or otherwise protected against the ambient environment of the container, so that there is no incursion into the vessel of atmospheric gases, e.g., oxygen or water vapor. In one embodiment, the interior surfaces of the container are passivated by a silane material, e.g., hexamethyldisilazane, to decrease the chemical reactivity of the interior surfaces of the vessel. The container interior surfaces in some specific embodiments of the invention may be coated, e.g., with a lining of glass or other inert material. [0029] Various standards that are preferably applicable to semiconductor reagent containers in the broad practice of the present invention, in specific embodiments, to assure appropriate cleanliness of the containment services, include, without limitation, ASTM Fl 397, ASTM F1398, ASTM Fl 374, SEMI F57, ASTM A479, ASTM A484, ASTM A276, ASTM A262, ASTM A751, ASTM E214, ASTM E45, ASTM D3294, ASTM D4894, ASME B46.1, SEMI F19, SEMI F37, SEMI F57, ASTM E1558 and ASTM A380, as variously applicable depending on the materials of construction of the container. ASTM refers to the American Society of Testing Materials, SEMI refers to the Semiconductor Equipment and Materials Institute, and the ASME refers to the American Society of Mechanical Engineers, as the source organizations for the specified standards.

[0030] In a specific implementation, the invention relates to a material storage and transport container including a vessel having a heater associated therewith, including embedded resistive heating element(s). Resistive elements of such type can for example be powered by a low voltage battery as a power supply, or alternatively the resistive elements can be coupled with an electrical system of a vehicle to provide on-board heating of the vessel and its contents. In one preferred embodiment, the voltage employed for resistive heating is less than 28 volts, for achievement of safety, so that any flammability issues are minimized. [0031] The heater used to maintain the chemical reagent in a liquid state may be incorporated in a wall of the vessel, such as a sidewall and/or floor and/or cover of the vessel, or the heater may be configured as an insert that is mounted in a fitting or structural part of the container, and adapted to heat the material in the container. The heater can be operatively arranged to maintain the material in the container at a temperature above freezing when ambient temperature conditions drop below the freezing point of the material, or when otherwise desired, e.g., when the material container is removed from storage and prepared for dispensing operation. [0032] In one embodiment, the material storage and transport container may be adapted for installation in a delivery cabinet of a chemical delivery system and the heater is constructed and arranged for use in such cabinet.

[0033] In another embodiment, the storage and transport container may utilize an insulating medium that is configured as a sleeve or cover for all or part of the vessel. The insulating structure in an alternative form is integrally built into the vessel. The insulating medium may be of any suitable type, and in one embodiment is constituted by a polymeric foam having a ruggedized outer coating that is resistant to wear and physical damage.

[0034] In another embodiment, a material storage and transport container of the invention is provided, which utilizes a phase state monitor. Such phase state monitor can be of any suitable type, as adapted to monitor the phase condition, e.g., solid or liquid phase condition, of the contained material. In one embodiment, an ultrasonic monitor is employed. The ultrasonic monitor can be disposed externally or internally in respect of the vessel, and is arranged for sensing to determine whether the contained material is in a solid state or in a liquid state or in a transition between such states.

[0035] Ultrasonic monitoring of the freeze-susceptible material takes advantage of the fact that the velocity of sound in a liquid medium is different from the velocity of sound in the corresponding solid phase of such material.

[0036] Accordingly, a given liquid will have a characteristic sound velocity that may be employed to select an appropriate ultrasonic energy level for the ultrasonic monitoring operation. The monitor therefore may be arranged for detection of sound velocity resulting from impingement of ultrasonic energy on the contained chemical reagent. For such purpose, an ultrasonic energy source may be incorporated into the monitor, as an ultrasonic energy source and detection module that can deployed externally or internally of the vessel.

[0037] In operation, a rapid decrease in the time between production of a sound burst from the ultrasonic energy source and reception by the ultrasonic energy detector is indicative of the onset of freezing of the contained material. The ultrasonic energy detector for such purpose may be fabricated as a transducer that converts sonic energy to an electrical or other output signal.

[0038] A characteristic relationship can be developed using acoustic propagation velocity that factors in the level of material in the vessel, such as is determinable from an inventory monitor, level sensor, or other amount detector, as well as the physical state of such material (e.g., liquid, solid or a mixture of liquid and solid near the freezing point). [0039] In another embodiment, a thermocouple or other suitable temperature sensor is employed to determine temperature of the contained material in the vessel, as indicative of the corresponding phase state of the contained material. The temperature sensor may be provided for example in an insulative structure that is thereby stabilized (by the surrounding insulative medium) against short term ambient temperature fluctuations in the environment of the vessel. [0040] In another embodiment, a strain gauge may be employed on the container, being arranged in strain sensing relationship to the vessel so that expansion of the contained material, imposing strain on the vessel wall, is detectable. For example, such strain gauge -based monitoring may be employed to determine when OMCTS in a container is freezing, since such change of state will change the wall strain characteristics of the containment vessel. In a specific implementation, such strain gauge is deployed on an exterior surface of the vessel. [0041] In another embodiment, a sensor is employed to determine level of liquid in the vessel, so that inventory monitoring capability is provided, in combination with a phase state monitor. The container system in such embodiment can optionally further include a heater with feedback control, arranged so that the heater is energized if freezing is detected or incipient, so that the chemical reagent is maintained in a liquid state.

[0042] Accordingly, the invention in one implementation utilizes acoustic monitoring to determine the phase state of a contained material susceptible to physical state change under variation of ambient temperature conditions, optionally with heating capability being provided so that the onset of freezing is countered with input of heat to maintain the chemical reagent in a liquid state for dispensing. [0043] While described herein in primary reference to packaging and methodology for maintaining a freeze-susceptible chemical reagent in liquid form in a container under ambient condition fluctuations that would otherwise cause the liquid to freeze, it will be appreciated that the invention more broadly is applicable to containment, storage and transport of any chemical reagents that are susceptible to any physical state change under variable ambient conditions, that would change the physical state of the chemical reagent from a desired physical state to an undesired physical state. Thus, the invention broadly contemplates maintaining a liquid, solid, gas or multiphase material in the desired physical state, by appropriate heat input to or heat withdrawal from the material, under variable ambient conditions that would otherwise cause a change of state of the material from the desired physical state to an undesired or less desired one.

[0044] Accordingly, the invention in a still further aspect of the invention relates to a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is susceptible to change of state under variable ambient conditions, and a heat transfer unit adapted to heat or cool the chemical reagent in the vessel to maintain same in a predetermined physical state when variable ambient conditions in the environment of the container would produce a change of physical state of the chemical reagent from such predetermined physical state.

[0045] Yet another aspect of the invention relates to a method of supplying a chemical reagent in a predetermined physical state, said chemical reagent being susceptible to change of state under variable ambient conditions, said method comprising providing said chemical reagent in a storage and transport container, and transferring heat to or from the chemical reagent in the container to maintain same in a predetermined physical state when variable ambient conditions in the environment of the container would produce a change of physical state of the chemical reagent from such predetermined physical state.

[0046] Referring now to the drawings, Figure 1 is a sectional elevation view of a container 10 according to one embodiment of the invention, in a process system in which the material from the container is dispensed to a chemical reagent-utilizing facility. [0047] The container 10 includes a vessel 11 having a floor 12, circumscribing sidewall 14 and cover 16, which cooperatively define an enclosed interior volume 20 holding a liquid chemical reagent 24. The liquid chemical reagent 24 in the interior volume 20 is overlaid by a headspace 22.

[0048] The cover 16 of the vessel has a feed tube 26 extending therethrough, with a flow control valve 28 disposed therein. Upon opening of the flow control valve 28, gas may be introduced into the headspace 22 in the interior volume 20, flowing in the direction indicated by arrow A, as supplied from a suitable source of such gas (not shown in Figure 1) to provide for pressure-dispensing of the liquid, as hereinafter more fully described. [0049] The cover 16 also has a dispensing tube 30 extending therethrough and extending downwardly in the interior volume to a lower portion thereof in proximity to the floor 12. The dispensing tube 30 has a flow control valve 32 therein, and such tube is connected to flow circuitry schematically indicated by line 34, having pump 36 therein, for dispensing liquid from the container to a chemical reagent-utilizing facility 38.

[0050] In a specific embodiment, the chemical reagent-utilizing facility 38 may comprise a vaporizer for volatilization of the chemical reagent, and a deposition chamber coupled with the vaporizer in vapor-receiving relationship. The vapor deposition chamber may be arranged for presentation of a wafer or other substrate article, which is contacted with the chemical reagent vapor, to form a deposited film thereon, deriving from the vapor. In the case of OMCTS as the chemical reagent, a silicon-containing low dielectric constant film may be formed on a wafer under chemical vapor deposition conditions.

[0051] In the dispensing operation, pressurized inert gas may be introduced in fill tube 26 (valve 28 being open) whereby pressure-mediated dispensing of liquid from the container is effected, by flow of liquid 24 from the bulk volume in the container, through the dispensing tube 30 (valve 32 being open), and subsequent flow to the downstream chemical reagent- utilizing facility. [0052] The feed tube 26 may be utilized in the first instance as a fill tube, whereby chemical reagent is introduced into the container from a bulk supply tank or other large-volume source of the reagent.

[0053] As illustrated, the container includes a heating element 18 that is mounted in a corresponding annular space within the circumscribing sidewall 14 of the vessel. As illustrated, the heating element 18 may be joined by electric wire 19 to an electrical power supply 21, whereby electrical energy is conducted to the heating element, for resistive heating of the vessel by such element.

[0054] In such arrangement, the heating element may be provided as cylindrical sleeve that is simply inserted into a corresponding cavity in the sidewall.

[0055] In another embodiment, the element 18 may be formed of a material that itself can be monitored as to its temperature. The material may for example have a monitorable characteristic that is temperature-varying, which can be monitored to determine when energy input for heating of the chemical reagent in the container is needed to maintain the chemical reagent in a liquid state. Alternatively, the element 18 can have embedded therein one or more thermocouples or other temperature sensors or monitoring devices by which thermal condition of the container contents can be determined and thermal input correspondingly delivered to such container contents.

[0056] Figure 2 is a sectional elevation view of a container according to another embodiment of the invention.

[0057] The container 50 shown in Figure 2 includes a vessel 52 having a floor 54, circumscribing sidewall 56 and cover 58 which cooperatively define an interior volume 61 of the vessel. The interior volume 61 contains liquid chemical reagent 62 and headspace 64 overlying the chemical reagent.

[0058] In this embodiment, the vessel 52 is encased in an insulative jacket 60, whereby the liquid chemical reagent 62 is buffered against changes in ambient temperature, to more readily maintain the chemical reagent in liquid form. [0059] As previously discussed, the jacket 60 may be equipped with thermocouples or other temperature sensors embedded therein, and coupled in signal transmission relationship to a monitoring and control module that is arranged to responsively input heat to the chemical reagent by actuating the heater described hereinafter.

[0060] The vessel 52 has a feed tube 70 containing flow control valve 72 therein, extending through the cover, with the lower extremity of the feed tube terminating in the headspace 64 in the interior volume 61 of the vessel. The valve 72 may be opened to accommodate flow therethrough of chemical reagent for filling of the container in the first instance, or pressurizing gas may be flowed therethrough to assist the dispensing operation, with the fluid in each case being flowed in the direction indicated by arrow A from an exterior source (not shown in Figure 2) into the interior volume of the container.

[0061] A dispensing tube 74 containing flow control valve 76 extends through cover 58 of the vessel, extending upwardly to an upper end that is exterior to the container, and extending downwardly into the interior volume of the container, to a lower extremity that is in proximity to the floor 54 of the vessel. The dispensing tube 74 at its upper end may be coupled with suitable flow circuitry, schematically indicated by line 78, so that the container is thereby connected for dispensing, to flow the dispensed chemical reagent through the flow circuitry 78 to a downstream locus of use (not shown in Figure 2).

[0062] The vessel 52 in Figure 2 has a collar 66 in the cover 58. The collar circumscribes a resistive heating element 68, which extends downwardly in the interior volume 61 of the vessel, so that the resistive heating element is in contact with chemical reagent in such vessel. The collar 66 for such purpose may be formed of a suitable electrical insulator material, such as a ceramic or glass material, or non-conductive polymer. The resistive heating element 68 is coupled by electrical wire 80 with an electrical power supply 82. The electrical power supply 82 is configured in an appropriate manner, to provide electrical energy to the resistive heating element 68, to thereby effect heating of the chemical reagent 62 in the container. The electrical power supply 82 may be coupled with an ambient temperature sensor, to actuate the resistive heating when ambient temperature drops to a level below the freezing point of the chemical reagent 62.

[0063] Alternatively, or additionally, the vessel could be arranged with embedded thermocouples in a wall surface thereof, or in the insulative medium, as already described, and coupled in feedback relationship with the electrical power supply 82. In such arrangement, the electrical power supply is actuated and provides resistive heating of the chemical reagent when the temperature indicated by the sensor is below a setpoint value (e.g., a temperature in the vicinity of, and lower than, the freezing point of the chemical reagent).

[0064] In one preferred embodiment of the container system shown in Figure 2, the chemical reagent 62 is OMCTS, and the downstream locus of use includes a semiconductor manufacturing facility.

[0065] Figure 3 is a sectional elevation view of a container according to another embodiment of the invention. The container 100 includes a vessel 102 having a floor 104, circumscribing sidewall 106 and cover 108 cooperatively enclosing an interior volume 110 holding chemical reagent 112 in liquid form overlaid by a headspace 114.

[0066] The vessel includes a fill tube 120 having flow control valve 122 therein, whereby chemical reagent, and/or pressurizing gas, can be introduced into the interior volume 110 of the container 102, flowing in the direction indicated by arrow A.

[0067] The vessel 102 also includes a dispensing tube 126 containing flow control valve

128 therein, for dispensing chemical reagent 112 from the vessel.

[0068] In the embodiment shown in Figure 3, the dispensing operation can be conducted with introduction of a pressurizing gas flowed in the direction indicated by arrow A through the feed tube 120 (valve 122 being open) into the headspace 114 of the interior volume 110, whereby chemical reagent 112 flows upwardly through the dispensing tube 126 (valve 128 being open) for flow into associated piping, conduits, manifolds, etc., as employed for conveying the chemical reagent to a downstream locus of use.

[0069] The container 100 shown in Figure 3 features a phase monitoring assembly including an ultrasonic monitor 130 secured to an exterior surface of the sidewall 106 of the vessel. The ultrasonic monitor may include ultrasonic energy generating componentry and detection componentry, in which the ultrasonic monitor includes an ultrasonic transducer as a generator that is powered by a power supply 134 joined to the ultrasonic unit by electrical wire 132. By this arrangement, the ultrasonic unit generates acoustic energy that is transmitted to the chemical reagent 112 in the vessel. The transducer produces a sound burst that is propagated through the liquid, and then receives the sonic response to produce a response signal. The response signal is conveyed by signal transmission wire 136 to a computational module 138, which responsively generates an output indicative of the phase state of the chemical reagent 112.

[0070] In the event that the ultrasonic unit 130 produces a signal indicative of onset of freezing of the chemical reagent, the computational module 138 may in turn generate a control signal that is transmitted to suitable heating elements or structure, of a type for example as is shown in Figures 1 and 2, to responsively heat the chemical reagent and maintain same in the liquid phase.

[0071] In some embodiments of the invention, multiple physical state change sensors may be employed to monitor the contained material, with the respective sensors deployed at different locations on or within the material storage and transport vessel, e.g., at different elevational positions on the vessel so that different fill levels of the vessel can be monitored. Alternatively, a physical state sensor can be provided in a movable assembly, e.g., as a float assembly, or as a repositionable sensor to accommodate change in the volume of inventor of chemical reagent in specific applications or in the dispensing use of the vessel. [0072] Figure 4 is a sectional elevation view of a container according to another embodiment of the invention.

[0073] As shown in Figure 4, the container 150 includes a vessel 152 having a floor 154, sidewall 156 and cover 158 enclosing an interior volume 160 holding chemical reagent 162 in liquid form. The chemical reagent 162 is overlaid by a headspace 164.

[0074] The vessel 152 is equipped with a feed tube 166 containing flow control valve 168 therein and dispensing tube 170 containing flow control valve 172 therein, in an arrangement similar to those described hereinabove in connection with the embodiments of Figures 1-3. The feed tube 166 thus may receive a pressurizing gas flowed into the vessel in the direction indicated by arrow A, for assisting the dispensing of chemical reagent by flow thereof through the dispensing tube 170 and into associated flow circuitry 184 for passage to a downstream chemical reagent-utilizing apparatus such as a semiconductor manufacturing tool.

[0075] In Figure 4, an ultrasonic transducer 174 is disposed in the headspace 164 of the vessel 152.

[0076] The ultrasonic transducer 174 is mounted in a collar 172, and a resistive heating element 176 passes through the transducer 174 and collar 172, being coupled by transmission cable 178 to control module 180. The transmission cable 178 may be a multi-wire cable including a transmission wire that is coupled to resistance heating element 176 for delivery of power from the control module 180 to the resistance heating element 176, as well as a transmission wire from the control module 180 to the ultrasonic unit 174, so as to power both components.

[0077] The transmission cable 178 may also include a signal transmission wire conveying an output signal from the ultrasonic unit 174 to the control module 180, whereby the control module receives a signal that is indicative of the phase state of the chemical reagent 162, and responsively energizes the resistive heating element 176 to an extent necessary to maintain the chemical reagent in a liquid state.

[0078] As a further variant, the container shown in Figure 4 may have thermocouples or other temperature sensing elements embedded in the collar 172 and arranged to produce an output that is transmitted by a separate signal transmission wire of transmission cable 178 to the control module 180.

[0079] It will therefore be appreciated that the invention contemplates a variety of specific forms, in which a container is adapted to hold a material susceptible to physical state change under varying ambient conditions, with monitoring and control elements arranged to maintain a contained chemical reagent in the container in a liquid state, e.g., for dispensing. [0080] The various container embodiments of the invention described herein are well suited for containment of OMCTS and other chemical reagents that are freeze-susceptible under variable ambient conditions.

[0081] Correspondingly, the invention contemplates a methodology in which a chemical reagent susceptible to physical state change under varying ambient temperature conditions is monitored in a container to determine the physical state of the chemical reagent, with inputting of heat to the chemical reagent as needed in response to the physical state sensing, so as to maintain the chemical reagent in a liquid state.

[0082] As will be apparent from the foregoing, the physical state monitoring of the chemical reagent may be effected in any suitable manner, including, for example, acoustic sensing, temperature sensing, strain sensing (of the container), etc. Heat can be inputted to the liquid in response to the physical state monitoring, for maintenance of the liquid state, in any suitable manner and using any suitable heat input device or elements, including resistive heating elements, radiative heating systems, conductive heat input to the container such as via a heating plug, indirect heat exchange such as by embedded heat exchange coils, convective heating of the container (e.g., in an oven enclosure), etc. In one embodiment, heat is generated by a chemical reaction and the heat is transferred from the reaction to the vessel as required to maintain the vessel contents in a desired physical state. For this purpose, the chemical reaction may be carried out in a separate vessel, and the evolved heat transferred either directly or through an intermediate heat transfer medium, to the material in the storage and transport vessel.

[0083] Thus, the invention provides a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent having a high freezing point, and a heater adapted to heat the chemical reagent in the vessel to maintain same in a liquid state when temperature of an ambient environment of the container is below such freezing point.

[0084] The heater can include one or more resistive heating element(s), and is suitably coupled to a power supply, such as a battery or the heater can be adapted for coupling with an electrical system of a vehicle to provide on-board heating of the chemical reagent in the vessel.

The power supply desirably provides a voltage < 28 volts. The heater may be incorporated in the wall of the container vessel, e.g., as an insert that is mounted in a fitting or structural part of the container.

[0085] The heater can be operatively arranged to maintain the chemical reagent in the container at a temperature above freezing when ambient temperature conditions drop below the freezing point of the chemical reagent. The container may include an insulative medium arranged to insulate the vessel against changes of temperature in an environment of the container.

[0086] The chemical reagent storage and transport container in a preferred configuration further includes a physical state monitor, e.g., an ultrasonic monitor. Such ultrasonic monitor is advantageously arranged to transmit ultrasonic energy to the chemical reagent and receive a corresponding response from the chemical reagent that is converted by the ultrasonic monitor to an output indicative of the physical state of the chemical reagent. The chemical reagent storage and transport container can further include a temperature sensor indicating the physical state of the chemical reagent, such as a thermocouple. The temperature sensor may be protectively disposed in an insulated structure against short-term ambient temperature fluctuations in an ambient environment of the container.

[0087] The container of the invention is advantageously employed for storage and transport of OMCTS.

[0088] The container may include a strain gauge on the vessel that is adapted to produce an output indicative of strain in a wall of the vessel, and/or a level sensor adapted to determine level of the chemical reagent in the vessel. The container in one embodiment includes a monitoring and control assembly that is adapted to actuate the heater in response to conditions mediating freezing of the chemical reagent in the vessel. Such assembly may include a physical state monitor.

[0089] The vessel of the container may have a cover with a fluid feed tube extending therethrough into the enclosed interior volume, and a dispensing tube extending through the cover and into the enclosed interior volume, to a depth below that of the fluid feed tube. The dispensing tube may be adapted for coupling with flow circuitry of a chemical reagent-utilizing facility, such as a semiconductor manufacturing tool. A flow control valve may be provided in each of the fluid feed tube and the dispensing tube.

[0090] The container vessel may include a wall having a cavity therein, with the heater including a heating element, e.g., a resistive heating element, of a form that is mountable in such cavity. The container may include a material having a temperature-varying characteristic, and a monitor adapted to monitor such temperature-varying characteristic and to responsively actuate the heater. Such material may for example constitute a wall of the vessel. [0091] The invention further contemplates a chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent, and a physical state monitor arranged to produce an output indicative of physical state of chemical reagent in the container.

[0092] The invention correspondingly provides a method of supplying a chemical reagent in liquid form, such chemical reagent having a high freezing point and being susceptible to physical state change under varying ambient temperature conditions, by the method comprising providing such chemical reagent in a storage and transport container, and inputting heat to the chemical reagent in the container in an amount as necessary to maintain the chemical reagent in a liquid state. Such method may further include monitoring the chemical reagent in the container to determine physical state of the chemical reagent, and inputting heat to the chemical reagent in response to the monitored physical state to maintain the chemical reagent in the liquid state.

[0093] The invention further provides a method of supplying a chemical reagent in liquid form, such chemical reagent being susceptible to physical state change under varying ambient temperature conditions. The method includes providing the chemical reagent in a storage and transport container, monitoring the chemical reagent in the container with a physical state monitor, and generating an output indicative of physical state of the chemical reagent in the container. [0094] The monitoring in such method may include transmitting an ultrasonic input to the chemical reagent, receiving a response from such ultrasonic input that is indicative of physical state of the chemical reagent, and producing an output signal indicative of the physical state of the chemical reagent.

[0095] Further, while the invention has been described herein in specific reference to liquid chemical reagents, it will be recognized at the invention is not thus limited, but rather extends to and includes other materials that may be susceptible to deleterious change of any type as a result of variation in ambient temperature conditions, including solids, liquids, gases, and multiphase materials. Such deleterious change may include, without limitation, deterioration, the composition, aggregation, precipitation, etc. As a specific example, germane may be susceptible to decomposition as a result of ambient temperature variation. [0096] While various features, aspects and embodiments of the invention have been illustratively shown and described herein, it will be appreciated that the invention is not thus limited, but rather extends to and comprehends variations, modifications and other embodiments than those described herein, as will suggest themselves to those ordinary skill in the art, based on the disclosure herein. The invention therefore is intended to be broadly construed, as encompassing all such variations, modifications and alternative embodiments, as being within the spirit and scope of the claims hereinafter set forth.

Claims

THE CLAIMSWhat is claimed is:

1. A chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is freeze-susceptible under variable ambient conditions, and a heater adapted to heat the chemical reagent in the vessel to maintain same in a liquid state when temperature of an ambient environment of the container is below the freezing point of the chemical reagent.

2. The chemical reagent storage and transport container of claim 1, wherein the heater comprises at least one resistive heating element.

3. The chemical reagent storage and transport container of claim 2, wherein the heater further comprises a power supply coupled to said at least one resistive heating element.

4. The chemical reagent storage and transport container of claim 3, wherein the power supply comprises a battery.

5. The chemical reagent storage and transport container of claim 1, wherein the heater is adapted for coupling with an electrical system of a vehicle to provide on-board heating of said chemical reagent in said vessel.

6. The chemical reagent storage and transport container of claim 1, further comprising a power supply for the heater.

7. The chemical reagent storage and transport container of claim 6, wherein the power supply has a voltage below 28 volts.

8. The chemical reagent storage and transport container of claim 1, wherein the heater is incorporated in a wall of the vessel.

9. The chemical reagent storage and transport container of claim 1, wherein the heater is configured as an insert that is mounted in a fitting or structural part of the container and adapted to heat the chemical reagent in the vessel.

10. The chemical reagent storage and transport container of claim 1, wherein the heater is operatively arranged to maintain the chemical reagent in the container at a temperature above freezing when ambient temperature conditions drop below the freezing point of said chemical reagent.

11. The chemical reagent storage and transport container of claim 1, wherein the container is adapted for installation in a delivery cabinet of a chemical delivery system.

12. The chemical reagent storage and transport container of claim 1, further comprising an insulative medium arranged to insulate the vessel against changes of temperature in an environment of the container.

13. The chemical reagent storage and transport container of claim 12, wherein the insulative medium is configured as a sleeve or cover for the vessel.

14. The chemical reagent storage and transport container of claim 12, wherein the insulative medium comprises a polymeric foam.

15. The chemical reagent storage and transport container of claim 14, wherein the polymeric foam has a ruggedized outer coating that is resistant to wear and physical damage.

16. The chemical reagent storage and transport container of claim 1, further comprising a physical state monitor.

17. The chemical reagent storage and transport container of claim 16, wherein the physical state monitor comprises an ultrasonic monitor.

18. The chemical reagent storage and transport container of claim 17, wherein the ultrasonic monitor transmits ultrasonic energy to the chemical reagent and receives a corresponding response from the chemical reagent that is converted by the ultrasonic monitor to an output indicative of the physical state of the chemical reagent.

19. The chemical reagent storage and transport container of claim 1, further comprising a temperature sensor indicating physical state of the chemical reagent.

20. The chemical reagent storage and transport container of claim 19, wherein said temperature sensor comprises a thermocouple.

21. The chemical reagent storage and transport container of claim 19, wherein said temperature sensor is protectively disposed in an insulated structure against short-term ambient temperature fluctuations in an ambient environment of the container.

22. The chemical reagent storage and transport container of claim 1, wherein the vessel contains octamethylcyclotetrasiloxane.

23. The chemical reagent storage and transport container of claim 1, further comprising a strain gauge on the vessel, wherein said strain gauge is adapted to produce an output indicative of strain in a wall of said vessel.

24. The chemical reagent storage and transport container of claim 1, further comprising a level sensor adapted to determine level of the chemical reagent in the vessel.

25. The chemical reagent storage and transport container of claim 1, further comprising a monitoring and control assembly that is adapted to actuate the heater in response to conditions mediating freezing of the chemical reagent in the vessel.

26. The chemical reagent storage and transport container of claim 25, wherein the monitoring and control assembly includes a physical state monitor.

27. The chemical reagent storage and transport container of claim 1, wherein the vessel includes a cover having a fluid feed tube extending therethrough into the enclosed interior volume, and a dispensing tube extending through the cover and into the enclosed interior volume, to a depth below that of the fluid feed tube.

28. The chemical reagent storage and transport container of claim 27, wherein the dispensing tube is adapted for coupling with flow circuitry of a chemical reagent-utilizing facility.

29. The chemical reagent storage and transport container of claim 28, wherein said flow circuitry is coupled with a semiconductor manufacturing tool.

30. The chemical reagent storage and transport container of claim 27, further comprising a flow control valve in each of the fluid feed tube and the dispensing tube.

31. The chemical reagent storage and transport container of claim 1, wherein the vessel includes a wall having a cavity therein, and said heater comprises a heating element of a form that is mountable in said cavity.

32. The chemical reagent storage and transport container of claim 31, wherein said heating element comprises a resistive heating element.

33. The chemical reagent storage and transport container of claim 1, further comprising a material having a temperature-varying characteristic, and a monitor adapted to monitor said temperature-varying characteristic and to responsively actuate said heater.

34. The chemical reagent storage and transport container of claim 33, wherein said material constitutes a wall of said vessel.

35. A semiconductor manufacturing system including a semiconductor manufacturing tool and a container as claimed in claim 1, arranged in chemical reagent- supplying relationship to said semiconductor manufacturing tool.

36. The semiconductor manufacturing system according to claim 35, wherein the semiconductor manufacturing tool comprises a chemical vapor deposition unit.

37. The semiconductor manufacturing system according to claim 36, wherein the semiconductor manufacturing tool further comprises a vaporizer coupled in vapor-supplying relationship to said chemical vapor deposition unit.

38. A chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent, and a physical state monitor arranged to produce an output indicative of physical state of chemical reagent in the container.

39. The storage and transport container of claim 38, wherein the physical state monitor comprises an ultrasonic monitor producing an ultrasonic input to the chemical reagent and receiving a response from such ultrasonic input that is indicative of physical state of the chemical reagent, wherein said monitor is adapted to produce an output signal indicative of the physical state of the chemical reagent.

40. The storage and transport container of claim 38, wherein said physical state monitor includes a temperature sensor arranged to detect temperature of the chemical reagent in the vessel and to produce an output indicative of the physical state of the chemical reagent.

41. The storage and transport container of claim 38, wherein said physical state monitor comprises a strain gauge adapted to sense vessel strain and to produce a correlative output indicative of physical state of the chemical reagent.

42. The storage and transport container of claim 41, wherein said strain gauge is disposed on an exterior surface of the vessel.

43. The storage and transport container according to claim 38, containing octamethylcyclotetrasiloxane.

44. The storage and transport container of claim 38, further including a heater adapted to input heat to chemical reagent in the vessel.

45. The storage and transport container of claim 44, wherein the heater includes an electrical resistance heater.

46. The storage and transport container of claim 45, wherein the resistive heater includes a cylindrical sleeve and the vessel includes a cylindrical wall having an annular cavity adapted to receive said cylindrical resistive heating element therein.

47. The storage and transport container of claim 38, as operatively disposed in a semiconductor manufacturing facility in chemical reagent flow relationship to a semiconductor manufacturing tool.

48. The storage and transport container of claim 47, wherein the semiconductor manufacturing tool comprises a vaporizer and a chemical vapor deposition chamber.

49. The storage and transport container of claim 48, wherein said chemical reagent is octamethylcyclotetrasiloxane.

50. The storage and transport container of claim 38, further comprising an electrically resistive heating element disposed in the interior volume of the vessel, to heat the chemical reagent therein.

51. The storage and transport container of claim 38, further including a heater that is operatively coupled to the physical state monitor and adapted to input heat to the chemical reagent in an amount maintaining the chemical reagent in a liquid state.

52. The storage and transport container of claim 51, wherein the chemical reagent comprises octamethylcyclotetrasiloxane.

53. A semiconductor manufacturing system including a semiconductor manufacturing tool and a container as claimed in claim 38, arranged in chemical reagent-supplying relationship to said semiconductor manufacturing tool.

54. The semiconductor manufacturing system according to claim 53, wherein the semiconductor manufacturing tool comprises a chemical vapor deposition unit.

55. The semiconductor manufacturing system according to claim 54, wherein the semiconductor manufacturing tool further comprises a vaporizer coupled in vapor-supplying relationship to said chemical vapor deposition unit.

56. A method of supplying a chemical reagent in liquid form, said chemical reagent being susceptible to physical state change under varying ambient temperature conditions, said method comprising providing said chemical reagent in a storage and transport container, and inputting heat to the chemical reagent in the container in an amount as necessary to maintain the chemical reagent in a liquid state.

57. The method of claim 56, further comprising monitoring said chemical reagent in said container to determine physical state of the chemical reagent, and inputting heat to the chemical reagent in response to the monitored physical state to maintain the chemical reagent in the liquid state.

58. The method of claim 56, wherein the inputting heat comprises energizing at least one resistive heating element.

59. The method of claim 58, wherein said energizing comprises providing power from a battery power supply.

60. The method of claim 56, wherein the inputting heat comprises energizing a heater by coupling said heater with an electrical system of a vehicle to provide on-board heating of said chemical reagent in said container.

61. The method of claim 56, wherein the inputting heat comprises energizing a heater with a power supply.

62. The method of claim 61, wherein the power supply has a voltage below 28 volts.

63. The method of claim 61, wherein the heater is incorporated in a wall of the container.

64. The method of claim 61, wherein the heater is configured as an insert that is mounted in a fitting or structural part of the container and adapted to heat the chemical reagent therein.

65. The method of claim 61, wherein the heater is operatively arranged to maintain the chemical reagent in the container at a temperature above freezing when ambient temperature conditions drop below the freezing point of said chemical reagent.

66. The method of claim 56, wherein the container is installed in a delivery cabinet of a chemical delivery system.

67. The method of claim 56, further comprising insulating the vessel against changes of temperature in an environment of the container.

68. The method of claim 57, wherein the physical state is monitored with an ultrasonic monitor.

69. The method of claim 68, wherein the ultrasonic monitor transmits ultrasonic energy to the chemical reagent and receives a corresponding response from the chemical reagent that is converted by the ultrasonic monitor to an output indicative of the physical state of the chemical reagent.

70. The method of claim 56, further comprising sensing temperature of the chemical reagent indicative of physical state of the chemical reagent.

71. The method of claim 56, wherein the chemical reagent comprises octamethylcyclotetrasiloxane.

72. The method of claim 56, further comprising monitoring strain of at least a portion of the container, and generating an output indicative of said strain.

73. The method of claim 56, further comprising sensing level of the chemical reagent in the vessel.

74. The method of claim 56, further comprising inputting heat in response to conditions mediating freezing of the chemical reagent in the vessel.

75. The method of claim 56, further comprising dispensing said chemical reagent from said storage and transport container.

76. The method of claim 75, wherein said chemical reagent is dispensed to a semiconductor manufacturing tool.

77. A method of a supplying a chemical reagent to a semiconductor manufacturing tool, comprising dispensing of said chemical reagent from a container as claimed in claim 1.

78. The method of claim 77, wherein the semiconductor manufacturing tool comprises a chemical vapor deposition unit.

79. The method of claim 78, wherein the semiconductor manufacturing tool further comprises a vaporizer coupled in vapor-supplying relationship to said chemical vapor deposition unit.

80. A method of supplying a chemical reagent in liquid form, said chemical reagent being susceptible to physical state change under varying ambient temperature conditions, said method comprising providing said chemical reagent in a storage and transport container, monitoring the chemical reagent in the container with a physical state monitor, and generating an output indicative of physical state of said chemical reagent in the container.

81. The method of claim 80, wherein said monitoring comprises transmitting an ultrasonic input to the chemical reagent, receiving a response from such ultrasonic input that is indicative of physical state of the chemical reagent, and producing an output signal indicative of the physical state of the chemical reagent.

82. The method of claim 80, further comprising detecting temperature of the chemical reagent in the vessel and producing an output indicative of the physical state of the chemical reagent.

83. The method of claim 80, further comprising sensing vessel strain and producing a correlative output indicative of physical state of the chemical reagent.

84. The method of claim 80, wherein the chemical reagent comprises octamethylcyclotetrasiloxane.

85. The chemical reagent storage and transport container of claim 16, wherein the physical state monitor comprises a plurality of physical state sensors.

86. The chemical reagent storage and transport container of claim 85, wherein each one of said plurality of physical state sensors is at a different location on or within the vessel.

87. The chemical reagent storage and transport container of claim 86, wherein each one of said plurality of physical state sensors is at a different elevation, arranged and adapted to monitor physical state of material in the vessel at different fill volumes therein.

88. A chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is susceptible to change of state under variable ambient conditions, and a heat transfer unit adapted to heat or cool the chemical reagent in the vessel to maintain same in a predetermined physical state when variable ambient conditions in the environment of the container would produce a change of physical state of the chemical reagent from said predetermined physical state.

89. A method of supplying a chemical reagent in a predetermined physical state, said chemical reagent being susceptible to change of state under variable ambient conditions, said method comprising providing said chemical reagent in a storage and transport container, and transferring heat to or from the chemical reagent in the container to maintain same in a predetermined physical state when variable ambient conditions in the environment of the container would produce a change of physical state of the chemical reagent from said predetermined physical state.

90. The chemical reagent storage and transport container of claim 1, wherein said vessel defining said enclosed interior volume is fabricated of a material encompassed by and in compliance with at least one of standards selected from the group consisting of ASTM Fl 397, ASTM Fl 398, ASTM Fl 374, SEMI F57, ASTM A479, ASTM A484, ASTM A276, ASTM A262, ASTM A751, ASTM E214, ASTM E45, ASTM D3294, ASTM D4894, ASME B46.1, SEMI F19, SEMI F37, SEMI F57, ASTM E1558 and ASTM A380.

91. A chemical reagent storage and transport container including a vessel defining an enclosed interior volume adapted to hold a chemical reagent that is susceptible to deleterious change under variable ambient conditions, and a heat transfer unit adapted to heat or cool the chemical reagent in the vessel to maintain same in a non-deleterious state when variable ambient conditions in the environment of the container would produce a deleterious change in the chemical reagent.

92. A method of supplying a chemical reagent, said chemical reagent being susceptible to a deleterious change under variable ambient conditions, said method comprising providing said chemical reagent in a storage and transport container, and transferring heat to or from the chemical reagent in the container to maintain same in a non-deleterious state when variable ambient conditions in the environment of the container would produce a deleterious change in the chemical reagent.