A storage and delivery vessel for storing GeH4 using zeolite adsorbents.

Abstract

A storage and dispensing system, and associated methods, for selectively dispensing germane (GeH4) as a reagent gas from a vessel in which germane is held in sorptive relationship to a solid adsorption medium comprising a zeolitic imidazolate framework are described.

Description

[Technical field]

[0001] The present invention relates generally to a dispensing and dispensing system, and associated methods, for selectively dispensing germane (GeH4) as a reagent gas from a vessel in which germane is held in sorptive relationship to a solid adsorbent medium comprising a zeolitic imidazolate framework. [Background technology]

[0002] Raw materials in the form of high purity gases ("reagent gases") are needed to manufacture semiconductor materials (e.g., wafers) and microelectronic devices. Gaseous raw materials are needed for processes including ion implantation, epitaxial growth, plasma etching, reactive ion etching, metallization, physical vapor deposition, chemical vapor deposition, atomic layer deposition, plasma deposition, photolithography, cleaning, and doping, among others.

[0003] One example of a high purity reagent gas is germane (GeH4), which is used in deposition techniques, ion implantation, and epitaxial growth. For use in these processes, germane should be supplied to the process in a substantially pure form and from a safe and reliable source.

[0004] Germane is a hydride compound known to be unstable and prone to spontaneous exothermic decomposition. In order to store, handle, and deliver germane under suitable and safe conditions, various storage systems store germane in a diluted form in combination with an inert stabilizing gas, such as nitrogen, hydrogen, or helium, at germane concentrations as low as 20 percent (%), 10%, or 5% germane (by volume) in the stabilizing gas. The stabilizing gas dilutes the germane and reduces the risk of decomposition. However, diluted germane (combined with a stabilizing gas) is significantly less useful than the more concentrated forms of gaseous germane, especially for use in certain types of deposition processes that require high flow rates of concentrated germane.

[0005] In other storage systems, undiluted germane may be stored in adsorbed form in a vessel containing a solid adsorbent material, i.e., in "sorbent-based" storage systems. These systems include a porous adsorbent material held inside a storage vessel, and the germane is stored in an adsorbed state on the adsorbent material.

[0006] With respect to the specific use of germane as a reagent gas, a further feature of the system for storing and delivering germane is the ability to deliver concentrated germane (i.e., substantially undiluted) at high flow rates (e.g., characterized as standard cubic centimeters per minute or "sccm") and over sustained, long delivery periods. High flow rate delivery of concentrated germane requires fast desorption rates, lower (compared to other sorbents) adsorption energy of gaseous germane at the sorbent surface, and fast diffusion kinetics for rapid delivery of desorbed gas from the interior of the sorbent to the gas phase of the storage vessel. To sustain high flow rate delivery of reagent gas over long delivery periods, the storage system must also exhibit sufficient storage capacity of the reagent gas with a high deliverable storage capacity, meaning that a large amount (percentage) of the stored reagent gas can be removed from the sorbent and delivered from the storage vessel. Additionally, the vessel and sorbent must have a high enough thermal conductivity to conduct heat energy from the exterior surface of the vessel to the sorbent to reduce cooling of the sorbent during high flow rate distribution of the sorbent gas.

[0007] A larger amount of deliverable germane in the storage vessel (higher "deliverable gas volume") improves the efficiency of the process in which the storage vessel is used, since the storage vessel can be used for a longer period between replacements, especially in high flow rate delivery applications. Fewer storage vessel replacements reduce equipment downtime and improve operational efficiency. Additionally, the amount of expensive gaseous material left unused or wasted inside the storage vessel can be reduced. Summary of the Invention

[0008] Applicants have discovered that zeolite adsorbents are capable of providing high flow rate delivery of concentrated gaseous germane stored in an adsorbed state over a longer continuous delivery period than comparable combinations of flow rate and delivery period of other adsorbents.

[0009] The storage system herein contains a quantity of concentrated germane within a storage vessel, and the storage vessel contains a zeolitic imidazolate framework (ZIF) adsorbent with at least a portion of the germane adsorbed on the surface of the adsorbent.

[0010] As has been demonstrated by the applicants, zeolitic imidazolate framework sorbents for storing concentrated germane have useful and advantageous performance characteristics. One useful performance characteristic is the ability to deliver high flow rates of stored concentrated germane over a sustained period of time (the delivery period). Exemplary systems are useful for providing flow rates of at least 250 standard cubic centimeters of germane per minute for at least 30 minutes per 2.2 liters of storage vessel volume.

[0011] In one embodiment, the following describes a method of dispensing germane from a container. The container comprises an interior volume containing a zeolitic imidazolate framework sorbent and germane adsorbed onto the sorbent. The described method includes dispensing the germane from the container at a dispensing rate of at least 250 standard cubic centimeters per minute (per liter of container volume) over a dispensing period of at least 15 minutes. [Brief description of the drawings]

[0012] [Figure 1] 1 illustrates an exemplary storage system of the present disclosure. [Figure 2A] 1 illustrates performance data for an exemplary storage system herein. [Figure 2B] 1 illustrates performance data for an exemplary storage system herein. [Diagram 3] 1 illustrates performance data for an exemplary storage system herein. [Figure 4]1 illustrates performance data for an exemplary storage system herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] This disclosure relates to a novel and inventive system that involves storing germane in a vessel containing a zeolitic imidazolate framework adsorbent, where the germane is adsorbed onto the adsorbent, as well as novel and inventive methods of storing, handling and delivering germane using the storage system.

[0014] The storage system includes a vessel containing a zeolitic imidazolate framework (ZIF) sorbent material therein. The sorbent material is effective to contain and store germane within the vessel and is effective to effectively deliver germane from the vessel, particularly at high flow rates over sustained periods of time. The germane is adsorbed onto the zeolitic imidazolate framework sorbent and exists as a gas within the vessel, with a portion of the germane being adsorbed by the zeolitic imidazolate framework and another portion being in gaseous form or in a condensed form in equilibrium with the adsorbed portion and gaseous form.

[0015] The amount of zeolitic imidazolate framework adsorbent material in the interior vessel can vary depending on the volumetric adsorption capacity of such material for germane (mass of germane adsorbed per liter of adsorbent). Zeolitic imidazolate framework materials with higher volumetric capacity require less adsorbent material. Correspondingly, the storage vessel can contain a volume of adsorbent that is less than the interior volume of the vessel. The adsorbent material can fill 99%, 95%, 90%, 80%, 70%, 60%, 50%, or less of the interior volume of the vessel.

[0016] The pressure inside the container may be less than atmospheric pressure, i.e., less than about 760 Torr (101.3 kPa) (absolute pressure). During storage of the container or during use of the container to dispense germane, the pressure inside the container may be less than 760 Torr (101.3 kPa), e.g., less than 700 Torr (93.3 kPa), less than 600 Torr (80.0 kPa), less than 400 Torr (53.3 kPa), less than 200 Torr (26.6 kPa), less than 100 Torr (13.3 kPa), less than 50 Torr (6.7 kPa), or less than 20 Torr (2.7 kPa).

[0017] The germane stored in the container is concentrated, i.e., not substantially diluted with an inert stabilizing gas. The gas stored in the container is at least 50%, 60%, 70%, 80%, 90%, 95% or 99% (volume %) germane. The germane does not need to be stored in combination with an inert stabilizing gas (e.g., argon, nitrogen, helium) and the container may contain less than 50%, 40%, 30%, 20%, 10%, 5%, or 1% (volume % based on the total gas in the container) of any non-germane gas, e.g., stabilizing gas.

[0018] According to an exemplary storage system, a zeolitic imidazolate framework ("ZIF") sorbent is included in a storage vessel adapted to store germane (GeH4) at subatmospheric pressure and to distribute the germane to semiconductor processing equipment. Applicants have determined that the use of a zeolitic imidazolate framework as a sorbent can enable useful or preferred storage and delivery capabilities for germane, including, for example, the ability to deliver high flow rates of stored concentrated germane over a sustained delivery period, e.g., at least 250 sccm (0.42 Pa m) per 2.2 liter vessel volume over a delivery period of at least 30 minutes. 3 The new system included the ability to deliver a flow rate of 1000 ng / sec of germane.

[0019] This performance is calibrated to a 1 liter reservoir volume and is measured at 250 sccm (0.42 Pa m) for at least 15 minutes per liter of reservoir volume.3 / sec) of germane. A storage vessel containing a larger volume and correspondingly larger amount of zeolite adsorbent can deliver the same flow rate of germane over a longer delivery period (i.e., twice the volume of adsorbent will produce the same flow rate over twice the length of the delivery period), or can deliver a greater flow rate of germane over the same delivery period (i.e., twice the volume of adsorbent can deliver twice the flow rate over the same delivery period), etc. For example, a 50 liter vessel containing a correspondingly larger amount of adsorbent can deliver 250 sccm (0.42 Pa m 3 / sec) for 682 minutes, or 500 sccm (0.85 Pa m 3 / sec) for 341 minutes.

[0020] The term "flow rate," as in "high flow rate," refers to a measure of the flow rate of a gas in volumes of gas per minute (standard cubic centimeters per minute, sccm) at a particular temperature and pressure. According to this specification, these standard conditions are a temperature of 0 degrees Celsius (0° C.) and a pressure of 760 Torr (101.3 kPa).

[0021] When described on an alternative basis of germane delivery from the vessel, the use of a zeolitic imidazolate framework as a sorbent can allow desirable amounts (by weight) of germane to be delivered at high flow rates and at typical operating temperatures for semiconductor processing (e.g., 22°C). A preferred storage system provides 200 sccm (0.34 Pa m) of germane per 2.2 liters of storage vessel volume. 3 This performance is calibrated to a 1 liter reservoir volume and can deliver 200 sccm (0.34 Pa m) of germane from a 1 liter reservoir. 3 / sec) is equivalent to delivering 35 grams of germane.

[0022] Germane, a compound having the chemical formula GeH4, also known as "germanium tetrahydride" or "germanomethane", is a well-known reagent gas used in the semiconductor industry.

[0023] According to the present disclosure, germane is stored adsorbed onto a zeolitic imidazolate framework adsorbent in a vessel containing the zeolitic imidazolate framework adsorbent. The storage system is of a type known as an adsorbent-based storage system, which includes a vessel containing a zeolitic imidazolate framework adsorbent. Zeolitic imidazolate framework adsorbents are known to be compositionally distinct from other known types of adsorbent media, such as carbon-based adsorbent media, polymeric adsorbent media, and silica.

[0024] Zeolitic imidazolate frameworks are a type of metal-organic framework (MOF) that are known to be useful as adsorbents for storing certain reagent gases, including the storage and delivery of reagent gases for use in semiconductor processing. Zeolitic imidazolate frameworks are metal-organic frameworks that contain tetrahedrally coordinated transition metals, such as iron (Fe), cobalt (Co), copper (Cu), or zinc (Zn), linked by imidazolate linkers, which may be the same or different within a particular ZIF composition or for single transition metal atoms in the ZIF structure. The ZIF structure contains four-coordinated transition metals linked through imidazolate units, resulting in an extended framework based on a tetrahedral topology. ZIFs are said to form structural topologies equivalent to those found in zeolites and other inorganic microporous oxide materials.

[0025] Zeolitic imidazolate frameworks are characterized by features including the specific transition metal (e.g., iron, cobalt, copper, or zinc) of the framework, the linker chemistry (e.g., chemical substituents of the imidazolate units), the pore size of the ZIF, the surface area of ​​the ZIF, and the pore volume of the ZIF, among other physical and chemical properties. Dozens (at least 105) of unique ZIF species or structures are known, each with a different chemical structure based on the type of transition metal and the type of linker that composes the framework. Each topology is identified using a unique ZIF designation, e.g., ZIF-1 through ZIF-105. For a description of ZIFs, including the specific chemical compositions and associated properties of many known ZIF species, see Phan et al., “Synthesis, Structure, and Carbon Dioxide Capture Properties of Zeolitic Imidazolate Frameworks,” Accounts of Chemical Research, 2010, 43(1), pp 58-67 (Received April 6, 2009).

[0026] The pore size of the ZIF can affect the performance of the ZIF as an adsorbent. Exemplary ZIFs can have pore sizes in the range of about 0.2-13 angstroms (0.02-1.3 nm), such as 2-12 angstroms (0.2-1.2 nm) or 3-10 angstroms (0.3-1 nm). Pore size refers to the diameter of the largest sphere passing through the surface of the ZIF crystal. For use as an adsorbent in the containers herein, the ZIF can have any pore size effective to provide the desired storage performance.

[0027] One example of a ZIF that has been found to be useful in a vessel as described for adsorbing concentrated germane gas in the vessel and storing the germane gas in the vessel at subatmospheric pressure is called "ZIF-8," which is zinc dimethylimidazolate (also known as "zinc(dimethylimidazolate)2"). This zeolitic imidazolate framework is reported to have a pore size of 3.4 angstroms (3.4 nm). See U.S. Patent No. 9,138,720, which describes ZIF-8, among other MOFs.

[0028] When contained within a container for storing germane as described herein, the zeolitic imidazolate framework may be in any useful form, such as granules (particles), monoliths, or other. For various exemplary embodiments, a preferred zeolitic imidazolate framework may be in the form of particles that can be easily placed (e.g., poured) into a container such as a cylinder with a relatively small opening. Additionally, other forms of zeolitic imidazolate frameworks may also be useful or preferred for different product designs, including monolith or block adsorbents, rods, or space-filling polyhedral adsorbents.

[0029] Useful or preferred ZIFs can provide useful storage and delivery properties to the stored concentrated germane. These properties include a high flux of concentrated germane over a sustained amount of time. Other useful storage properties can include a useful storage capacity of concentrated germane, a useful delivery capacity of concentrated germane, and preferably a relatively small (or slow) rate of degradation of the stored concentrated germane.

[0030] In an exemplary storage system, a zeolitic imidazolate framework as the adsorbent is used to deliver stored concentrated germane at a high flow rate over a sustained delivery period, e.g., at least 50 sccm (0.085 Pa m) from a vessel having an internal volume of 2.2 liters over a delivery period of at least 30 minutes. 3A storage vessel having a larger internal volume can be used to accommodate a larger amount of sorbent, allowing a larger rate of concentrated germane to be delivered over a similar period of time, or a similar rate of concentrated germane (e.g., at least 50 sccm (0.085 Pa m) can be delivered). 3 300 g / sec) of concentrated germane) over a longer period of time, such as 40 minutes, 50 minutes, or 60 minutes.

[0031] In addition to delivering high fluxes of concentrated germane over sustained delivery periods, the described examples of useful or preferred storage systems for storing concentrated germane adsorbed by zeolitic imidazolate framework adsorbents can exhibit useful storage capacities of germane, e.g., germane storage capacities of at least 100 grams per liter of adsorbent (g / L), or preferably 200 g / L, or more preferably greater than 300 g / L.

[0032] The exemplary storage system may also exhibit a useful or advantageous dispensable capacity of concentrated germane, for example, a dispensable capacity of at least 80%, 90%, 95%, or 99%, i.e., the storage container may dispense at least 80%, 90%, 95%, or 99% of the total amount of germane stored within the container. The exemplary storage system may dispense germane at pressures as low as 50 Torr (6.7 kPa), 20 Torr (2.7 kPa), 10 Torr (1.3 kPa), 5 Torr (0.67 kPa), 3 Torr (0.40 kPa), 1 Torr (0.13 kPa), or 0.5 Torr (0.067 kPa).

[0033] Furthermore, the concentrated germane can exhibit a favorable level of stability when stored on a ZIF adsorbent. Examples of useful or preferred systems of germane stored in a storage vessel containing a zeolitic imidazolate framework adsorbent can exhibit a useful or relatively small amount of germane decomposition during storage of the stored germane. For example, germane stored in the described storage vessel can undergo less than 1%, or preferably less than 0.1%, or more preferably less than 0.01%, decomposition based on the total initial adsorbed germane capacity over a period of 365 days at ambient temperature.

[0034] Within the exemplary container, at the temperature at which the container is used to dispense germane from the storage container (e.g., 22°C), the contained germane may be in a form that includes a portion that is in a condensed or gaseous form (i.e., as gaseous germane) in equilibrium with the germane adsorbed on the zeolitic imidazolate framework. The temperature of the container and germane may be within the range of temperatures to which the container may be exposed during use (e.g., temperatures ranging from about 0 to about 50°C). This range includes operating temperatures, which are typical temperatures at which the container is maintained during controlled storage and use in an "ambient" or room temperature environment, which is generally understood to include temperatures in the range of about 20 to about 26°C.

[0035] At the temperature at which the container is used to deliver the reagent gas, the gaseous germane may be at a pressure below atmospheric pressure, i.e., less than about 1 atmosphere (760 torr (101.3 kPa)) (absolute pressure). The internal pressure of the container may be within this range during use and may be highest when the container contains a maximum amount of germane, i.e., when the container is "full" of germane. During use, as germane is gradually removed from the container, the internal container pressure will gradually decrease and may reach pressures of less than 700 Torr (93.3 kPa), 600 Torr (80 kPa), 400 Torr (53.3 kPa), 200 Torr (26.7 kPa), 100 Torr (13.3 kPa), 50 Torr (6.6 kPa), 20 Torr (2.7 kPa), 10 Torr (1.3 kPa), 5 Torr (0.67 kPa), 3 Torr (0.40 kPa), 1 Torr (0.13 kPa), or 0.5 Torr (0.067 kPa).

[0036] The container of the described storage system may contain a zeolitic imidazolate framework adsorbent as the only type of adsorption medium present inside the container, or may contain a zeolitic imidazolate framework adsorbent in combination with another type of adsorption medium, if desired. In certain presently preferred embodiments, the adsorption medium contained within the container may be substantially (e.g., at least 50%, 80%, 90%, 95%, or 97%) or entirely a zeolitic imidazolate framework adsorbent as described herein, and no other type of adsorption medium is required and may be excluded from the container interior. In other words, the total amount of adsorbent contained within the container may comprise, consist essentially of, or consist of a zeolitic imidazolate framework adsorbent, particularly the general and specific types of zeolitic imidazolate framework adsorbents described herein.

[0037] According to this specification, a composition consisting essentially of a particular material or combination of materials is a composition that contains the particular material and at most a minor amount of any other material, e.g., 2%, 1%, 0.5%, 0.1%, or 0.05% or less by weight of any other material. For example, a description of a vessel interior containing an adsorbent consisting essentially of a zeolitic imidazolate framework adsorbent refers to a vessel having an interior containing a zeolitic imidazolate framework adsorbent and 2%, 1%, 0.5%, 0.1%, or 0.05% or less by weight of any other type of adsorbent media, based on the total weight of the adsorbent media within the vessel interior.

[0038] Various examples of vessel structures for storing reagent gases may be useful for storing germane using a zeolitic imidazolate framework as the adsorbent, as adapted herein. Exemplary vessels include a cylindrical vessel ("cylinder") with a rigid cylindrical sidewall defining the vessel interior and an outlet (or "port") at the end of the cylinder. The vessel sidewall may be made from metal or another rigid, e.g., reinforced, material, and is designed to withstand pressure levels that reliably exceed the maximum desired pressure recommended for containing the reagent gas within the vessel interior.

[0039] FIG. 1 shows an example of a fluid delivery system (or "gas storage system" or simply "storage system") as described, in which a zeolitic imidazolate framework sorbent is disposed for storage and delivery of germane. As shown, the fluid delivery package 10 comprises a vessel 12 having a cylindrical wall 14 and a bed enclosing an interior volume 16 of the vessel 12 in which a zeolitic imidazolate framework sorbent 18 is disposed. The vessel 12 is joined at its upper end portion to a cap 20, which may be flat on its outer periphery and surround an upwardly extending boss 28 on its upper surface. The cap 20 has a central threaded opening that receives a correspondingly threaded lower portion 26 of a fluid distribution assembly.

[0040] The valve head 22 is movable between open and closed positions by any suitable manipulation, such as by altering the orientation of a manually operated hand wheel 30 or a pneumatically operated activator 30 coupled to the valve head 22. The fluid distribution system includes an outlet port 24 for dispensing gaseous germane from the fluid supply system when the valve is opened by manipulation of the hand wheel 30.

[0041] The zeolitic imidazolate framework sorbent 18 in the interior volume 16 of the vessel 12 may be of any suitable type as disclosed herein, including, for example, sorbent in powder, particulate, pellet, bead, monolith, tablet, or other suitable form. The zeolitic imidazolate framework sorbent has a sorption affinity for germane, allowing for storage and distribution of germane within the vessel. Distribution may be accomplished by opening the valve head 22 to facilitate desorption of germane stored in adsorbed form on the sorbent and release of germane from the vessel through the fluid distribution assembly to the outlet port 24 and associated flow circuitry (not shown), where pressure at the outlet port 24 effects desorption and release of germane from the fluid supply package by pressure. For example, the distribution assembly may be connected to the flow circuitry at a pressure lower than that within the vessel for such pressure desorption and distribution, e.g., below atmospheric pressure appropriate for downstream tools connected by the flow circuitry to the fluid supply package. Optionally, dispensing may include opening valve head 22 in conjunction with heating of sorbent 18 to cause thermal desorption of the fluid for release from the fluid supply package.

[0042] After an initial discharge of fluid from the interior volume 16 of the vessel 12, the fluid supply package 10 can be loaded with germane for storage on the sorbent by flowing the germane into the vessel through the outlet port 24, thereby serving the dual function of loading and dispensing fluid from the fluid supply package. Alternatively, the valve head 22 can be provided with separate fluid introduction ports for loading the vessel and loading the sorbent with introduced fluid.

[0043] The germane in the container may be stored at any suitable pressure condition, preferably subatmospheric or low subatmospheric pressure, thereby enhancing the safety of the fluid supply package in conjunction with fluid supply packages such as pressurized gas cylinders. EXAMPLES

[0044] Example 1 FIG. 2A is a graph of the process of delivering germane from a storage system as described. The graph shows the period of delivery of germane (approximately 100% concentration) from a storage vessel having a volume of 2.2 liters filled with ZIF-8 sorbent (ZIF-8 MOF extrudates). The ZIF-8 sorbent in the 2.2 liter vessel delivered a controlled 522 sccm (0.88 Pa m) flow rate over approximately 44 minutes when flowed at cylinder pressures between 443 Torr (59.1 kPa) and 75 Torr (10.0 kPa). 3 The flow rate was maintained at 522 sccm (0.88 Pa m ) / sec, delivering approximately 76 grams of germane. After the vessel reached 75 Torr (10.0 kPa), the flow was continued but at a rate of 522 sccm (0.88 Pa m ). 3 Approximately 25 grams of additional germane can be delivered at progressively lower rates from 75 Torr (10.0 kPa) to 20 Torr (2.7 kPa). When the starting pressure of the test cylinder was greater than 443 Torr (59.1 kPa), the flow rate was 522 sccm (0.88 Pa m 3 An additional flow rate duration of 18 g / sec can be achieved. For example, by starting at a pressure of 540 Torr (72.0 kPa), an additional 18 grams of GeH4 can be delivered.

[0045] FIG. 2B is a table showing the conditions and performance of the storage vessel for this Example 1. 937 grams of dry ZIF-8 adsorbent were added to a high-pressure cylinder with an internal volume of 2.2 liters. A total of 118 grams of germane were adsorbed to an equilibrium pressure of 443 Torr (59.1 kPa). The storage vessel was charged to 522 sccm (0.88 Pa m 3A flow rate test was used to determine the duration of sustained flow rate at 1000 rpm (1000 rpm / sec). The flow rate can be sustained for 44 minutes and 78 grams of GeH4 can be delivered under the conditions of this experiment. Higher deliverable volumes can be achieved with higher starting pressures and flow conditions closer to equilibrium. The deliverable volume from a pressure of 540 Torr (72.0 kPa) to 75 Torr (10.0 kPa) at equilibrium was calculated to be 101 grams. This calculation was performed using the data from the isotherm in Figure 3.

[0046] Example 2 FIG. 3 is a table showing the adsorption of germane on ZIF-8 in the described storage vessels (grams of germane per gram of ZIF-8) at subatmospheric pressure versus delivery pressure. The linearity of the data line indicates that a high percentage of the germane contained in the vessel can be delivered. In addition, the linear relationship between pressure and adsorption allows for easy determination of the amount of GeH4 stored in the ZIF-8-filled cylinder when it is plugged in for use, as opposed to the more complicated relationship for a carbon-filled cylinder.

[0047] FIG. 4 shows the hydrogen content of germane stored on ZIF-8 over extended storage time. The following table shows the amount of germane retained by a given amount of ZIF-8 in the described storage system at various pressures. Also listed is the amount that can be delivered from the system and the deliverable capacity of the system.

[0048] [Table 1]

[0049] For this example, the characteristics relating to the reservoir, the germane, and the packaging and testing conditions are as follows: Initial hydrogen content of germane when filled into the container: less than 10 ppmV (parts per million by volume); Total volume of the storage container: 0.5 liters, Amount of ZIF in storage container (mass): 140 grams; Surface area of ​​ZIF: 1500~1600m 2 / g nitrogen BET surface area, Shape and form of ZIF: extrudate, diameter 1-3 mm, length 1-5 cm; Storage vessel and adsorbent temperature for loading: GeH4 was loaded at 21° C. in a temperature controlled enclosure.

[0050] Container and ZIF treatment before loading: ZIF-8 was stored in a glove box atmosphere with O2 levels below 10 ppm and H2O levels below 2 ppm at all times. The storage container was loaded with ZIF-8 in the glove box to prevent air impurities from adsorbing onto the material. The storage container with ZIF-8 was heated at 150°C with pumping for 24 hours to remove adsorbed air impurities including water.

[0051] In Figure 3, the adsorption of GeH4 onto ZIF-8 was determined gravimetrically. The net amount of ZIF-8 was measured after loading and evacuating the test cylinder. The weight change was measured after the initial charge of GeH4 and every time an amount of GeH4 was withdrawn to reach a stable target pressure. Pressure was measured with a capacitance manometer (MKS model 722 "Baratron").

[0052] FIG. 4 details the technique and equipment used to periodically measure the H2 concentration of delivered germane samples over a storage period of several days. Storage conditions (temperature): 21°C in a temperature-controlled enclosure.

[0053] Gas chromatographic technique for measuring H2 in delivered germane: Gow-Mac Series 580 GC test equipment, Hayesep porous polymer column, and 50°C 35 cm 3 A gas chromatograph equipped with a thermal conductivity detector (TCD) using temperatures and flow rates of 1000 s / min.

Claims

1. 1. A method for dispensing germane from a container, comprising: the vessel having an interior volume containing a zeolitic imidazolate framework adsorbent and germane adsorbed thereon; The method comprises: dispensing germane from said container at a dispensing rate of at least 250 standard cubic centimeters per minute (per liter of container volume) over a dispensing period of at least 15 minutes. A method comprising:

2. 10. The method of claim 1, comprising dispensing germane from said container at a dispensing rate of at least 500 standard cubic centimeters per minute (per liter of container volume) over a dispensing period of at least 15 minutes.

3. 10. The method of claim 1, comprising dispensing germane from said container at a dispensing rate of at least 500 standard cubic centimeters per minute (per liter of container volume) over a dispensing period of at least 60 minutes.

4. 10. The method of claim 1 comprising dispensing at least 100 grams of germane per liter of sorbent.

5. 10. The method of claim 1 comprising dispensing at least 200 grams of germane per liter of sorbent.

6. 10. The method of claim 1 comprising dispensing at least 300 grams of germane per liter of sorbent.

7. 10. The method of claim 1, wherein the dispensed gas comprises at least 95% germane.

8. 10. The method of claim 1, wherein the vessel has an internal pressure of less than 760 Torr (101.3 kPa).

9. 2. The method of claim 1, wherein the zeolitic imidazolate framework comprises tetrahedrally coordinated zinc atoms connected by imidazolate linkers.

10. 2. The method of claim 1, wherein the zeolitic imidazolate framework is zinc dimethylimidazolate.

11. 10. The method of claim 1 comprising delivering the germane at a delivery pressure of less than 50 Torr (6.7 kPa).

12. A storage vessel containing an adsorbent, a zeolitic imidazolate framework (ZIF) adsorbent; and germane adsorbed on at least a portion of the ZIF adsorbent; A storage container used to dispense germane from said storage container.

13. 13. The storage vessel of claim 12, wherein the storage vessel has a storage capacity of at least 100 grams of germane per liter of sorbent (g / L).

14. 13. The storage vessel of claim 12, wherein the storage vessel has a storage capacity of at least 200 g / L.

15. 13. The storage vessel of claim 12, wherein the storage vessel has a storage capacity of at least 300 g / L.

16. 13. The storage container of claim 12, wherein the decomposition of the germane is less than 2% of the amount of germane adsorbed over a 365 day period stored at ambient temperature.

17. 13. The storage container of claim 12, wherein the decomposition of the germane is less than 0.5% of the amount of germane adsorbed over a 365 day period stored at ambient temperature.

18. 13. The storage container of claim 12, wherein the decomposition of the germane is less than 0.1% of the amount of germane adsorbed over a 365 day period stored at ambient temperature.

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