Wafer carrier with moisture trapping function

Abstract

The wafer carrier includes a housing having an interior space and a moisture scavenging compound in fluid communication with the interior space. The carrier provides a moisture-controlled microenvironment for semiconductor wafers enclosed within the carrier as the semiconductor wafers move through manufacturing process steps. According to a first aspect of the present invention, a wafer carrier is provided. The wafer carrier includes (a) a housing having an interior space and (b) a moisture scavenging compound in fluid communication with the interior space. Optionally, the wafer carrier further includes an oxygen scavenging compound in fluid communication with the interior space.

Description

[Technical Field]

[0001] Priority claims This application claims priority to U.S. Provisional Patent Application No. 63 / 448,843, filed February 28, 2023, having Attorney Docket No. 1202303-US-F, which is incorporated herein by reference in its entirety.

[0002] Technical Field The present disclosure relates generally to wafer carriers, and more particularly to wafer carriers for encapsulating semiconductor wafers in a moisture-trapping microenvironment as the semiconductor wafers move through one or more manufacturing process steps. [Background technology]

[0003] background As semiconductor manufacturing technology advances, with continued miniaturization of devices, there are more stringent requirements in the manufacturing environment, particularly in minimizing contamination of semiconductors.

[0004] The adverse effects of moisture and oxygen on semiconductor wafers typically depend on two parameters: contaminant concentration and exposure time. Existing solutions to this problem may focus on shortening exposure time. Alternatively, if this is uneconomical or technically not possible, steps may be taken to reduce contaminant concentration levels in any environment to which the wafers are exposed. Such reduction is typically achieved by purging the environment containing the wafers with extremely clean, dry air or a pure inert gas such as nitrogen.

[0005] Sealed containers such as FOUPs (Front Opening Integrated Pods), FOSBs (Front Opening Transfer Boxes) or SMIF (Standard Mechanical Interface) pods may be used as wafer containers or reticle pods. To address and / or solve contamination issues, means may be provided for flushing the interior volume of such containers containing wafers with nitrogen during use.

[0006] However, such flushing processes are unable to meet technical requirements as technology advances, and therefore the problem of maintaining a suitable environment for semiconductor wafers still needs to be addressed. Summary of the Invention [Means for solving the problem]

[0007] overview SUMMARY OF THE INVENTION Embodiments of the present disclosure address the above-mentioned problems.

[0008] According to a first aspect of the present invention, there is provided a wafer carrier comprising: (a) a housing having an interior space; and (b) a moisture scavenging compound in fluid communication with the interior space. Optionally, the wafer carrier further comprises an oxygen scavenging compound in fluid communication with the interior space.

[0009] According to a second aspect of the present invention, there is provided a method for protecting semiconductor wafers from moisture, and optionally also oxygen, contamination, comprising the steps of (i) selecting a wafer carrier according to the first aspect, and (ii) placing a semiconductor wafer to be protected within the interior space of the wafer carrier.

[0010] According to a third aspect of the present invention there is provided the use of a wafer carrier according to the first aspect for protecting a semiconductor wafer from oxygen and, if necessary, further contamination by oxygen.

[0011] According to a fourth aspect of the present invention there is provided a novel moisture-scavenging composition comprising a moisture-scavenging compound according to the first aspect. DETAILED DESCRIPTION OF THE INVENTION

[0012] Detailed Description Reference is made below to various embodiments of wafer carriers, methods for protecting semiconductor wafers from moisture and, optionally, oxygen contamination, and other aspects of the present invention.

[0013] This disclosure is not to be construed as being limited to the embodiments described herein, but rather these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the subject matter to those skilled in the art.

[0014] Any aspect of any invention described herein may be combined with any feature described in any other aspect of any invention or embodiment described herein, mutatis mutandis.

[0015] term

[0016] Unless expressly defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting.

[0017] Unless otherwise expressly stated, it is not intended that any of the methods disclosed herein be construed as requiring that its steps be performed in a particular order, or that any of the articles described herein be construed as requiring a particular order or orientation of its individual components.

[0018] Unless expressly stated otherwise, it is intended that any composition or mixture disclosed herein may comprise, consist essentially of, or consist of the disclosed components.

[0019] As used herein, the singular form of a term is intended to include the plural form of that term, unless the context clearly indicates otherwise.

[0020] As used herein, numerical values ​​are not strictly limited to the exact numerical value recited. Instead, unless expressly stated otherwise, each numerical value is intended to mean both the exact numerical value and "about" a numerical value encompassing a functionally equivalent range surrounding that numerical value, whereby either possibility is contemplated as an embodiment disclosed herein.

[0021] As used herein, the term "formed from" (including related terms such as "formed"), with respect to an article (or component of an article) and a thermoplastic material, refers to the article (or component of an article) being extruded, molded, shaped, pressed, or otherwise made in whole or in part from a thermoplastic material under sufficient heat to permit such forming. Thus, the term "formed from" (including related terms such as "formed") means that in some embodiments, the article (or component of an article) can comprise, consist essentially of, or consist of the material, and in other embodiments, the article (or component of an article) consists of the material because the article (or component of an article) is made by, for example, an extrusion or molding process.

[0022] Wafer Carrier

[0023] According to an aspect of the present invention, a wafer carrier includes (a) a housing having an interior space, and (b) a moisture scavenging compound in fluid communication with the interior space. In an embodiment, the wafer carrier further includes an oxygen scavenging compound in fluid communication with the interior space.

[0024] The wafer carrier may be for enclosing a wafer, such as a semiconductor wafer, and, in use, houses the wafer within an interior space.

[0025] The moisture scavenging compound is suitably positioned to be in fluid communication with a potential source of moisture contamination. Similarly, in embodiments, if an oxygen scavenging compound is provided, it is suitably positioned to be in fluid communication with a potential source of oxygen contamination. The compound(s) are preferably positioned within an interior space. The interior space is preferably configured to store wafers.

[0026] Thus, in embodiments, the carrier can provide a moisture-controlled, and optionally oxygen-controlled, microenvironment for the semiconductor wafer encapsulated within the carrier as the semiconductor wafer moves through one or more manufacturing process steps.

[0027] For example, the wafer carriers disclosed herein may be FOUP (Front Opening Integrated Pod) or SMIF (Standard Mechanical Interface) pods. SMIF pods may be arranged to store multiple wafers horizontally when in use. The bottom of the SMIF pod may include an opening door that is suitably pivotable between an open position and a closed position.

[0028] A wafer carrier according to the present disclosure can include any one or more features of a commercially available FOUP or SMIF pod to the extent that such features do not negate or contradict any essential aspect of the present disclosure.

[0029] Non-limiting examples of commercially available FOUPs include the Entegris A300 FOUP or Spectra FOUP.

[0030] wafer

[0031] In an embodiment, one or more semiconductor wafers reside within the interior space.

[0032] The semiconductor wafer may have a diameter of at least 100 mm, and in embodiments at least 150 mm. For example, the semiconductor wafer may have a diameter in the range of 100 mm to 1000 mm, or in embodiments, in the range of 150 mm to 600 mm, or in embodiments, in the range of 150 mm to 500 mm.

[0033] For example, the wafer diameter accommodated in a SMIF pod may be 150 mm or 200 mm, while a FOUP may accommodate larger diameter wafers, for example, 300 mm or 450 mm.

[0034] The container can hold at least 10 semiconductor wafers, for example, 10 to 50 or 10 to 25 wafers.

[0035] chassis

[0036] The wafer carrier disclosed herein includes a housing having an interior space.

[0037] The housing has an interior space adapted to store one or more semiconductor wafers. The housing may include a pivotable door for providing access to the interior space. The door may include a door housing and a latch mechanism operably coupled to the door housing for securing the door closed. The door may be openable to access the interior space and, in use, to access a plurality of wafers that may be stored in the interior space. The door may define an interior side facing the interior space. The pivotable door may be a front-opening door.

[0038] The wafer carrier, e.g., its interior space, can include support means for supporting a plurality of wafers. The wafer carrier, e.g., its interior space, can be configured to house at least 10 silicon wafers. In use, when filled with silicon wafers, the wafer carrier can have a weight of at least 1 kg or at least 5 kg.

[0039] The wafer carrier may have a maximum external width of at least 30 cm, or in embodiments at least 40 cm, and in embodiments less than 80 cm or less than 60 cm. The wafer carrier may have a maximum external depth of at least 20 cm, or in embodiments at least 30 cm, and in embodiments less than 60 cm or less than 45 cm. The wafer carrier may have a maximum external height of at least 20 cm, or in embodiments at least 30 cm, and in embodiments less than 60 cm or less than 45 cm. The wafer carrier may have a maximum external height of at least 20,000 cm. 3 , or in embodiments at least 40,000 cm 3 and in embodiments, the external volume is 100,000 cm 3 It may be less than.

[0040] The wafer carrier may be made from any suitable material or combination of materials. The housing of the wafer carrier may include a barrier material, e.g., a thermoplastic material. In embodiments, the wafer carrier, e.g., the housing, may include an ESD (electrostatic discharge) material. The thermoplastic may be selected from polycarbonate, cyclic olefin polymer (COC), and cyclic olefin copolymer (COP). In one embodiment, the housing may include a carbon-filled thermoplastic polymer, e.g., a polycarbonate carbon-filled material.

[0041] In embodiments, the wafer carrier housing may be the same as or similar to an A300 FOUP or a Spectra FOUP available from Entegris.

[0042] In embodiments, the wafer carrier preferably includes wafer supports and / or wafer contact areas. Such supports and / or areas may include the same materials as described for the housing, or may include alternative materials. For example, an alternative material may be polyaryletherketone, such as PEEK.

[0043] moisture scavenging compounds

[0044] The wafer carriers disclosed herein include a moisture scavenging compound in fluid communication with the interior space.

[0045] Suitable moisture scavenging compounds may include conventional or commercially available moisture scavenging compounds. One type of moisture scavenging compound can be used alone or in combination with one or more other types of moisture scavenging compounds.

[0046] In embodiments, the moisture scavenging compound may be inorganic or organic, and / or may be polymeric or non-polymeric, and / or may include one or more petroleum-based polymeric materials, inorganic materials, or bio-based materials.

[0047] In embodiment I, the moisture-trapping compound may be configured to generate molecular hydrogen upon reaction with moisture, and thus, in this case, moisture is trapped by a chemical reaction involving the moisture and the moisture-trapping compound.

[0048] Further, in embodiment I, the moisture scavenging compound may comprise a matrix having associated therewith, e.g., embedded therein, or preferably dispersed therein, an active material arranged to generate molecular hydrogen upon reaction with moisture.

[0049] Suitable polymer matrix materials can be selected based on the solubility of water in the bulk polymer. Suitable polymer matrix materials include, but are not limited to, polyolefins, low-density polyethylene, high-density polyethylene, polypropylene, styrene-ethylene-butylene (SEBS) copolymer, nylon 6, styrene, styrene-acrylate copolymer, and ethylene vinyl acetate. The matrix may be a polymer matrix, and the active material may be dispersed therein.

[0050] In embodiments, the polymer matrix may comprise at least 1 wt%, preferably at least 2 wt%, of the active material. The polymer matrix may comprise less than 70 wt% of the active material. Suitably, the polymer matrix comprises 1-50 wt%, preferably 2-40 wt%, of the active material. The remainder of the material in the polymer matrix may comprise primarily polymeric material.

[0051] In embodiments, the active material may include a metal and / or a hydride. The metal may be one or more of sodium, lithium, potassium, magnesium, zinc, and aluminum. The hydride may be inorganic, such as a metal hydride or borohydride, or may be organic.

[0052] For example, suitable active materials that release molecular hydrogen upon contact with water include, but are not limited to, sodium metal, lithium metal, potassium metal, calcium metal, sodium hydride, lithium hydride, potassium hydride, calcium hydride, magnesium hydride, sodium borohydride, and lithium borohydride.

[0053] Non-limiting examples of other active substances include organic hydrides such as tetramethyldisiloxane and trimethyltin hydride, and metals such as magnesium, zinc, or aluminum.If the reaction rate between the active material and water is too slow, it is expressly contemplated to add a hydrolysis catalyst and / or agent.For example, the hydrolysis rate of silicon hydride can be improved by using hydroxide or fluoride ions, transition metal salts, or noble metal catalysts.

[0054] In embodiments, the active material may also be a polymer matrix. For example, a polymeric silicon hydride such as poly(methylhydro)siloxane provides both a polymer matrix and an active substance that can release molecular hydrogen when in contact with moisture. In embodiments, the active material may be a polymer-bound material such as a polymer-bound borohydride.

[0055] In an embodiment, the moisture scavenging compound and / or active material comprises calcium hydride.

[0056] In embodiment II, the moisture-trapping compound may be inorganic and may be a porous inorganic material suitably arranged to absorb water into pores defined in the material and retain the absorbed water therein. Such moisture-trapping compounds may include one or more of metal silicates (e.g., molecular sieves, magnesium aluminum silicate, or zeolites), fumed silica, amorphous silica (e.g., silica gel), activated alumina, activated carbon, silicon dioxide, mesoporous silica, clay, or bentonite.

[0057] In embodiment III, the moisture scavenging compound may be inorganic and may be an oxide, which may be an oxide of a Group I or II metal (e.g., sodium oxide or calcium oxide), a mixed metal oxide (e.g., soda lime), or a phosphorus-containing oxide (e.g., phosphorus pentoxide).

[0058] In embodiment IV, the moisture scavenging compound may be inorganic and may be a salt, which may be a salt of a Group I or II metal whose counterion is sulfate (e.g., sodium sulfate or calcium sulfate) or carbonate (e.g., potassium carbonate or magnesium carbonate).

[0059] In embodiment V, the moisture scavenging compound may be inorganic and may be a hydroxide. It may be a Group I or Group II hydroxide (e.g., potassium hydroxide or magnesium hydroxide).

[0060] In embodiment VI, the moisture scavenging compound may be inorganic and may be a halide (eg, calcium chloride or lithium bromide).

[0061] In embodiment VII, the moisture scavenging compound may be a polymeric material, preferably a hygroscopic material, which may include one or more of alcohol- or acrylate-functionalized polymers such as polyvinyl alcohol, ethylene vinyl alcohol, and polyacrylates.

[0062] In embodiment VIII, the moisture scavenging compound may be a hygroscopic bio-based material, which may include, for example, one or more of polycaprolactone (PCL), starch (e.g., corn starch or rice starch), sugar, fiber (e.g., cotton fiber, water hyacinth fiber, sisal fiber, hemp fiber, and agave fiber).

[0063] In embodiments, the moisture scavenging compound may be selected from one or more of anhydrous calcium chloride, soda lime, silicon dioxide, mesoporous silica, magnesium aluminum silicate, molecular sieves, silica gel, and clay.

[0064] In embodiments, the moisture scavenging compound may be selected from one or more of polycaprolactone (PCL), starch, cotton fiber, and water hyacinth fiber.

[0065] If the moisture scavenging compound is particulate, the size of the particles of the compound can be selected to optimize scavenging.

[0066] In embodiments, the compound is preferably in the form of particles.The particle of the compound can have a d50 of less than 50 μm, preferably less than 25 μm, more preferably less than 10 μm, particularly 5 μm or less.In some embodiments, the particle can have a d50 of less than 2 μm.The d50 of the particle can be greater than 10 nm, for example, greater than 20 nm.The d50 can be measured by laser diffraction, for example, using a Beckman Coulter LS230 Laser Diffraction Particle Size Analyzer.

[0067] In embodiments, less than 5 vol%, less than 3 vol%, or less than 1 vol% of the particles have a particle size greater than 100 μm, or greater than 5 μm, as measured by laser diffraction as described herein. Suitably, less than 5 vol% of the particles have a particle size greater than 5 μm. Suitably, more than 5 vol%, preferably more than 25 vol%, more preferably more than 50 vol%, especially more than 75 vol% of the particles have a particle size greater than 20 nm.

[0068] The particle size distribution can be expressed in terms of "span (S)", where S is calculated by the following formula:

[0069] S=(d90-d10) / d50

[0070] Here, d90 represents the particle size where 90% of the volume is made up of particles with a diameter smaller than the stated d90, d10 represents the particle size where 10% of the volume is made up of particles with a diameter smaller than the stated d10, and d50 represents the particle size where 50% of the volume is made up of particles with a diameter larger than the stated d50 value and 50% of the volume is made up of particles with a diameter smaller than the stated d50 value. A particle size distribution of particles with a span (S) of, for example, 0.01 to 10, or 0.01 to 5, or 0.1 to 3 may be preferred.

[0071] moisture scavenging composition

[0072] In embodiments, the moisture scavenging compound is part of a moisture scavenging composition.

[0073] Preferably, a moisture scavenging composition comprising a moisture scavenging compound is provided within the wafer carrier in fluid communication with the interior space.

[0074] The moisture scavenging composition preferably comprises a moisture scavenging compound.

[0075] In embodiments, the moisture-scavenging composition can include a moisture-scavenging compound (e.g., particles thereof) associated with (e.g., dispersed within) a polymer matrix. Examples of polymer matrices include, but are not limited to, polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, polyolefin copolymers, polystyrene, polystyrene copolymers, polyacrylate, polymethacrylate, polyester, polyvinyl chloride, fluoropolymers, polyamide, polyetherimide, polyphenylene sulfide, polysulfone, polyacetal, polycarbonate, polyphenylene oxide, polyurethane, thermoplastic elastomer, epoxy, alkyd, melamine, phenolic resin, urea, vinyl ester, liquid crystal polymer, cellulose, thermoplastic starch, polyhydroalkane, polylactic acid, or combinations thereof.

[0076] In particular, particles of the moisture-scavenging compounds of embodiments I-VI may be associated with, eg, dispersed within, a polymer matrix to form at least a portion of a moisture-scavenging composition.

[0077] In addition to the moisture scavenging compound, an oxygen scavenging compound may also be in fluid communication with the interior space.

[0078] Oxygen Scavenging Compounds

[0079] In embodiments, the wafer carriers disclosed herein can include an oxygen scavenging compound in fluid communication with the interior space.

[0080] Suitable oxygen scavenging compounds can include conventional or commercially available oxygen scavenging compounds. One type of oxygen scavenging compound can be used alone or in combination with one or more other types of oxygen scavenging compounds.

[0081] In embodiments, the oxygen-scavenging compound comprises an oxygen-scavenging segment. For example, the oxygen-scavenging compound can be an oxidizable organic compound. As a further example, the oxygen-scavenging compound can be an oxygen-scavenging polymer or copolymer.

[0082] In embodiment A1, the oxygen-scavenging compound may be an ethylenically unsaturated compound, an amide-containing compound, such as an aliphatic or at least partially aromatic polyamide, and / or a polyester modified by the inclusion of an ether moiety, such as, for example, a polyether-polyester.

[0083] When the oxygen scavenging compound is an ethylenically unsaturated compound, the compound may contain at least two double bonds. For example, it is a poly(ethylenically unsaturated). In embodiments, it is a polymer. For example, it is a polymer comprising repeating units of Formula I:

[0084] -[CH2-CR 1 =CR 2 -CH2-] n (I)

[0085] where R 1 and R 2 represents an optional substituent, which may independently be a hydrogen atom or an optionally substituted alkyl group. In embodiments, n may be greater than 0, greater than 1, greater than 2, greater than 10, greater than 100, or greater than 1000.

[0086] In embodiments, the double bonds in the compounds may be conjugated.

[0087] In embodiment A1, the oxygen scavenging compound may be a polybutadiene-based polymer, a farnesene-based polymer, or a polyisoprene-based polymer. Such polymers, such as polybutadiene-based polymers, may contain terminal -OH, -COOH, or -NH moieties, or may be essentially free of terminal functionality. For example, the polybutadiene-based polymer may include hydroxyl-terminated polybutadiene (PBD-OH) or elastomeric polybutadiene (E-PBD), the latter of which may be essentially free of terminal functionality.

[0088] In embodiment A2, the oxygen-scavenging compound may be a copolymer, in which case it is an oxygen-scavenging copolymer that may include segments of the oxygen-scavenging moiety referred to as "oxygen-scavenging moiety segments" or OSM segments.

[0089] For example, the copolymer may comprise polycondensate segments (and in embodiments, the copolymer comprises predominantly polycondensate segments) and OSM segments (and in embodiments, the copolymer comprises a lower wt% of OSM segments compared to the wt% of the polycondensate segments).

[0090] The OSM segment may be present in any amount necessary to impart the degree of oxygen scavenging capacity required for a particular application. In embodiments, the OSM segment may consist of a polyolefin oligomer segment incorporated into the oxygen scavenging copolymer. However, other oxygen scavenging moiety segments, such as polypropylene oxide oligomers and methyl-pendant aromatic compounds, may also be included in the oxygen scavenging copolymer.

[0091] The OSM segment of the oxygen-scavenging copolymer can be produced by reacting an OSM segment precursor with a polymer (referred to as "polymer X1"), e.g., a polyester. The OSM segment precursor can be at least monofunctionally terminated with a group capable of participating in polycondensation polymerization and / or reacting with a previously formed portion of polymer X1 to form a new covalent bond. Alternatively, the OSM segment precursor can react with a polymer end group to provide a copolymer structure. A functionally terminated OSM segment precursor can be represented by Formula II:

[0092] X-(OSM)-Y (II)

[0093] Although bifunctionality is shown in Formula II as one possibility, the OSM segment precursor may be monofunctionally terminated or functionalized to greater than two degrees. Those skilled in the art will recognize that functionally terminated OSM segment precursors are commercially available, obviating the need for such additional functionalization. The OSM segment precursor of Formula II is preferably selected to be readily oxidizable at ambient temperatures so that its autoxidation does not produce significant volatile or extractable by-products. In embodiments, the OSM segment precursor may comprise a polyolefin oligomer, a polypropylene oxide oligomer, or a methyl-pendant aromatic compound having a molecular weight of 100 to 10,000.

[0094] In embodiments, the OSM segment precursor may include a polybutadiene moiety. When incorporated as a segment into an oxygen-scavenging copolymer, the polybutadiene moiety can advantageously provide suitable oxygen scavenging. For example, such an OSM segment may be derived from an unhydrogenated polybutadiene oligomer having a molecular weight of 1,000 to 3,000. In Formula II, X and Y are typically the same and may be any species capable of participating in polycondensation and / or transesterification with polymer X1. Non-limiting examples of species that may be represented by X or Y include -OH, -COOH, -NH2, epoxides, and substituted derivatives thereof capable of participating in step-growth, condensation, and / or transesterification reactions with polymer X1, for example.

[0095] In one example of embodiment A2, the oxygen-scavenging copolymer may comprise an OSM segment derived from a polyolefin oligomer and / or comprising a polyolefin oligomer chain. In another example, the oxygen-scavenging copolymer may comprise an OSM segment derived from a polybutadiene oligomer and / or comprising a polybutadiene oligomer chain. The OSM segment is preferably covalently bonded to a polyester polymer X1, e.g., a PET segment, of the oxygen-scavenging copolymer.

[0096] In embodiments, the oxygen-scavenging copolymer may contain at least 60 wt%, or at least 75 wt%, polyester segments (e.g., polyethylene terephthalate segments), based on the weight of the oxygen-scavenging copolymer. In embodiments, the oxygen-scavenging copolymer may contain up to 25 wt% OSM segments, e.g., polyolefin oligomer segments, which may be derived from polybutadiene polymers and / or contain polybutadiene oligomer chains. The oxygen-scavenging copolymer suitably contains 75 to 99.5 wt%, or 75 to 85 wt%, or 77 to 82 wt% polyester segments (e.g., polyethylene terephthalate segments), and 0.5 to 25 wt%, or 15 to 25 wt%, or 18 to 23 wt% polyolefin oligomer segments (e.g., derived from polybutadiene polymers and / or containing polybutadiene oligomer chains).

[0097] In embodiment A2, when the oxygen scavenging compound is, for example, a described copolymer comprising copolymerization of an OSM segment into polymer X1, the compound may further comprise a chain extender moiety derived from, for example, an anhydride, for example, an anhydride comprising more than one reactive moiety, such as pyromellitic dianhydride (PMDA) or maleic anhydride. The described chain extenders may facilitate compatibilization of the oxygen scavenger moiety.

[0098] Oxygen Scavenging Composition

[0099] In embodiments, the oxygen scavenging compound is part of an oxygen scavenging composition.

[0100] Preferably, an oxygen-scavenging composition including an oxygen-scavenging compound is provided within the wafer carrier in fluid communication with the interior space.

[0101] The oxygen scavenging composition may suitably comprise an oxygen scavenging compound and a catalyst, e.g., a transition metal catalyst, suitable for catalyzing the oxygen scavenging reaction between the oxygen scavenging compound and oxygen that may be present in the wafer carrier during use.

[0102] The catalyst may be in the form of a salt, and the transition metal may be selected from the first, second, or third transition series of the periodic table. Suitable metals and their oxidation states include, but are not limited to, manganese II or III, cobalt II or III, nickel II or III, copper I or II, rhodium II, III, or IV, and ruthenium. Preferably, the catalyst is iron-free. The oxidation state of the metal upon introduction does not necessarily have to be in its active form. The metal may be nickel, manganese, cobalt, or copper, more preferably manganese or cobalt, and even more preferably cobalt. Suitable counterions for the metal include, but are not limited to, chloride, acetate, propionate, oleate, stearate, palmitate, 2-ethylhexanoate, neodecanoate, or naphthenate.

[0103] The transition metal catalyst may be selected from cobalt stearate, cobalt oleate, cobalt linoleate, cobalt acetylacetonate, cobalt neodecanoate, manganese stearate, manganese oleate, manganese linoleate, and manganese acetylacetonate.

[0104] In embodiments, the oxygen scavenging composition may include a transition metal catalyst that is a cobalt catalyst. The catalyst may include an organic counterion. The catalyst may be selected from cobalt stearate, cobalt oleate, cobalt linoleate, and cobalt acetylacetonate.

[0105] The oxygen scavenging composition may contain at least 0.009 wt.%, or at least 0.09 wt.%, of a transition metal catalyst. The composition preferably contains less than 1.50 wt.%, or less than 1.00 wt.%, of a transition metal catalyst. The foregoing amounts preferably refer to the amount of transition metal excluding any counterions, etc.

[0106] In embodiments, the oxygen scavenging composition may contain at least 0.009 wt%, or at least 0.09 wt%, of a cobalt fraction. The composition suitably contains less than 1.50 wt%, or less than 1.00 wt%, of a cobalt fraction.

[0107] In embodiments, the oxygen scavenging composition may contain at least 0.09 wt%, or at least 0.9 wt%, of a transition metal catalyst compound, such as cobalt stearate. The composition suitably contains less than 15.0 wt%, or less than 10.0 wt%, of a transition metal catalyst compound, such as cobalt stearate.

[0108] In embodiments, the oxygen-scavenging composition may comprise a total of at least 50 wt. %, or at least 75 wt. %, or at least 90 wt. % thermoplastic polymer. For example, the thermoplastic polymer may be the oxygen-scavenging compound of embodiments A1 and A2, as well as any of the thermoplastic polymers TP described herein. The composition suitably comprises a total of less than 99 wt. %, or less than 98 wt. % thermoplastic polymer.

[0109] The oxygen-scavenging composition may comprise a thermoplastic polymer TP or a residue of a thermoplastic polymer TP. The thermoplastic polymer TP may differ from the oxygen-scavenging compound in that the thermoplastic polymer TP is not covalently bonded to the oxygen-scavenging compound, or in some embodiments, at least a portion of the oxygen-scavenging polymer may be covalently bonded to the thermoplastic polymer TP, such that, for example, a copolymer is formed between at least a portion of the oxygen-scavenging polymer and the thermoplastic polymer TP (in which case the copolymer may comprise a residue of the thermoplastic polymer TP and a residue of the oxygen-scavenging polymer).

[0110] If the oxygen-scavenging composition is as described in embodiment A1 and includes an oxygen-scavenging compound that does not contain the relevant terminal functionality (e.g., does not contain the described terminal -OH, -COOH, or -NH moieties), the oxygen-scavenging compound may not be covalently bonded to the thermoplastic polymer TP. However, the oxygen-scavenging composition may be made using an oxygen-scavenging compound that does contain the relevant terminal functionality (e.g., the described terminal -OH, -COOH, or -NH moieties), in which case the oxygen-scavenging polymer can be covalently bonded to the thermoplastic polymer TP. In this latter case, the oxygen-scavenging compound may be a copolymer as described in embodiment A2.

[0111] In embodiments, the thermoplastic polymer TP can be polar. For example, the thermoplastic polymer TP can have polar functionality. For example, the thermoplastic polymer TP can include a carbonyl-containing group (e.g., an ester or ketone) or a hydroxyl-containing group (e.g., an alcohol). In embodiments, the thermoplastic polymer TP is thermoplastic. Hansen solubility parameters can be used to select a suitable thermoplastic polymer TP. These parameters are a set of three parameters that numerically describe the ability of a material to dissolve in a selected solvent: the "dispersion" parameter (δ d ) describes the dispersion forces of the material, and the "polarity" parameter (δ p ) describes the polarity of the material, and the "hydrogen bonding" parameter (δ h ) describe the ability of a material to form hydrogen bonds. These parameters provide a quantitative way to distinguish between "polar / non-polar" or "hydrophilic / hydrophobic" materials. If a thermoplastic polymer TP is non-polar or lacks hydrogen bonds (δ p =0 and δ h If the thermoplastic polymer TP is polar or contains hydrogen bonds, relatively high levels of oxygen scavenging may occur.

[0112] In an embodiment, the thermoplastic polymer TP has a molecular weight of δ p >0 and / or δ h>0.

[0113] In embodiments, the thermoplastic polymer TP may be selected from polylactic acid, polyester, polyethylene terephthalate, polycarbonate, polyolefins functionalized with carbonyl / carboxyl groups, In further embodiments, the thermoplastic polymer TP may be selected from polylactic acid and / or polyester, such as polyethylene terephthalate.

[0114] In embodiments, the addition of certain oils to the oxygen scavenging composition can enhance the oxygen scavenging capacity (eg, scavenging rate).

[0115] In embodiments, the oil may be selected from:

[0116] (a) olive oil,

[0117] (b) macadamia oil,

[0118] (c) avocado oil,

[0119] (d) Butaua oil,

[0120] (e) hazelnut seed oil,

[0121] (f) Oil PQ containing:

[0122] (i) less than 25% linoleic acid, and / or

[0123] (ii) less than 10% linolenic acid, and / or

[0124] (iii) greater than 40% oleic acid, and / or

[0125] (iv) more than 40% monounsaturated fatty acids, and / or

[0126] (v) less than 40% polyunsaturated fatty acids, and / or

[0127] (vi) at least 0.1% squalene;

[0128] References herein to "ppm" or "parts per million" (or similar expressions) refer to parts per million of a specified material by weight.

[0129] The percentage of a component in an oil, for example, an oil, can be assessed by GC-HRMS. The analysis can be, for example, as described in "Column Selection for the Analysis of Fatty Acid Methyl Esters; Authors: Frank David, Pat Sandra, Allen K Vickers. Agilent Technologies 5989-3760EN and citations therein. This method involves derivatization of fatty acids to methyl esters, followed by analysis of the fatty acid methyl esters (FAMEs), as described in W.W. Christie, "Gas Chromatography and Lipids, A Practical Guide," (1989), The Oily Press, Ayr, Scotland (ISBN 0-9514171-OX).

[0130] In an embodiment, the oil PQ may have the following characteristics:

[0131] - less than 25% linoleic acid,

[0132] - Less than 10% linolenic acid, and

[0133] - More than 40% oleic acid.

[0134] In an embodiment, the oil PQ may have the following characteristics:

[0135] 1 to 15%, preferably 2 to 10% of linoleic acid,

[0136] 0.1 to 10%, preferably 0.1 to 5%, of linolenic acid, and

[0137] - 40-80%, preferably 45-70% oleic acid.

[0138] In an embodiment, the oil PQ may have the following characteristics:

[0139] - more than 40% monounsaturated fatty acids,

[0140] - less than 40% polyunsaturated fatty acids, and

[0141] - At least 0.1% squalene.

[0142] In an embodiment, the oil PQ may have the following characteristics:

[0143] - 40 to 80%, preferably 45 to 75%, of monounsaturated fatty acids,

[0144] - 3 to 30%, preferably 4 to 15%, of polyunsaturated fatty acids, and

[0145] - 0.1 to 5.0%, preferably 0.1 to 4.0% squalene.

[0146] In embodiments, the oxygen scavenging composition may be in the form of a powder, compressed powder, film, pellet, compressed pellet, or foam, preferably in the form of a powder, compressed powder, or compressed pellet.

[0147] The oxygen scavenging composition (Composition I) may include:

[0148] (i) one or more thermoplastic polymers, wherein the total wt% of the thermoplastic polymers in the composition is in the range of 50 to 99 wt%, or in the range of 80 to 99 wt%, and

[0149] (ii) 0.009 wt% to 1.00 wt%, or 0.09 wt% to 1.00 wt% of a transition metal catalyst.

[0150] Unless otherwise indicated, the balance of the oxygen scavenging composition may include other polymers or additives (eg, oils as described) and / or counterions for the transition metal catalyst.

[0151] The one or more thermoplastic polymers may include one or more oxygen-scavenging compounds, which may include a polymer or copolymer described in embodiment A1 or A2. The oxygen-scavenging composition (composition II) may include:

[0152] (i) one or more oxygen-scavenging compounds, wherein the total wt% of the oxygen-scavenging compounds in the composition is in the range of 50 to 99 wt%, or in the range of 80 to 99 wt%, and

[0153] (ii) 0.009 wt% to 1.00 wt%, or 0.09 wt% to 1.00 wt% of a transition metal catalyst.

[0154] The one or more oxygen-scavenging compounds may include, for example, an ethylenically unsaturated compound that may be included in a polymer or copolymer described in embodiment A1 or A2. In this case, the oxygen-scavenging composition (composition III) may include:

[0155] (i) one or more oxygen-scavenging compounds comprising ethylenically unsaturated compounds, wherein the total wt% of the ethylenically unsaturated compounds in the composition is in the range of 50 to 99 wt%, preferably in the range of 80 to 99 wt%, and

[0156] (ii) 0.009 wt% to 1.00 wt%, preferably 0.09 wt% to 1.00 wt%, of a transition metal catalyst.

[0157] The one or more oxygen-scavenging compounds may comprise polybutadiene or residues of polybutadiene (collectively referred to herein as "polybutadiene-based compounds"), which may be included in a copolymer, for example, as described in embodiment A1 or A2. In this case, the oxygen-scavenging composition (composition IV) may comprise:

[0158] (i) one or more polybutadiene-based compounds, wherein the total wt% of the polybutadiene-based compounds in the composition is in the range of 50 to 99 wt%, preferably in the range of 80 to 99 wt%, and

[0159] (ii) 0.009 wt% to 1.00 wt%, preferably 0.09 wt% to 1.00 wt%, of a transition metal catalyst.

[0160] Each of the foregoing compositions I-IV may contain 0.09 to 15.0 wt %, for example 0.90 to 10.0 wt %, of a transition metal catalyst compound, for example a cobalt compound such as cobalt stearate.

[0161] In an exemplary embodiment, the oxygen-scavenging composition may contain at least a portion of an ethylenically unsaturated compound, such as polybutadiene, that is not covalently bonded to another polymer (such as polymer X1 and / or any polyester) to form a copolymer. In this case, the oxygen-scavenging composition may contain at least 20 wt%, or at least 30 wt%, or at least 40 wt% of an ethylenically unsaturated compound, such as polybutadiene, that is not copolymerized with polymer X1 and / or any polyester. In some cases, the oxygen-scavenging composition may contain at least 70 wt%, or at least 80 wt%, or at least 90 wt% of an ethylenically unsaturated compound, such as polybutadiene, that is not copolymerized with polymer X1 and / or any polyester. The remainder of such an oxygen-scavenging composition may contain a polyester and / or a catalyst compound.

[0162] In embodiments, the oxygen scavenging composition may include 30-98 wt %, 40-98 wt %, 50-98 wt %, or 80-98 wt % of polybutadiene that is not covalently bonded to another polymer (such as polymer X1 and / or any polyester) to form a copolymer, 0.09-15.0 wt %, e.g., 0.90-10.0 wt %, of a transition metal catalyst compound as described, and 0-60 wt % of a polyester, e.g., PET.

[0163] The described oxygen scavenging compositions may be capable of relatively high oxygen uptake. For example, in the test referred to in Example 4 below, the oxygen uptake may be at least 1 cc per gram of composition. The uptake may be at least 5 or at least 10 cc per gram of composition.

[0164] Receptacle

[0165] In embodiments, the moisture scavenging compound and / or composition may be provided in a receptacle, which is then positioned so that the moisture scavenging compound is in fluid communication with the interior space of the wafer carrier housing. The receptacle may be positioned within the interior space. In embodiments, the receptacle may be porous and may include a porous canister, envelope, or bag, such as a mesh bag.

[0166] In embodiments, the receptacle may be releasably securable within the interior space. For example, the receptacle may be releasably securable to a door of the housing or to an alternative interior region of the housing.

[0167] As an alternative to the receptacles described, a polymer sheet or film containing the moisture scavenging compound and / or composition may be provided and placed within the wafer carrier.

[0168] In embodiments where an oxygen-scavenging compound and / or composition is provided, the oxygen-scavenging compound and / or composition may be provided in a receptacle as described above, which is then disposed so that the oxygen-scavenging compound is in fluid communication with the interior space of the wafer carrier housing. Alternatively, a polymer sheet or film containing the oxygen-scavenging compound and / or composition may be provided and disposed within the wafer carrier.

[0169] In embodiments, the receptacle (or sheet or film) for the moisture scavenging compound and / or composition may be a different receptacle than the receptacle (or sheet or film) for the oxygen scavenging compound and / or composition.

[0170] Getter Module

[0171] In embodiments, the wafer carrier may further include a rigid polymer housing having an access opening, and a getter module including a moisture-trapping compound and / or composition disposed within the getter module housing. The getter module may be as described in WO2016145338, the contents of which are incorporated by reference with respect to the following features.

[0172] The getter module may include at least one rigid polymer connection feature extending from or as part of the getter module housing, the connection feature adapted to removably secure the getter module to one or a specific interior side of one or a specific door of the housing. The getter module housing may include a base and at least one cover secured to the base. A getter material may be disposed between the cover and the base. The getter module may further include a filter disposed between the cover and the moisture trapping compound and / or composition.

[0173] In embodiments where an oxygen scavenging compound and / or composition is provided, the oxygen scavenging compound and / or composition may be associated with a getter module as described above.

[0174] Method for protecting wafers

[0175] According to an aspect of the present invention, there is provided a method for protecting one or more semiconductor wafers from moisture contamination, the method comprising the steps of: (i) selecting a wafer carrier according to the first aspect; and (ii) placing the wafers to be protected within the interior space of the wafer carrier.

[0176] In embodiments, the method may extend to protecting one or more semiconductor wafers from moisture contamination and oxygen contamination.

[0177] Used to protect wafers

[0178] According to an aspect of the present invention, there is provided a use of a wafer carrier as described according to the first aspect for protecting one or more semiconductor wafers from moisture contamination.

[0179] In embodiments, uses may extend to protecting one or more semiconductor wafers from moisture and oxygen contamination.

[0180] new composition

[0181] According to an aspect of the present invention, there is provided a novel moisture scavenging composition according to the first aspect.

[0182] The moisture-scavenging composition may have any feature or combination of features described for the moisture-scavenging composition of the first aspect.

[0183] All documents cited herein are incorporated herein by reference in their entirety unless otherwise specified. The citation of any document should not be construed as an admission that it is prior art with respect to any invention disclosed or claimed herein. In the event that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall control.

[0184] The present invention is not limited to the details of the foregoing embodiments. It will be apparent that modifications and variations are possible without departing from the scope of the present disclosure, as defined in the appended claims. Although certain aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects. The present invention extends to any novel one or any novel combination of features disclosed herein (including this specification and the appended claims, abstract, and drawings), or any novel one or any novel combination of steps of any method or process so disclosed.

Claims

1. (a) a housing having an interior space; and (b) a moisture scavenging compound in fluid communication with the interior space; a wafer carrier including:

2. The carrier of claim 1 , wherein one or more semiconductor wafers reside within the interior space.

3. 3. The carrier of claim 1 or claim 2, wherein the moisture scavenging compound is disposed in fluid communication with a potential source of moisture contamination and is disposed within the interior space within a boundary defined by an outer wall of the carrier.

4. 10. The carrier of any preceding claim, wherein the wafer carrier is a FOUP (Front Opening Integrated Pod) or a SMIF (Standard Mechanical Interface) pod.

5. 10. A carrier according to any preceding claim, wherein the wafer carrier is arranged to accommodate wafers having a diameter of 300 mm or 450 mm.

6. 10. The carrier of any preceding claim, wherein the housing comprises an ESD (electrostatic discharge) material.

7. 10. A carrier according to any preceding claim, wherein the moisture scavenging compound is arranged to generate molecular hydrogen on reaction with moisture.

8. 10. A carrier according to any preceding claim, wherein the moisture scavenging compound is part of a composition comprising a matrix in which is associated, e.g. embedded or preferably dispersed, an active material arranged to generate molecular hydrogen upon reaction with moisture.

9. 9. The carrier of claim 8, wherein the matrix is ​​a polymer matrix comprising one or more of polyolefin, low density polyethylene, high density polyethylene, polypropylene, styrene-ethylene-butylene (SEBS) copolymer, nylon 6, styrene, styrene-acrylate copolymer, and ethylene vinyl acetate.

10. 10. The carrier of claim 8 or claim 9, wherein the active material comprises one or more of a metal and a hydride.

11. 11. The carrier of claim 10, wherein the metal comprises one or more of sodium, lithium, potassium, magnesium, zinc, and aluminum, and the hydride comprises one or more of a metal hydride and a borohydride.

12. The carrier of any one of claims 8 to 11, wherein the active material comprises calcium hydride.

13. 7. The carrier of claim 1, wherein the moisture scavenging compound comprises a porous inorganic material, the porous inorganic material being configured to absorb water into pores defined in the material and retain the absorbed water therein, as needed.

14. 14. The carrier of claim 13, wherein the moisture scavenging compound comprises one or more of metal silicates, fumed silica, amorphous silica, activated alumina, activated carbon, silicon dioxide, mesoporous silica, clay, and bentonite.

15. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises an oxide of a Group I or II metal, or an oxide containing phosphorus.

16. 7. The carrier of claim 1, wherein the moisture scavenging compound comprises a salt of a Group I or II metal whose counterion is sulfate or carbonate.

17. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises a Group I or Group II hydroxide.

18. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises a halide.

19. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises an alcohol or acrylate functionalized polymer, such as polyvinyl alcohol, ethylene vinyl alcohol, and polyacrylate.

20. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises a hygroscopic bio-based material.

21. 7. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises one or more of anhydrous calcium chloride, soda lime, silicon dioxide, mesoporous silica, magnesium aluminum silicate, molecular sieves, silica gel, and clay.

22. The carrier of any one of claims 1 to 6, wherein the moisture scavenging compound comprises one or more of polycaprolactone (PCL), starch, cotton fibers, and water hyacinth fibers.

23. 10. A carrier according to any preceding claim, wherein the moisture scavenging compound is part of a moisture scavenging composition.

24. 10. The carrier of any preceding claim, wherein the moisture scavenging compound and / or composition is provided in a receptacle arranged such that the moisture scavenging compound is in fluid communication with the interior space of the housing of the wafer carrier.

25. 25. The carrier of claim 24, wherein the receptacle is disposed within the interior space and is porous.

26. 1. A method for protecting semiconductor wafers from moisture contamination, comprising the steps of: (i) selecting a wafer carrier according to any preceding claim; and (ii) placing the semiconductor wafers to be protected within the interior space of the wafer carrier.

27. 10. Use of a wafer carrier according to any of the preceding claims for protecting semiconductor wafers from moisture contamination.

28. 26. The carrier of any one of claims 1 to 25, further comprising an oxygen scavenging compound in fluid communication with the interior space.

29. 30. A method for protecting semiconductor wafers from moisture and oxygen contamination, comprising the steps of: (i) selecting a wafer carrier according to claim 28; and (ii) placing the semiconductor wafers to be protected within the interior space of the wafer carrier.

30. Use of a wafer carrier according to any one of claims 28 to 29 for protecting semiconductor wafers from contamination by moisture and oxygen.

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