Purification of photoresist polymer by surface-modified porous polyethylene membrane

Abstract

Described are ligand-modified porous membranes that include a porous polymeric membrane having a ligand-modified surface, the ligand-modified surface having a hydrogen bond-acceptor group-containing ligand, a hydrogen bond-donor group-containing ligand, or both of these; methods of making the ligand-modified porous membrane; and method of using the ligand-modified porous membrane to filter a photoresist solution and remove unwanted polymer molecules from the photoresist solution.

Description

Attorney Docket No.: E000941 WOPURIFICATION OF PHOTORESIST POLYMER BY SURFACE-MODIFIED POROUS POLYETHYLENE MEMBRANEBACKGROUND

[0001] Photolithography is a process used in micro-fabrication, such as semiconductor fabrication, to selectively remove regions of a thin film or a substrate surface. The process uses light to transfer a pattern from a photomask onto a light-sensitive layer, i.e., a layer of photoresist solution (or “photoresist” for short) applied to the substrate. The process begins by applying a thin coating of the photoresist solution onto the substrate surface, followed by using the photomask to apply a pattern of light to the photoresist. A developer solution is then applied to the photoresist. A photoresist may be a “positive” photoresist or a “negative” photoresist. In the case of a positive photoresist, the light causes the photoresist to degrade and the developer dissolves away regions of the photoresist that were exposed to the light to leave behind patterned regions of the photoresist. In the case of a negative photoresist, the light strengthens the photoresist and the developer dissolves away only the regions of photoresist that were not exposed to light, leaving behind a photoresist coating in areas where the mask was not placed.

[0002] Any portion of the photoresist solution that is left behind at the surface of the substrate after photoresist solution is removed from the substrate can create a defect in a semiconductor device that is processed using the photoresist solution. Significant research efforts have been directed toward methods and filtering equipment that will remove different forms of contaminantsfrom photoresist solutions. United States Patent 11,772,055, for example, describes a need to remove ionic materials such as dissolved anions or cations from different process fluids, including photochemicals used in microelectronics processing; ionic contaminants present in very small concentrations in these process fluids may adversely affect the quality and performance of microprocessors and memory devices. Similarly, United States patent 11,731,085 describes methods of removing metal contaminants from organic liquids used as photoresist.SUMMARY

[0003] Commonly-used photoresist solutions contain polymeric and non-polymeric chemicals that are effective to allow the photoresist solution to function by absorbingAttorney Docket No.: E000941 WOlight applied to the photoresist solution to thereby cause a chemical reaction that will either degrade or strengthen the photoresist solution. Example photoresist solutions include photoresist polymer molecules that have pendant (chemically attached through a covalent bond) acid labile groups (ALGs, or “acid labile protecting groups”) and may optionally contain pendant photon absorption groups (PhAGs). Photoresist solutions additionally contain photoacid generator (PAG), which may be a pendant group that is chemically attached to the polymer molecule or may instead be a chemical molecule separately contained in the photoresist solution.

[0004] When the photoresist solution is exposed to patterned light from a photomask, the photoacid generator releases an acid. The acid causes acid labile groups attached to the photoresist polymer to be cleaved and separated from the polymer. The attachment or removal of the acid labile groups (ALGs) from the photoresist polymer will affect the solubility of the photoresist polymer. For example, while the acid labile group remains attached to the photoresist polymer, the acid labile group prevents the photoresist polymer from dissolving in an alkaline developing solution. If the acid labile group is removed from the photoresist polymer by exposure to acid, the photoresist may be dissolved in an alkaline developing solution.

[0005] Individual photoresist polymer molecules of a photoresist solution exhibit a range of molecular weights and monomeric compositions. Photoresist polymer molecules are synthesized by polymerizing individual monomers, including acid labile group-containing monomers (“ALG-containing monomers”), optional photon absorption group-containing monomers (“PhAG-containing monomers”), and optional photoacid generator-containing monomers (“PAG-containing monomers”), to form the polymer molecules from these monomers. Due to potentially imbalanced or inconsistent polymerization of monomers during the synthesis reaction, the reaction produces polymer molecules that have a range of molecular weights and varied monomer content.

[0006] A photoresist solution will include polymer molecules having both low molecular weights and high molecular weights. A photoresist solution will also contain polymer molecules that contain different amounts and distributions of acid labile groups, photon absorption groups, or photoacid generator groups, potentially including blocks of multiple monomers of the same type connected within the polymerat adjacent locations. Polymer molecules that contain a concentrated amount of one of these groups as aAttorney Docket No.: E000941 WOblock may be referred to as “group-rich” molecules with reference to each type of group. A polymer molecule that contains a high relative amount of acid labile groups in the form of a block of two or more ALG-containing monomers is referred to as an “ALG-rich” polymer molecule. A polymer molecule that contains a high relative amount of photon absorption groups in the form of a block of two or more PhAG-containing monomers is referred to as an “PhAG-rich” polymer molecule. A polymer molecule that contains a high relative amount of photoacid generator groups in the form of a block of two or more PAG-containing monomers is referred to as an “PAG-rich” polymer molecule.

[0007] Photoresist polymer molecules having different molecular weights and having different monomeric content will behave differently during use in the presence solvents or developer solution. Some species of photoresist polymer molecules are capable of producing defects during a photolithography process. For example, some polymer molecules have an imbalanced monomer content, meaning that a polymer molecule contains a block of at least two monomers polymerized in sequence, e.g., a block of two or more ALG-containing monomers, or a block of at least two PhAG-containing monomers, or a block of at least two PAG-containing monomers. These group-rich molecules can form molecular aggregates that are relatively insoluble compared to nongroup-rich molecules. The aggregates may be difficult to dissolve using solvent during a photolithography process. Aggregates that are not properly dissolved can produce defects that reduce yield of a photolithography process. Accordingly, methods of removing these group-rich molecules from a photoresist solution before the photoresist solution is used in a photolithography process would be effective to prevent these molecules from producing defects.

[0008] The following description relates to ligand-modified porous membranes and methods of using ligand-modified porous membranes to selectively remove certain group-rich polymer molecule from a photoresist solution.

[0009] In one aspect, the description relates to a method of filtering a photoresist solution usinga ligand-modified porous membrane. The photoresist solution comprising a photoresist polymer that comprises a block of acid labile groups; the ligand-modified porous membrane comprising a porous polymeric membrane and (i) a hydrogen-bond acceptorgroup-containingligand, (ii) a hydrogen-bond donorgroup-containingligand, or (iii) a combination of (i) and (ii). The method includes passing the photoresist solutionAttorney Docket No.: E000941 WOthrough the ligand-modified porous membrane to remove molecules of photoresist polymer from the photoresist solution.

[0010] In another aspect, the description relates to a ligand-modified porous membrane for filtering photoresist solutions. The ligand-modified porous membrane includes a porous polymeric membrane, and (i) a hydrogen-bond acceptorgroup-containingligand, or (ii) a hydrogen-bond donor group-containing ligand, or (iii) a combination of (i) and (ii).

[0011] Any two or more of the features described in this specification, including in this summary section, may be combined to form implementations not specifically explicitly described in this specification.DEFINITIONS

[0012] In order for the present disclosure to be more readily understood, certain terms used herein are defined below. Additional definitions for the following terms and other terms may be set forth throughout the specification.

[0013] In this application, unless otherwise clear from context or otherwise explicitly stated, (i) the term “a” may be understood to mean “at least one”; (ii) the term “or” may be understood to mean “and / or”; (iii) the terms “comprising” and “including” may be understood to encompass itemized components or steps whether presented by themselves or together with one or more additional components or steps; (iv) the terms “about” and “approximately” may be understood to permit standard variation as would be understood by those of ordinary skill in the relevant art; and (v) where ranges are provided, endpoints are included. In certain embodiments, the term "approximately" or "about" refers to a range of values that fall within 25%, 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less in either direction (greater than or less than) of the stated reference value unless otherwise stated or otherwise evident from the context (except where such number would exceed 100% of a possible value).BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Drawings are presented herein for illustration purposes, not for limitation. The foregoing and other objects, aspects, features, and advantages of the disclosure will become more apparent and may be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which:Attorney Docket No.: E000941 WO

[0015] FIG. 1 presents an exemplary filter device comprising disclosed membranes, accordin to illustrative embodiments of the present disclosure; and

[0016] FIG. 2 presents a chart useful for characterizing dye binding capacity of disclosed membranes, according to illustrative embodiments of the present disclosure.DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

[0017] It is contemplated that systems, devices, methods, and processes of the disclosure encompass variations and adaptations developed using information from the embodiments described herein. Adaptation and / or modification of the systems, devices, methods, and processes described herein may be performed by those of ordinary skill in the relevant art.

[0018] Throughout the description, where articles, devices, and systems are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are articles, devices, and systems according to certain embodiments of the present disclosure that consist essentially of, or consist of, the recited components, and thatthere are processes and methods accordingto certain embodiments of the present disclosure that consist essentially of, or consist of, the recited processing steps.

[0019] It should be understood that the order of steps or order for performing certain action is immaterial so long as operability is not lost. Moreover, two or more steps or actions may be conducted simultaneously. As is understood by those skilled in the art, the terms “over”, “under”, “above”, “below”, “beneath”, and “on” are relative terms and can be interchanged in reference to different orientations of the layers, elements, and substrates included in the present disclosure. For example, a first layer on a second layer, in some embodiments means a first layer directly on and in contact with a second layer. In other embodiments, a first layer on a second layer can include another layer there between.

[0020] Headers are provided for the convenience of the reader and are not intended to be limiting with respect to the claimed subject matter.

[0021] The following description relates to ligand-modified porous membranes, methods of using the ligand-modified porous membranes to remove certain group-richAttorney Docket No.: E000941 WOspecies of polymer molecules from a photoresist solution, and to methods of preparing the ligand-modified porous membranes.

[0022] The ligand-modified porous membrane is effective to selectively remove certain group-rich species of polymer molecules from a photoresist solution, while preferentially allowing other useful species of polymer molecules to pass through the ligand-modified porous membrane. According to certain examples, the ligand-modified porous membrane can selectively remove ALG-rich polymer molecules (polymer molecules that contain a block of at least 2, 3, 4, or 5 consecutive ALG-containing monomers) from a photoresist solution while not removing polymer molecules which are not ALG-rich from the photoresist solution.

[0023] Photoresist solutions contain photoresist polymer molecules that are derived from polymerizing a combination of monomers. The monomers include monomers that have an acid labile group (ALG) (“ALG-containing monomers), optionally monomers that have a photon absorption group (PhAG) (“PhAG-containing monomers”), and, optionally, monomers that have a photoacid generator group (PAG) (“PAG-containing monomers”).

[0024] An “acid labile group,” also referred to as “acid labile protecting group” or “ALG,” is a pendant group of a photoresist polymer molecule that can be separated from the molecule by exposure to acid. While the acid labile group remains attached to the photoresist polymer, the acid labile group prevents the photoresist polymer from dissolving in an alkaline developing solution. If the acid labile group is removed from the photoresist polymer by exposure to acid, the photoresist may be dissolved in an alkaline developing solution.

[0025] Various acid labile groups have been used in photoresist solutions, with examples including: t-butyl, tetrahydropyran-2-yl, 2-methyl tetrahydropyran-2-yl, tetra hydrofuran-2-yl, 2-methyl tetrahydrofuran-2-yl, 1-methoxyprophyl, 1-methoxy-1-methylethyl, 1 -ethoxypropyl, 1 -ethoxy-1 -methylethyl, 1 -methoxyethyl, 1 -ethoxyethyl, t-butoxyethyl, 1 -isobutoxyethyl and 2-acetylmenth-1-yl.

[0026] A “photon absorption group,” also referred to as “sensitization group” or “PhAG,” is a pendant group of a photoresist polymer molecule that can improve the light sensitivity of the photoresist solution. Examples of photon absorption groups include 2,3, 4-trihydroxybenzophenone-1, 2-diazonaphthoquinone-5-sulfonate; 2,3,4, 4' tetrahydroxybenzophenone-1, 2-diazonaphthoquinone-5-sulfonate; nitroaniline;Attorney Docket No.: E000941 WOanthraquinone; benzophenone; diazo naphtho quinone; 1,2-naphthoquinonediazo-5- or 4-sulfonic acid esters or 1,2-benzoquinone diazo-4-sulfonic acid esters of polyhydroxy compounds having three or more phenolic hydroxyl groups; diphenyl iodonium triflate; diphenyl iodonium nonaflate; diphenyl iodonium hexafluorophosphate; diphenyl iodonium hexafluoroarsenate; diphenyl iodonium hexafluoroantimonate; diphenyl p-methoxyphenyl sulfonium triflate; diphenyl p-toluenyl sulfonium; triphenylsulfonium triflate; tris(p-tert-butylphenyl) sulfonium triflate; diphenyl p-methoxyphenyl sulfonium nonaflate; diphenyl p-toluenyl sulfonium nonaflate; diphenyl p-tert-butylphenyl sulfonium nonaflate; diphenyl p-isobutylaflate; nonaflate, tris(p-tert-butylphenyl) sulfonium nonaflate; triphenylsulfonium hexafluoroarsenate; triphenylsulfonium hexafluoroantimonate; triphenylsulfonium triflate; and dibutylnaphthylsulfonium triflate.

[0027] The a photoacid generator group (PAG) may be selected from any of conventional compounds which can generate acid by light. Useful PAGs may include onium salts, selenium salts, phosphonium salts, iodonium, sulfonium salts, organic halogen compounds, O-nitrobenzylsulfonate compounds, N-iminosulfonate compounds, N-imidosulfonate compounds, diazosulfonate compound, sulfonimide compounds, diazodisulfonate compounds, and disulfone compounds. As more specific but nonlimiting examples: diphenyl iodide hexafluorophosphate; diphenyl iodide hexafluoro arsenate; diphenyl iodide hexafluoroantimonate; diphenyl p-methoxyphenylsulfonium triflate; diphenyl p-toluenylsul fonium triflate; diphenyl p-isobutylphenylsulfonium triflate; diphenyl p-t-butylphenylsulfonium triflate; triphenylsulfo nium hexafluorophosphate; triphenylsulfonium hexafluoro arsenate; triphenylsulfonium hexafluoroantimonate; triph enylsulfonium triflate; dibutylnaphthylsulfonium triflate; phthalimidotrifluoromethane sulfonate; dinitrobenzyltosylate; n-decyl disulfone; naphthylimido trifluoromethane sulfonate; and any combination thereof.

[0028] The polymer molecules of the photoresist solution are contained in a liquid solvent that may contain other useful chemical ingredients such as surfactant, to allow the photoresist solution to be applied as a thin coating onto a surface of a substrate duringa photolithography process. Example solvents include alcohols such as methanol, ethanol, propanol, butanol, isopropanol, polyols such as propylene glycol, chlorinated hydrocarbon, glycol ethers such as propylene glycol methyl ether (PGME), methyletherAttorney Docket No.: E000941 WOacetate (PGMEA), cyclohexanone, methyl 3-methoxypro pionate, ethyl 3-ethoxypropionate, 2-heptanone, ethyl lactate, and combinations of these.

[0029] Examples of useful photoresist polymers and photoresist solutions are described, e.g., in United States Patent Publication Numbers 2017 / 0227852, 20050026080; United States Patent Number 10,353,290; and Wang et al., “Trends in photoresist materials for extreme ultraviolet lithography: A review,” Materials Today Volume 67, July / August 2023.

[0030] During synthesis of photoresist polymers from its relevant monomers, the polymer that is produced can include “blocks” of a single type of monomer that reacts consecutively during the polymerization reaction. A polymer molecule may contain blocks of consecutively-reacted monomers to form blocks of acid labile group monomers, blocks of photon absorption groups, or blocks of photoacid generator groups. A polymer molecule that contains a block of two or more consecutive monomers is referred to as a group-rich molecule with respect to that type of monomer.

[0031] Example ALG-rich polymer molecules can contain a block of at least two consecutive acid labile groups. Example PhAG-rich polymer molecules can contain a block of at least two consecutive photon absorption groups. Example PAG-rich polymer molecules can contain a block of at least two consecutive photoacid generator groups.

[0032] Group-rich polymer molecules can be relatively insoluble in solvent used during a photolithography process, and, by not being properly dissolved during the process, may result in defects at a surface of a substrate. Accordingly, this description relates to ligand-modified porous membranes and methods of using a ligand-modified porous membrane to selectively remove group-rich polymer molecules from a photoresist solution.

[0033] The ligand-modified porous membrane includes a porous polymeric membrane (or “porous membrane”) that is chemically modified to chemically attach or “graft” ligands to polymer at surfaces of the porous membrane. The ligands attached to the porous membrane are effective to selectively remove certain species of photoresist polymer molecules from a photoresist solution, while preferentially allowing other species of photoresist polymer molecules to pass through the membrane. According to specific examples, a ligand-modified porous membrane may include ligands selected from: i) a hydrogen-bond acceptor group-containing ligand, or ii) a hydrogen-bond donor group-containing ligand, or both i) a hydrogen-bond acceptor group-containing ligandAttorney Docket No.: E000941 WOand ii) a hydrogen-bond donor group-containing ligand. Examples of ligand-modified porous membranes that contain i), ii), or both i) and ii) are effective to selectively remove group-rich polymer molecules from a photoresist solution, including to selectively remove ALG-rich polymer molecules from a photoresist solution.

[0034] The porous membrane can be any polymeric membrane that can be chemically modified to produce a ligand-modified porous membrane as described. The porous membrane may be any of a general variety of porous polymeric filter materials that are known to be useful for applications in filtering high purity liquids. A porous membrane and a ligand-modified porous membrane can be characterized based on one or more of polymeric composition, pore size, porosity, bubble point, removal efficiency (e.g., based on dye-binding capacity), flow rate (based on a measured flow time), and thickness, among other physical and performance features.

[0035] A useful porous membrane may be formed from a variety of known polymers, with examples including polyamides (nylons), polysulfones, polyether-sulfones, polyolefins (e.g., polyethylene, polypropylene, UPE), and halogenated polymers such as fluorinated polymers.

[0036] The porous membrane may have pores of a size (average pore size) to be considered either a microporous membrane or an ultrafilter membrane. A microporous membrane can have an average pore size in a range on from about 0.05 microns to about 10 microns, with the pore size be selected based on one or more factors that include: the particle size ortype of impurity to be removed, pressure and pressure drop requirements, and viscosity requirements of a liquid being processed by the filter. An ultrafilter membrane can have an average pore size in a range from 0.001 microns to about 0.05 microns. Pore size is often reported as average pore size of a porous material, which can be measured by known techniques such as by Mercury Porosimetry (MP), Scanning Electron Microscopy (SEM), Liquid Displacement (LLDP), or Atomic Force Microscopy (AFM).

[0037] Bubble point is a known feature of a porous membrane. By a bubble point test method, a sample porous membrane is immersed in and wetted with a liquid having a known surface tension, and a gas pressure is applied to one side of the sample. The gas pressure is gradually increased. The minimum pressure at which the gas flows through the sample is called a bubble point. Examples of useful bubble points of a porousAttorney Docket No.: E000941 WOpolymeric filter layer that is useful or preferred according to the present description, measured using HFE 7200, at a temperature of 20-25 degrees Celsius, can be in a range from 2 to 400 psi, e.g., in a range from 20 to 200 psi.

[0038] A porous membrane as described may have a porosity that will allow the porous membrane to be effective in filtering a photoresist solution as described. Example porous membranes may have a relatively high porosity, for example a porosity of at least 70 or 80 percent, e.g., a porosity in a range from 85 to 95 or 98 percent. As used herein, and in the art porous membranes, a “porosity” of a porous membrane (also sometimes referred to as void fraction) is a measure of the void (i.e. “empty”) space in the membrane as a percent of the total volume of the membrane and is calculated as a fraction of the volume of voids of the membrane overthe total volume of the membrane.

[0039] A porous membrane as described can be in the form of a sheet having any useful thickness, e.g., a thickness in a range from 5 to 100 microns, e.g., from 20 to 70 microns.

[0040] Membrane isopropanol (IPA) flow times as reported herein are determined by measuring the time required for 500 ml of isopropyl alcohol (IPA) fluid to pass through a membrane with a 47 mm membrane disc with an effective surface area of 13.8 cm2, at 14.2 psi, and at a temperature of 21 degrees Celsius. Water flow time can be measured usingthe same procedure as IPA flow time exceptwater is used instead of IPA. Example porous membranes can have an isopropanol flow time for 500 ml IPA that is at least about 200 seconds, e.g., a flow time in a range from about 200 to 50,000 seconds, or from about 200 to about 20,000 seconds, or from about 200 to about 15,000 seconds, or from about 200 to about 8, 000 seconds, or from about 200 to about 1,000 seconds, or from about 500 to about 50,000 seconds, or from about 500 to about 20,000 seconds, or from about 500 to about 15,000 seconds, or from about 200 to about 8,000 seconds, or from about 500 to about 1,000 seconds, orfrom about 1,000 to about 50,000 seconds, orfrom about 1,000 to about 20,000 seconds, orfrom about 1,000 to about 15,000 seconds, or from about 200 to about 8, 000 seconds, including and any ranges and subranges therebetween.

[0041] Generally, porous filter membranes can be useful to remove a dissolved or suspended contaminant or impurity from a liquid that is caused to flow through the porous filter membrane, either by a sieving mechanism or a non-sieving mechanism. A sieving mechanism is a mode of filtration by which a particle is removed from a flow ofAttorney Docket No.: E000941 WOliquid by mechanical retention of the particle within a physical pore of a filter membrane, which acts to mechanically interfere with the movement of the particle and retain the particle within the filter, mechanically preventing flow of the particle through the filter. Typically, the particle can be larger than pores of the filter. A “non-sieving” filtration mechanism is a mode of filtration by which a filter membrane retains a suspended particle or dissolved material contained in a liquid flowing through the filter membrane in a manner that is not exclusively mechanical, e.g., that includes an electrostatic mechanism.

[0042] A ligand-modified porous membrane as described can be useful to selectively remove group-rich polymer molecules from photoresist solution by causing the photoresist to flow through the ligand-modified porous membrane, and either by a sieving or a non-sieving mechanism. The ligand-modified porous membrane, before having ligands chemically attached to the surface of the polymer, may exhibit sieving and non-sieving filtering properties for various particulate and dissolved contaminants or impurities. The same porous membrane that further includes chemically attached ligands as described can exhibit comparable sieving filtering properties, and additionally is capable of selectively removing group-rich polymer molecules from photoresist solution passing through the membrane, potentially by a non-sieving mechanism.

[0043] The hydrogen-bond acceptor group-containing ligand or hydrogen-bond donor group-containing ligand, or both, can be any such ligands that can be chemically attached to a porous membrane, and will be effective to selectively remove group-rich polymer molecules from a photoresist solution. Non-limiting examples of monomers that contain a H-bond donor or an H-bond acceptor, that can be used to add the H-bond donor or the H-bond acceptor to a porous membrane, include the following.Structure H-Bond Donor / H-Bond AcceptorAcceptorC3H3N (Acrylonitrile)Attorney Docket No.: E000941 WOAcceptorC5H5N (Pyridine)AcceptorC5H6N2(1-Vinylimidazole)OH HO / DonorC2H5O4P (vinyl phosphate)I IAcceptorC16H21N3([1-(4-vinylbenzyl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2- pyrimidine])0HHl >rH Donor / Acceptor C6H13NONylon 6CH,I ©H I©C1-CH3|| CH3Acceptor 0C9H18ClN2O ((3-acrylamidopropyl) trimethylammoniumchloride)OH OHDonor < CH3OH OHC16H25NO56-(methyl(4-vinylbenzyl)amino)hexane-1, 2, 3,4,5-pentaolAttorney Docket No.: E000941 WOoH3cAcceptor I CH3C5H9NO (N, N-Dimethylacrylamide)0Hprr If NH nAcceptor °CnH18N2O2Aromatic NylonAcceptorC19H25N ([N-(4-vinylbenzyl)tricyclo[3.2.1,3,6]octan-1-amine]0DonorC3H4O2 (acrylic acid)(OC2H4)4F2 I F2,r _ / c\lp-c^ XT p- L F2F2 JnDonor (OC2H4O)4C10H12F8Lumiflon resinN-Methyl-D-glucamineAcceptor C7H17NO5Attorney Docket No.: E000941 WON, N-dimethylacrylamideDonorC6H11NO

[0044] The ligand-modified porous membrane can be prepared by modifying a porous membrane by reacting the polymeric membrane with a reactive compound that contains a H-bond donorora H-bond acceptortochemicallyattach (graft) the reactive compound onto the polymeric membrane, to place the H-bond donor or the H-bond acceptor as chemically-attached ligands on the polymeric surface of the porous membrane. Methods of grafting monomers onto a polymeric membrane are generally known and are described in the Examples below. Example methods may generally include first forming a monomer solution that contains the reactive monomer, crosslinker, solvent, and an initiator (e.g., photoinitiator). The monomer solution is applied to the membrane and solvent in the monomer solution is removed by evaporation. The initiator is activated, e.g., by exposure to radiation. The radiation causes the initiator to initiate a reaction between the reactive monomer and polymer of the porous membrane, whereby the reactive monomer becomes chemically attached to, i.e., “grafted” to, the polymer, through a covalent chemical bond. The reaction also polymerizes the monomers and / or crosslinks the monomers and forms a crosslink network.

[0045] A membrane disclosed herein can be contained within a larger filter structure such as a filter or a filter cartridge that is used in a filtering system. The filtering system will place an exemplary membrane, e.g., as part of a filter or filter cartridge, in a flow path of a fluid (e.g., a disclosed photoresist solution) to cause the fluid (e.g., a disclosed photoresist solution) to flow through an exemplary membrane and allow an exemplary membrane to remove a component, for example an ALG-rich polymer molecule, from the fluid. The structure of a filter or filter cartridge may include one or more of various additional materials and structures that support an exemplary membrane within the filter product to cause a fluid (e.g., a disclosed photoresist solution) to flow from a filter inlet, through an exemplary membrane, and through a filter outlet, thereby passing through an exemplary membrane when passing through the filter product. An exemplaryAttorney Docket No.: E000941 WOmembrane supported by the filter product can be in any useful shape, e.g., a pleated cylinder, cylindrical pads, one or more non-pleated (flat) cylindrical sheets, a pleated sheet, among others.

[0046] An exemplary membrane may be used in combination with a second filter membrane to provide a combination of filtering retention of different types of other contaminants. As an example, a disclosed membrane may be used in series with a second filter membrane in the form of a non-woven polymeric membrane that is made of a useful filtering material, e.g., polyolefin fibers such as high-density polyethylene, polysulfonic acid, among others. The non-woven membrane may be surface-modified (e.g., “functionalize”), for example to include a negative charge at the membrane surface to improve retention of metal ions.

[0047] An example of a useful filter device is shown at shown at FIG. 1. Filter 100 includes a membrane 102, for example a disclosed ligand-modified porous membrane. Filter 100 can have a housing 104 that provides a structure to the filter 100 and that fluidically seals an internal portion of the filter. The housing 104 can be any shape and size, such as cylindrical, polygonal, etc.

[0048] One portion of the housing 104 includes inlet port 106 to receive a fluid (e.g., a disclosed photoresist solution) to be filtered. The fluid (e.g., a disclosed photoresist solution) can flow through inlet port 106 in the direction indicated by arrow 116, and into a headspace 114 in the filter 100, as defined by an input-facing surface 124 of coated membrane 102, the internal surface of the housing 104, and the inlet port 106.

[0049] One portion of the housing 104 includes outlet port 108 to allow filtered fluid (e.g., a disclosed photoresist solution) to exit from filter 100. The filtered fluid (e.g., a disclosed photoresist solution) can flow in the direction indicated by arrow 118 through outlet port 108 from backspace 120, as defined by an output facing surface 126 of coated membrane 102, the internal surface of the housing 104, and the outlet port 108.

[0050] The interior of filter 100 can contain membrane 102 in any suitable placement or arrangement, with FIG. 1 showing membrane 102 having a disc-like form (a crosssectionalview is shown). A side 122 of membrane 102, such as the outer circumference of the membrane, can be in contact with the inner surface of the housing 104. Membrane 102 can also have an input-facing surface 124, which first contacts the purified water, and an output-facing surface 126, from which the filtered fluid (e.g., a disclosedAttorney Docket No.: E000941 WOphotoresist solution) with reduced amounts components to be removed (e.g., ALG-rich polymer molecules) flows.

[0051] Filter 100 can also include one or more structures to support an exemplary membrane 102 within the filter housing. Any arrangement for supporting membrane 102 can be used and can include one or more distinct structural features, such as a frame, frame, bracket, clip, web, net, and cage, and the like, or a material such as an adhesive can be used to support the membrane.

[0052] As illustrated, with reference to FIG. 1, the filter 100 includes a frame having frame portions 110 and 112, with frame portion 110 in contact with the interior of housing 104, which is attached to portion 112. Portion 112 can be in contact with the output-facing surface 124 of membrane 102 and can provide support to the membrane during filtering. Frame portion 112 can have a grid-like structure to freely allow filtered liquid to pass into the backspace 120 of the filter, while still providing structural support to the membrane under increased fluidic pressures.

[0053] In use, a fluid (e.g., a disclosed photoresist solution) enters filter 100 through inlet port 106 in direction indicated by arrow 116, and then fills the headspace 114 within the filter 100. Sufficient fluidic pressure is applied to cause the fluid to move through the membrane at a desired flow rate.EXAMPLES

[0054] Example 1: Preparation of Surface Modification Solution Containing Monomer Having Positively Charged, H-Bond Acceptor Groups.

[0055] This example demonstrates the preparation of a surface modification solution which includes positively charged, H-bond acceptor monomer (e.g., monomer with positive charges, such as (3-Acrylamidopropyl) trimethylammonium chloride), radical initiator, and crosslinker. A surface modification solution was prepared by dissolving 0.3% lrgacure-2959; 2.5% (3-Acrylamidopropyl) trimethylammonium chloride solution (APTAC) and 0.75% N, N'-Methylenebisacrylamide (MBAm) in 96.45% of methanol.

[0056] Example 2: Surface Modification of UPE Membrane with Positively Charged, H-Bond Acceptor Monomer Ligand.

[0057] The present example demonstrates surface modification of an ultrahigh molecular weight polyethylene (UPE) porous flat sheet with the surface modificationAttorney Docket No.: E000941 WOsolution of Example 1 having polymerized positively charged, H-Bond acceptor monomer, radical initiator, and crosslinker. In a representative experiment, an A4 size porous flat sheet of UPE membrane was immersed in a dish containing the surface modification solution described in Example 1. The dish was covered and the porous membrane was soaked in the solution for 2 minutes. The porous membrane was removed and dried for 10 minutes. The flat sheet porous membrane with dried surface modification solution was then placed between 1 mil polyethylene sheets and prewetted with a fluorinated solvent (e.g., Galden HT80). The excess solution was removed by rolling a rubber roller over the polyethylene / membrane sheet / polyethylene sandwich as it laid flat on a table. The polyethylene sandwich was then taped to a transport unit which conveyed the assembly through a Fusion Systems Broadband UV exposure lab unit (Model # P300MT) emitting at wavelength from 200 to 600 nm. Time of UV exposure was controlled by how fast the assembly moved through the UV unit. In this example, the assembly moved through the UV chamber at 8 feet per minute. After emerging from the UV unit, the membrane was removed from the sandwich and immediately placed in DI water for 5minutes to remove any unreacted monomers. Next, the treated membrane sheet was washed in methanolfor 5 minutes. Followingthis washing procedure the membrane was dried on a holder in an oven operating at 50 °C. for 10 minutes. The modified membrane was characterized by IPA flow time as disclosed herein and surface charge was characterized by red dye binding capacity test as disclosed herein, the results of each reported in Table 1:DBC IPA Flow time ThicknessSample(pg / cm2) (Sec / 500ml) (pm) Unmodified0 3488 45UPE MembraneExample 2 60 3935 44

[0058] Table 1. IPA Flow Time and Dye Binding Capacity of Unmodified UPE Substrate and Example 2 Modified UPE.

[0059] Example 3: Preparation of Surface Modification Solution Containing Both H-Bond Donor Monomer and H-Bond Acceptor Monomer

[0060] The present example demonstrates the preparation of a surface modification solution which includes H-bond donor monomer (in the present example, N-Methyl-D-glucamine), H-bond acceptor monomer (in the present example, N, N-Attorney Docket No.: E000941 WOdimethylacrylamide), radical initiator, and crosslinker. First, a stock solution of 4% by weight VBC / NMDG was prepared by reacting vinyl benzyl chloride (VBC) with N-Methyl-D-glucamine (NMDG) in a solvent solution of Dimethylformamide (DMF) and de-ionized water (DIW) according to Table 2.DMF (g) DIW(g) VBC (g) NMDG (g) Temperature °C Time (hrs)7920 720 220 140 40 24

[0061] Table 2. 4wt% VBC / NMDG Solution Preparation Parameters

[0062] After 24 hours at 40 °C, the solution containing the VBC / NMDG was allowed to cool down to room temperature and was vacuum filtered through a 1.0 pm polyethylene vacuum filter. See, for example, US Patent Publication No. 2020 / 0254398 A1, which is hereby incorporated by reference in its entirety. A surface modification solution was prepared by dissolving 0.3% lrgacure-2959; 2% N, N-dimethylacrylamide (DMAm), 0.75% N, N'-Methylenebisacrylamide (MBAm) & a 2% solution of 4-Vinylbenzylchloride / N-Methyl-D-glucamine monomer (VBC / NMDG) prepared from the 4% by weight VBC / NMDG in 94.95% of methanol.

[0063] Example 4: Surface Modification of UPE Membrane with H-Bond Donor Monomer and H-Bond Acceptor Monomer

[0064] The present example demonstrates surface modification of an ultrahigh molecular weight polyethylene (UPE) porous flat sheet with the surface modification solution described in Example 3, having polymerized H-bond donor monomer, polymerized H-bond acceptor monomer, radical initiator and crosslinker. An A4 size porous UPE sheet was immersed into the surface modification solution and soaked in for 2 minutes. After 2-minutes the sheet was removed from the surface modification solution tank and dried under air for 10minutes. It was then placed between two polyethylene sheets and wetted with fluorinated solvent (e.g., Galden HT80) and the excess liquid and air were removed by applying pressure with a rubber roller. The polyethylene sheets containing the UPE flat sheet was exposed to UV by transporting it through a Fusion UV system, Inc broadband UV at 8 ft per minute. After emerging from the UV chamber, the resulting porous membrane sheet was removed from the polyethylene sheets and immediately immersed in deionized water and soaked for 5-minutes. It was further washed with methanol to remove any unreacted monomers and finally dried on a restraining holder in an oven at 50°C for 10 minutes. The modifiedAttorney Docket No.: E000941 WOmembrane was characterized by IPA flow time as disclosed herein and surface charge was characterized by red dye binding capacity test as disclosed herein, the results of each reported below in the Table 3:DBC IPA Flow time ThicknessSample(pg / cm2) (Sec / 500ml) (pm) Unmodified UPE0 3488 45MembraneExample 4 24 3200 44

[0065] Table 3. IPA Flow Time and Dye Binding Capacity of Unmodified UPE Substrate and Example 4 Modified UPE

[0066] Example 5: Preparation of Surface Modification Solution Containing Monomer Having H-Bond Donor Groups.

[0067] This example describes the preparation of a surface modification solution containing H-bond donor monomer (e.g., 4-vinylbenzyl chloride / N-methyl-D-glucamine (4VBC / NMDG)) and radical initiator. The surface modification solution was prepared by dissolving 0.3% lrgacure-2959 and 5% solution of 4-vinylbenzylchloride / N-methyl-D-glucamine monomer (4VBC / NMDG, prepared in a manner similarly to that presented in Example 3) in 94.7% methanol.

[0068] Example 6: Surface Modification of UPE Membrane with H-Bond Donor Monomer.

[0069] A4 size UPE membranes sheets were imbibed with the above surface modification solution containing 4VBC / NMDG radical initiator for 2-minutes of Example 5. The sheets were then dried in air for 10 minutes. The sheet was then placed between two polyethylene sheets and wetted with fluorinated solvent (e.g., Galden HT80) and the excess liquid and air was removed by applying pressure with a rubber roller. The polyethylene sheets containing the UPE flat sheet were exposed to UV by transporting through a Fusion UV system, Inc broadband UV at 10 ft per minute. After emerging from the UV chamber, the resulting porous membrane sheet was removed from the polyethylene sheets and immediately immersed in deionized water and soaked for 5-minutes. It was further washed with methanol to remove any unreacted monomers and finally dried on a restraining holder in an oven at 50°C for 10 minutes. The modified membrane sheets were characterized by red dye binding capacity test as disclosed herein and IPA flow time as disclosed herein, the results of each reported in Table 4:Sample DBC IPA Flow time ThicknessAttorney Docket No.: E000941 WO(pg / cm2) (sec / 500ml) (pm) Unmodified UPEMembrane 0 3488 53 SubstrateExample 6 51 4218 52

[0070] Table 4. IPA Flow Time and Dye Binding Capacity of Unmodified UPE Substrate and Example 6 Modified UPE.

[0071] Example 7: Red Dye Binding Capacity Test Protocol.

[0072] This example illustrates how the dye binding capacity of the membrane modified according to Examples 2, 4, and 6 was determined. To confirm that the process of Example 2, 4, and 6 resulted in a positively charged UPE membrane, the following experiment was carried out using Ponceau S solution 0.1% (w / v) in 5% acetic acid. A dry 47 mm disk from a membrane was cut and wetted by IPA and exchanged by deionized water (DIW). The disks were then placed in a 50ml polypropylene tube containing 0.01250 weight % Ponceau S solution in DIW. The tubes containing the membrane disks were then soaked for 2hrs under continuous mixing at room temperature. The membrane disks were then removed, and the absorbance of the dye solution was measured using a Cary spectrophotometer (Agilent Technologies) operating at 512 nm, and compared to the absorbance of starting feed solution (before membrane soaking). Because the dye is anionic in nature, the dye is bound to the positively charged membrane with an average dye binding capacity measured in micrograms (pg) per centimeter squared of 60 pg / cm2, 24 pg / cm2& 51 pg / cm2for examples 2, 4, and 6 respectively. The calibration curve depicted in FIG. XX was used to convert dye solution absorbance data to weight percent, and then to mass of dye bound per membrane unit area.

[0073] Example 8: ALG-Rich Polymer Removal Efficiency

[0074] The present example demonstrates the removal efficiencies of acid labile group (ALG)-rich polymers of a photoresist in a solution with ethyl lactate (EL) and propylene glycol methyl ether acetate (PGMEA) (EL / PGMEA=70 / 30). A 90mm 4> coupon was cut from the unmodified UPE membrane substrates and surface modified UPE membranes described in Examples 2, 4, and 6. Each coupon was put in a coupon holder of a testing line and challenged with EL / PGMEA=70 / 30 feed solution of 100 ppm of photoresist copolymer containing ALGs in solution with EL and PGMEA solvent. The photoresist solution was flowed through the 90mm 4> coupons at a flow rate of 30ml / min underAttorney Docket No.: E000941 WOrecirculation mode (30 pass). The filtered solution was then analyzed to measure the removal of ALG-rich polymer from solution. Table 5 reports the normalized removal efficiencies of ALG-rich polymer of a photoresist and results as compared with an unmodified UPE membrane substrate. Example 2 and 4 membranes demonstrated 100% removal efficiency compared with Example 6 that showed around 78% removal of higher MW ALG chains from a photoresist polymer. Membranes having (i) positively charged H-bond acceptor ligands (e.g., Example 2 membranes) or (ii) both H-bond donor ligands and H-bond acceptor ligands (e.g., Example 4 membranes) were found to be more effective at removing higher MW polymer aggregates compared to membranes having H-bond donor ligands only (e.g., Example 6 Membranes).Normalized Removal Efficiency of MembranesALG GroupUnmodified UPE0Membrane SubstrateExample 2 1Example 4 1Example 6 0.78

[0075] Table 5. ALG Removal Efficiencies of Surface Modified UPE Membranes and Unmodified UPE Membranes

[0076] Without wishing to be limited by any theory, removing ALG-rich polymers from photoresist solutions may be facilitated by electrostatic interactions (e.g., H-bond interactions and / or electrostatic charges) between (i) ALGs of disclosed photoresist polymers, which may be characterized as being H-bond acceptors; and (ii) disclosed ligands, which may be characterized as having H-bond participating groups. In some cases, ALG-rich polymer removal efficiency from photoresist solutions may be higher due to the presence of ligands as described herein having at least one form of H-bond participating groups (i.e., H-bond donor groups or H-bond acceptor groups) in combination with another electrostatic interaction participating group (e.g., a different form of H-bond participating groups or a positive charge). For example, as demonstrated by Example 2 membranes (i.e., membranes having ligands with H-bond acceptor groups and positive charges), a 100% normalized removal efficiency of ALG-rich polymers from photoresist solutions was achieved. Similarly, as demonstrated by Example 4Attorney Docket No.: E000941 WOmembranes (i.e., membranes having ligands with H-bond donor groups and H-bond acceptor groups) a 100% normalized removal efficiency of ALG-rich polymers from photoresist solutions was achieved. In comparison, as demonstrated by Example 6 membranes (i.e., membranes having ligands with only H-bond donor groups) a 78% normalized removal efficiency of ALG-rich polymers from photoresist solutions was achieved. Thus, while it has been demonstrated that the presence of at least one form of H-bond participating group on ligands can provide for useful levels of ALG-rich polymer removal efficiency, it is believed that ALG-rich polymer removal efficiency levels are improved by the presence of H-bond participating groups in combination with another form of electrostatic interaction group. Furthermore, without being bound by any theory, it could be expected that photoresist solution compositions may also impact ALG-rich polymer removal efficiency as such compositions may alter electrostatic interactions between ALGs and disclosed ligands.EXEMPLARY ENUMERATED EMBODIMENTS

[0077] 1. A method of filtering a photoresist solution using a ligand-modified porous membrane, the photoresist solution comprising a photoresist polymer that comprises a block of acid labile groups; the ligand-modified porous membrane comprising a porous polymeric membrane and (i) a hydrogen-bond acceptor group-containing ligand, (ii) a hydrogen-bond donor group-containing ligand, or (iii) a combination of (i) and (ii); the method comprising passing the photoresist solution through the ligand-modified porous membrane to remove molecules of photoresist polymer from the photoresist solution.

[0078] 2. The method of embodiment 1, comprising passing the photoresist solution through the membrane to selectively remove acid labile group-rich photoresist polymer molecules from the photoresist solution.

[0079] 3. The method of embodiment 1 or 2, wherein the photoresist solution comprises acid labile group-rich photoresist polymer molecules that include a block of acid labile groups, the block having at least two consecutive acid labile groups.

[0080] 4. The method of embodiment 3, wherein the block of acid labile groups comprises: t-butyl, tetrahydropyran-2-yl, 2-methyl tetrahydropyran-2-yl, tetra hydrofuran-2-yl, 2-methyl tetrahydrofuran-2-yl, 1-methoxyprophyl, 1-methoxy-1-Attorney Docket No.: E000941 WOmethylethyl, 1 -ethoxypropyl, 1 -ethoxy-1 -methylethyl, 1 -methoxyethyl, 1 -ethoxyethyl, t-butoxyethyl, 1 -isobutoxyethyl and 2-acetylmenth-1 -yl, or any combination thereof.

[0081] 5. The method of any preceding embodiment, wherein the photoresist polymer comprises a block of at least two consecutive photon absorption groups selected from: 2,3, 4-trihydroxybenzophenone-1, 2-diazonaphthoquinone-5-sulfonate; 2,3,4, 4' -tetrahydroxybenzophenone-1, 2-diazonaphthoquinone-5-sulfonate; nitroaniline; anthraquinone; benzophenone; diazo naphtho quinone; 1,2-naphthoquinonediazo-5- or 4-sulfonic acid esters or 1,2-benzoquinone diazo-4-sulfonic acid esters of polyhydroxy compounds having two or more phenolic hydroxyl groups; diphenyl iodonium triflate; diphenyl iodonium nonaflate; diphenyl iodonium hexafluorophosphate; diphenyl iodonium hexafluoroarsenate; diphenyl iodonium hexafluoroantimonate; diphenyl p-methoxyphenyl sulfonium triflate; diphenyl p-toluenyl sulfonium; triphenylsulfonium triflate; tris(p-tert-butylphenyl) sulfonium triflate; diphenyl p-methoxyphenyl sulfonium nonaflate; diphenyl p-toluenyl sulfonium nonaflate; diphenyl p-tert-butylphenyl sulfonium nonaflate; diphenyl p-isobutylaflate; nonaflate, tris(p-tert-butylphenyl) sulfonium nonaflate; triphenylsulfonium hexafluoroarsenate; triphenylsulfonium hexafluoroantimonate; triphenylsulfonium triflate; and dibutylnaphthylsulfonium triflate; and any combination thereof.

[0082] 6. The method of any preceding embodiment, wherein the photoresist polymer comprises a block of at least two photoacid generator groups comprising: diphenyl iodide hexafluorophosphate; diphenyl iodide hexafluoro arsenate; diphenyl iodide hexafluoroantimonate; diphenyl p-methoxyphenylsulfonium triflate; diphenyl p-toluenylsul fonium triflate; diphenyl p-isobutylphenylsulfonium triflate; diphenyl p-t-butylphenylsulfonium triflate; triphenylsulfo nium hexafluorophosphate; triphenylsulfonium hexafluoro arsenate; triphenylsulfonium hexafluoroantimonate; triph enylsulfonium triflate; dibutylnaphthylsulfonium triflate; phthalimidotrifluoromethane sulfonate; dinitrobenzyltosylate; n-decyl disulfone; naphthylimido trifluoromethane sulfonate; and any combination thereof.

[0083] 7. The method of any preceding embodiment, wherein the porous polymeric membrane is a porous polyolefin membrane.

[0084] 8. The method of any preceding embodiment, wherein the porous polymeric membrane is a porous ultrahigh molecular weight polyethylene membrane.Attorney Docket No.: E000941 WO

[0085] 9. The method of any one of embodiments 1 through 8, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand.

[0086] 10. The method of embodiment 9, wherein the hydrogen-bond acceptor group-containing ligand further comprises a positive charge.

[0087] 11. The method of embodiment 9 or 10, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, C16H21N3, C6H13NO, C9H18ClN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

[0088] 12. The method of embodiment 10 or 11, wherein the hydrogen-bond acceptor group-containing ligand comprises (3-acrylamidopropyl) trimethylammonium chloride.

[0089] 13. The method of any one of embodiments 1 through 8, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand and a hydrogen-bond donor group-containing ligand.

[0090] 14. The method of embodiment 13, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, C16H21N3, C6H13NO, C9H18ClN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

[0091] 15. The method of embodiment 13 wherein the hydrogen-bond donor group-containing ligand comprises any of: C2H5O4P, C6H13NO, C16H25NO5, C3H4O2and C10H12F8.

[0092] 16. The method of embodiment 13 wherein: (i) the hydrogen-bond acceptor group-containing ligand comprises N-methyl-D-glucamine, and (ii) the hydrogen-bond donor group-containing ligand comprises N, N-dimethylacrylamide.

[0093] 17. A ligand-modified porous membrane for filtering photoresist solutions, the ligand-modified porous membrane comprising a porous polymeric membrane, and (i) a hydrogen-bond acceptor group-containing ligand, or (ii) a hydrogen-bond donor group-containing ligand, or (iii) a combination of (i) and (ii).

[0094] 18. The ligand-modified porous membrane of embodiment 17, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand.

[0095] 19. The ligand-modified porous membrane of embodiment 18, wherein the hydrogen-bond acceptor group-containing ligand further comprises a positive charge.Attorney Docket No.: E000941 WO

[0096] 20. The ligand-modified porous membrane of embodiment 18 or 19, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, CieH2iN3, C6HI3NO, C9H18ClN2O, C5H9NO, C13HiaN2O2, C19H25N, or C7H17NO5.

[0097] 21. The ligand-modified porous membrane of embodiment 19 or 20, wherein the hydrogen-bond acceptor group-containing ligand comprises (3-acrylamidopropyl) trimethylammonium chloride.

[0098] 22. The ligand-modified porous membrane of embodiment 17, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand and a hydrogen-bond donor group-containing ligand.

[0099] 23. The ligand-modified porous membrane of embodiment 22, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, Ci6H2iN3, C6HI3NO, C9H18ClN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

[0100] 24. The ligand-modified porous membrane of embodiment 22, wherein the hydrogen-bond donor group-containing ligand comprises any of: C2H5O4P, C6H13NO, C16H25NO5, C3H4O2, and C10H12F8.

[0101] 25. The ligand-modified porous membrane of embodiment 22 wherein (i) the hydrogen-bond acceptorgroup-containing ligand comprises N-methyl-D-glucamine and (ii) the hydrogen-bond donor group-containing ligand comprises N, N-dimethylacrylamide.

[0102] 26. The ligand-modified porous membrane of embodiment 17, wherein the polymeric porous membrane is a porous membrane comprising polymer selected from: polyamide, polysulfone, a polyether-sulfone, a polyolefin, a halogenated polymer, and a combination thereof.

[0103] 27. A filter comprising the ligand-modified porous membrane of any of one of embodiments 17-26.

[0104] 28. A photoresist solution comprising a photoresist polymer molecule, the photoresist polymer molecule comprising: a solvent; an acid-labile group-containing monomer; a photoacid generator group-containing monomer; and a photon absorption group-containing monomer; wherein the photoresist solution is substantially free of photoresist polymer molecules comprising two or more consecutive acid-labile groups.

[0105] 29. The photoresist solution of embodi ment 28 wherein at most 50%, at most 45%, at most 40%, at most 35%, at most 30%, at most 25%, at most 20%, at most 15%, at mostAttorney Docket No.: E000941 WO10%, at most at most 5%, at most 3%, at most 2%, at most 1 %, at most 0.5%, or at most 0.1% of the photoresist polymer molecules comprise two or more consecutive acid-labile groups.

[0106] 30. The photoresist solution of embodiment 28 or 29, wherein the two or more consecutive acid-labile groups comprises: t-butyl, tetrahydropyran-2-yl, 2-methyl tetrahydropyran-2-yl, tetrahydrofuran-2-yl, 2-methyl tetrahydrofuran-2-yl, 1-methoxyprophyl, 1-methoxy-1 -methylethyl, 1 -ethoxypropyl, 1 -ethoxy-1 -methylethyl, 1-methoxyethyl, 1 -ethoxyethyl, t-butoxyethyl, 1 -isobutoxyethyl, 2-acetylmenth-1-yl, or any combination thereof.

[0107] 31. The photoresist solution of any one of embodiments 28-30 comprising ethyl lactate and propylene glycol methyl ether acetate.

[0108] 32. The photoresist solution of any one of embodiments 28-31 characterized as having a substantial portion of photoresist polymer molecules substantially dissolved within the solvent.

[0109] 33. The photoresist solution of any one of embodiments 28-32 characterized as not producing defects at a substrate surface when the photoresist solution is disposed onto the substrate surface.

[0110] 34. The photoresist solution embodiment 33 wherein the substrate of the substrate surface is useful in a semiconductor manufacturing process.

[0111] Certain embodiments of the present disclosure were described above. It is, however, expressly noted that the present disclosure is not limited to those embodiments, but rather the intention is that additions and modifications to what was expressly described in the present disclosure are also included within the scope of the disclosure. Moreover, it is to be understood that the features of the various embodiments described in the present disclosure were not mutually exclusive and can exist in various combinations and permutations, even if such combinations or permutations were not made express, without departing from the spirit and scope of the disclosure. The disclosure has been described in detail with particular reference to certain embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the claimed invention.

Claims

Attorney Docket No.: E000941 WOCLAIMS1. A method of filtering a photoresist solution using a ligand-modified porous membrane,the photoresist solution comprising a photoresist polymer that comprises a block of acid labile groups;the ligand-modified porous membrane comprisinga porous polymeric membrane and (i) a hydrogen-bond acceptor group-containing ligand, (ii) a hydrogen-bond donor group-containing ligand, or (iii) a combination of (i) and (ii);the method comprising passing the photoresist solution through the ligand- modified porous membrane to remove molecules of photoresist polymer from the photoresist solution.

2. The method of claim 1, comprising passing the photoresist solution through the membrane to selectively remove acid labile group-rich photoresist polymer molecules from the photoresist solution.

3. The method of claim 1 or 2, wherein the photoresist solution comprises acid labile group-rich photoresist polymer molecules that include a block of acid labile groups, the block having at least two consecutive acid labile groups.

4. The method of claim 3, wherein the block of acid labile groups comprises: t-butyl, tetrahydropyran-2-yl, 2-methyl tetrahydropyran-2-yl, tetrahydrofuran-2-yl, 2-methyl tetrahydrofuran-2-yl, 1-methoxyprophyl, 1-methoxy-1 -methylethyl, 1-ethoxypropyl, 1-ethoxy-1 -methylethyl, 1 -methoxyethyl, 1 -ethoxyethyl, t-butoxyethyl, 1 -isobutoxyethyl, 2-acetylmenth-1-yl, or any combination thereof.Attorney Docket No.: E000941 WO5. The method of any preceding claim, wherein the photoresist polymer comprises a block of at least two consecutive photon absorption groups selected from: 2,3, 4-trihydroxybenzophenone-1, 2-diazonaphthoquinone-5-sulfonate; 2,3,4, 4' -tetrahydroxybenzophenone-1, 2-diazonaphthoquinone-5-sulfonate; nitroaniline; anthraquinone; benzophenone; diazo naphtho quinone; 1,2-naphthoquinonediazo-5- or 4-sulfonic acid esters or 1,2-benzoquinone diazo-4-sulfonic acid esters of polyhydroxy compounds having two or more phenolic hydroxyl groups; diphenyl iodonium triflate; diphenyl iodonium nonaflate; diphenyl iodonium hexafluorophosphate; diphenyl iodonium hexafluoroarsenate; diphenyl iodonium hexafluoroantimonate; diphenyl p-methoxyphenyl sulfonium triflate; diphenyl p-toluenyl sulfonium; triphenylsulfonium triflate; tris(p-tert-butylphenyl) sulfonium triflate; diphenyl p-methoxyphenyl sulfonium nonaflate; diphenyl p-toluenyl sulfonium nonaflate; diphenyl p-tert-butylphenyl sulfonium nonaflate; diphenyl p-isobutylaflate; nonaflate, tris(p-tert-butylphenyl) sulfonium nonaflate; triphenylsulfonium hexafluoroarsenate; triphenylsulfonium hexafluoroantimonate; triphenylsulfonium triflate; and dibutylnaphthylsulfonium triflate, or any combination thereof.

6. The method of any preceding claim, wherein the photoresist polymer comprises a block of at least two photoacid generator groups selected from: diphenyl iodide hexafluorophosphate; diphenyl iodide hexafluoro arsenate; diphenyl iodide hexafluoroantimonate; diphenyl p-methoxyphenylsulfonium triflate; diphenyl p-toluenylsul fonium triflate; diphenyl p-isobutylphenylsulfonium triflate; diphenyl p-t-butylphenylsulfonium triflate; triphenylsulfo nium hexafluorophosphate; triphenylsulfonium hexafluoro arsenate; triphenylsulfonium hexafluoroantimonate; triph enylsulfonium triflate; dibutylnaphthylsulfonium triflate; phthalimidotrifluoromethane sulfonate; dinitrobenzyltosylate; n-decyl disulfone; naphthylimido trifluoromethane sulfonate; and any combination thereof.

7. The method of any preceding claim, wherein the porous polymeric membrane is a porous polyolefin membrane.

8. The method of any preceding claim, wherein the porous polymeric membrane is a porous ultrahigh molecular weight polyethylene membrane.Attorney Docket No.: E000941 WO9. The method of any one of claims 1 through 8, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand.

10. The method of claim 9, wherein the hydrogen-bond acceptor group-containing ligand further comprises a positive charge.

11. The method of claim 9 or 10, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, C16H21N3, C6H13NO, C9H18ClN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

12. The method of claim 10 or 11, wherein the hydrogen-bond acceptor group-containing ligand comprises (3-acrylamidopropyl) trimethylammonium chloride.

13. The method of any one of claims 1 through 8, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand and a hydrogen-bond donor group-containing ligand.

14. The method of claim 13, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, C16H21N3, C6H13NO, C9H18ClN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

15. The method of claim 13 wherein the hydrogen-bond donor group-containing ligand comprises any of: C2H5O4P, C6H13NO, C16H25NO5, C3H4O2, and C10H12F8.

16. The method of claim 13 wherein:(i) the hydrogen-bond acceptor group-containing ligand comprises N-methyl-D- glucamine, and(ii) the hydrogen-bond donor group-containing ligand comprises N, N- dimethylacrylamide.

17. A ligand-modified porous membrane for filtering photoresist solutions, the ligand-modified porous membrane comprising a porous polymeric membrane, and(i) a hydrogen-bond acceptor group-containing ligand, or(ii) a hydrogen-bond donor group-containing ligand, or(iii) a combination of (i) and (ii).Attorney Docket No.: E000941 WO18. The ligand-modified porous membrane of claim 17, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand.

19. The ligand-modified porous membrane of claim 18, wherein the hydrogen-bond acceptor group-containing ligand further comprises a positive charge.

20. The ligand-modified porous membrane of claim 18 or 19, wherein the hydrogenbond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, C5H6N2, C16H21N3, C6H13NO, C9H18ClN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

21. The ligand-modified porous membrane of claim 19 or 20, wherein the hydrogenbond acceptor group-containing ligand comprises (3-acrylamidopropyl) trimethylammonium chloride.

22. The ligand-modified porous membrane of claim 17, wherein the ligand-modified porous membrane comprises a hydrogen-bond acceptor group-containing ligand and a hydrogen-bond donor group-containing ligand.

23. The ligand-modified porous membrane of claim 22, wherein the hydrogen-bond acceptor group-containing ligand comprises any of: C3H3N, C5H5N, CsHeN;,, C16H21N3, C6H13NO, C9H18CIN2O, C5H9NO, C13H18N2O2, C19H25N, or C7H17NO5.

24. The ligand-modified porous membrane of claim 22, wherein the hydrogen-bond donor group-containing ligand comprises any of: C2H5O4P, C6H13NO, C16H25NO5, C3H4O2, and C10H12F8.

25. The ligand-modified porous membrane of claim 22 wherein (i) the hydrogen-bond acceptor group-containing ligand comprises N-methyl-D-glucamine and (ii) the hydrogen-bond donor group-containing ligand comprises N, N-dimethylacrylamide.

26. The ligand-modified porous membrane of claim 17, wherein the polymeric porous membrane is a porous membrane comprising polymer selected from: polyamide, polysulfone, a polyether-sulfone, a polyolefin, a halogenated polymer, and a combination thereof.Attorney Docket No.: E000941 WO27. A filter comprising the ligand-modified porous membrane of any of one of claims 17-26.

28. A photoresist solution comprising a photoresist polymer molecule, the photoresist polymer molecule comprising:a solvent;an acid-labile group-containing monomer;a photoacid generator group-containing monomer; anda photon absorption group-containing monomer;wherein the photoresist solution is substantially free of photoresist polymer molecules comprising two or more consecutive acid-labile groups.

29. The photoresist solution of claim 28 wherein at most 50%, at most 45%, at most 40%, at most 35%, at most 30%, at most 25%, at most 20%, at most 15%, at most 10%, at most at most 5%, at most 3%, at most 2%, at most 1 %, at most 0.5%, or at most 0.1 % of the photoresist polymer molecules comprise two or more consecutive acid-labile groups.

30. The photoresist solution of claim 28 or 29, wherein the two or more consecutive acid-labile groups comprises: t-butyl, tetrahydropyran-2-yl, 2-methyl tetrahydropyran-2-yl, tetrahydrofuran-2-yl, 2-methyl tetrahydrofuran-2-yl, 1-methoxyprophyl, 1-methoxy-1-methylethyl, 1 -ethoxypropyl, 1 -ethoxy-1 -methylethyl, 1 -methoxyethyl, 1 -ethoxyethyl, t-butoxyethyl, 1 -isobutoxyethyl, 2-acetylmenth-1-yl, or any combination thereof.

31. The photoresist solution of any one of claims 28-30 comprising ethyl lactate and propylene glycol methyl ether acetate.

32. The photoresist solution of any one of claims 28-31 characterized as having an substantial portion of photoresist polymer molecules substantially dissolved within the solvent.

33. The photoresist solution of any one of claims 28-32 characterized as not producing defects at a substrate surface when the photoresist solution is disposed onto the substrate surface.Attorney Docket No.: E000941 WO34. The photoresist solution claim 33 wherein the substrate of the substrate surface is useful in a semiconductor manufacturing process.

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