Photoresist compositions and pattern formation methods

Abstract

The photoresist composition comprises: an acid-sensitive polymer comprising a first repeating unit formed by a first radical polymerizable monomer containing an acid-degradable group and a second repeating unit formed by a second radical polymerizable monomer containing a carboxylic acid group; a compound comprising two or more enol ether groups, wherein the compound is different from the acid-sensitive polymer; a material containing a base-indestabilized group; a photoacid generator; and a solvent. This photoresist composition and the patterning method using the photoresist composition are particularly useful for forming fine photolithographic patterns in the semiconductor manufacturing industry.

Description

Technical Field

[0001] This invention relates generally to the manufacture of electronic devices. More specifically, the invention relates to photoresist compositions and to patterning methods using such compositions. These compositions and methods are particularly used for forming photolithographic patterns for manufacturing semiconductor devices. Prior Technology

[0002] In the semiconductor manufacturing industry, photoresist layers are used to transfer images onto one or more underlying layers disposed on a semiconductor substrate, such as metal, semiconductor, or dielectric layers, as well as the substrate itself. To increase the integration density of semiconductor devices and enable the formation of structures with dimensions in the nanometer range, photoresist compositions and photolithography tools with high resolution capabilities have been and continue to be developed.

[0003] Chemically enhanced photoresist compositions are commonly used for high-resolution processing. These compositions typically utilize polymers with acid-degradable groups, photoacid generators (PAGs), and solvents. A layer formed from such a photoresist composition is patterned and exposed to activated radiation, causing the acid generator to form acid. During post-exposure baking, this acid breaks down the acid-degradable groups in the exposed areas of the photoresist layer. This creates a difference in solubility properties between the exposed and unexposed areas of the layer in the developer solution. During positive development (PTD), the exposed areas of the photoresist layer become soluble in an aqueous alkaline developer and are removed from the substrate surface, while the unexposed areas, insoluble in the developer, are retained after development to form a positive image. The resulting embossed image allows for selective processing of the substrate.

[0004] One approach to achieving nanoscale feature sizes in semiconductor devices involves using short-wavelength light, such as 193 nm or less, during exposure to chemically enhanced photoresist. To further improve lithography performance, immersion lithography tools (e.g., immersion scanners with an ArF (193 nm) light source) have been developed to effectively increase the numerical aperture (NA) of the imaging device's lens. This is achieved by using a fluid with a higher refractive index (typically water) between the last surface of the imaging device and the top surface of the semiconductor wafer. ArF immersion tools are currently pushing the boundaries of lithography to the 16 nm and 14 nm nodes by using multiple (secondary or higher-level) patterning. However, as lithographic resolution increases, the linewidth roughness (LWR) of the photoresist pattern becomes more critical in producing high-resolution patterns. For example, excessive linewidth variations along the gate length adversely affect the threshold voltage and can increase leakage current, both of which negatively impact device performance and yield. Therefore, a photoresist composition that allows for the desired LWR properties is required.

[0005] Process production volume is a highly interesting area in the semiconductor manufacturing industry. This is especially true for photoresist exposure processes, as they occur frequently throughout the device fabrication process. Advanced photoresist exposure tools typically move across the wafer, exposing the photoresist layer of one die at a time. Processing all dies on the wafer can be quite time-consuming. Photoresist compositions with improved photosensitivity would allow target critical dimensions (CDs) to be achieved with shorter exposure times. Therefore, photoresist compositions with improved sensitivity are needed.

[0006] US Patent Application Publication No. US 2006 / 0160022 A1 discloses a chemically reinforced positive photoresist composition containing a crosslinked resin. The crosslinked resin contains polymeric units formed from monomers acting as crosslinking agents. Each polymeric unit contains two acetal groups designed to decompose upon exposure and during post-exposure baking by reacting with photoacids, thereby making the exposed areas of the photoresist layer soluble in aqueous developers. Such photoresist compositions are considered to exhibit shelf-life stability issues and may also present manufacturing challenges due to the relative instability of the acetal groups during synthesis. Therefore, more stable photoresist compositions are needed.

[0007] Therefore, there is a need in the art for improved photoresist compositions and patterning methods that address one or more problems associated with prior art. Summary of the Invention

[0008] According to a first aspect of the invention, a photoresist composition is provided. The photoresist composition comprises: an acid-sensitive polymer comprising a first repeating unit formed by a first radical polymerizable monomer containing an acid-degradable group and a second repeating unit formed by a second radical polymerizable monomer containing a carboxylic acid group; a compound comprising two or more enol ether groups, wherein the compound is different from the acid-sensitive polymer; a material containing a base-indestabilized group; a photoacid generator; and a solvent.

[0009] A pattern forming method is also provided. The pattern forming method includes: (a) applying a layer of photoresist composition as described herein on a substrate; (b) soft baking the photoresist composition layer; (c) exposing the soft-baked photoresist composition layer to active radiation; (d) post-exposure baking the photoresist composition layer; and (d) developing the post-exposure baked photoresist composition layer to provide a resist relief image. Simple Explanation of the Diagram

[0010] none Implementation

[0011] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context otherwise indicates, the singular forms "a / an" and "the" are intended to include both the singular and plural forms. The full scope disclosed herein includes endpoints, and these endpoints can be independently combined with each other. When an element is referred to as being "on" or "on" another element, it may be in direct contact with that other element or there may be an intervening element between them. Conversely, when an element is referred to as being "directly" "on" another element, there is no intervening element.

[0012] As used herein, "acid-degradable group" refers to a group in which a bond is broken by the catalytic action of an acid (as desired and typically in conjunction with heat treatment), resulting in the formation of a polar group (e.g., a carboxylic acid or alcohol group) on the polymer and, as desired and typically, the portion connected to the broken bond detaches from the polymer. Acid-degradable groups include, for example, tertiary alkyl ester groups, secondary or tertiary aryl ester groups, secondary or tertiary ester groups having a combination of alkyl and aryl groups, or tertiary alkoxy groups. Acid-degradable groups are also commonly referred to in the art as "acid-crackable groups," "acid-crackable protecting groups," "acid-unstable groups," "acid-unstable protecting groups," "acid-degrading groups," and "acid-sensitive groups."

[0013] Unless otherwise stated, a "substituted" group refers to a group in which one or more of its hydrogen atoms are replaced by one or more substituents. Exemplary substituent groups include, but are not limited to, hydroxyl (-OH), halogens (e.g., -F, -Cl, -I, -Br), C1-18 alkyl, C1-8 haloalkyl, C3-12 cycloalkyl, C6-12 aryl having at least one aromatic ring (e.g., phenyl, biphenyl, naphthyl, etc., each ring being substituted or unsubstituted aromatic), C7-19 arylalkyl having at least one aromatic ring, C7-12 alkylaryl, and combinations thereof. For the purpose of determining the carbon number, when the group is substituted, the number of carbon atoms in the group is the total number of carbon atoms in the group, excluding those of any substituents.

[0014] The photoresist composition of the present invention comprises an acid-sensitive polymer, a compound containing two or more enol ether groups (wherein the compound is different from the acid-sensitive polymer), a material containing a base-indestabilized group, a photoacid generator, and a solvent, and may include one or more additional components as desired. The inventors have unexpectedly discovered that certain photoresist compositions of the present invention can achieve significantly improved lithography performance, such as reduced linewidth roughness (LWR) and improved photosensitivity.

[0015] The acid-sensitive polymer comprises a first repeating unit formed by a first free radical polymerizable monomer containing an acid-degradable group and a second repeating unit formed by a second free radical polymerizable monomer containing a carboxylic acid group, and may include one or more other types of repeating units. The polymer should have good solubility in the solvent of the photoresist composition.

[0016] The acid-degradable group can be of the type that forms a carboxylic acid group or an alcohol group on the polymer upon decomposition. Preferred acid-degradable groups are tertiary ester groups, and more preferably tertiary alkyl ester groups. Suitable repeating units having acid-degradable groups can, for example, be derived from one or more monomers of formulas (1a), (1b), or (1d): .

[0017] In formulas (1a) and (1b), R is a hydrogen, fluorine, cyano, substituted or unsubstituted C1-10 alkyl, or substituted or unsubstituted C1-10 fluoroalkyl. Preferably, R is a hydrogen, fluorine, or substituted or unsubstituted C1-5 alkyl, typically methyl.

[0018] In formula (1a), the L1 group comprises a divalent linking group consisting of at least one carbon atom, at least one heteroatom, or a combination thereof. For example, L1 may comprise 1 to 10 carbon atoms and at least one heteroatom. In typical examples, L1 may be -OCH 2-, -OCH 2CH 2O-, or -N(R 21)-, wherein R 21 is hydrogen or a C1-6 alkyl group.

[0019] In formulas (1a) and (1b), R1 to R6 are each independently hydrogen, a straight-chain or branched C1-20 alkyl, a monocyclic or polycyclic C3-20 cycloalkyl, a monocyclic or polycyclic C1-20 heterocyclic alkyl, a straight-chain or branched C2-20 alkenyl, a monocyclic or polycyclic C3-20 cycloalkenyl, a monocyclic or polycyclic C3-20 heterocyclic alkenyl, a monocyclic or polycyclic C6-20 aryl, or a monocyclic or polycyclic C2-20 heteroaryl, wherein each of them except hydrogen is substituted or unsubstituted; the premise is that only one of R1 to R3 can be hydrogen, and only one of R4 to R6 can be hydrogen, and the premise is that when one of R1 to R3 is hydrogen, the remaining one or two of R1 to R3 are substituted or unsubstituted monocyclic or polycyclic C6 alkyl. The aryl group consists of 6-20 aryl groups or substituted or unsubstituted monocyclic or polycyclic C4-20 heteroaryl groups, and when one of R4 to R6 is a hydrogen group, the remaining one or two of R4 to R6 are substituted or unsubstituted monocyclic or polycyclic C6-20 aryl groups or substituted or unsubstituted monocyclic or polycyclic C4-20 heteroaryl groups. Preferably, R1 to R6 are each independently a straight-chain or branched C1-6 alkyl group, or a monocyclic or polycyclic C3-10 cycloalkyl group, each of which is substituted or unsubstituted.

[0020] In formula (1a), any two of R1 to R3 together may form a ring as required, and each of R1 to R3 may include one or more groups selected from -O-, -C(O)-, -C(O)-O-, -S-, -S(O)2-, and -N(R42)-S(O)2- as part of its structure, wherein R42 may be hydrogen, a straight-chain or branched C1-20 alkyl, a monocyclic or polycyclic C3-20 cycloalkyl, or a monocyclic or polycyclic C1-20 heterocyclic alkyl. In formula (2b), any two of R4 to R6 together may form a ring as required, and each of R4 to R6 may include one or more groups selected as part of its structure, namely -O-, -C(O)-, -C(O)-O-, -S-, -S(O)2-, and -N(R43)-S(O)2-, wherein R43 is hydrogen, a straight-chain or branched C1-20 alkyl, a monocyclic or polycyclic C3-20 cycloalkyl, or a monocyclic or polycyclic C1-20 heterocyclic alkyl.

[0021] In formula (1c), R7 to R9 can each independently be hydrogen, a straight-chain or branched C1-20 alkyl, a monocyclic or polycyclic C3-20 cycloalkyl, a monocyclic or polycyclic C1-20 heterocyclic alkyl, a monocyclic or polycyclic C6-20 aryl, or a monocyclic or polycyclic C2-20 heteroaryl, wherein each of them except hydrogen is substituted or unsubstituted, any two of R7 to R9 together may form a ring as desired, and each of R7 to R9 may, as desired, contain as part of its structure one or more groups selected from -O-, -C(O)-, -C(O)-O-, -S-, -S(O)2-, and -N(R44)-S(O)2-, wherein R44 may be hydrogen, a straight-chain or branched C1-20 alkyl, a monocyclic or polycyclic C6-20 alkyl, a monocyclic or polycyclic C6-20 aryl, or a monocyclic or polycyclic C6-20 heteroaryl. 3-20 cycloalkyl, or monocyclic or polycyclic C1-20 heterocyclic alkyl; provided that when the acid-decomposable group is not an acetal group, only one of R7 to R9 can be hydrogen, provided that when one of R7 to R9 is hydrogen, the remaining one or two of R7 to R9 are substituted or unsubstituted monocyclic or polycyclic C6-20 aryl or substituted or unsubstituted monocyclic or polycyclic C4-20 heteroaryl.

[0022] In formula (1c), X1 refers to polymerizable groups selected from vinyl and norbornel groups; and L2 refers to single-bonded or divalent linked groups, provided that when X1 is vinyl, L2 is not a single bond. Preferably, L2 is a monocyclic or polycyclic C6-30 aryl or monocyclic or polycyclic C6-30 cycloalkyl, each of which may be substituted or unsubstituted. In formula (1c), a refers to 0 or 1. It should be understood that when a is 0, the L2 group is directly attached to an oxygen atom.

[0023] Non-limiting examples of monomer (1a) include: .

[0024] Non-limiting examples of monomers having formula (1b) include: Wherein R is as defined above; and R' and R'' are each independently a straight-chain or branched C1-20 alkyl, monocyclic or polycyclic C3-20 cycloalkyl, monocyclic or polycyclic C1-20 heterocyclic alkyl, straight-chain or branched C2-20 alkenyl, monocyclic or polycyclic C3-20 cycloalkenyl, monocyclic or polycyclic C3-20 heterocyclic alkenyl, monocyclic or polycyclic C6-20 aryl, or monocyclic or polycyclic C4-20 heteroaryl, each of which is substituted or unsubstituted.

[0025] Non-limiting examples of monomers (1c) include: .

[0026] Repeating units with acid-degradable groups are typically present in acid-sensitive polymers in amounts of 10 to 80 mol%, more typically 25 to 75 mol%, and even more typically 30 to 70 mol%, based on the total repeating units in the acid-sensitive polymer.

[0027] The second repeating unit of the acid-sensitive polymer is formed from a second radically polymerizable monomer containing a carboxylic acid group. Typically, the second repeating unit has formula (2): Wherein: R 10 is hydrogen, fluorine, substituted or unsubstituted C 1-10 straight-chain, C 3-10 branched, or C 3-10 cycloalkyl, typically hydrogen or methyl; L 3 is a divalent linking group containing at least one carbon atom, for example, substituted or unsubstituted C 1-10 straight-chain, C 3-10 branched, or C 3-10 cycloalkyl or combinations thereof, and may contain one or more heteroatoms; and b is 0 or 1, O is typical. R 10 and L 3 may, as needed, contain one or more groups selected from -O-, -C(O)-, -C(O)O- (e.g., -C(O)OH), or -S-, each independently as part of its structure.

[0028] Suitable monomers of formula (2) include, for example, the following: .

[0029] Repeating units with carboxylic acid groups are typically present in acid-sensitive polymers in amounts of 1 to 35 mol%, more typically 1 to 25 mol%, and even more typically 5 to 15 mol% of the total repeating units based on the acid-sensitive polymer.

[0030] Acid-sensitive polymers may include repeating units containing lactone groups. Suitable such repeating units may, for example, be derived from monomers of formula (3): (3)

[0031] In formula (3), R11 is hydrogen, fluorine, cyano, substituted or unsubstituted C1-10 alkyl, or substituted or unsubstituted C1-10 fluoroalkyl. Preferably, R11 is hydrogen, fluorine, or substituted or unsubstituted C1-5 alkyl, typically methyl. L4 can be a single bond or a divalent linker comprising one or more of the following: substituted or unsubstituted C1-30 alkyl, substituted or unsubstituted C1-30 heteroalkyl, substituted or unsubstituted C3-30 cycloalkyl, substituted or unsubstituted C1-30 heterocycloalkyl, substituted or unsubstituted C6-30 aryl, substituted or unsubstituted C7-30 arylalkyl, or substituted or unsubstituted C1-30 heteroaryl, or substituted or unsubstituted C3-30 heteroarylalkyl, wherein L4 may further comprise, as desired, one or more groups selected from, for example, -O-, -C(O)-, -C(O)-O-, -S-, -S(O)2- and -N(R44)-S(O)2-, wherein R44 can be hydrogen, straight-chain or branched C1-20 alkyl, monocyclic or polycyclic C 3-20 cycloalkyl, or monocyclic or polycyclic C3-20 heterocyclic alkyl. R12 series contains lactone groups, such as monocyclic, polycyclic, or fused polycyclic C4-20 containing lactone groups.

[0032] Non-limiting examples of monomers having formula (3) include: The R11 series is as described herein. Other exemplary lactone-containing monomers include, for example, the following: .

[0033] When present, acid-sensitive polymers typically contain lactone repeating units in amounts of 5 to 60 mol%, typically 20 to 55 mol%, and more typically 25 to 50 mol%, based on the total repeating units in the acid-sensitive polymer.

[0034] Acid-sensitive polymers may contain base-soluble repeating units with a pKa of less than or equal to 12. For example, base-soluble repeating units may be derived from monomers having formula (4): (4) In formula (4), R13 can be hydrogen, fluorine, cyano, substituted or unsubstituted C1-10 alkyl, or substituted or unsubstituted C1-10 fluoroalkyl. Preferably, R13 is hydrogen, fluorine, or substituted or unsubstituted C1-5 alkyl, typically methyl. Q1 can be one or more of the following: substituted or unsubstituted C1-30 alkylene, substituted or unsubstituted C3-30 cycloalkylene, substituted or unsubstituted C1-30 heterocycloalkylene, substituted or unsubstituted C6-30 aryl, substituted or unsubstituted divalent C7-30 arylalkyl, substituted or unsubstituted C1-30 heteroaryl, or substituted or unsubstituted divalent C3-30 heteroarylalkyl or -C(O)-O-. The W-type base can be soluble in groups and can be selected from, for example: fluorinated alcohols, such as -C(CF3)2OH; amides; amides; or -NHS(O)2Y1, and -C(O)NHC(O)Y1, wherein Y1 is an F or C1-4 perfluoroalkyl group. In formula (4), c refers to integers from 1 to 3.

[0035] Non-limiting examples of monomers having formula (4) include: R13 and Y1 are as described above.

[0036] When present, base-soluble repeating units can typically be present in acid-sensitive polymers in amounts ranging from 2 to 75 mol%, typically 5 to 25 mol%, and more typically 5 to 15 mol%, based on the total repeating units in the acid-sensitive polymer.

[0037] The acid-sensitive polymer may, as needed, include one or more additional repeating units. These additional repeating units may include one or more units, for example, for the purpose of adjusting the properties of the photoresist composition, such as etch rate and solubility. Exemplary additional units may include one or more of (meth)acrylates, vinyl ethers, vinyl ketones, and vinyl esters. One or more additional repeating units in the acid-sensitive polymer (if present) may be used in amounts up to 70 mol%, typically 3 to 50 mol%, based on the total repeating units of the acid-sensitive polymer.

[0038] Suitable acid-sensitive polymers include, for example, the following: The total molar percentage of units in each polymer is 100 mol%, and can be selected, for example, within the range described above.

[0039] Acid-sensitive polymers typically have a weight-average molecular weight (Mw) of 1,000 to 50,000 Da, more typically 2,000 to 30,000 Da, 3,000 to 20,000 Da, or 3,000 to 10,000 Da. The polydispersity index (PDI) of acid-sensitive polymers (which is the ratio of Mw to the number-average molecular weight (Mn)) is typically 1.1 to 5, and more typically 1.1 to 3. Molecular weight values ​​as described herein are determined using polystyrene standards by gel permeation chromatography (GPC).

[0040] In the photoresist composition of the present invention, the acid-sensitive polymer is typically present in the photoresist composition in an amount of 0.5 to 99.9 wt%, more typically 30 to 90 wt%, or 50 to 80 wt%, based on the total solids of the photoresist composition. It will be understood that the total solids include the polymer, PAG, and other non-solvent components.

[0041] Acid-sensitive polymers can be prepared using any suitable method in the art, such as free radical polymerization, anionic polymerization, cationic polymerization, etc. For example, one or more monomers corresponding to the repeating units described herein can be fed together or separately using suitable one or more solvents and initiators and polymerized in a reactor. For example, polymers and acid-sensitive polymers can be obtained by polymerization of the respective monomers under any suitable conditions, such as by heating at an effective temperature, irradiation with photochemical radiation at an effective wavelength, or a combination thereof.

[0042] Compounds containing two or more enol ether groups (enol ether compounds) differ from acid-sensitive polymers and can be in non-polymeric or polymeric forms. Without being bound by any particular theory, it is believed that enol ether compounds undergo a coupling reaction between their enol ether groups and the carboxylic acid groups of the acid-sensitive polymer during the soft baking step of the photoresist. This is believed to lead to crosslinking of the acid-sensitive polymer, thereby increasing the inhibition of its dissolution in aqueous alkaline developer solutions. After exposure of the photoresist layer during the post-exposure baking step, it is believed that the acid generated by the photoacid generator breaks the acetal or ketal bonds of the crosslinked polymer to reform carboxylic acid groups on the polymer in the exposed areas. This enhances the dissolution of the exposed areas in the developer solution, while the polymer remains crosslinked, and its dissolution in the unexposed areas is inhibited. This results in higher dissolution contrast, which can lead to improved LWR of the photoresist pattern.

[0043] Non-polymerized enol ether compounds can, for example, have formula (5): Wherein: R14 independently represents -H, C1-4 alkyl, or C1-4 fluoroalkyl, and may include, as required, one or more groups selected from -O-, -S-, -N(R15)-, -C(O)-, -C(O)O-, or -C(O)N(R15)- as part of its structure, wherein R15 represents hydrogen or a substituted or unsubstituted C1-10 alkyl, and any two R14 groups together may form a ring as required; L5 represents a linking group having a valence d, typically a C2-10 straight-chain alkyl, C3-10 branched alkyl, C3-10 cycloalkyl, C5-12 aryl, or combinations thereof, each of which may be substituted or unsubstituted, and may include, as required, one or more groups selected from -O-, -S-, -N(R16)-, -C(O)-, -C(O)O-, or -C(O)N(R15)- as part of its structure. 16)- One or more groups, wherein R 16 represents -H or a substituted or unsubstituted C1-10 alkyl group; and d is an integer from 2 to 4.

[0044] The preferred enol ether compounds of formula (5) are compounds of formula (5-1): CH₂=CH-OR 17-O-CH=CH₂(5-1) R 17 represents C 1-10 straight-chain extended alkyl, C 3-10 branched extended alkyl, C 3-10 cycloextended alkyl, or a combination thereof, each of which may be substituted or unsubstituted.

[0045] Suitable polymeric enol ether compounds comprise repeating units formed from free-radical polymerizable monomers containing one or more enol ether groups. The enol ether groups are typically side-attached to the polymer backbone. Monomers are typically vinyl aromatic, (meth)acrylate, or norbornene monomers, with vinyl aromatic monomers and (meth)acrylate monomers being preferred. Polymeric enol ether compounds can be homopolymers or copolymers containing two, three, or more different repeating units. Polymeric enol ether compounds typically have a weight-average molecular weight (Mw) of 200 to 100,000 Da and a PDI of 1.1 to 5.

[0046] Suitable enol ether compounds include, for example, the following: .

[0047] Enol ether compounds are typically present in photoresist compositions in amounts of 0.01 to 60 wt%, typically 1 to 30 wt%, and more typically 3 to 15 wt% of the total solids of the photoresist composition. Suitable enol ether compounds are commercially available and / or can be readily prepared by those skilled in the art.

[0048] Photoresist compositions also include photoacid generators (PAGs). PAGs are typically nonpolymeric but can be polymeric, for example, present in repeating units of an acid-sensitive polymer or as part of a different polymer. Suitable PAGs generate acids that cause the acid-degradable groups present on the polymer of the photoresist composition to cleave during post-exposure baking. Suitable PAG compounds are known in the field of chemically reinforced photoresists and can be ionic or nonionic. Suitable PAG compounds include, for example, onmium salts, such as triphenylstrontium trifluoromethane sulfonate, (p-tributoxyphenyl)diphenylstrontium trifluoromethane sulfonate, tri(p-tributoxyphenyl)strontium trifluoromethane sulfonate, triphenylstrontium p-toluene sulfonate; di- and tri-butylphenyl iodomonium perfluorobutane sulfonate and di- and tri-butylphenyl iodomonium camphor sulfonate. It is also known that nonionic sulfonates and sulfonyl compounds act as photoacid generators, such as nitrobenzyl derivatives, such as 2-nitrobenzyl-p-toluenesulfonate, 2,6-dinitrobenzyl-p-toluenesulfonate, and 2,4-dinitrobenzyl-p-toluenesulfonate; sulfonates, such as 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and 1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, such as bis(benzenesulfonyl)diazomethane and bis(p-toluenesulfonyl)diazomethane; ethylene glycol Oxime derivatives, such as bis-O-(p-toluenesulfonyl)-α-dimethylglyoxime and bis-O-(n-butanesulfonyl)-α-dimethylglyoxime; sulfonate derivatives of N-hydroxyaceimine compounds, such as N-hydroxysuccinimine methanesulfonate and N-hydroxysuccinimine trifluoromethanesulfonate; and halogen-containing trihalomethane compounds, such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-trihalomethane and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-trihalomethane. Suitable photoacid generators are further described in U.S. Patent No. 8,431,325 to Hashimoto et al., in columns 37, lines 11-47 and 41-91. Other suitable sulfonate PAGs include sulfonated esters and sulfonylureas, nitrobenzyl esters, s-trisyl derivatives, benzoin toluenesulfonate, α-(p-toluenesulfonylurea)-acetic acid tributylphenyl ester, and α-(p-toluenesulfonylurea)-acetic acid tributyl ester; as described in U.S. Patent Nos. 4,189,323 and 8,431,325.

[0049] Particularly suitable PAGs have the formula G+A-, where G+ is an organic cation and A- is an organic anion. The organic cations include, for example, iodonium cations substituted with two alkyl, aryl, or combinations of alkyl and aryl groups; and strontium cations substituted with three alkyl, aryl, or combinations of alkyl and aryl groups. In some embodiments, G+ is an iodonium cation substituted with two alkyl, aryl, or combinations of alkyl and aryl groups; or a strontium cation substituted with three alkyl, aryl, or combinations of alkyl and aryl groups. In some embodiments, G+ can be one or more of a substituted strontium cation having formula (6A) or an iodonium cation having formula (6B). (6A) (6B) Each Raa is independently a C1-20 alkyl, C1-20 fluoroalkyl, C3-20 cycloalkyl, C3-20 fluorocycloalkyl, C2-20 alkenyl, C2-20 fluoroalkenyl, C6-30 aryl, C6-30 fluoroaryl, C6-30 iodoaryl, C4-30 heteroaryl, C7-20 arylalkyl, C7-20 fluoroarylalkyl, C5-30 heteroarylalkyl, or C5-30 fluoroheteroarylalkyl, each of which is substituted or unsubstituted, wherein each Raa is independently or via a single bond or divalent linker to another Raa to form a ring. Each Raa may, as needed, include one or more groups selected from the following as part of its structure: -O-, -C(O)-, -C(O)-O-, -C 1-12 elongatinyl-, -O-(C 1-12 elongatinyl)-, -C(O)-O-(C 1-12 elongatinyl)-, and -C(O)-O-(C 1-12 elongatinyl)-O-. Each Raa may independently, as needed, include acid-degradable groups selected from, for example, the following: tertiary alkyl ester group, secondary or tertiary aryl ester group, secondary or tertiary ester group having a combination of alkyl and aryl groups, tertiary alkoxy group, acetal group, or ketal group. Suitable divalent linkers for linking Raa groups include, for example, -O-, -S-, -Te-, -Se-, -C(O)-, -C(S)-, -C(Te)- or -C(Se)-, substituted or unsubstituted C1-5 alkyl groups, and combinations thereof.

[0050] Exemplary strontium cations of formula (6A) include the following: .

[0051] An exemplary iodonium cation of formula (6B) includes the following: .

[0052] PAGs that are onium salts typically contain anion with a sulfonate group or a non-sulfonate group, such as a sulfonamide group, a sulfonimidate group, a methyl group, or a borate group. Exemplary suitable anions with a sulfonate group include the following: .

[0053] Suitable non-sulfonated anions include the following: .

[0054] The photoresist composition may contain a variety of PAGs as needed. Typically, the photoacid generator is present in the photoresist composition in an amount of 1 to 65 wt%, more typically 5 to 55 wt%, and still more typically 8 to 30 wt%, based on the total solids of the photoresist composition.

[0055] The photoresist composition further includes a material comprising one or more base-indestructible groups (“base-indestructible material”). As mentioned herein, the base-indestructible group can undergo a cleavage reaction in the presence of an aqueous base developer after the exposure and post-exposure baking steps to provide functional groups of polar groups (such as hydroxyl, carboxylic acid, sulfonic acid, etc.). The base-indestructible group will not undergo significant reaction prior to the development step of the photoresist composition containing the base-indestructible group (e.g., it will not undergo bond breaking reaction). Therefore, for example, the base-indestructible group will be substantially inert during the pre-exposure soft baking step, the exposure step, and the post-exposure baking step. “Substantially inert” means during the pre-exposure soft baking step, the exposure step, and the post-exposure baking step. 5%, which is better 1% of the base-indestructible group (or portion) will decompose, cleave, or react. The base-indestructible group is reactive under typical photoresist development conditions using, for example, aqueous base photoresist developers (such as a 0.26 N standard aqueous solution of tetramethylammonium hydroxide (TMAH)). For example, a 0.26 N aqueous solution of TMAH can be used for single-immersion or dynamic development, where, for example, 0.26 N TMAH developer is dispensed onto the imaged photoresist layer for a suitable duration (e.g., 10 to 120 seconds). Exemplary base-indestructible groups are ester groups, typically fluorinated ester groups. Preferably, the base-indestructible material is substantially immiscible with the first and second polymers of the photoresist composition and other solid components and has a lower surface energy than them. Thus, when coated onto a substrate, the base-indestructible material can separate from the other solid components of the photoresist composition to reach the top surface of the formed photoresist layer.

[0056] In some aspects, alkali-insecure material systems may include polymeric materials (also referred to herein as alkali-insecure polymers) comprising one or more repeating units containing one or more alkali-insecure groups. For example, an alkali-insecure polymer may comprise repeating units containing two or more identical or different alkali-insecure groups. Preferred alkali-insecure polymers comprise at least one repeating unit containing two or more alkali-insecure groups, such as repeating units containing two or three alkali-insecure groups.

[0057] Alkali-unstable polymers can be polymers containing repeating units of monomers derived from formula (7-1). (7-1) Wherein X2 is selected from polymerizable groups of vinyl and acrylic acid, L6 contains one or more of the following divalent linking groups: substituted or unsubstituted linear or branched C1-20 alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, -C(O)-, or -C(O)O-; and R18 is a substituted or unsubstituted C1-20 fluoroalkyl group, provided that the carbon atom bonded to the carbonyl group (C=O) in formula (7-1) is substituted with at least one fluorine atom.

[0058] The exemplary monomers of formula (7-1) include the following: .

[0059] Alkali-insecure polymers may include repeating units comprising two or more alkali-insecure groups. For example, alkali-insecure polymers may include repeating units of monomers derived from formula (7-2). (7-2) Wherein the X 2 and R 18 series are as defined in formula (7-1); the L 7 series contains one or more of the following polyvalent linking groups: substituted or unsubstituted straight-chain or branched C 1-20 alkyl groups, substituted or unsubstituted C 3-20 cycloalkyl groups, -C(O)- or -C(O)O-; and the e series is 2 or a larger integer, for example, 2 or 3.

[0060] The exemplary monomers of formula (7-2) include the following: .

[0061] Base-instable polymers may comprise repeating units including one or more base-instable groups. For example, base-instable polymers may comprise repeating units of monomers derived from formula (7-3): (7-3) Wherein, X2 is as defined in formula (7-1); L8 comprises one or more of the following divalent linking groups: substituted or unsubstituted straight-chain or branched C1-20 alkyl, substituted or unsubstituted C3-20 cycloalkyl, -C(O)- or -C(O)O-; Lf is a substituted or unsubstituted C1-20 fluoroalkyl, wherein the carbon atom bonded to the carbonyl (C=O) in formula (7-3) is substituted by at least one fluorine atom; and R19 is a substituted or unsubstituted straight-chain or branched C1-20 alkyl, or a substituted or unsubstituted C3-20 cycloalkyl.

[0062] The exemplary monomers of formula (7-3) include the following: .

[0063] In another preferred aspect of the invention, the alkali-insecure polymer may comprise one or more alkali-insecure groups and one or more acid-insecure groups, such as one or more acid-insecure ester moieties (e.g., tert-butyl ester) or acid-insecure acetal groups. For example, the alkali-insecure polymer may comprise repeating units including both alkali-insecure and acid-insecure groups, i.e., where both alkali-insecure and acid-insecure groups are present on the same repeating unit. In another example, the alkali-insecure polymer may comprise a first repeating unit containing alkali-insecure groups and a second repeating unit containing acid-insecure groups. The preferred photoresist of the present invention can exhibit reduced defects associated with resist relief images formed from photoresist compositions.

[0064] Base-instable polymers can be prepared using any suitable method in the art, including those described herein with respect to the first and second polymers. For example, base-instable polymers can be obtained by polymerization of the respective monomers under any suitable conditions, such as by heating at an effective temperature, irradiation with photochemical radiation at an effective wavelength, or a combination thereof. Alternatively or additionally, suitable methods can be used to graft one or more base-instable groups onto the polymer backbone.

[0065] In some respects, alkali-instable materials are single molecules comprising one or more alkali-instable ester groups, preferably one or more fluorinated ester groups. Single-molecule alkali-instable materials can have a MW of 50 to 1,500 Da. Exemplary alkali-instable materials include the following: .

[0066] The photoresist composition may further include one or more polymers other than and different from the acid-sensitive polymers described above. For example, the photoresist composition may contain other polymers as described above but with different compositions, or polymers similar to those described above but without the required repeating units. Additionally or alternatively, the one or more additional polymers may include those well-known in the field of photoresists, such as those selected from: polyacrylates, polyvinyl ethers, polyesters, polynorcamphene, polyacetals, polyethylene glycol, polyamide, polyacrylamide, polyphenols, phenolic varnishes, styrene polymers, polyvinyl alcohol, or combinations thereof.

[0067] The photoresist composition further includes a solvent for dissolving the components of the composition and promoting its coating on a substrate. Preferably, the solvent is an organic solvent commonly used in the manufacture of electronic devices. Suitable solvents include, for example: aliphatic hydrocarbons, such as hexane and heptane; aromatic hydrocarbons, such as toluene and xylene; halogenated hydrocarbons, such as dichloromethane, 1,2-dichloroethane, and 1-chlorohexane; alcohols, such as methanol, ethanol, 1-propanol, isopropanol, tributanol, 2-methyl-2-butanol, and 4-methyl-2-pentanol; propylene glycol monomethyl ether (PGME), ethers such as diethyl ether, tetrahydrofuran, 1,4-dimethyl ether, and anisole; ketones, such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone (CHO); esters, such as ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone (CHO); and esters such as ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone (CHO). Ethyl acetate, n-butyl acetate, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl hydroxyisobutyrate (HBM), and ethyl acetate; lactones, such as γ-butyrolactone (GBL) and ε-caprolactone; lactones, such as N-methylpyrrolidone; nitriles, such as acetonitrile and propionitrile; cyclic or acyclic carbonates, such as propylene carbonate, dimethyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, and propylene carbonate; polar aprotic solvents such as dimethyl sulfoxide and dimethylformamide; water; and combinations thereof. Among these, preferred solvents are PGME, PGMEA, EL, GBL, HBM, CHO, and combinations thereof. The total solvent content in the photoresist composition (i.e., the cumulative solvent content of all solvents) is based on the total solids of the photoresist composition, typically 40 to 99 wt%, for example 70 to 99 wt%, or 85 to 99 wt%. The desired solvent content will depend on, for example, the desired thickness of the photoresist layer and the coating conditions.

[0068] Photoresist compositions may further include one or more additional optional additives. Such optional additives may include, for example, photochemical dyes and contrast dyes, anti-stripping agents, plasticizers, accelerators, sensitizers, photodegradable quenchers (also known as photodegradable bases), alkaline quenchers, surfactants, etc., or combinations thereof. If present, optional additives are typically present in the photoresist composition in an amount of 0.01 to 10 wt% based on the total solids of the photoresist composition.

[0069] Photodegradable quenchers produce weak acids upon irradiation. The acids produced by photodegradable quenchers are not strong enough to react rapidly with the acid-degradable groups present in the resist matrix. Exemplary photodegradable quenchers include, for example, photodegradable cations, and preferably those that can also be used to prepare strong acid-generating compounds but are paired with the anions of weak acids (pKa > 1) (e.g., C1-20 carboxylic acids or C1-20 sulfonic acids). Exemplary carboxylic acids include formic acid, acetic acid, propionic acid, tartaric acid, succinic acid, cyclohexanecarboxylic acid, benzoic acid, salicylic acid, etc. Exemplary carboxylic acids include p-toluenesulfonic acid, camphorsulfonic acid, etc. In a preferred embodiment, the photodegradable quencher is a photodegradable organic zwitterionic compound, such as diphenyliodonium-2-carboxylic acid ester.

[0070] Exemplary basic quenchers include, for example: linear aliphatic amines such as tributylamine, trioctylamine, triisopropanolamine, tetra(2-hydroxypropyl)ethylenediamine, tributyldiethanolamine, tri(2-acetoxy-ethyl)amine, 2,2',2'',2'''-(ethane-1,2-diylbis(azanetriyl))tetraethanol, 2-(dibutylamino)ethanol, and 2,2',2''-nitrotriethanol; cyclic aliphatic amines such as 1-(tributoxycarbonyl)-4-hydroxypiperidine, tributyl 1-pyrrolidinecarboxylate, tributyl 2-ethyl-1H-imidazolium-1-carboxylate, dibutyl-1,4-dicarboxylate, and N-(2-acetoxy-ethyl)oxoline; aromatic amines such as pyridine, dibutyl... Butylpyridine and pyridinium; linear and cyclic amides and their derivatives, such as N,N-bis(2-hydroxyethyl)palmitinamide, N,N-diethylacetamide, N1,N1,N3,N3-tetrabutylpropanediamide, 1-methylazacycloheptan-2-one, 1-allylazacycloheptan-2-one and tert-butyl 1,3-dihydroxy-2-(hydroxymethyl)propyl-2-ylaminocarbamate; ammonium salts, such as quaternary ammonium salts of sulfonates, aminosulfonates, carboxylates and phosphonates; imines, such as primary and secondary aldehyde imines and ketimines; diamines, such as pyridines, piperazines and phenazines substituted as desired; diazoles, such as pyrazoles, thiadiazoles and imidazoles substituted as desired; and pyrrolidones substituted as desired, such as 2-pyrrolidone and cyclohexylpyrrolidine.

[0071] Exemplary surfactants include fluorinated and nonfluorinated surfactants and can be ionic or nonionic, with nonionic surfactants being preferred. Exemplary fluorinated nonionic surfactants include perfluorinated C4 surfactants, such as FC-4430 and FC-4432 surfactants available from 3M Corporation; and fluorinated glycols, such as POLYFOX PF-636, PF-6320, PF-656, and PF-6520 fluorinated surfactants from Omnova. In this aspect, the photoresist composition may further include a surfactant polymer containing fluorinated repeating units.

[0072] A method for patterning the photoresist composition of the present invention will now be described. Suitable substrates on which the photoresist composition can be coated include electronic device substrates. A wide variety of electronic device substrates can be used in the present invention, such as: semiconductor wafers; polycrystalline silicon substrates; packaging substrates, such as multi-chip modules; flat panel display substrates; substrates for light-emitting diodes (LEDs) including organic light-emitting diodes (OLEDs); etc., wherein semiconductor wafers are typical. Such substrates are typically composed of one or more of silicon, polycrystalline silicon, silicon oxide, silicon nitride, silicon oxynitride, silicon germanide, gallium arsenide, aluminum, sapphire, tungsten, titanium, titanium-tungsten, nickel, copper, and gold. Suitable substrates can be in the form of wafers, such as those used for manufacturing integrated circuits, optical sensors, flat panel displays, integrated optical circuits, and LEDs. Such substrates can be of any suitable size. Typical wafer substrate diameters are 200 to 300 millimeters (mm), although wafers with smaller and larger diameters can be suitably used according to the present invention. The substrate may include one or more layers or structures, which may include, as needed, active or operable portions of the formed device.

[0073] Typically, prior to coating the photoresist composition of the present invention, one or more photolithographic layers, such as hard mask layers (e.g., spin-coated carbon (SOC), amorphous carbon, or metal hard mask layers), CVD layers (e.g., silicon nitride (SiN), silicon oxide (SiO), or silicon oxynitride (SiON) layers), organic or inorganic underlayers (e.g., bottom antireflective coating (BARC) layers), or combinations thereof, are provided on the upper surface of the substrate. These layers, together with the externally coated photoresist layers, form a photolithographic material stack.

[0074] If desired, an adhesion promoter layer can be applied to the substrate surface prior to coating the photoresist composition. If an adhesion promoter is desired, any suitable adhesion promoter for polymer films can be used, such as silanes, typically organosilanes like trimethoxyvinylsilane, triethoxyvinylsilane, hexamethyldisilazane, or aminosilane coupling agents like γ-aminopropyltriethoxysilane. Particularly suitable adhesion promoters include those sold from DuPont Electronics & Imaging (Marlborough, Massachusetts) under the names AP 3000, AP 8000, and AP 9000S.

[0075] Photoresist compositions can be coated onto a substrate by any suitable method, including spin coating, spraying, dip coating, blade coating, etc. For example, applying a photoresist layer can be accomplished by spin coating the photoresist in a solvent using a coating track, wherein the photoresist is dispensed onto a rotating wafer. During the dispensing process, the wafer is typically rotated at speeds up to 4,000 rpm, for example 200 to 3,000 rpm, or for example 1,000 to 2,500 rpm, for 15 to 120 seconds to obtain a photoresist composition layer on the substrate. Those skilled in the art will understand that the thickness of the coated layer can be adjusted by changing the rotation speed and / or the solids content of the composition. Photoresist layers formed from the compositions of the present invention typically have a dry layer thickness of 10 to 3000 nanometers (nm), more typically 15 to 500 nm, 20 to 200 nm, or 50 to 150 nm.

[0076] Next, the photoresist composition is typically soft-baked to minimize the solvent content in the layer, thereby forming a non-stick coating and improving the layer's adhesion to the substrate. Soft baking is also believed to induce a reaction between the enol ether-containing compound and the carboxylic acid groups of the acid-sensitive polymer, leading to crosslinking of the acid-sensitive polymer. Soft baking is typically performed, for example, on a heated plate or in an oven, with the heated plate being typical. The soft baking temperature and time will depend, for example, on the specific photoresist composition and thickness. Soft baking temperatures are typically 90°C to 170°C, for example, 110°C to 150°C. Soft baking times are typically 10 seconds to 20 minutes, for example, 1 minute to 10 minutes, or 1 minute to 5 minutes. Those skilled in the art can readily determine the soft baking temperature and time based on the composition of the composition.

[0077] Next, the photoresist layer is patterned and exposed to activating radiation to create a solubility difference between the exposed and unexposed areas. A delay may be necessary between the soft bake and the exposure. Suitable delay times include, for example, 5 seconds to 30 minutes or 1 to 5 minutes. The exposure of the photoresist composition to radiation that activates the composition, as described herein, indicates that the radiation can form a latent image in the photoresist composition. Exposure is typically performed using a patterned photomask with optically transparent and optically opaque regions corresponding to the areas of the photoresist layer to be exposed and the areas of the unexposed photoresist layer, respectively. Alternatively, this exposure can be performed without a photomask in a direct-write method, typically used in electron beam lithography. Activating radiation typically has wavelengths less than -400 nm, less than -300 nm, or less than -200 nm, such as 248 nm (KrF), 193 nm (ArF), and 13.5 nm (Extreme Ultraviolet, EUV) or in electron beam lithography. This method can be used in immersion or dry (non-immersion) lithography techniques. Exposure energy is typically 1 to 200 millijoules per square centimeter (mJ / cm²), preferably 10 to 100 mJ / cm², and more preferably 20 to 50 mJ / cm², depending on the exposure tool and the composition of the photoresist. Preferably, the activation radiation system is 193 nm (ArF), and particularly preferably 193 nm immersion lithography.

[0078] After exposing the photoresist layer, post-exposure baking (PEB) of the exposed photoresist layer is performed. A post-exposure delay (PED) may be required between exposure and PEB. Suitable PEB times include, for example, 5 seconds to 30 minutes or 1 to 5 minutes. PEB can be performed, for example, on a heated plate or in an oven, with the heated plate being typical. The conditions of PEB will depend, for example, on the specific photoresist composition and layer thickness. PEB is typically performed at temperatures from 80°C to 150°C for 30 to 120 seconds. A latent image is formed in the photoresist, defined by polarity-converted regions (exposed regions) and unconverted regions (unexposed regions). It is believed that during the PEB process, photogenerated acids break the ketal bonds of the crosslinked polymer to reform carboxylic acid groups on the polymer in the exposed regions.

[0079] Next, the exposed photoresist layer is developed with a suitable developer to selectively remove areas of the layer that are soluble in the developer while retaining insoluble areas, thus forming the resulting photoresist pattern relief image. In the case of a positive development (PTD) process, the exposed areas of the photoresist layer are removed during development, while the unexposed areas are retained. Conversely, in a negative development (NTD) process, the exposed areas of the photoresist layer are retained during development, while the unexposed areas are removed. The application of the developer can be accomplished by any suitable method, as described above regarding the application of the photoresist composition, with spin coating being typical. The development time is the period of time during which the soluble areas of the photoresist are effectively removed, typically 5 to 60 seconds. Development is typically performed at room temperature.

[0080] Suitable developers for PTD processes include aqueous alkaline developers, such as quaternary ammonium hydroxide solutions, such as tetramethylammonium hydroxide (TMAH) (preferably 0.26 standard (N) TMAH), tetraethylammonium hydroxide, tetrabutylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, etc. Suitable developers for NTD processes are based on organic solvents, meaning that the cumulative content of organic solvents in the developer is 50 wt% or more, typically 95 wt% or more, 95 wt% or more, 98 wt% or more, or 100 wt% based on the total weight of the developer. Suitable organic solvents for NTD developers include, for example, those selected from ketones, esters, ethers, hydrocarbons, and mixtures thereof. Typical developers are 2-heptanone or n-butyl acetate.

[0081] The coated substrate can be formed from the photoresist composition of the present invention. Such a coated substrate includes: (a) a substrate having one or more layers to be patterned on its surface; and (b) a photoresist composition layer on the one or more layers to be patterned.

[0082] Photoresist patterns can be used, for example, as etch masks to transfer patterns to one or more sequentially arranged underlying layers using known etch techniques, typically dry etching (such as reactive ion etching). Photoresist patterns can also be used, for example, to transfer patterns to an underlying hard mask layer, which in turn serves as an etch mask for transferring patterns to one or more layers below the hard mask layer. If the photoresist pattern is not lost during pattern transfer, it can be removed from the substrate using known techniques (such as oxygen plasma ashing). When used in one or more such patterning processes, photoresist compositions can be used to manufacture semiconductor devices such as memory devices, processor chips (CPUs), graphics chips, optoelectronic chips, LEDs, OLEDs, and other electronic devices.

[0083] The following non-limiting examples illustrate the present invention. Example [, Polymer Synthesis , ] [, , ]

[0084] Polymers were synthesized using the following monomers according to the procedure described below: . Example 1 (Polymer P1) []

[0085] 5.0 g of a polymer containing repeating units of monomers M1, M2, M3, and M4 (molar ratios of 35 / 30 / 25 / 10) was dissolved in 13 g of methyl 2-hydroxyisobutyrate and 7 g of propylene glycol monomethyl ether acetate under stirring to obtain a clear solution. 0.15 g of difluoroacetic acid and 0.30 g of water were added to the stirred solution. The mixture was heated to 35°C and stirred. After 72 hours, the reaction mixture was cooled to room temperature, and the polymer was precipitated by directly adding the reaction mixture to 300 mL of methanol. The solid was collected by filtration and vacuum dried to obtain 3.5 g of white solid as polymer P1. The molecular weight was determined by GPC relative to a polystyrene standard, and the number average molecular weight (Mn) was found to be 3710 Da, the weight average molecular weight (Mw) to be 5560 Daltons, and the PDI (polydispersity index) to be 1.5. [, Preparation of photoresist composition , ] Example 3-5

[0086] The photoresist composition was prepared by dissolving the solid components in a solvent using the materials and amounts listed in Table 1. The resulting mixture, prepared in quantities of 16–50 g, was shaken on a mechanical shaker for 3–24 hours and then filtered through a PTFE disc filter with a pore size of 0.2 micrometers. [] [Table 1] [Example] [Photoresist] [P1] [P2] [PAG 1] [Q1] [Enol compounds] [S1] [S2] Example 3 PR-1 2.098 0.093 0.550 0.111 E1 / 0.248 58.140 38.760 Example 4 PR-2 2.098 0.093 0.550 0.111 E2 / 0.248 58.140 38.760 Example 5 (Comparison) PR-3 2.346 0.093 0.550 0.111 - 58.140 38.760 All quantities are provided as a weight percentage (wt%) of the total pattern trimming composition. [, , ] [, Photolithography Evaluation , ] Example 6-8

[0087] A first BARC layer with a thickness of 800 Å was formed by spin-coating a 300 mm silicon wafer with AR™ 40A antireflective agent (DuPont Electronics & Imaging) at a curing temperature of 205°C for 60 seconds. A second BARC layer with a thickness of 400 Å was then formed by spin-coating the wafer with AR™ 104 antireflective agent (DuPont Electronics & Imaging) at a curing temperature of 175°C for 60 seconds. The wafer was then spin-coated with the corresponding photoresist composition prepared in Examples 3-5 and soft-baked at 110°C for 60 seconds to provide a photoresist layer with a thickness of 900 Å. The BARC and photoresist layers were then coated using a TEL Clean Track Lithius coating tool. The wafer was exposed using an ASML 1900i immersion scanner (1.3 NA, 0.86 / 0.61 inner / outer σ, dipole illumination with 35°Y polarization) with a mask having a 1:1 line-space pattern (55 nm linewidth / 110 nm spacing). The exposed wafer was baked at 100°C for 60 seconds and developed with a 0.26 N TMAH aqueous solution for 12 seconds. The wafer was then rinsed with deionized water and spin-dried to form the photoresist pattern. The CD linewidth of the formed pattern was measured using a Hitachi High Technologies Co. CG4000 CD-SEM. The E dimension, which is the exposure dose when the pattern CD is equal to the CD of the mask pattern (55 nm linewidth), was also determined. The LWR was determined using 3-σ values ​​from a distribution of a total of 100 arbitrary linewidth measurement points. The results are shown in Table 2. [Table 2] [Example] [Photoresist] [Composition] [E] [, 尺寸 , ] [(] [mJ / cm, 2 , ] [)] [LWR] [(] [nm] [)] Example 6 PR-1 42 3.44 Example 7 PR-2 26 3.45 Example 8 (Comparison) PR-3 27 4.22

[0088] none

[0089] none

Claims

1. A photoresist composition comprising: an acid-sensitive polymer comprising a first repeating unit formed by a first radical polymerizable monomer containing an acid-degradable group and a second repeating unit formed by a second radical polymerizable monomer containing a carboxylic acid group; a compound comprising two or more enol ether groups, wherein the compound is different from the acid-sensitive polymer; and a material comprising a base-indegradable group, wherein... The material containing the base-unstable group is a polymer comprising repeating units derived from monomers selected from formulas (7-1) to (7-3): (7-1); (7-2); (7-3), wherein: X2 is a polymerizable group selected from vinyl and acrylic acid; L6 is a divalent linking group comprising one or more of the following: substituted or unsubstituted linear or branched C1-20 alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, -C(O)-, or -C(O)O-; R18 is a substituted or unsubstituted C1-20 fluoroalkyl group, provided that the carbon atom bonded to the carbonyl group (C=O) is substituted with at least one fluorine atom; L7 is a polyvalent linking group comprising one or more of the following: substituted or unsubstituted linear or branched C1-20 alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, -C(O)-, or -C(O)O-; e is an integer of 2 or greater. The L8 series comprises one or more of the following divalent linking groups: substituted or unsubstituted straight-chain or branched C1-20 alkyl groups, substituted or unsubstituted C3-20 cycloalkyl groups, -C(O)- or -C(O)O-, the Lf series comprises substituted or unsubstituted C1-20 fluoroalkyl groups, wherein the carbon atom bonded to the carbonyl group (C=O) is substituted by at least one fluorine atom, and the R19 series comprises substituted or unsubstituted straight-chain or branched C1-20 alkyl groups, or substituted or unsubstituted C3-20 cycloalkyl groups; photoacid generators; and solvents.

2. The photoresist composition as described in claim 1, wherein, The compound has formula (5): where: R14 independently represents -H, C1-4 alkyl, or C1-4 fluoroalkyl, and may include, as required, one or more groups selected from -O-, -S-, -N(R15)-, -C(O)-, -C(O)O-, or -C(O)N(R15)- as part of its structure, wherein R15 represents hydrogen or a substituted or unsubstituted C1-10 alkyl, and any two R14 groups together may form a ring as required; L5 represents a linking group having a valence d; and d is an integer from 2 to 4.

3. The photoresist composition as described in claim 2, wherein, The compound has the formula (5-1): CH2=CH-O-R17-O-CH=CH2 (5-1) where R17 represents a C1-10 straight-chain extended alkyl group, a C3-10 branched extended alkyl group, a C3-10 cycloextended alkyl group, or a combination thereof, each of which may be substituted or unsubstituted.

4. The photoresist composition as described in claim 1, wherein, The compound is a polymer comprising a first repeating unit, which includes an enol ether group side-attached to the polymer backbone.

5. The photoresist composition as described in claim 4, wherein, The first repeating unit of the compound is formed from a vinyl aromatic monomer or a (meth)acrylate monomer.

6. The photoresist composition as described in any one of claims 1 to 5, wherein, The acid can decompose into tertiary ester groups of the formula -C(=O)OC(R5)3, wherein: each R5 is independently a straight-chain C1-20 alkyl, a branched C3-20 alkyl, a monocyclic or polycyclic C3-20 cycloalkyl, a straight-chain C2-20 alkenyl, a branched C3-20 alkenyl, a monocyclic or polycyclic C3-20 cycloalkenyl, a monocyclic or polycyclic C6-20 aryl, or a monocyclic or polycyclic C2-20 heteroaryl, each of which is substituted or unsubstituted, and each R5 may include, as required, one or more groups selected from -O-, -S-, -N(R6)-, -C(O)-, -C(O)O-, or -C(O)N(R6)- as part of its structure, wherein R6 represents hydrogen or a substituted or unsubstituted C1-10 alkyl, and any two R5 groups together may form a ring as required.

7. The photoresist composition as described in claim 6, wherein, R5 is independently a straight-chain C1-6 alkyl, a branched C3-6 alkyl, or a monocyclic or polycyclic C3-10 cycloalkyl, each of which may be substituted or unsubstituted.

8. The photoresist composition as described in any one of claims 1 to 5, wherein, The first radical polymerizable monomer and the second radical polymerizable monomer are independently vinyl aromatic monomers or (meth)acrylate monomers.

9. The photoresist composition as described in any one of claims 1 to 5, wherein, The acid-sensitive polymer further includes a third repeating unit containing a lactone group.

10. The photoresist composition as described in any one of claims 1 to 5, wherein, The material containing the base-unstable group is a fluorinated polymer.

11. A method for forming a pattern, comprising: (a) Applying a layer of photoresist composition as described in any one of claims 1 to 10 onto a substrate; (b) Soft-baking the photoresist composition layer; (b) exposing the soft-baked photoresist composition layer to activation radiation; (d) post-exposure baking the photoresist composition layer; and (c) developing the post-exposure baked photoresist composition layer to provide a photoresist relief image.