Photoacid generator, photoresist composition, and pattern forming method

Abstract

Disclosed are photoacid generators comprising a moiety of formula (1): wherein: Ar 1 is a substituted or unsubstituted aryl group; R 1 is an alkyl group or an aryl group, each of which can be substituted or unsubstituted, wherein Ar 1 and R 1 are optionally linked together by a single bond or a divalent linking group to form a ring; Y is a single bond or a divalent group; and * is the point of attachment of the moiety to another atom of the photoacid generator. These photoacid generator compounds are particularly useful in photoresist compositions that can be used to form photolithographic patterns that are used to form electronic devices.

Description

Background Technology

[0001] 1. Field of Invention

[0002] This invention generally relates to the manufacture of electronic devices. More specifically, the invention relates to photoacid generators (PAGs), photoresist compositions containing these PAGs, and patterning methods using these photoresist compositions. These PAGs, photoresist compositions, and patterning methods are particularly used to form photolithographic patterns that can be used to manufacture semiconductor devices.

[0003] 2. Related technical specifications

[0004] Photoresist compositions are photosensitive materials used to transfer images onto one or more underlying layers (such as metal, semiconductor, or dielectric layers) disposed on a substrate. Positively chemically enhanced photoresist compositions are commonly used for high-resolution processing. Such resist compositions typically comprise a polymer with acid-indestabilized groups and a photoacid generator (PAG). A layer of the photoresist composition is patterned and exposed to activating radiation, and the PAG generates acid in the exposed areas. During post-exposure baking, the acid causes the acid-indestabilized groups of the polymer to cleave. This creates a difference in solubility properties between the exposed and unexposed areas of the photoresist layer in the developer solution. During positive development (PTD), the exposed areas of the photoresist layer become soluble in the developer (typically an aqueous alkaline developer) and are removed from the substrate surface. The unexposed areas, insoluble in the developer, are retained after development to form a positive relief image. The resulting relief image allows for selective processing of the substrate.

[0005] To increase the integration density of semiconductor devices and allow for the formation of structures with dimensions in the nanometer (nm) range, photoresists and lithography tools with high-resolution capabilities have been and continue to be developed. One method for achieving nm-level feature sizes in semiconductor devices is to expose the photoresist layer using activation radiation with short wavelengths (e.g., 193 nm or less). To further improve lithography performance, immersion lithography tools (e.g., scanners with ArF (193 nm) light sources) have been developed to effectively increase the numerical aperture (NA) of the lens of the imaging device. This is achieved by using a fluid with a high refractive index (typically water) between the last surface of the imaging device and the top surface of the semiconductor wafer.

[0006] ArF immersion tooling is currently pushing the boundaries of photolithography to 16nm and 14nm device nodes by using multiple (double, triple, or more) patterning techniques. However, using multiple patterning can be expensive in terms of increased material usage and the number of process steps required (compared to single-step, direct-imaging patterning). Therefore, the demand for photoresist compositions for next-generation (e.g., EUV) lithography is becoming increasingly important for advanced device nodes. At the extreme feature sizes associated with these nodes, the performance requirements for photoresist compositions are becoming increasingly stringent. Desired performance characteristics include, for example, high sensitivity to activation radiation, low unexposed film thickness loss (UFTL), good contrast, high resolution, low surface roughness, good critical size uniformity (CDU), and minimal patterning defects.

[0007] Typical PAG compounds used in advanced photoresist compositions include anions (conjugate bases of the photogenerated acid) and hydrophobic ononium cations. However, the hydrophobicity of the cations can lead to poor solubility in the exposed areas of the resist layer during aqueous alkaline development. This can result in patterning defects that may adversely affect device performance and product yield. The hydrophobic cations may further contribute to instability of the latent image after exposure, which can negatively impact the outline of the resist pattern formed after development.

[0008] To address the solubility issue of PAG developers, acid-insecure groups can be included on the cations. During post-exposure baking, the cleavage of these acid-insecure groups in the exposed regions of the photoresist layer generates hydrophilic groups on the cations, thereby increasing solubility in aqueous alkaline developers. The use of PAG cations comprising acid-insecure groups in photoresist compositions has been proposed. For example, US 2008 / 0248422 A1 discloses PAG cations containing acid-dissociable dissolution-inhibiting groups. Examples of such groups are disclosed as including cyclic or linear tertiary alkyl ester groups and acetal-type groups. Given the current performance standards and chemical compositions of photoresists at advanced device nodes, novel photoacid generators are desirable.

[0009] There is a need in the art for photoacid generators, photoresist compositions, and patterning methods that address one or more problems related to the prior art. Summary of the Invention

[0010] According to a first aspect of the invention, photoacid generators are provided. These photoacid generators comprise a portion having formula (1):

[0011]

[0012] Among them: Ar 1 It is a substituted or unsubstituted aryl group; R 1It is an alkyl or aryl group, each of which may be substituted or unsubstituted, wherein Ar 1 and R 1 Optionally linked together by single bonds or divalent linking groups to form a ring; Y is a single bond or a divalent group; and * is the attachment point of this part to another atom of the photoacid generator.

[0013] Photoresist compositions are also provided. These compositions comprise a photoacid generator and a solvent as described herein. Typically, the photoresist compositions comprise an acid-sensitive polymer. In such cases, the photoacid generator may be present as part of the polymerization unit of the acid-sensitive polymer or as a separate component from the acid-sensitive polymer.

[0014] Patterning methods are also provided. These patterning methods include: (a) forming a photoresist layer on a substrate using a photoresist composition as described herein; (b) exposing the photoresist layer to activating radiation; and (c) developing the exposed photoresist layer to provide a photoresist relief image. Detailed Implementation

[0015] 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 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 said 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.

[0016] The term "aromatic group" refers to a monocyclic or polycyclic ring system that satisfies Hückel's rule and can be carbocyclic (containing only carbon atoms in the aromatic ring) or heterocyclic (containing one or more heteroatoms (e.g., N, O, or S) as ring atoms); "aryl" refers to a monovalent aromatic group; and "arylene" refers to an aromatic group having a valence of 2.

[0017] The term "alkyl" refers to a straight-chain, branched, or cyclic saturated hydrocarbon group or a combination thereof having a valence of one; "alkylene" refers to an alkyl group having a valence of two.

[0018] The prefix "heterogeneous" indicates that a compound or group includes one or more heteroatoms (e.g., 1, 2, 3, or 4 or more heteroatoms), each of which replaces a corresponding carbon atom, wherein the heteroatoms can be independently, for example, N, O, S, Se, Te, Si, or P.

[0019] "Substituted" means that at least one hydrogen atom on the group is replaced by another group, provided that the normal valence of the specified atom is not exceeded. Combinations of substituents or variables are permitted. Exemplary groups that may be present at the "substituted" position include, but are not limited to, nitro (-NO2), cyano (-CN), hydroxyl (-OH), amino (-NH2), mono- or di-(C... 1-6 )alkylamino, alkanoyl (such as C 2-6 Alkyl groups (such as acyl groups), formyl groups (-C(=O)H), carboxylic acids or their alkali metal salts or ammonium salts, esters (including lactones, such as C... 2-6 Alkyl esters (-C(=O)O-alkyl or -OC(=O)-alkyl) and C 7-13 Aryl esters (-C(=O)O-aryl or -OC(=O)-aryl), amide groups (-C(=O)NR2, where R is hydrogen or C) 1-6 Alkyl), formamido (-CH2C(=O)NR2, where R is hydrogen or C 1-6 Alkyl groups, halogens, mercapto groups (-SH), C 1-6 Alkylthio (-S-alkyl), cyanothio (-SCN), C 1-6 Alkyl, C 2-6 alkenyl, C 2-6 alkynyl group, C 1-6 Haloalkyl, C 1-9 Alkoxy, C 1-6 Halogenated alkoxy groups, C 3-12 cycloalkyl, C 5-18 Cycloalkenyl, C having at least one aromatic ring 6-12 Aryl groups (e.g., phenyl, biphenyl, naphthyl, etc., each ring being substituted or unsubstituted aromatics), having 1 to 3 separate or fused rings and 6 to 18 ring carbon atoms. 7-19 Arylalkyl, arylalkoxy having 1 to 3 separate or fused rings and 6 to 18 ring carbon atoms, C 7-12 alkylaryl, C 4-12 Heterocyclic alkyl, C 3-12 heteroaryl, C 1-6 alkylsulfonyl (-S(=O)2-alkyl), C 6-12 Arylsulfonyl (-S(=O)2-aryl), or toluenesulfonyl (CH3C6H4SO2-), and vinyl and vinyl-containing groups (such as acrylics, vinyl ethers, ketenes, and norbornyl). When the group is substituted, the indicated number of carbon atoms is the total number of carbon atoms in the group, excluding those with any substituents. For example, the group -CH2CH2CN is a C2 alkyl group substituted with a cyano group.

[0020] As used herein, an "acid-indestructible group" refers to a group in which a bond is broken by the catalytic action of an acid (optionally and typically in conjunction with heat treatment), resulting in the formation of a polar group (such as a carboxylic acid or alcohol group, formed on the polymer) and, optionally and typically, the portion attached to the broken bond detaches from the polymer. Such acids are typically photogenerated acids that undergo bond cleavage during post-exposure baking. Suitable acid-indestructible 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, tertiary alkoxy groups, acetal groups, or ketal groups. Acid-indestructible groups are also referred to in the art as "acid-crackable groups," "acid-crackable protecting groups," "acid-indestructible protecting groups," "acid-leaving groups," "acid-decomposable groups," and "acid-sensitive groups."

[0021] Photoacid generator

[0022] The photoacid generator (PAG) of the present invention is photodegradable upon exposure to activating radiation and produces acid upon photodegradation. The intensity of the acid produced by the PAG can vary widely, for example having a pKa of -20 to 20, -15 to 15, -12 to 12, -15 to -1, or greater than -1 to 6. The PAG comprises a portion having formula (1):

[0023]

[0024] Among them: Ar 1 It is a substituted or unsubstituted aryl group, for example, C 6-40 Carbocyclic aryl or C 4-40 Heterocyclic aryl groups, each of which is monocyclic or polycyclic and is substituted or unsubstituted, wherein substituted or unsubstituted C6-carbon aryl groups are preferred; R 1 It is a substituted or unsubstituted alkyl or aryl group, for example, C 1-20 straight-chain alkyl, C 3-20 Branched alkyl, monocyclic or polycyclic C 3-20 Cycloalkyl, monocyclic or polycyclic C 6-40 C-rings of aryl, monocyclic, or polycyclic rings 6-40 Heterocyclic aryl groups, each of which is substituted or unsubstituted, wherein substituted or unsubstituted alkyl groups are preferred, wherein Ar 1 and R 1 Optionally linked together by single bonds or divalent linkers to form a ring, exemplary divalent linkers include -O-, -S-, -Te-, -Se-, -C(O)-, -C(S)-, -C(Te)-, -S(O)-, -S(O)2-, -N(R)-, or -C(Se-), substituted or unsubstituted C 1-5 Alkylenes and combinations thereof, wherein R is hydrogen, C is carbon, and C is hydrogen. 1-20 Alkyl, C1-20 Heteroalkyl, C 6-30 Carbocyclic aryl, or C 4-30 Heterocyclic aryl groups, wherein each of the groups except hydrogen can be substituted or unsubstituted; Y is a single bond or a divalent group, for example, -O-, -S-, -Te-, -Se-, -C(O)-, -C(O)O-, -N(R a )-、-C(O)N(R 2a )-、-N(R 2a S(O)2-, substituted or unsubstituted C 1-30 Alkylene, substituted or unsubstituted C 3-30 Cycloalkylene, substituted or unsubstituted C 1-30 Heterocyclic alkyl, substituted or unsubstituted C 6-30 aryl, substituted or unsubstituted C 7-30 Arylalkylene, substituted or unsubstituted C 1-30 Heteroaryl, substituted or unsubstituted C 3-30 Heteroarylalkylene, wherein R a and R 2a Independently, it is hydrogen and C 1-20 Alkyl, C 1-20 Heteroalkyl, C 6-30 Aryl, or C 4-30 The heteroaryl group, or a combination thereof, wherein each of the groups other than hydrogen may be substituted or unsubstituted, and optionally further comprises one or more of the following: -S(O)-, -S(O)2-, -C(S)-, -C(Te)-, or -C(Se)-, wherein for Y, -CH2C(O)O- is preferred; and * is the attachment point of the moiety to another atom of the photoacid generator. The moiety having formula (1) comprises an acid-instantaneous secondary ester group. Using a photo-generated acid, the OC bond of the secondary ester breaks, leaving a carboxylic acid group on the decomposed PAG.

[0025] The photoacid generator having a portion of formula (1) is not particularly limited and can be ionic or nonionic. Preferably, PAG is ionic and is represented by formula (2):

[0026] G + Z - (2)

[0027] Among them G + It is a cation containing a portion having formula (1) and Z - These are counterions to the anions, which in this text can be referred to as the cationic and anionic moieties, respectively. These cations and anions are typically organic. The acid strength of a photogenerated acid is determined by the anionic moieties.

[0028] Ionic PAGs can be selected from, for example, onium salts, such as sulfonium salts, iodonium salts, haloonium salts, quaternary ammonium salts, phosphonium salts, arsenic salts, sulfonium oxide salts, tellurium salts, or selenium salts. Preferably, the PAG is a sulfonium salt or an iodonium salt. For example, the acid-generating group may comprise a negatively charged aromatic sulfonate or perfluoroalkyl sulfonate and a substituted triarylsulfonium or a substituted diaryliodonium countercation. A preferred ionic PAG is represented by formula (2-1):

[0029]

[0030] Among them: Ar 1 R 1 Ar and Y are each independently defined as described above with respect to equation (1); 2 Independently representing substituted or unsubstituted aryl groups, for example, C 6-40 Carbocyclic aryl or C 4-40 Heterocyclic aryl groups, each of which is monocyclic or polycyclic and is substituted or unsubstituted, and preferably substituted or unsubstituted C6-carbon aryl groups; X is S or I; R 2 Independently representing substituted or unsubstituted alkyl or aryl groups, for example, C 1-20 straight-chain alkyl, C 3-20 Branched alkyl, monocyclic or polycyclic C 3-20 Cycloalkyl, monocyclic or polycyclic C 6-40 C-rings of aryl, monocyclic, or polycyclic rings 4-40 Heterocyclic aryl groups, each of which is substituted or unsubstituted, and preferably C6-carbon aryl groups; Z - It is a counter anion; a is 1 to Ar 2 The above can be an integer of the total number of carbon atoms, typically 1 to 5, and more typically 1 or 2; when X is S, b is 1, 2, or 3 and c is 3; and when X is I, b is 1 or 2 and c is 2; where (i) two R 2 Group or (ii) an Ar 2 Group and an R 2 The groups are optionally linked together to form a ring via single bonds or divalent linkers. Exemplary divalent linkers include -O-, -S-, -Te-, -Se-, -C(O)-, -C(S)-, -C(Te)-, -S(O)-, -S(O)2-, -N(R)-, or -C(Se-), substituted or unsubstituted C- groups. 1-5 Alkylenes and combinations thereof, wherein R is hydrogen, C is carbon, and C is hydrogen. 1-20 Alkyl, C 1-20 Heteroalkyl, C 6-30 Carbocyclic aryl, or C 4-30 Heterocyclic aryl groups, wherein each of the groups except for hydrogen can be substituted or unsubstituted. When two R groups are... 2 Group or one Ar2 Group and an R 2 When groups are linked together to form a ring, single bonds, -O-, -S-, or -C(O)- are preferred.

[0031] Suitable exemplary PAG cations having formula (2-1) include the following:

[0032]

[0033]

[0034]

[0035]

[0036] The selection of a suitable PAG anion will depend, for example, on the pKa of the desired photogenerated acid. Preferred PAG anions include groups selected from sulfonate anions, methylate anions, sulfonamide anions, sulfonamide anions, aminosulfonate anions, phenol anions, or carboxylate anions. Suitable exemplary PAG anions that can pair with the above-mentioned cations include the following:

[0037]

[0038]

[0039] Suitable nonionic PAGs include, for example, nitrobenzyl derivatives, diazomethane derivatives, sulfonate derivatives, glyoxime derivatives, β-ketosulfonate derivatives, disulfonate derivatives, nitrobenzylsulfonate derivatives, iminosulfonate derivatives, oxime sulfonate derivatives, iminosulfonate derivatives, and triazine derivatives, which contain the portion having formula (1) as described above.

[0040] Suitable exemplary nonionic PAGs include, for example, the following:

[0041]

[0042]

[0043]

[0044] PAG can take the form of non-polymeric compounds or polymers. Suitable non-polymeric compounds include monomers and non-polymerizable compounds. Typical monomers include radically polymerizable groups, such as vinyl groups, typically styrene, acrylic, vinyl ethers, vinyl ketones, and norbornyl monomers.

[0045] In some respects, ionic or nonionic PAGs can optionally be covalently bonded to the polymer as side groups within the polymer's polymeric units. In the case of ionic PAGs, anions or cations can be covalently bonded to the polymer. For example, in formula (2-1), a sulfonium salt or iodonium salt having formula (1) can optionally be used as a side group via the Ar of the cation moiety. 1 R 1 、or R 2 Substituents on the polymer can be covalently bonded to the polymer, or the anionic moiety of a sulfonium salt or iodonium salt having formula (1) can be covalently bonded to the polymer via Z- as a side group. For example, the side group can be attached to the main chain or backbone of the polymer.

[0046] The polymeric unit containing PAG can be derived, for example, from the following exemplary monomers:

[0047]

[0048]

[0049] Among them G + and Z - It is as defined above.

[0050] The polymer may be a homopolymer, or more typically, a copolymer containing one or more additional repeating units different from those containing PAG. Suitable additional repeating units may include, for example, one or more additional units, as described below with respect to acid-sensitive polymers of photoresist compositions. If used in a copolymer, the repeating units containing PAG are typically present in amounts of 1 to 90 mol%, 1 to 40 mol%, more typically 1 to 25 mol%, and even more typically 2 to 15 mol%, based on the total repeating units in the polymer.

[0051] The polymer typically has an M value of 1500 to 50,000 Da, 2000 to 30,000 Da, more specifically 3000 to 20,000 Da, and even more specifically 3000 to 10,000 Da. w The PDI of polymers (which is M) w With M n The ratio (to) is typically 1.1 to 5, more typically 1.3 to 2.5. Molecular weight is determined by GPC using polystyrene standards.

[0052] The photoacid generator of the present invention can be prepared by those skilled in the art. For example, PAG can be synthesized by covalently attaching a portion having formula (1) to an onium salt cation or nonionic PAG. Covalent attachment can be accomplished, for example, by alkylation or esterification of a hydroxyl-substituted cation of an onium salt or nonionic PAG with a derivative having a portion of formula (1). An exemplary alkylation reaction is the reaction of a hydroxyl-substituted onium salt or hydroxyl-substituted nonionic photoacid generator with a derivative of Hal-YC(=O)-O-CH(R) 1 )Ar 1 The reactions of compounds represented by Y and R in the presence of a base are shown. 1 and Ar 1 It is as defined above with respect to formula (1). In the case of onium salts, the product of the alkylation step is typically an onium halide, which can then be reacted with a compound having formula Z. - X + The salt undergoes an ion exchange reaction (where Z) - It is as defined above and X + (It is an inorganic or organic countercation) to produce a photoacid generator having formula (2-1).

[0053] Photoresist composition

[0054] The photoacid generators described herein can be used in a variety of applications, and particularly in photoresist compositions used in the manufacture of electronic devices, such as semiconductor devices, circuit boards, and display devices. The photoresist compositions comprise the photoacid generators and solvents as described above, and may contain one or more additional optional components. Depending on the strength of the generated acid and the other components of the photoresist composition, PAGs can play a variety of roles in the composition. For example, on one hand, a PAG can act as an acid source to deprotect acid-insecure groups on the PAG and / or acid-sensitive polymers alone. On another hand, a PAG can act as a photodegradable quencher (PDQ) (when used in combination with a second PAG), wherein the corresponding photoacid of the second PAG has a lower pKa than the corresponding photoacid of the PDQ.

[0055] In view of the acid-sensitive nature of the PAG of the present invention, in one aspect of the invention, the PAG itself can serve as a photoresist matrix (whether in polymeric or non-polymeric form). Therefore, the photoresist composition may optionally be free of acid-sensitive polymers chemically different from PAG. Alternatively and more typically, the photoresist composition may include acid-sensitive polymers chemically different from PAG. Therefore, based on the total solids of the photoresist composition, the PAG of the present invention can be present in a wide range of photoresist compositions, for example, in amounts from 1 to 100 wt%. When using acid-sensitive polymers chemically different from PAG, PAG is typically present in amounts from 1 to 65 wt%, more typically 5 to 55 wt%, and even more typically 8 to 30 wt%, based on the total solids of the photoresist composition. When PAG acts as the sole or primary acid-sensitive component of a photoresist composition, whether in polymeric or non-polymeric form, it typically exists in amounts of 50 to 100 wt%, more typically 90 to 100 wt%, and even more typically 95 to 99.5 wt%, based on the total solids of the photoresist composition.

[0056] The photoresist composition may comprise one or more acid-sensitive polymers. Acid-sensitive polymers include polymeric units containing acid-indestabilized groups (e.g., tertiary ester or acetal groups). Alternatively or concurrently, the polymeric units containing acid-indestabilized groups may be derived from the PAG monomers of this invention. Other suitable monomers for these polymeric units include, for example, the following:

[0057]

[0058]

[0059] Where R d It is hydrogen, fluorine, C 1-5 Alkyl, or C 1-5 Fluoroalkyl groups, typically hydrogen or methyl.

[0060] Repeating units with acid-indestabilized 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.

[0061] In some respects, acid-sensitive polymers may comprise repeating units having an aromatic group, wherein the aromatic group may be substituted or unsubstituted. The aromatic group is optionally a monocyclic or polycyclic C-shaped structure comprising one or more aromatic cyclic heteroatoms selected from N, O, S, or combinations thereof. 5-60Aromatic groups. When the aromatic group is polycyclic, the rings or cyclic groups can be fused (e.g., naphthyl), directly linked (e.g., biaryl, biphenyl), bridged by heteroatoms (e.g., triphenylamino or diphenylene ether), and / or may include combinations of fused and directly linked rings (e.g., binaphthyl).

[0062] C of single or multiple rings 5-60 The aromatic group may be substituted or unsubstituted. Exemplary substituents include, but are not limited to, substituted or unsubstituted C groups. 1-30 Alkyl, substituted or unsubstituted C 1-30 Halogenated alkyl, substituted or unsubstituted C 3-30 cycloalkyl, substituted or unsubstituted C 1-30 Heterocyclic alkyl, substituted or unsubstituted C 2-30 alkenyl, substituted or unsubstituted C 2-30 Alkyne group, substituted or unsubstituted C 6-30 aryl, substituted or unsubstituted C 7-30 arylalkyl, substituted or unsubstituted C 7-30 alkylaryl, substituted or unsubstituted C 3-30 heteroaryl, substituted or unsubstituted C 4-30 Heteroarylalkyl, halogen, -OR 51 -SR 52 , or -NR 53 R 54 , where R 51 To R 54 Each is independently hydrogen, or a substituted or unsubstituted C. 1-30 Alkyl, substituted or unsubstituted C 3-30 cycloalkyl, substituted or unsubstituted C 2-30 Heterocyclic alkyl, substituted or unsubstituted C 6-30 aryl, substituted or unsubstituted C 7-30 arylalkyl, substituted or unsubstituted C 3-30 heteroaryl, or substituted or unsubstituted C 4-30 Heteroarylalkyl. Preferably, the aromatic group is a substituted C. 6-30 Aryl or substituted C 7-30 Heteroaryl groups, wherein the aromatic group is replaced by a substituent containing a heteroatom, such as -OR. 51 -SR 52 , or -NR 53 R 54 Replace, where R 51 To R 54 Each is independently hydrogen, or a substituted or unsubstituted C. 1-10 Alkyl, substituted or unsubstituted C 3-20 cycloalkyl, substituted or unsubstituted C 2-20 Heterocyclic alkyl, substituted or unsubstituted C6-30 aryl, substituted or unsubstituted C 7-30 arylalkyl, substituted or unsubstituted C 3-30 heteroaryl, or substituted or unsubstituted C 4-30 Heteroarylalkyl.

[0063] Repeating units with aromatic groups are typically present in acid-sensitive polymers in amounts of 5 to 80 mol%, more typically 10 to 50 mol%, and even more typically 10 to 40 mol% of the total repeating units in the acid-sensitive polymer.

[0064] Acid-sensitive polymers may include repeating units comprising lactone groups. Suitable repeating units may, for example, be derived from monomers having formula (5a) or formula (5b):

[0065]

[0066] In formula (5a), R is hydrogen, fluorine, cyano, substituted or unsubstituted C. 1-10 Alkyl, or substituted or unsubstituted C 1-10 Fluoroalkyl. Preferably, R d It is hydrogen, fluorine, or substituted or unsubstituted C. 1-5 Alkyl (typically methyl). L 3 It can be a single bond or a divalent linker containing one or more of the following: substituted or unsubstituted C 1-30 Alkylene, substituted or unsubstituted C 1-30 Heteroalkyl, substituted or unsubstituted C 3-30 Cycloalkylene, substituted or unsubstituted C 1-30 Heterocyclic alkyl, substituted or unsubstituted C 6-30 aryl, substituted or unsubstituted C 7-30 arylene alkyl, or substituted or unsubstituted C 1-30 heteroaryl, or substituted or unsubstituted C 3-30 Heteroarylalkyl, wherein L 3 Optionally, it may further include, for example, -O-, -C(O)-, -C(O)-O-, -S-, -S(O)2- and -N(R)-. 44 One or more groups in )-S(O)2-, wherein R 44 It can be hydrogen, straight-chain or branched C 1-20 alkyl, monocyclic or polycyclic C 3-20 Cycloalkyl, or monocyclic or polycyclic C 3-20 Heterocyclic alkyl. R 14 C can be monocyclic, polycyclic, or fused polycyclic. 4-20 Contains a lactone group. In formula (5b), R 15 It is a hydrogen or non-hydrogen substituent, typically a substituted or unsubstituted C.1-10 Alkyl group, and n is 1 or 2.

[0067] Suitable exemplary lactone-containing monomers having formulas (5a) and (5b) include the following:

[0068]

[0069]

[0070] Wherein R is as described above. When present, the acid-sensitive polymer typically contains 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.

[0071] Acid-sensitive polymers may contain base-soluble repeating units having a pKa of less than or equal to 12. For example, base-soluble repeating units may be derived from monomers having formula (6):

[0072]

[0073] In equation (6), R g It can be hydrogen, fluorine, cyano, substituted or unsubstituted C 1-10 Alkyl, or substituted or unsubstituted C 1-10 Fluoroalkyl. Preferably, R g It is hydrogen, fluorine, or substituted or unsubstituted C. 1-5 Alkyl group, typically methyl group. Q 4 It may include one or more of the following: substituted or unsubstituted C 1-30 Alkylene, substituted or unsubstituted C 3-30 Cycloalkylene, substituted or unsubstituted C 1-30 Heterocyclic alkyl, substituted or unsubstituted C 6-30 aryl, substituted or unsubstituted divalent C 7-30 arylalkyl, substituted or unsubstituted C 1-30 Heteroaryl, or substituted or unsubstituted divalent C 3-30 Heteroarylalkyl or -C(O)-O-. W is a base-soluble group and can be selected from, for example, hydroxyl (-OH); -C(O)-OH; fluorinated alcohols such as -C(CF3)2OH; imides; or -NH-S(O)2-Y. 1 , where Y 1 It is C 1-4 Alkyl or fluoroalkyl, typically C1-4 perfluoroalkyl. In formula (6), a is an integer from 1 to 3.

[0074] Non-limiting examples of monomers having formula (6) include:

[0075]

[0076] Where R g As described above. When present, acid-sensitive polymers typically contain the aforementioned alkali-soluble repeating units, in an amount 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.

[0077] The acid-sensitive polymer may optionally contain 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 etching rate and solubility). The additional units may include one or more units of the following types: styrene, (meth)acrylate, vinyl ether, vinyl ketone, or vinyl ester. One or more additional repeating units in the acid-sensitive polymer (if present) may be used in an amount up to 70 mol%, typically 3 to 50 mol%, based on the total repeating units of the acid-sensitive polymer.

[0078] Non-limiting examples of acid-sensitive polymers include the following:

[0079]

[0080]

[0081]

[0082] Where a, b, c, and d represent the mole fraction of the corresponding repeating unit.

[0083] Acid-sensitive polymers typically have a weight-average molecular weight (Mw) of 1,000 to 50,000 Daltons (Da), specifically 2,000 to 30,000 Da, more specifically 3,000 to 20,000 Da, and even more specifically 3,000 to 10,000 Da. The polydispersity index (PDI) of acid-sensitive polymers (which is the ratio of Mw to number-average molecular weight (Mn)) is typically 1.1 to 3, specifically 1.1 to 2. Molecular weight values ​​are determined by gel permeation chromatography (GPC) using polystyrene standards.

[0084] Acid-sensitive polymers and any other polymers in photoresist compositions can be prepared using suitable methods known in the art. For example, one or more monomers corresponding to repeating units of the polymer can be fed together or separately with one or more suitable solvents and initiators and polymerized in a reactor. The polymer can be obtained by polymerization under any suitable conditions, such as by heating at an effective temperature, irradiation with photochemical radiation at an effective wavelength, or a combination thereof.

[0085] The photoresist composition may further include an alkaline quencher and / or a photodegradable quencher (PDQ) (also known as a photodegradable alkali). If used, the respective amounts are typically 0.01 to 10 wt% based on the total solids of the photoresist composition.

[0086] Exemplary alkaline quenchers include, for example: linear aliphatic amines such as tributylamine, trioctylamine, triisopropanolamine, tetra(2-hydroxypropyl)ethylenediamine, n-tert-butyldiethanolamine, tris(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-(tert-butoxycarbonyl)-4-hydroxypiperidine, tert-butyl 1-pyrrolidinecarboxylate, tert-butyl 2-ethyl-1H-imidazolium-1-carboxylate, di-tert-butyl piperazine-1,4-dicarboxylate, and N-(2-acetoxy-ethyl)morpholine; aromatic amines such as pyridine, di-tert-butyl... Pyridine and pyridinium; linear and cyclic amides and their derivatives, such as N,N-bis(2-hydroxyethyl)palmitamide, N,N-diethylacetamide, N1,N1,N3,N3-tetrabutylmalonamide, 1-methylazacycloheptan-2-one, 1-allylazacycloheptan-2-one and tert-butyl 1,3-dihydroxy-2-(hydroxymethyl)propyl-2-ylcarbamate; ammonium salts, such as quaternary ammonium salts of sulfonates, aminosulfonates, carboxylates and phosphonates; imines, such as primary and secondary aldehyde imines and ketimines; diazines, such as optionally substituted pyrazines, piperazines and phenazines; diazoles, such as optionally substituted pyrazoles, thiadiazoles and imidazoles; and optionally substituted pyrrolidones, such as 2-pyrrolidone and cyclohexylpyrrolidine.

[0087] Photodegradable quenchers (PDQ) generate a relatively weak acid upon irradiation, which does not react rapidly with acid-indestructible groups in the photoresist composition. Exemplary photodegradable quenchers include, for example, photodegradable cations, and are preferably also used to prepare strong acid generators but not reacting with weak acids (e.g., like C). 1-20 Carboxylic acid or C 1-20 Those anionic pairs of 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.

[0088] In addition to the PAG of the present invention, the photoresist composition may also contain one or more photoacid generators. Such additional PAGs are typically non-polymeric, but may be polymeric, for example, present in repeating units of an acid-sensitive polymer or as part of a different polymer. Suitable PAG compounds include, for example, onium salts, such as triphenylsulfonium trifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, tri(p-tert-butoxyphenyl)sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate; di-tert-butylphenyliodomonium perfluorobutanesulfonate and di-tert-butylphenyliodomonium camphorsulfonate. 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-hydroxyimide compounds, such as N-hydroxysuccinimide methanesulfonate and N-hydroxysuccinimide trifluoromethanesulfonate; and halogenated triazine compounds, such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. Other suitable sulfonate PAGs include sulfonated esters and sulfonyloxy ketones, nitrobenzyl esters, s-triazine derivatives, benzoin toluenesulfonate, α-(p-toluenesulfonyloxy)-tert-butylphenyl acetate and α-(p-toluenesulfonyloxy)-tert-butyl acetate. Typically, these are onium salts, such as matte or iodonium salts. Such additional PAGs (if present) are present in amounts of 1 to 65 wt%, more typically 5 to 55 wt%, and even more typically 8 to 30 wt%, based on the total solids of the photoresist composition.

[0089] The photoresist composition may further comprise a material containing one or more base-indestructible groups (“base-indestructible material”). As mentioned herein, a base-indestructible group is a functional group that can undergo a cleavage reaction in the presence of an aqueous base developer after the exposure step and the post-exposure baking step to provide a polar group (such as hydroxyl, carboxylic acid, sulfonic acid, etc.). The base-indestructible group will not react significantly prior to the development step of the photoresist composition containing the base-indestructible group (e.g., will not undergo a 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 that ≤5%, preferably ≤1%, of the base-indestructible group (or portion) will decompose, cleave, or react during the pre-exposure soft baking step, the exposure step, and the post-exposure baking step. The base-indestructible group is reactive under typical photoresist development conditions using, for example, an aqueous base photoresist developer (such as an aqueous solution of 0.26 standard (N) tetramethylammonium hydroxide (TMAH)). For example, a 0.26N aqueous solution of TMAH can be used to develop a resist pattern using a single-immersion developing or dynamic developing process, whereby a 0.26N TMAH developer is dispensed onto the imaged photoresist layer for a suitable duration (e.g., 10 to 120 seconds). Exemplary base-insecure groups are ester groups, typically fluorinated ester groups. Preferably, the base-insecure material is substantially immiscible with the other solid components of the photoresist composition and has a lower surface energy than them. Thus, when coated onto a substrate, the base-insecure material can separate from the other solid components of the photoresist composition and reach the top surface of the formed photoresist layer.

[0090] Alkali-insecure materials are preferably polymeric materials (also referred to herein as alkali-insecure polymers) that may comprise 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.

[0091] Base-unstable polymers can be polymers comprising repeating units derived from monomers having the formula (E1):

[0092]

[0093] Where X b It is a polymerizable group selected from vinyl and acrylic acid, L 5 It is a divalent linker containing one or more of the following: substituted or unsubstituted straight-chain or branched C-chains. 1-20 Alkylene, substituted or unsubstituted C 3-20Cycloalkylene, -C(O)- or -C(O)O-; and R k Is it substituted or unsubstituted C? 1-20 Fluoroalkyl, provided that the carbon atom bonded to the carbonyl group (C=O) in formula (E1) is replaced by at least one fluorine atom.

[0094] The exemplary monomers of formula (E1) include the following:

[0095]

[0096] Base-instable polymers may include repeating units comprising two or more base-instable groups. For example, a base-instable polymer may contain repeating units derived from a monomer having the formula (E2):

[0097]

[0098] Where X b and R k It is as defined in equation (E1); L 6 It is a multivalent linker containing one or more of the following: substituted or unsubstituted straight-chain or branched C 1-20 Alkylene, substituted or unsubstituted C 3-20 Cycloalkylene, -C(O)- or -C(O)O-; and n represents an integer of 2 or greater, such as 2 or 3.

[0099] The exemplary monomers of formula (E2) include the following:

[0100]

[0101] Base-instable polymers may comprise repeating units including one or more base-instable groups. For example, base-instable polymers may comprise repeating units derived from monomers having the formula (E3):

[0102]

[0103] Where X b It is as defined in equation (E1); L 7 It is a divalent linker containing one or more of the following: substituted or unsubstituted straight-chain or branched C-chains. 1-20 Alkylene, substituted or unsubstituted C 3-20 Cycloalkylene, -C(O)- or -C(O)O-; L f Is it substituted or unsubstituted C? 1-20 Fluoride, wherein the carbon atom bonded to the carbonyl group (C=O) in formula (E1) is substituted with at least one fluorine atom; and R m It is a substituted or unsubstituted linear or branched C 1-20Alkyl, or substituted or unsubstituted C 3-20 Cycloalkyl.

[0104] The exemplary monomers of formula (E3) include the following:

[0105]

[0106] In another preferred aspect of the invention, the alkali-instable polymer may comprise one or more alkali-instable groups and one or more acid-instable groups, such as one or more acid-instable ester moieties (e.g., tert-butyl ester) or acid-instable acetal groups. For example, the alkali-instable polymer may comprise repeating units including alkali-instable and acid-instable groups, i.e., wherein both alkali-instable and acid-instable groups are present on the same repeating unit. In another example, the alkali-instable polymer may comprise a first repeating unit containing alkali-instable groups and a second repeating unit containing acid-instable groups. Preferred photoresists of the present invention can exhibit reduced defects associated with resist relief images formed from photoresist compositions. If present, the content of the alkali-instable polymer is typically 0.01 to 10 wt% based on the total solids of the photoresist composition.

[0107] 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. Furthermore or alternatively, suitable methods can be used to graft one or more base-instable groups onto the polymer backbone.

[0108] The photoresist composition may further include one or more additional optional additives. For example, optional additives may include photochemical dyes and contrast dyes, anti-stripping agents, plasticizers, accelerators, sensitizers, surfactants, etc., or combinations thereof. If present, the amount of each optional additive is typically from 0.01 to 10 wt% based on the total solids of the photoresist composition.

[0109] Exemplary surfactants include fluorinated and nonfluorinated surfactants and may 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 (3M Corporation); and fluorinated glycols such as POLYFOX PF-636, PF-6320, PF-656, and PF-6520 fluorinated surfactants (Omnova).

[0110] The photoresist composition further comprises 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, tert-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol, and diacetone alcohol (4-hydroxy-4-methyl-2-pentanone); propylene glycol monomethyl ether (PGME); ethers such as diethyl ether, tetrahydrofuran, 1,4-dioxane, and anisole; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, and cyclohexane. Ketones (CHO); esters, such as ethyl acetate, n-butyl acetate, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl hydroxyisobutyrate (HBM), and ethyl pyruvate; lactones, such as γ-butyrolactone (GBL) and ε-caprolactone; lactams, 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 typically 40 to 99 wt%, for example 70 to 99 wt%, or 85 to 99 wt%, based on the total solids of the photoresist composition. The desired solvent content will depend on, for example, the desired thickness of the photoresist layer and the coating conditions.

[0111] Photoresist compositions can be prepared according to known procedures. For example, a composition can be prepared by dissolving the solid components of a photoresist composition in a solvent. The photoresist composition or one or more components of the composition may optionally undergo one or more purification processes, such as filtration and / or ion exchange. The desired total solids content of the composition will depend on factors such as the desired final layer thickness. Based on the total weight of the composition, the solids content of the photoresist composition is typically 1 to 10 wt%, more preferably 1 to 5 wt%.

[0112] Pattern Formation Method

[0113] The following describes a patterning method using the photoresist composition of the present invention. 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 optionally include active or operable portions of the formed device.

[0114] 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, or combinations thereof, are provided on the upper surface of the substrate. These layers, together with the externally coated photoresist layer, form a photolithographic material stack.

[0115] Optionally, an adhesion promoter layer may 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 may 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.

[0116] 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 a 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 a speed 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 200 nanometers (nm), preferably 15 to 100 nm, and more preferably 20 to 60 nm.

[0117] 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 typically performed, for example, on a heated plate or in an oven, with a 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 heating time based on the composition's components.

[0118] Next, the photoresist layer is patterned and exposed to activating radiation to create a solubility difference between the exposed and unexposed areas. 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 photoresist layer to be unexposed, respectively. Alternatively, this exposure can be performed without a photomask in a direct-write method, typically used in electron beam lithography. The activating radiation typically has wavelengths sub-400 nm, sub-300 nm, or sub-200 nm, with preferred wavelengths being 248 nm (KrF), 193 nm (ArF), and 13.5 nm (Extreme Ultraviolet, EUV) or 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). 2 Preferably 10 to 100 mJ / cm 2 And more preferably 20 to 50 mJ / cm 2This depends on the composition of the exposed tool and the photoresist composition. In some respects, the activation radiation is EUV at a wavelength of 13.5 nm.

[0119] After the photoresist layer is exposed, post-exposure baking (PEB) of the exposed photoresist layer is performed. PEB can be performed, for example, on a heated plate or in an oven, with a 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 non-polarity-converted regions (unexposed regions).

[0120] The exposed photoresist layer is then developed with a suitable developer to selectively remove areas of the layer that are soluble in the developer while retaining insoluble areas, 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.

[0121] 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.

[0122] The coated substrate can be formed from the photoresist composition of the present invention. Such a coated substrate comprises: (a) a substrate having one or more layers on its surface; and (b) a layer of photoresist composition on the one or more layers.

[0123] Photoresist patterns can be used, for example, as an etch mask to transfer the pattern 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 a pattern to an underlying hard mask layer, which in turn serves as an etch mask for transferring the pattern 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 or wet stripping processes. 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.

[0124] The following non-limiting examples illustrate the present invention.

[0125] Example

[0126] PAG synthesis

[0127] Example 1

[0128] PAG A1 was prepared according to Scheme 1 as described below:

[0129]

[0130] Chloroacetyl chloride (46.0 g, 0.40 mol) was added dropwise to a stirred solution of (±)-1-phenylethanol (compound 1, 50 g, 0.40 mol) and 1,8-diazabicycloundec-7-ene (DBU, 63 g, 0.40 mol) in dichloromethane (300 mL). The mixture was heated to room temperature and stirred for 8 hours. The organic phase was washed with saturated ammonium chloride aqueous solution (2 × 250 mL) and then with water (2 × 250 mL). The solvent was removed from the organic phase to produce a crude product. The crude product was dissolved in 20 mL of heptane and passed through a short silica gel stopper (heptane was initially used as the eluent). Fractions containing the product were combined and heptane was completely removed under reduced pressure to produce a pure product, 1-phenylethyl 2-chloroacetate (2), as a colorless liquid. Yield: 35 g (43%). 1 H NMR (acetone-d6), δ (ppm): 7.75 (d, 2H, ArH), 7.44-3, 31 (m, 5H, ArH), 5.94 (q, 1H, Ar-CH), 1.56 (d, 3H, CH3).

[0131] Under a nitrogen atmosphere, N,N-dimethylformamide (150 mL), compound 2 (20 g, 100 mmol), and (4-hydroxyphenyl)diphenylsulfonium iodide (compound 3, 25 g, 61.3 mmol) were placed in an oven-dried flask. The resulting solution was heated to 50 °C and cesium carbonate (25 g, 129.6 mmol) was added in a single batch. The reaction mixture was stirred at the same temperature for 36 hours and then cooled to room temperature. The mixture was filtered to remove insoluble salts and the solvent in the filtrate was removed under reduced pressure. The remaining residue was dissolved in dichloromethane (150 mL) and washed with water (3 × 150 mL). Dichloromethane was removed under reduced pressure, and the resulting residue was dissolved in 50 mL of acetone and poured into 500 mL of methyl tert-butyl ether to produce salt product 4, which was collected and dried under vacuum at 35 °C for 24 hours. Yield: 32.0 g (91%). 1 H NMR (acetone-d6), δ (ppm): 8.20 (d, 2H, ArH), 7.98 (d, 4H, ArH), 7.88 (m, 2H, ArH), 7.83 (m, 4H, ArH), 7.41-7.29 (m, 7H, ArH), 5.96 (q, 1H, Ar-CH), 5.06 (s, 2H, OCH2), 1.56 (d, 3H, CH3).

[0132] 100 mL of water and 100 mL of dichloromethane were added to a mixture of salt 4 (10 g, 17.58 mmol) and salt C1 (8.5 g, 19.93 mmol). The resulting mixture was stirred at room temperature for 16 hours. The organic phase was separated, and each time the mixture was washed five times with 100 mL of deionized water. The solvent was completely removed from the organic phase under reduced pressure to produce a waxy crude product. The crude product was dissolved in 50 mL of acetone and poured into 500 mL of methyl tert-butyl ether. A waxy solid of PAG A1 was obtained, which was separated by solvent decantation and dried under reduced pressure at 35 °C. Yield: 7.5 g (38%). 1¹H NMR (acetone-d6), δ (ppm): 7.94 (m, 8H, ArH), 7.84 (m, 4H, ArH), 7.39 (m, 6H, ArH), 7.35 (m, 1H, ArH), 6.08 (q, 1H, Ar-CH), 5.10 (s, 2H, OCH₂), 4.33 (q, 2H, OCH₂), 2.77 (M, 2H, CH₂CF₂), 1.95–1.5 (¹⁴H, adamantane proton). ¹⁹F NMR δ (ppm): -112.30 (²F, CF₂SO₃), -119.40 (²F, CH₂CF₂). The purity of the PAG sample was analyzed by LC-MS. For example, the purity of the cation was determined to be >96.0% by UV detection at 232 nm, and the purity was >98% by positive ion mass spectrometry. Similarly, the purity of the anion was determined to be >98% by negative ion LC-MS measurement.

[0133] Example 2

[0134] PAG A2 was prepared according to Scheme 2 as described below:

[0135]

[0136] Add 100 mL of water and 100 mL of dichloromethane to a mixture of salt 4 (10 g, 17.58 mmol) (prepared as described in Example 1) and salt C2 (7.76 g, 18.27 mmol). Stir the resulting mixture at room temperature for 16 hours. Separate the organic phase, washing five times each time with 100 mL of deionized water. Completely remove the solvent from the organic phase under reduced pressure to produce a waxy crude product. Dissolve the crude product in 50 mL of acetone and pour into 500 mL of heptane. Collect product PAG A2 and dry it at 35 °C under reduced pressure. Yield: 7.5 g (55.7%). The purity of the PAG sample was analyzed by LC-MS. The purity of the cation was determined to be >98.0% by UV detection at 232 nm, and the purity was >98% by positive ion mass spectrometry. The purity of the anion was >98% by negative ion LC-MS. 19F NMR δ (ppm) = -110.2 (s, 2F).

[0137] Example 3

[0138] PAG A3 was prepared according to Scheme 3 as described below:

[0139]

[0140] 100 mL of water and 100 mL of dichloromethane were added to a mixture of salt 4 (10 g, 17.58 mmol) (prepared as described in Example 1) and salt C3 (6.10 g, 18.41 mmol). The resulting mixture was stirred at room temperature for 24 hours. The organic phase was separated, and the mixture was washed five times with 100 mL of deionized water each time. The solvent was completely removed from the organic phase under reduced pressure to produce a waxy crude product. The crude product was dissolved in 50 mL of acetone and poured into 500 mL of heptane. The product was separated by solvent decantation to obtain an oily product. The product PAG A3 was further dried under reduced pressure at 35 °C. Yield: 8.7 g (67.4%). 1 ¹H NMR (acetone-d6), δ (ppm): 7.94 (m, 8H, ArH), 7.84 (m, 4H, ArH), 7.39 (m, 6H, ArH), 7.35 (m, 1H, ArH), 6.08 (q, 1H, Ar-CH), 5.10 (s, 2H, OCH₂). The purity of the PAG samples was analyzed by LC-MS. The purity of the cations was determined to be >98.0% by UV detection at 232 nm, and >98% by positive ion mass spectrometry. The purity of the anions was >98% by negative ion LC-MS.

[0141] Example 4

[0142] PAG A4 was prepared according to Scheme 4 as described below:

[0143]

[0144] The procedure used to synthesize compound 2 in Example 1, starting with (±)-1-(4-methylphenyl)ethanol (5) and chloroacetyl chloride, was used to prepare compound 6. Under a nitrogen atmosphere, N,N-dimethylformamide (150 mL), compound 6 (25 g, 117.55 mmol), and (4-hydroxyphenyl)diphenylsulfonium chloride (compound 3, 20.0 g, 49.2 mmol) were placed in an oven-dried flask. The resulting solution was heated to 50 °C and cesium carbonate (25 g, 129.6 mmol) was added in a single addition. The reaction mixture was stirred at the same temperature for 36 hours and then cooled to room temperature. The mixture was filtered to remove insoluble salts and the filtrate solvent was removed under reduced pressure. The remaining residue was dissolved in dichloromethane (150 mL) and washed with water (3 × 150 mL). Dichloromethane was removed under reduced pressure, and the resulting residue was dissolved in 50 mL of acetone and poured into 500 mL of methyl tert-butyl ether to produce salt product 7. This product was collected and dried under vacuum at 35 °C for 24 hours. Yield: 21.5 g (75%). 1H NMR (acetone-d6), δ (ppm): 8.03 (d, 2H, ArH), 7.92 (d, 4H, ArH), 7.88 (m, 2H, ArH), 7.83 (m, 4H, ArH), 7. 41-7.29 (7H, ArH), 5.93 (q, 1H, Ar-CH), 5.03 (s, 2H, OCH2), 2.30 (s, 3H, ArCH3), 1.52 (d, 3H, CH3).

[0145] Add 75 mL of water and 75 mL of dichloromethane to a mixture of salt 7 (10 g, 171.6 mmol) and salt C1 (11.0 g, 25.80 mmol). Stir the resulting mixture at room temperature for 24 hours. Separate the organic phase, washing five times with 100 mL of deionized water each time. Completely remove the solvent from the organic phase under reduced pressure to produce a waxy crude product. Dissolve the crude product in 50 mL of acetone and pour it into 500 mL of heptane. Collect the resulting PAG A4 and dry it under reduced pressure at 35 °C. Yield: 13.5 g (67%). 1 ¹H NMR (acetone-d6), δ (ppm): 7.95-7.89 (8H, ArH), 7.85-7.81 (4H, ArH), 7.37 (d, 2H, ArH), 7.27 (d, 2H, ArH), 7.16 (d, 2H, ArH), 5.92 (q, 1H, Ar-CH), 5.05 (s, 2H, OCH2), 4.33 (q, 2H, OCH2), 2.77 (m, 2H, CH2CF2), 1.95-1.50 (14H, adamantane proton), 1.55 (d, 3H, CH3). ¹⁹F NMR δ (ppm): -112.26 (2F, CF2SO3), -119.37 (2F, CH2CF2).

[0146] Example 5

[0147] PAG A5 was prepared according to Scheme 5 as described below:

[0148]

[0149] Add 75 mL of water and 75 mL of dichloromethane to a mixture of salt 7 (10 g, 17.16 mmol) and salt C4 (11.0 g, 26.3 mmol). Stir the resulting mixture at room temperature for 24 hours. Separate the organic phase, washing five times with 100 mL of deionized water each time. Completely remove the solvent from the organic phase under reduced pressure to produce a waxy crude product. Dissolve the crude product in 50 mL of acetone and pour it into 500 mL of heptane. Collect the resulting PAG A5 and dry it at 35 °C under reduced pressure. Yield: 11.6 g (78%). 1¹H NMR (acetone-d6), δ (ppm): 7.95-7.82 (¹²H, ArH), 7.37 (d, 2H, ArH), 7.27 (d, 2H, ArH), 7.18 (d, 2H, ArH), 5.97 (q, ¹H, Ar-CH), 5.02 (s, 2H, OCH₂), 1.55 (d, 3H, CH₃). ¹⁹F NMR δ (ppm): -77.45 (9F, 3CF₃). The purity of the PAG sample was analyzed by LC-MS. The purity of the cation was determined to be >98.0% by UV detection at 232 nm, and >98% by positive ion mass spectrometry. The purity of the anion was >98% by negative ion LC-MS.

[0150] Example 6

[0151] PAG A6 was prepared according to Scheme 6 as described below:

[0152]

[0153] The procedure used to synthesize compound 2, starting with (±)-1-(4-biphenyl)ethanol (8) and chloroacetyl chloride, was used to prepare compound 9. Under a nitrogen atmosphere, N,N-dimethylformamide (150 mL), compound 9 (20.0 g, 72.79 mmol), and (4-hydroxyphenyl)diphenylsulfonium chloride (compound 3, 29.5 g, 72.6 mmol) were placed in an oven-dried flask. The resulting solution was heated to 50 °C and cesium carbonate (20 g, 103.7 mmol) was added in a single addition. The reaction mixture was stirred at the same temperature for 24 hours and then cooled to room temperature. The mixture was filtered to remove insoluble salts, and the filtrate solvent was removed under reduced pressure. The remaining residue was dissolved in dichloromethane (150 mL) and washed with water (3 × 150 mL). Dichloromethane was removed under reduced pressure, and the resulting residue was dissolved in 50 mL of acetone and poured into 1 L of methyl tert-butyl ether to produce salt product 10. This product was collected and dried under vacuum at 35 °C for 24 hours. Yield: 28.5 g (61%). 75 mL of water and 75 mL of dichloromethane were added to a mixture of salt 10 (15.0 g, 23.27 mmol) and salt C1 (11.0 g, 25.8 mmol). The resulting mixture was stirred at room temperature for 24 hours. The organic phase was separated and washed five times each with 100 mL of deionized water. The solvent was completely removed from the organic phase under reduced pressure to produce a waxy crude product. The crude product was dissolved in 50 mL of acetone and poured into 500 mL of heptane. The resulting PAG A6 was collected and dried under reduced pressure at 35 °C. Yield: 18.9 g (88%). 1¹H NMR (acetone-d6), δ (ppm): 7.94–7.79 (¹²H, ArH), 7.65 (⁴H, ArH), 7.48 (⁴H, ArH), 7.40 (⁻³H, ArH), 6.10 (q, ¹H, Ar-CH), 5.08 (s, 2H, OCH₂), 4.33 (q, 2H, OCH₂), 2.69 (m, 2H, CH₂CF₂), 1.80–1.57 (¹⁴H, adamantane proton), 1.59 (d, 3H, CH₃). ¹⁹F NMR δ (ppm): -112.35 (²F, CF₂SO₃), -119.43 (²F, CH₂CF₂).

[0154] Example 7

[0155] PAG A7 was prepared according to Scheme 7 as described below:

[0156]

[0157] The procedure used to synthesize compound 2, starting with (±)-1-(4-iodophenyl)ethanol and chloroacetyl chloride, was used to prepare compound 11. Under a nitrogen atmosphere, N,N-dimethylformamide (100 mL), compound 11 (9.0 g, 27.73 mmol), and (4-hydroxyphenyl)diphenylsulfonium chloride (compound 3, 9.0 g, 22.15 mmol) were placed in an oven-dried flask. The resulting solution was heated to 50 °C and cesium carbonate (20 g, 103.7 mmol) was added in a single addition. The reaction mixture was stirred at the same temperature for 24 hours and then cooled to room temperature. The mixture was filtered to remove insoluble salts, and the solvent in the filtrate was removed under reduced pressure. The remaining residue was dissolved in 50 mL of acetone and poured into 500 mL of methyl tert-butyl ether to produce salt product 12, which was collected and dried under vacuum at 35 °C for 24 hours. Yield: 15.5 g. Add 75 mL of water and 75 mL of dichloromethane to a mixture of salt 12 (8.0 g, 11.5 mmol) and salt C1 (5.2 g, 12.2 mmol). Stir the resulting mixture at room temperature for 24 hours. Separate the organic phase, washing five times with 100 mL of deionized water each time. Completely remove the solvent from the organic phase under reduced pressure to produce a waxy crude product. Dissolve the crude product in 50 mL of acetone and pour into 500 mL of heptane. Collect the resulting PAGA7 and dry it at 35 °C under reduced pressure. Yield: 7.9 g (70%). 1¹H NMR (acetone-d6), δ (ppm): 7.92–7.80 (8H, ArH), 7.81–7.78 (4H, ArH), 7.37 (d, 2H, ArH), 7.27 (d, 2H, ArH), 7.16 (d, 2H, ArH), 5.98 (q, 1H, Ar-CH), 5.10 (s, 2H, OCH₂), 4.34 (q, 2H, OCH₂), 2.79 (m, 2H, CH₂CF₂), 1.95–1.50 (14H, adamantane proton), 1.55 (d, 3H, CH₃). ¹⁹F NMR δ (ppm): -112.26 (2F, CF₂SO₃), -119.37 (2F, CH₂CF₂).

[0158] Example 8

[0159] PAG A8 was prepared according to Scheme 8 as described below:

[0160]

[0161] The procedure used to synthesize compound 2 in Example 1, starting with 1-(benzo[b]thiophen-2-yl)ethyl-1-ol (14) and chloroacetyl chloride, was used to prepare compound 15. Under a nitrogen atmosphere, N,N-dimethylformamide (150 mL), compound 15 (8.0 g, 31.4 mmol), and (4-hydroxyphenyl)diphenylsulfonium chloride (compound 3, 8.5 g, 21 mmol) were placed in an oven-dried flask. The resulting solution was heated to 50 °C and cesium carbonate (7.0 g, 36 mmol) was added in a single batch. The reaction mixture was stirred at the same temperature for 36 hours and then cooled to room temperature. The mixture was filtered to remove insoluble salts and the solvent in the filtrate was removed under reduced pressure. The remaining residue was dissolved in 50 mL of acetone and poured into 500 mL of methyl tert-butyl ether to produce salt product 16, which was collected and dried under vacuum at 35 °C for 24 hours. Yield: 8.5 g. Add 75 mL of water and 75 mL of dichloromethane to a mixture of salt 16 (8.0 g, 12.8 mmol) and salt C1 (5.5 g, 12.9 mmol). Stir the resulting mixture at room temperature for 24 hours. Separate the organic phase, washing five times with 100 mL of deionized water each time. Completely remove the solvent from the organic phase under reduced pressure to produce a waxy crude product. Dissolve the crude product in 50 mL of acetone and pour it into 500 mL of heptane. Collect the resulting PAG A8 and dry it under reduced pressure at 35 °C. Yield: 6.9 g (60%). 1¹H NMR (acetone-d6), δ (ppm): 7.96–7.76 (¹²H, ArH), 7.40–7.30 (⁶H, ArH), 6.36 (q, ¹H, Ar-CH), 5.07 (s, 2H, OCH₂), 4.30 (q, 2H, OCH₂), 2.69 (m, 2H, CH₂CF₂), 1.95–1.50 (¹⁴H, adamantane proton), 1.55 (d, 3H, CH₃). ¹⁹F NMR δ (ppm): -112.4 (²F, CF₂SO₃), -119.68 (²F, CH₂CF₂).

[0162] Example 9

[0163] PAG A9 was prepared according to Scheme 9 as described below:

[0164]

[0165] Under a nitrogen atmosphere, N,N-dimethylformamide (250 mL), 1-phenylethyl 2-chloroacetate (compound 2, 25 g, 125.8 mmol), and 5-(4-hydroxy-3,5-dimethylphenyl)-5H-dibenzo[b,d]thiophenonium bromide (compound 17, 38.5 g, 100 mmol) were placed in an oven-dried flask. The resulting solution was heated to 50 °C and cesium carbonate (25.0 g, 130.0 mmol) was added in a single batch. The reaction mixture was stirred at the same temperature for 36 hours and then cooled to room temperature. The mixture was filtered to remove insoluble salts and the solvent in the filtrate was removed under reduced pressure. Most of the N,N-dimethylformamide was removed by vacuum distillation, and the resulting residue was poured into a saturated aqueous solution of ammonium chloride. The resulting solid was filtered, air-dried, dissolved in dichloromethane (50 mL), and poured into 500 mL of methyl tert-butyl ether (MTBE). The resulting residue was suspended in acetone (100 mL) to form a white solid, salt product 18, which was filtered and dried, yielding 22.5 g. 100 mL of water and 100 mL of dichloromethane were added to a mixture of salt 18 (10.0 g, 18.20 mmol) and salt C1 (7.9 g, 18.52 mmol). The resulting mixture was stirred at room temperature for 24 hours. The organic phase was separated, washed five times each with 50 mL of deionized water. The solvent was completely removed from the organic phase under reduced pressure to produce a waxy crude product. The crude product was dissolved in 50 mL of acetone and poured into 500 mL of heptane. The resulting PAG A9 was collected and dried at 35 °C under reduced pressure. Yield: 12.8 g (75%). 1¹H NMR (acetone-d6), δ (ppm): 8.53 (d, 2H, ArH), 8.37 (d, 2H, ArH), 8.03 (t, 2H, ArH), 7.83 (t, 2H, ArH), 7.52 (s, 2H, ArH), 7.41–7.30 (m, 6H, ArH), 6.0 (q, 1H, Ar-CH), 4.62 (s, 2H, OCH2), 4.33 (q, 2H, OCH2), 2.69 (m, 2H, CH2CF2), 2.30 (6H, 2CH3), 1.95–1.50 (14H, adamantane proton), 1.55 (d, 3H, CH3). 19F NMRδ (ppm): -112.2 (2F, CF2SO3), -119.54 (2F, CH2CF2).

[0166] Example 10

[0167] PAG A10 was prepared according to Scheme 10 as described below:

[0168]

[0169] Starting with salts C4 and 18, the procedure used to synthesize PAG A9 was used to prepare PAG A10. 1 H NMR (acetone-d6), δ (ppm): 8.53 (d, 2H, ArH), 8.33 (d, 2H, ArH), 8.04 (t, 2H, ArH), 7.88 (t, 2H, ArH), 7.50 (s, 2 H, ArH), 7.43-7.30 (m, 6H, ArH), 5.99 (q, 1H, Ar-CH), 4.71 (s, 2H, OCH2), 2.29 (6H, 2CH3), 55 (d, 3H, CH3). 19F NMR δ (ppm): -77.45 (9F, 3CF3).

[0170] Photoresist composition and photolithography evaluation

[0171] The photoresist composition was prepared, photolithographically processed, and evaluated as follows:

[0172]

[0173] Example 11-21

[0174] Photoresist compositions were prepared by dissolving the solid components in a solvent to achieve a total solids content of 1.5 wt% using the materials and proportions described in Table 1. The resulting mixture was vibrated on a mechanical vibrator and subsequently filtered through a PTFE disc filter with a pore size of 0.2 μm. The corresponding photoresist compositions were spin-coated onto each BARC stack (60 nm thick AR) on a TEL Clean Track ACT 8 wafer track. TM 3 Antireflective agents in 80nm thick AR TM A 200mm silicon wafer was coated with 40A antireflective agent (DuPont Electronics & Imaging) and baked at 110°C for 60 seconds to provide a photoresist layer with a target thickness of approximately 40nm. The photoresist layer thickness was measured using a THERMA-WAVE OP7350. The photoresist layer thickness was measured using a Canon FPA-5000 ES4 scanner with 248nm radiation at 3 to 53 mJ / cm². 2 The wafer is exposed to a specific exposure dose. After exposure at 100°C, the wafer is baked for 60 seconds, and then exposed using MF (Medium Fat). TM Develop with CD26 TMAH developer (DuPont Electronics & Imaging) for 60 seconds, rinse with deionized water, and dry. Photoresist layer thickness was measured in both exposed and unexposed areas of the layer. A contrast profile was generated for each wafer by plotting the remaining photoresist layer thickness in the exposed areas against the exposure dose. The dose-to-clear (E0) was determined from the contrast profile as the exposure dose at which the remaining photoresist layer thickness was less than 10% of the initial coating thickness. Unexposed film thickness loss (UFTL) was determined based on the photoresist layer thickness measurements in the unexposed areas. The results are shown in Table 1.

[0175] Table 1

[0176]

[0177] The amount of solid components is provided as wt% of total solids; S1 = propylene glycol monomethyl ether acetate; S2 = methyl 2-hydroxyisobutyrate; *The S1 / S2 solvent blend is 1:1 (wt / wt); Comp = comparative example.

[0178] Example 22-29

[0179] Photoresist compositions were prepared by dissolving the solid components in a solvent to achieve a total solids content of 1.5 wt% using the materials and proportions described in Table 2. The resulting mixture was vibrated on a mechanical vibrator and subsequently filtered through a PTFE disc filter with a pore size of 0.2 μm. The corresponding photoresist compositions were spin-coated onto each BARC stack (60 nm thick AR) on a TEL Clean Track ACT 8 wafer track. TM3 Antireflective agents in 80nm thick AR TM A 200mm silicon wafer was coated with 40A antireflective agent (DuPont Electronics & Imaging) and baked at 110°C for 60 seconds to provide a photoresist layer with a target thickness of approximately 40nm. The photoresist layer thickness was measured using a THERMA-WAVE OP7350. The photoresist layer thickness was measured using a Canon FPA-5000 ES4 scanner with 248nm radiation at 3 to 53 mJ / cm². 2 The wafer is exposed to a specific exposure dose. After exposure at 100°C, the wafer is baked for 60 seconds, and then exposed using MF (Medium Fat). TM Develop with CD26 TMAH developer (DuPont Electronics & Imaging) for 60 seconds, rinse with deionized water, and dry. Photoresist layer thickness was measured in the exposed areas of the layer. A contrast profile was generated for each wafer, and E0 was determined from the contrast profile as described above. An additional contrast profile was generated for each wafer by plotting the logarithm of the normalized photoresist layer thickness contrast dose in the exposed areas. The contrast (γ) was determined from this normalized contrast profile as the slope between the 80% and 20% photoresist film thickness points. The results are shown in Table 2.

[0180] Table 2

[0181]

[0182] The amount of solid components is provided as wt% of total solids; S1 = propylene glycol monomethyl ether acetate; S2 = methyl 2-hydroxyisobutyrate; *The S1 / S2 solvent blend is 1:1 (w / w); Comp = comparative example.

[0183] Examples 30-34

[0184] Photoresist compositions were prepared by dissolving the solid components in a solvent to achieve a total solids content of 4.3 wt% using the materials and proportions described in Table 3. The resulting mixture was vibrated on a mechanical vibrator and subsequently filtered through a PTFE disc filter with a pore size of 0.2 micrometers. The corresponding photoresist compositions were spin-coated onto each BARC stack (60 nm thick AR) on a TEL Clean Track ACT 8 wafer track. TM 3 Antireflective agents in 80nm thick AR TMA 200mm silicon wafer was coated with 40A antireflective agent (DuPont Electronics & Imaging Corporation) and baked at 110°C for 60 seconds to provide a 120nm thick photoresist layer. Each wafer was exposed to 248nm radiation using a mask with a 1:1 contact hole pattern of 200nm diameter / 400nm spacing on a Canon FPA-5000 ES4 scanner (NA=0.8, outer sigma=0.85, inner sigma=0.57). After exposure at 100°C, the wafer was baked for 60 seconds and then photographed using MF. TM Develop with CD26 TMAH developer (DuPont Electronics & Imaging) for 60 seconds, rinse with deionized water, and dry. The critical dimension (CD) of the formed contact hole pattern was measured using a Hitachi S-9380CD SEM. The sizing energy (E) was determined based on the CD measurements. 尺寸 Exposure latitude (EL) and CD consistency (3σ) (CDU) are also considered. Size energy is the radiant energy required to resolve a target 200 nm diameter / 400 nm pitch contact hole pattern. Exposure latitude is the difference in exposure energy required to print contact holes at ±10% of the target diameter, normalized by size energy. The results are shown in Table 3.

[0185] Table 3

[0186]

[0187] The amount of solid components is provided as wt% of total solids; S1 = propylene glycol monomethyl ether acetate; S2 = methyl 2-hydroxyisobutyrate; *The S1 / S2 solvent blend is 1:1 (w / w); Comp = comparative example.

[0188] Examples 35-36

[0189] A photoresist composition was prepared by dissolving the solid components in a solvent to achieve a total solids content of 1.55 wt% using the materials and proportions described in Table 4. The resulting mixture was vibrated on a mechanical vibrator and subsequently filtered through a PTFE disc filter with a pore size of 0.2 micrometers. The outer coating of approximately... A 200mm silicon wafer with a thick organic BARC layer was cut into samples. Each sample was spin-coated with a suitable photoresist composition and soft-baked at 110°C for 90 seconds to provide a 40nm thick photoresist layer. The photoresist-coated samples were exposed to electron beam radiation using a JEOL Ltd. JBX-9500FS electron beam lithography system to print a 1:1 contact hole pattern with a diameter of 35nm and a spacing of 70nm. After exposure at 90°C, the samples were baked for 60 seconds and then lithographically processed using MF. TMDevelop with CD26 TMAH developer (DuPont Electronics & Imaging) for 45 seconds, rinse with deionized water, and dry. Images were acquired and the printed pattern analyzed using a Hitachi S-9380CD SEM. Based on the SEM images, the contact hole pattern's CD was measured using Fralilia MetroLER metrology software. The sizing energy (E) was determined based on this measurement. 尺寸 The 3σ (CDU) consistency of the CD (35 nm diameter contact hole pattern) was used to determine the size energy. The CDU was determined based on the CD of the 35 contact holes. The results are shown in Table 4.

[0190] Table 4

[0191]

[0192] The amount of solid components is provided as wt% of total solids; S1 = propylene glycol monomethyl ether acetate; S2 = methyl 2-hydroxyisobutyrate; *The S1 / S2 solvent blend is 1:1 (w / w); Comp = comparative example.

Claims

1. A photoacid generator represented by formula (2-1): (2-1) in: Ar 1 Independently represents substituted or unsubstituted aryl groups; R 1 Independently representing alkyl or aryl, each of which may be substituted or unsubstituted, wherein Ar 1 and R 1 Optionally linked together by single bonds or divalent connecting groups to form a ring; Y independently represents a single bond or -CH2-O- ,and It is connected to Ar 2 The point; Ar 2 Independently represents a substituted or unsubstituted aryl group; X is S or I; R 2 Independently representing substituted or unsubstituted alkyl or aryl groups; Z - It is a counter anion; a is 1 to Ar 2 The integers of the total number of carbon atoms can be used; when X is S, b is 1, 2, or 3 and c is 3; and when X is I, b is 1 or 2 and c is 2; where (i) two R 2 Group or (ii) an Ar 2 Group and an R 2 The groups are optionally linked together to form a ring via single bonds or divalent linkages.

2. The photoacid generator as described in claim 1, wherein, X is S.

3. The photoacid generator as described in claim 1, wherein, X is I.

4. The photoacid generator as described in claim 1, wherein, Ar 1 It is a substituted aryl group.

5. The photoacid generator as described in claim 1, wherein, The photoacid generator is in polymer form.

6. A photoresist composition comprising a photoacid generator as described in any one of claims 1 to 5 and a solvent.

7. The photoresist composition of claim 6, wherein, The photoresist composition comprises an acid-sensitive polymer.

8. A method for forming a pattern, comprising: (a) A photoresist layer is formed on a substrate using the photoresist composition as described in claim 6 or 7; (b) Exposing the photoresist layer to activation radiation; and (c) Develop the exposed photoresist layer to provide a photoresist relief image.

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