An ammonia contamination inhibiting additive for thick film photoresist and a method of preparing the same

Abstract

The application discloses an ammonia pollution inhibiting additive for thick film photoresist and a preparation method thereof, and further provides a photoresist composition, a preparation method and application thereof. The raw material of the photoresist composition comprises a random copolymer, a photoacid generator, a photosensitive polymer and an organic solvent. The random copolymer is a random copolymer with a weight average molecular weight of 1000-50000 and composed of structural units represented by general formula Ia, Ib and Ic, wherein the molar percentage of the structural units Ia, Ib and Ic is 0≤Ia<90%, 0≤Ib<90% and 0<Ic<50%. The photoresist composition provided by the application can prevent the problem of distortion of photoetching patterns caused by ammonia and amine pollution in the atmosphere in I-line and KrF photoetching processes.

Description

TECHNICAL FIELD

[0001] The present invention relates to an ammonia contamination inhibiting additive for thick film photoresist and a method for preparing the same. BACKGROUND

[0002] With the recent high integration and high speed of large scale integrated circuits, the patterns of photoresist are required to be more and more fine. The photoresist mainly uses i-line (365 nm), KrF (248 nm) and ArF (193 nm) as light sources when the patterns are exposed. The recent semiconductor chips can be roughly classified into storage type and non-storage type, and the storage type can be further classified into dram and nand flash. The representative non-storage type chip is logic. The integrated circuits are developing toward the technology of storing more and more information in smaller space, and thus the fine patterning that the photoresist technology can achieve is also increasing. In addition, with the recent advent of ArF immersion technology, various fine patterning technologies such as double patterning and quadruple patterning are applied to the dram; and in the nand flash, in order to store more capacity of information, the 3D nand flash based on the 3-dimensional build-up technology is emerging on the basis of the existing 2-dimensional planar design.

[0003] With the technology of increasingly requiring the carrying capacity and high information, the 3D nand flash is required to satisfy the higher build-up technology. In order to achieve the design technology, the I-line and KrF PR of the CAR type, which has already emerged and is mature in technology, is newly required, thereby having a new market and more demand. However, the I-line PR here is not the PAC type using the existing Novolac resin, but is the material using the same CAR type PAG as KrF and ArF, and the thickness of the photoresist used in the 3D NAND Flash is basically in the range of 1 um ~ 15 um. Thus, the demand for the newly emerging I-line and KrF PR requires the photoresist technology and high level quality management capable of satisfying the new function and role in the 3D NAND FLUSH design on the basis of the existing mature technology.

[0004] Therefore, in order to prevent the distortion of the photoresist pattern due to the contamination of ammonia and amine in the atmosphere, thereby not guaranteeing the higher level of the CAR type I-line and KrF PR quality, a high molecular additive for I-line and KrF PR needs to be developed. SUMMARY

[0005] The present application provides an ammonia contamination inhibiting additive for thick film photoresist and a preparation method thereof.

[0006] The ammonia contamination inhibiting additive and the photoresist composition provided by the present application, when used in photoresist to form a photoresist film, the ammonia contamination inhibiting additive moves to the upper part of the photoresist film and thus plays a barrier role of preventing air from contacting the PR surface. When the photoresist is in a pattern process, acid diffusion occurs due to the surface of the photoresist being exposed to light. Therefore, adding the ammonia contamination inhibiting additive of the present application or using the photoresist composition provided by the present application can prevent the pattern from being distorted due to the reaction between the acid generated on the PR surface and ammonia in the air.

[0007] In a first aspect, the present application provides a random copolymer with a weight average molecular weight of 1000-50000, which is composed of structural units represented by general formulae Ia, Ib and Ic, characterized in that,

[0008]

[0009] wherein the molar percentage of the above-mentioned structural units Ia, Ib and Ic in the total moles of the three is: 0≤Ia<90%, 0≤Ib<90%, 0<Ic<50%;

[0010] R1 and R2 are each independently H, C 3-10 cycloalkyl, C 1-20 alkyl or C 1-20 alkyl-C(O)-, said C 1-20 alkyl, C 1-20 alkyl-C(O)- and C 3-10 cycloalkyl is optionally substituted by one or more R 1-1 each R 1-1 is independently halogen or C 1-4 alkyl;

[0011] and at least one of R1 and R2 contains halogen;

[0012] R3 is H or C 1-20 alkyl.

[0013] In some embodiments, the weight average molecular weight of the random copolymer can be 8500-12000, for example, 9500-11000.

[0014] In some embodiments, the value of the molecular weight distribution of the random copolymer can be 1.62-1.73, for example, 1.62, 1.65, 1.69, 1.72 or 1.73.

[0015] In some embodiments, the mole percent of structural units la, lb and Ic in the random copolymer, based on the total moles of the three, is 0 < la < 75%, 0 < lb < 20%, 0 < Ic < 25%; preferably 60% < la < 75%, 0 < lb < 20%, 20% < Ic < 25%; for example la: 60%, lb: 20%, Ic: 20%; or, la: 75%, lb: 0%, Ic: 25%.

[0016] Preferably, R1 is halo-substituted C 1-20 alkyl-C(O)-.

[0017] Preferably, R1 is More preferably, R1 is

[0018] Preferably, R2 is C 1-20 alkyl, C 3-10 cycloalkyl, C 1-4 alkyl-substituted C 3-10 cycloalkyl (e.g., ethyl-substituted cyclopentyl, for example ), or wherein R4 is halo or C 1-9 alkyl substituted with one or more halogens.

[0019] Preferably, R4 is fluoro or trifluoromethyl.

[0020] Preferably, R2 is t-butyl,

[0021] Preferably, R3 is H.

[0022] In the present invention, C 1-20 alkyl, as it occurs anywhere, can be C 1-10 alkyl, for example C 1-4 alkyl.

[0023] In the present invention, C 3-10 cycloalkyl, as it occurs anywhere, can be C 5-8 cycloalkyl.

[0024] In the present invention, halo, as it occurs anywhere, can be fluoro, chloro, bromo or iodo, preferably fluoro.

[0025] In the present invention, the structural units represented by general formulas la, lb and Ic that make up the random copolymer can be selected from any one of the following combinations 1-7:

[0026] Combination 1: formula la is formula lb is formula Ic is

[0027] Combination 2: Formula Ia is Formula Ib is Formula Ic is

[0028] Combination 3: Formula Ia is Formula Ib is Formula Ic is

[0029] Combination 4: Formula Ia is Formula Ib is Formula Ic is

[0030] Combination 5: Formula Ia is Formula Ib is Formula Ic is

[0031] Combination 6: Formula Ia is Formula Ib is Formula Ic is

[0032] Combination 7: Formula Ia is Formula Ic is Formula Ib is 0 mol-%;

[0033] wherein R3and R4are as defined in the present application.

[0034] In the present application, preferably, the structural units represented by Formulae Ia, Ib and Ic making up the random copolymer can be selected from any one of the following combinations 8 to 12:

[0035] Combination 8: Formula Ia is Formula Ib is Formula Ic is

[0036] Combination 9: Formula Ia is Formula Ib is Formula Ic is

[0037] Combination 10: Formula Ia is Formula Ib is Formula Ic is

[0038] Combination 11: Formula Ia is Formula Ib is Formula Ic is

[0039] Combination 12: Formula Ia is Formula Ic is Formula Ib is 0 mol-%.

[0040] In some embodiments, the random copolymer is prepared by polymerization of monomer A, monomer B and monomer C simultaneously in an organic solvent in the presence of an initiator;

[0041]

[0042] wherein the mole percentage of monomers A, B and C in the total mole percentage of the three is: 0≤A<90%, 0≤B<90%, 0<C<50%;

[0043] R1, R2and R3are as defined in the present application.

[0044] Preferably, the mole percentage of monomers A, monomers B and monomers C in the total mole percentage of the three is: 0≤A<75%, 0≤B<20%, 0<C<25%; more preferably A: 60%≤A<75%, 0≤B<20%, 20%<C<25%; for example, A: 60%, B: 20%, C: 20%; or, A: 75%, B: 0%, C: 25%.

[0045] In the present application, preferably, the monomers A, monomers B and monomers C can be selected from any one of the following combinations 13-17:

[0046] Combination 13: monomer A is monomer B is monomer C is

[0047] Combination 14: monomer A is monomer B is monomer C is

[0048] Combination 15: monomer A is monomer B is monomer C is

[0049] Combination 16: monomer A is monomer B is monomer C is

[0050] Combination 17: monomer A is monomer C is monomer B is 0 mole percentage.

[0051] In the present application, the organic solvent in the polymerization reaction can be a conventional organic solvent in the art, preferably methyl ethyl ketone.

[0052] In the present application, the initiator can be conventional in the art, for example dimethylamine borane.

[0053] In the present application, the polymerization reaction is preferably carried out under gas protection, for example, under nitrogen.

[0054] In the present application, the temperature of the polymerization reaction can be conventional in the art, for example, 50-90℃, for example, 70℃.

[0055] In the present application, the time of the polymerization reaction can be conventional in the art, for example, 4-6 hours, for example, 5 hours.

[0056] In the present application, the polymerization reaction can further include a post-treatment process after the end of the polymerization reaction, which can be conventional in the art, for example, including the process of removing the reaction liquid phase, washing the residue with an alcohol solvent (for example, methanol), and drying. The drying is preferably carried out at 50℃ for 24 hours.

[0057] In a second aspect, the present application provides a random copolymer with a weight average molecular weight of 1000-50000, which consists of a structural unit represented by the following general formula Ia, Ib and Ic, characterized in that,

[0058]

[0059] The random copolymer is prepared by simultaneously polymerizing the double bonds of monomer A, monomer B and monomer C in an organic solvent in the presence of an initiator;

[0060]

[0061] Among them, the mole percentage of monomers A, B and C in the total mole amount of the three is: 0≤A<90%, 0≤B<90%, 0<C<50%;

[0062] R1, R2 and R3 are as defined in the present application.

[0063] In the random copolymer of the second aspect of the present application, the value of the molecular weight distribution of the random copolymer can be 1.62-1.73, for example, 1.62, 1.65, 1.69, 1.72 or 1.73.

[0064] In the random copolymer of the second aspect of the present application, the conditions of the polymerization reaction (such as the mole amount of monomers A, B and C, the organic solvent, the initiator, the reaction temperature, the reaction time, etc.) can be as described in the first aspect of the present application.

[0065] In a third aspect, the present application provides a preparation method of the random copolymer as described in the first aspect or the second aspect, characterized in that, it comprises the following steps: simultaneously polymerizing the double bonds of monomer A, monomer B and monomer C in an organic solvent in the presence of an initiator to prepare the random copolymer;

[0066]

[0067] wherein R1, R2 and R3 are as described above;

[0068] wherein the mole percentages of the monomers A, B and C in the total mole percentages of the three are: 0≤A<90%, 0≤B<90%, 0<C<50%.

[0069] In the preparation method of the third aspect of the present application, the conditions of the polymerization reaction (such as the mole percentages of the monomers A, B and C, the organic solvent, the initiator, the reaction temperature, the reaction time, etc.) can be as described in the first aspect of the present application.

[0070] In the fourth aspect, the present application provides an application of the random copolymer as described in the first aspect or the second aspect as an ammonia contamination inhibiting additive for thick film photoresist.

[0071] In the fifth aspect, the present application further provides a photoresist composition, characterized in that it is prepared from the following raw materials, which include: the random copolymer as described in the first aspect or the second aspect, a photoacid generator, a photosensitive polymer and an organic solvent.

[0072] In an embodiment of the photoresist composition, the content of the random copolymer, in terms of mass fraction, can be 0.05wt%-5wt% of the photoresist composition, for example 0.058wt%.

[0073] Photoacid generator

[0074] In an embodiment of the photoresist composition, the photoacid generator can be a photoacid generator commonly used in photoresist in the art, for example the cation of the photoacid generator can be a phenylsulfonium cation as shown in formula (II) and / or a phenyliodonium cation as shown in formula (III),

[0075]

[0076] wherein R 5 and R 6 are independently phenyl, carboxyl, -C 1-60 alkylene-COOH, R a substituted or unsubstituted C 1-60 alkyl, R a substituted or unsubstituted C 1-60 alkoxy, R a substituted or unsubstituted C 2-60 alkenyl, R a substituted or unsubstituted C 2-60 alkynyl, or R a substituted or unsubstituted C 3-60 cycloalkyl; Ra independently C 1-6 alkyl, C 1-6 alkoxy, C 6-12 aromatic ring, halogen atom, OH, NH2, aldehyde group, or carboxyl group.

[0077] In an embodiment of the photoresist composition, the anion of the photoacid generator can be a non-nucleophilic anion that is conventional in photoacid generators in the art; for example, the anion of the photoacid generator can be a halogen ion, (R7(SO2))(R8(SO2))N - , (R7(SO2))(R8(SO2))(R9(SO2))C - , or R 10 (SO3) - ; wherein R7, R8, R9 are each independently a fully-fluorinated C 2-4 alkyl group, a fully-fluorinated phenyl group, -phenyl-(fully-fluorinated or unsubstituted C 2-46 alkyl group), -(fully-fluorinated C 2-4 alkylene)-O-fully-fluorinated C2-C4 alkyl group, -(fully-fluorinated C 2-4 alkylene)-fully-fluorinated 6-membered heterocycle containing 1 oxygen atom, or -(C 1-3 alkylene)-(7-10 membered bridged ring containing C=O group); or R7, R8 are linked to form a fully-fluorinated 6-8 membered heterocycle containing -(SO2)N - (SO2)-; and R 10 is a fully-fluorinated or unsubstituted C 6-10 aryl group, or a fully-fluorinated or unsubstituted C 1-10 alkyl group.

[0078] In an embodiment of the photoresist composition, the anion of the photoacid generator can be a nonafluorobutanesulfonate ion.

[0079] In an embodiment of the photoresist composition, the photoacid generator can be

[0080] In an embodiment of the photoresist composition, the content of the photoacid generator can be a conventional content used in photoresists in the art, for example, the content of the photoacid generator can be 0.1 wt% to 10 wt% (e.g., 0.1 wt% to 0.36 wt%, or for example, 0.36 wt% to 10 wt%) in mass fraction, which is the percentage of the mass of the photoacid generator over the total mass of the raw materials. When the content of the photoacid generator is too low, for example, less than 0.1 wt%, the chemical amplification can be insufficient; when the content of the photoacid generator is too high, for example, greater than 10 wt%, the product such as hydrogen gas can be generated in excess to reduce the quality of the material layer.

[0081] Photosensitive polymer

[0082] The photosensitive polymer can be a polymer that is capable of undergoing a photochemical reaction with deep ultraviolet (DUV) light. For example, the photosensitive polymer can be a polymer that undergoes a chemical reaction when an acid is generated upon exposure of a photoacid generator (PAG) mixed together with the photosensitive polymer to light, such as DUV light, and the acid thus generated causes the polymer to undergo a chemical reaction to increase its hydrophilicity or hydrophobicity. It should be appreciated that the photosensitive polymer need not be directly sensitive to light (e.g., exposure of the photosensitive polymer to light need not change the chemical composition of the photosensitive polymer, although the chemical composition of the photosensitive polymer can change due to the acid generated by the PAG mixed together with the photosensitive polymer upon exposure to light). In some embodiments, the solubility of the photosensitive polymer in a base can increase due to the photochemical reaction. In some embodiments, the photosensitive polymer can have a structure in which a protecting group is bonded to a repeating unit, and the protecting group can be deprotected during exposure to light, such that the photosensitive polymer is well solubilized in a base. The photoresist can be a positive photoresist, in which the portions of the photoresist that are to be removed after development of the photoresist are exposed to light (e.g., DUV light). The deprotected protecting group can generate a new acid to undergo a chemical amplification.

[0083] The photosensitive polymer can be obtained by polyaddition of the polymer monomers, which is conventional in the art. In some embodiments of the photoresist composition, the photosensitive polymer consists of structural units x 1 , y 1 , and z 1

[0084]

[0085]

[0086] wherein the mole percentages of the above structural units x 1 : y 1 : z 1 are 1 : 1 : 1, the weight average molecular weight Mw of the photosensitive polymer is 9000-11000 (e.g., 9800), and the molecular weight distribution coefficient is 1.5-2.0 (e.g., 1.75).

[0087] In some embodiments of the photoresist composition, the content of the photosensitive polymer can be a conventional content used in photoresists in the art, for example, the content of the photosensitive polymer can be 5wt% to 60wt% (e.g., 5.83%) in terms of mass fraction, which is the percentage of the mass of the photosensitive polymer to the total mass of the raw materials.

[0088] Organic solvent ​

[0089] In an embodiment of the photoresist composition, the organic solvent can be a conventional organic solvent in the art, for example, propylene glycol monoethyl ether acetate.

[0090] In an embodiment of the photoresist composition, the content of the organic solvent can be a conventional content used in the photoresist in the art, for example, the content of the organic solvent can be 20 wt% to 95 wt% (for example, 93.23 wt%) in terms of mass fraction, the mass fraction being the percentage of the mass of the photosensitive polymer to the total mass of the raw materials.

[0091] Other components

[0092] In an embodiment of the photoresist composition, the photoresist composition can further comprise other components, which are components conventionally added in the photoresist in the art, for example, leveling agents, surfactants, adhesion promoters, quenching agents, crosslinking agents, and the like.

[0093] In an embodiment of the photoresist composition, the leveling agents and surfactants can be leveling agents and surfactants conventionally used in the art, examples of which can include, but are not limited to, fluoroalkyl benzene sulfonate, fluoroalkyl carboxylate, fluoroalkyl polyoxyethylene ether, fluoroalkyl ammonium iodide, fluoroalkyl betaine, fluoroalkyl sulfonate, diglycerol tetra(fluoroalkyl polyoxyethylene ether), fluoroalkyl trimethyl ammonium salt, fluoroalkyl sulfamate, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene tridecyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene laurate, polyoxyethylene oleate, polyoxyethylene stearate, polyoxyethylene lauryl amine, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan oleate, sorbitan fatty acid ester, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan oleate, polyoxyethylene naphthyl ether, alkyl benzene sulfonate, alkyl diphenyl ether disulfonate, or a combination thereof.

[0094] In an embodiment of the photoresist composition, the content of the leveling agents or surfactants can be a conventional content used in the photoresist in the art, for example, the content of the leveling agents or surfactants can each be 0.001 wt% to 0.1 wt% in terms of mass fraction, the mass fraction being the percentage of the mass of the leveling agents or surfactants to the total mass of the raw materials.

[0095] In certain embodiments of the photoresist composition, the adhesion promoter can be an adhesion promoter conventionally used in the art for enhancing adhesion to a substrate. The adhesion promoter can include, but is not limited to, a silane-based, an aluminum-based, or a titanate-based compound. Specifically, the adhesion promoter can include, for example, 3-glycidyloxypropyldimethylethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltrimethoxysilane, acetylalkoxydiisopropylaluminum, tetraisopropyl bis(dioctylphosphite) titanate, or a combination thereof.

[0096] In certain embodiments of the photoresist composition, the adhesion promoter can be an adhesion promoter conventionally used in the art for enhancing adhesion to a substrate. The adhesion promoter can include, but is not limited to, a silane-based, an aluminum-based, or a titanate-based compound. Specifically, the adhesion promoter can include, for example, 3-glycidyloxypropyldimethylethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltrimethoxysilane, acetylalkoxydiisopropylaluminum, tetraisopropyl bis(dioctylphosphite) titanate, or a combination thereof.

[0097] In certain embodiments of the photoresist composition, the quencher can be a quencher conventionally used in the art for adjusting a diffusion rate of a material such as generated acid, examples of which can include, but are not limited to, a primary, secondary, or tertiary amine compound, and more particularly, an amine compound having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate ester bond, or an amine compound obtained by protecting a primary or secondary amine with a carbamate group; a salt such as a sulfonium, iodonium, or ammonium salt of a carboxylic acid; or a combination thereof.

[0098] In certain embodiments of the photoresist composition, the adhesion promoter can be an adhesion promoter conventionally used in the art for enhancing adhesion to a substrate. The adhesion promoter can include, but is not limited to, a silane-based, an aluminum-based, or a titanate-based compound. Specifically, the adhesion promoter can include, for example, 3-glycidyloxypropyldimethylethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltrimethoxysilane, acetylalkoxydiisopropylaluminum, tetraisopropyl bis(dioctylphosphite) titanate, or a combination thereof.

[0099] In certain embodiments of the photoresist composition, the crosslinking agent can be a crosslinking agent conventionally used in the art, examples of which can include, but are not limited to, a nitrogen-containing compound having at least two crosslinking substituents (e.g., a hydroxymethyl group, a methoxymethyl group, or a butoxymethyl group). Specifically, the crosslinking agent can include, for example, hexamethoxymethyl melamine, tetramethoxymethyl benzoguanamine, 1,3,4,6-tetra(methoxymethyl) glycoluril, 1,3,4,6-tetra(butoxymethyl) glycoluril, 1,3,4,6-tetra(hydroxymethyl) glycoluril, 1,3-bis(hydroxymethyl) urea, 1,1,3,3-tetra(butoxymethyl) urea, 1,1,3,3-tetra(methoxymethyl) urea, or a combination thereof.

[0100] In an embodiment of the photoresist composition, the content of the crosslinking agent can be a conventional content used in photoresist in the art, for example, the content of the crosslinking agent can be 0.01 wt% to 5 wt% in terms of mass fraction, the mass fraction being the percentage of the mass of the crosslinking agent to the total mass of the raw materials.

[0101] In an embodiment of the photoresist composition, the photoresist composition can further comprise other components; for example, salicylic acid and / or triethylamine, wherein the content of the salicylic acid can be 0.1 wt% to 10 wt% (for example, 1 wt% to 5 wt%, or for example, 2 wt%) and the content of the triethylamine can be 0.1 wt% to 10 wt% (for example, 1 wt% to 5 wt%, or for example, 2 wt%) in terms of mass fraction, the mass fraction being the percentage of the mass of each component to the total mass of the raw materials.

[0102] The present application provides a preparation method of the photoresist composition, which comprises mixing the raw materials as described above to obtain a mixture.

[0103] The present application provides the use of the ammonia contamination inhibiting additive or the photoresist composition in photoresist.

[0104] Another aspect of the present application also provides the use of the photoresist composition described above in the manufacture of semiconductor devices.

[0105] In the present application, the values of the weight average molecular weight and the molecular weight distribution can be measured by conventional methods in the art, for example, gel permeation chromatography (GPC).

[0106] On the basis of not violating the common sense in the art, the above-mentioned preferred conditions can be combined arbitrarily, thereby obtaining each preferred example of the present application.

[0107] The reagents and raw materials used in the present application are commercially available.

[0108] The present application has the following advantages:

[0109] The ammonia contamination inhibiting additive provided by the present application can be used to prevent the distortion of patterns caused by the contamination of photoresist by ammonia and amines in the air. A small amount of the ammonia contamination inhibiting additive is added to the composition of the photoresist, and the ammonia contamination inhibiting additive is designed to be located on the upper layer of the PR film when the photoresist is spin-coated on a wafer. For this purpose, an action group including a halogen element, particularly fluorine, is introduced into the main chain of the polymer mainly used in I-line and KrF PR, a protective film is formed on the contact surface between the upper layer of the photoresist and the atmosphere, and the direct contact of ammonia or amines in the atmosphere is prevented, thereby achieving the effect of preventing the distortion of T-top-shaped patterns caused by ammonia contamination. BRIEF DESCRIPTION OF DRAWINGS

[0110] Figure 1 For the pattern formed using the photoresist not containing the additive, a T-top shaped pattern distortion caused by ammonia contamination was formed on the upper portion of the pattern.

[0111] Figure 2 For the pattern formed using the random copolymer prepared in Example 1 of the present application in the photoresist, an improvement effect of completely removing the T-top was obtained. DETAILED DESCRIPTION

[0112] The following detailed description of the embodiments of the present application will make it easier for those having ordinary knowledge in the art to which the present application pertains to carry out the present application. The present application can be implemented in various forms, and is not limited to the embodiments implemented herein.

[0113] In the following examples, the values of the weight average molecular weight and the molecular weight distribution were measured by gel permeation chromatography.

[0114] Example 1

[0115] [Synthesis Example: Synthesis of additive including halogen group]

[0116] (Monomer Synthesis Example 1)

[0117]

[0118] In a flask, 120 g (1 mol) of hydroxystyrene (monomer A) and 231 g (1.1 mol) of trifluoroacetic anhydride were mixed in 1.5 L of dichloromethane and stirred, and 111 g (1.1 mol) of triethylamine was slowly dropped while stirring at room temperature. After the dropping was completed, the mixture was stirred for 3 hours at room temperature, and the end point of the reaction was confirmed by using a thin layer chromatograph (TLC: Thin layer chloromatography) to confirm whether the spot of the monomer A was completely disappeared and whether the Rf value of the reaction product was increased. After confirming the end point of the reaction, 1 L of water was added to the reaction solution, and the upper water layer was removed after sufficiently stirring. Then, 1 L of water was further added to the organic layer in the dichloromethane solution, and the obtained organic layer was collected and distilled under reduced pressure. The monomer B obtained after the distillation under reduced pressure was 210 g (0.97 mol).

[0119] (Polymer Synthesis Example 1)

[0120]

[0121] After 40 g (0.223 mol) of the monomer B synthesized in the above monomer synthesis example 1, 7.7 g (0.074 mol) of the monomer C (styrene) and 9.5 g (0.074 mol) of the monomer D (t-butyl acrylate), 6.8 g (0.0296 mol) of dimethylamine borane, and 171 g of methyl ethyl ketone were all put into a flask, the inside of the flask was replaced with nitrogen gas using nitrogen gas, and the inside of the flask was warmed to 70°C. After the warming, the inside of the flask was stirred at 70°C for 5 hours. After the reaction, the reaction solution was taken, and the weight average molecular weight was measured using GPC (Gelpermeation chromatography). After the reaction, the inside of the reaction vessel was cooled to normal temperature, 500 ml of methyl alcohol was added, stirred, and left to stand. After the upper organic layer was removed, the same amount of methyl alcohol was added, stirred, and the upper organic layer was removed again. This was repeated once more. The lower polymer was redissolved in methyl ethyl ketone, taken out of the reaction vessel, and the methyl ethyl ketone was removed using a reduced pressure distiller. The polymer after the removal of the solvent was collected, and dried at 50°C for 24 hours using a reduced pressure drying device. After the drying, 145.7 g (yield: 80%) of example 1 was obtained, the weight average molecular weight was 9,700, and the value of the molecular weight distribution was 1.72.

[0122] Example 2

[0123] (Polymer synthesis example 2)

[0124]

[0125] All the methods were the same as the above polymer synthesis example 1, but 12.4 g (0.074 mol) of the monomer E was used instead of the monomer D. After the drying, 46.9 g (yield: 78%) of example 2 was obtained, the weight average molecular weight was 10,200, and the molecular weight distribution was 1.69.

[0126] Example 3

[0127] (Polymer synthesis example 3)

[0128]

[0129] All the methods were the same as the above polymer synthesis example 1, but 12.4 g (0.074 mol) of the monomer F was used instead of the monomer E. After the drying, 48.7 g (yield: 81%) of example 3 was obtained, the weight average molecular weight was 9,500, and the molecular weight distribution was 1.73.

[0130] Example 4

[0131] (Polymer synthesis example 4)

[0132]

[0133] The monomer G was synthesized by the same method as in Polymer Synthesis Example 1, except that 197 g (1.1 mol) of pentafluoroethane carbonyl chloride was used instead of trifluoroacetic acid hydride in Monomer Synthesis Example 1. After distillation under reduced pressure, 159 g (0.89 mol) of monomer G was obtained. All the procedures for the additive D were the same as in Polymer Synthesis Example 1, except that 59.3 g (0.223 mol) of monomer G was used instead of monomer B. After drying, 57.3 g (yield: 75%) of Example 4 was obtained, having a calculated weight molecular weight of 10,500 and a molecular weight distribution of 1.65.

[0134] Example 5

[0135] (Polymer Synthesis Example 5)

[0136]

[0137] All the procedures for Example 5 were the same as in Polymer Synthesis Example 1, except that 40 g (0.223 mol) of monomer B and 12.4 g (0.074 mol) of monomer F were used. After drying, 38.8 g (yield: 74%) of Example 5 was obtained, having a calculated weight molecular weight of 11,000 and a molecular weight distribution of 1.62.

[0138] Example 6

[0139] As an additive for a photoresist composition, 0.5 g of each of the random copolymers synthesized in Examples 1 to 5, 5 g of a base polymer for a photoresist (Mw: 9800 / mol, Mw / Mn: 1.75, molar ratio of each repeating unit IIa: IIb: IIc: 1:1:1) composed of structural units represented by General Formulae IIa, IIb and IIc, and 0.31 g of an acid generator represented by Chemical Formula 21 were dissolved in 80 g of propylene glycol methyl ether acetate (PGMEA) and filtered through a 0.2-μm polypropylene filter to prepare a photoresist film composition. On a silicon substrate, hexamethyldisilazane (HMDS) was formed to a thickness of 90 nm, and the photoresist film composition prepared as above was applied to the substrate on which the film was formed, and baked at 120°C for 60 seconds to form a photoresist film to a thickness of 4 μm. The change in the thickness of the photoresist protective film before and after development was observed by developing the silicon substrate on which the photoresist protective film was formed using an aqueous solution of trimethylammonium hydroxide (TMAH) having a concentration of 2.38 wt%, and the degree of T-top formation due to ammonia contamination in the atmosphere was observed from the cross-sectional image of the silicon substrate.

[0140] In the comparative example, the silicon substrate was prepared by the same method as above, except that the random copolymers synthesized in Examples 1 to 5 were not added.

[0141] T-top degree is classified into 5 grades: A: very good, B: good, C: ordinary, D: not good, and E: very not good

[0142] Substrate polymer for photoresist:

[0143] [Chemical Formula 21]

[0144]

[0145] Table 1

[0146]

[0147]

[0148] As shown in Table 1, the photoresist protective film obtained by coating the photoresist composition added with the polymer prepared in Examples 1-5 as an additive on a substrate and then treating it has a T-top degree on the cross section of the slice caused by ammonia contamination much less than that of the comparative example.

[0149] Figure 1 For the pattern formed using the photoresist without the additive, the pattern distortion in the form of T-top caused by ammonia contamination is formed on the upper part of the pattern.

[0150] Figure 2 For the pattern formed using the photoresist to which the random copolymer prepared in Example 1 of the present application is applied, the improvement effect of completely no T-top is obtained.

[0151] Thus, it can be seen that the random copolymer provided in the present application, when used as an additive in the photoresist composition, can effectively prevent the pattern distortion in the form of T-top caused by ammonia contamination.

Claims

1. A photoresist composition characterized in that, which is prepared from raw materials including: a random copolymer, a photoacid generator, a photosensitive polymer, and an organic solvent; the random copolymer is a random copolymer having a weight average molecular weight of 1000-50000, which is composed of structural units represented by general formulae Ia, Ib, and Ic below, Ia, Ib, Ic; wherein the molar percentage of the above structural units Ia, Ib, and Ic in the total moles of the three is: 0 R1is C 1-20 alkyl-C(O)-, said C 1-20 alkyl-C(O)- is optionally substituted with one or more R 1-1 substituents; R2is C 3-10 cycloalkyl, C 1-20 alkyl or C 1-20 alkyl-C(O)-, said C 1-20 alkyl, C 1-20 alkyl-C(O)- and C 3-10 cycloalkyl is optionally substituted with one or more R 1-1 substituents; each R 1-1 is independently halogen or C 1-4 alkyl; and at least one of R1 and R2 contains halogen; R3 is H.

2. The photoresist composition according to claim 1, wherein the content of the random copolymer is 0.05wt%-5wt% of the photoresist composition, in terms of mass fraction; and / or, the content of the photoacid generator is 0.1wt% to 10wt%, in terms of mass fraction; and / or, the content of the photosensitive polymer is 5wt% to 60wt%, in terms of mass fraction; and / or, the content of the organic solvent is 20wt% to 95wt%, in terms of mass fraction; and / or the photoacid generator is ; and / or, the photosensitive polymer consists of structural units x 1 , y 1 and z 1 ​ ， x 1 y 1 z 1 ; wherein the above structural unit x 1 : y 1 : z 1 The molar percentage of the above structural units x, y and z is 1:1:1, the weight average molecular weight Mw of the photosensitive polymer is 9000-11000, and the molecular weight distribution coefficient is 1.5-2.

0. and / or, the organic solvent is propylene glycol monoethyl ether acetate; and / or, the weight average molecular weight of the random copolymer is 8500-12000; and / or, the value of the molecular weight distribution of the random copolymer is 1.62-1.73; and / or, the molar percentage of the structural units Ia, Ib, and Ic in the total moles of the three in the random copolymer is 0 and / or, R1is halogen-substituted C 1-20 alkyl-C(O)-; and / or, R2is C 1-20 alkyl, C 3-10 cycloalkyl, C 1-4 alkyl-substituted C 3-10 cycloalkyl, or wherein R4is halogen or C 1-9 alkyl.

3. The photoresist composition according to claim 2, wherein the content of the random copolymer is 0.058wt% of the photoresist composition, in terms of mass fraction; and / or, the content of the photoacid generator is 0.1wt% to 0.36wt%, in terms of mass fraction; and / or, the content of the photosensitive polymer is 5.83wt%, in terms of mass fraction; and / or, the content of the organic solvent is 93.23wt%, in terms of mass fraction; and / or, the weight average molecular weight of the random copolymer is 9500-11000; and / or, the value of the molecular weight distribution of the random copolymer is 1.62, 1.65, 1.69, 1.72, or 1.73; and / or, the molar percentage of the structural units Ia, Ib, and Ic in the total moles of the three is: 60 and / or, R1is or ; and / or, R4 is fluorine or trifluoromethyl; and / or, R2is tert-butyl, or .

4. The photoresist composition according to claim 3, wherein R1 is .

5. The photoresist composition according to claim 2, wherein the content of the photoacid generator is 0.36wt% to 10wt%, in terms of mass fraction; and / or, the molar percentage of the structural units Ia, Ib, and Ic in the total moles of the three in the random copolymer is: Ia: 60%, Ib: 20%, Ic: 20%; or, Ia: 75%, Ib: 0%, Ic: 25%.

6. The photoresist composition according to claim 1, wherein The structural units represented by general formulae Ia, Ib and Ic constituting the random copolymer are selected from any one of the following combinations 1-5: Combination 1 : Formula Ia is , Formula Ib is , Formula Ic is ; Combination 2: Formula Ia is , Formula Ib is , Formula Ic is ; Combination 3: Formula Ia is , Formula Ib is , Formula Ic is ; Combination 4: Formula Ia is , Formula Ib is , Formula Ic is ; Combination 5: Formula la is , Formula Ic is , the mole percent of Formula lb is 0; wherein R3 and R4 are as defined in any one of claims 1-5.

7. The photoresist composition of claim 6, wherein, The structural units represented by general formulae Ia, Ib and Ic constituting the random copolymer are selected from any one of the following combinations 8-12: Combination 8: Formula Ia is , Formula Ib is , Formula Ic is ; Combination 9: Formula Ia is , Formula Ib is , Formula Ic is ; Combination 10: Formula Ia is , Formula Ib is , Formula Ic is ; Combination 11: Formula Ia is , Formula Ib is , Formula Ic is ; or, Combination 12: Formula la is , Formula Ic is , the mole percent of Formula lb is 0.

8. The photoresist composition of claim 1, wherein, The random copolymer is prepared by simultaneously polymerizing the monomers A, B and C in an organic solvent in the presence of an initiator; ， A B C; wherein the mole percentage of the monomers A, B and C in the total mole amount of the three is: 0 < A < 90%, 0 ≤ B < 90%, 0 < C < 50%; R1, R2 and R3 are as defined in claim 1.

9. The photoresist composition of claim 8, wherein, In the polymerization reaction, the mole percentage of the monomers A, B and C in the total mole amount of the three is: 0 < A < 75%, 0 ≤ B < 20%, 0 < C < 25%; and / or, in the polymerization reaction, the organic solvent is 1,4-methyl ethyl ketone; and / or, in the polymerization reaction, the initiator is dimethylamine borane; and / or, the temperature of the polymerization reaction is 50-90℃; and / or, the time of the polymerization reaction is 4-6 hours.

10. The photoresist composition of claim 9, wherein In the polymerization reaction, the mole percentage of the monomers A, B and C in the total mole amount of the three is: 60% ≤ A < 75%, 0 ≤ B < 20%, 20% < C < 25%; and / or, the temperature of the polymerization reaction is 70℃; and / or, the time of the polymerization reaction is 5 hours.

11. The photoresist composition of claim 9, wherein, In the polymerization reaction, the mole percentage of the monomers A, B and C in the total mole amount of the three is: A: 60%, B: 20%, C: 20%; or, A: 75%, B: 0%, C: 25%.

12. The photoresist composition of any one of claims 1-11, wherein, The photoresist composition further comprises other components, which are selected from one or more of leveling agents, surfactants, adhesion promoters, quenching agents and crosslinking agents.

13. The photoresist composition of claim 12, wherein by mass fraction, The content of the leveling agent or surfactant is 0.001wt% to 0.1wt%; and / or, the content of the adhesion promoter is 0.1wt% to 10wt%; and / or, the content of the quenching agent is 0.01wt% to 5wt%; and / or, the content of the crosslinking agent is 0.01wt% to 5wt%.

14. A method for producing the photoresist composition according to any one of claims 1 to 13, characterized by, After mixing the raw materials, a mixture is obtained.

15. Use of the photoresist composition of any one of claims 1-13 as a photoresist, or use of the photoresist composition in the manufacture of a semiconductor device.

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