A photoresist composition and its use

Abstract

The present application provides a photoresist composition and its use. The photoresist composition, by adding an additive containing a polyhydroxyphenyl compound, improves the dissolution rate of non-exposed areas, thereby resolving the problem of residues on the surface of the photoresist pattern after development. Furthermore, due to the large number of cross-linkable hydroxyl groups in the structure of the photoresist composition and the high cross-linking density in the exposed areas, the dissolution rate difference between the exposed and non-exposed areas is further increased, thereby improving the contrast of the photoresist and resolving the problem of bridging defects in the spacers of the photoresist pattern after development. When used as a deep ultraviolet KrF negative photoresist, the photoresist composition of the present application exhibits higher resolution and a better process window.

Description

Technical Field

[0001] The present application relates to the field of semiconductor material technology, and in particular to a photoresist composition and its use. Background Art

[0002] With the increasing integration density of integrated circuits and the shrinking of process linewidths, photolithography technology has evolved from G-line (436nm) lithography, I-line (365nm) lithography, to deep ultraviolet (DUV) KrF (248nm) lithography, ArF (193nm) lithography, and extreme ultraviolet (EUV, 13.5nm) lithography. As exposure wavelengths change, the composition and structure of photoresists also evolve to ensure that their overall performance meets the requirements of the corresponding integrated process.

[0003] Design criteria for semiconductor device processing with critical dimensions greater than 0.5μm can be achieved through G-line (436nm) exposure wavelength lithography. Design criteria for semiconductor device processing with critical dimensions between 0.5μm and 0.35μm can be achieved through I-line (365nm) exposure wavelength lithography. Design criteria for semiconductor device processing with critical dimensions between 0.30μm and 0.13μm can be achieved through KrF excimer laser lithography with an exposure wavelength of 248nm.

[0004] In G-line and I-line lithography, phenolic resin-naphthoquinone diazide positive-tone photoresist is used. However, due to the significant non-bleaching absorption of phenolic resin at the 248nm exposure wavelength, phenolic resin-naphthoquinone diazide positive-tone photoresist is no longer suitable for 248nm lithography. Poly(p-hydroxystyrene) has high light transmittance at 248nm and is widely used in 248nm photoresists.

[0005] Existing deep ultraviolet 248nm negative photoresist, while solving the problem of residues on the surface of the photoresist pattern after development, is difficult to solve the problem of bridging defects in the spacing area of ​​the photoresist pattern after development. Summary of the Invention

[0006] The purpose of this application is to provide a photoresist composition and its use to solve the problem of residues on the surface of the photoresist pattern after development and bridge defects in the spacer area of ​​the photoresist pattern. The specific technical solution is as follows:

[0007] In a first aspect, the present application provides a photoresist composition comprising an additive containing a polyhydroxyphenyl compound, wherein the additive containing the polyhydroxyphenyl compound is selected from at least one of a polyhydroxyphenyl compound represented by general formula (I), a polyhydroxypolyphenyl compound represented by general formula (II), and a polyhydroxypolyphenyl compound represented by general formula (III):

[0008]

[0009] In the general formula (I), R1 and R2 are each independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0010] m1 represents the number of hydroxyl groups, and m1 is an integer from 2 to 6;

[0011]

[0012] In the general formula (II), R3, R4, R5 and R6 are each independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0013] m2 and n2 represent the number of hydroxyl groups, and m2 and n2 are each independently an integer of 1 to 5;

[0014] A is a linking group, p represents the number of repetitions of the linking group, and p is an integer from 1 to 4;

[0015] The connecting group is selected from any one of the following groups A1 to A5:

[0016]

[0017] Wherein, R7 is selected from hydrogen atom or C1-C4 alkyl; R8, R9, R 10 and R 11 Each is independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0018] m3 represents the number of hydroxyl groups, m3 is an integer from 1 to 5; m4 represents the number of hydroxyl groups, m4 is an integer from 1 to 4;

[0019] * indicates the attachment site;

[0020]

[0021] In the general formula (III), R 12 、R 13 、R 14 and R 15 Each is independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0022] m5 and n5 represent the number of hydroxyl groups, and m5 and n5 are each independently an integer of 1 to 4;

[0023] The number of hydroxyl groups in each polyhydroxyphenyl group is independently selected from 2 to 6.

[0024] A second aspect of the present application provides a use of the photoresist composition of the present application as a deep ultraviolet KrF negative photoresist.

[0025] Beneficial effects of the embodiments of the present application:

[0026] The present application provides a photoresist composition and its use, wherein the photoresist composition includes an additive containing a polyhydroxyphenyl compound, wherein the additive containing the polyhydroxyphenyl compound is selected from at least one of a polyhydroxyphenyl compound represented by general formula (I), a polyhydroxypolyphenyl compound represented by general formula (II), and a polyhydroxypolyphenyl compound represented by general formula (III). By adding the additive containing the polyhydroxyphenyl compound, the photoresist composition of the present application improves the dissolution rate of the non-exposed area, solving the problem of residues on the surface of the photoresist pattern after development. On the other hand, due to the large number of cross-linkable hydroxyl groups in the structure of the photoresist composition and the high cross-linking density in the exposed area, the dissolution rate difference between the exposed area and the non-exposed area is further increased, thereby improving the contrast of the photoresist, thereby solving the problem of bridging defects in the spacer area of ​​the photoresist pattern after development. When used as a deep ultraviolet KrF negative photoresist, the photoresist composition of the present application has higher resolution and a better process window. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0028] Figure 1 A schematic diagram showing residues on the surface of a photoresist pattern in the prior art;

[0029] Figure 2 A schematic diagram of a bridge defect occurring in a spacer region of a photoresist pattern in the prior art. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the embodiments described are only part of the embodiments of the present application, not all of them. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application are within the scope of protection of the present application.

[0031] The deep ultraviolet 248nm negative photoresist in the prior art has a main polymer of poly (p-hydroxystyrene) polymer or a copolymer of p-hydroxystyrene and styrene. However, this negative photoresist is prone to the phenomenon of unclean development, and there are residues 10 (such as Figure 1 The problem of residues after development can be solved by reducing the copolymerization ratio of styrene in the polymer or reducing the molecular weight of the polymer. However, bridge defects 20 (such as Figure 2 Therefore, there is a need for a method that can solve the problem of residues on the surface of the photoresist pattern after development and the problem of bridge defects in the spacer area of ​​the photoresist pattern after development. In view of this, the present application provides a photoresist composition and its use.

[0032] In a first aspect, the present application provides a photoresist composition comprising an additive containing a polyhydroxyphenyl compound, wherein the additive containing the polyhydroxyphenyl compound is selected from at least one of a polyhydroxyphenyl compound represented by general formula (I), a polyhydroxypolyphenyl compound represented by general formula (II), and a polyhydroxypolyphenyl compound represented by general formula (III):

[0033]

[0034] In the general formula (I), R1 and R2 are each independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0035] m1 represents the number of hydroxyl groups, and m1 is an integer from 2 to 6;

[0036]

[0037] In the general formula (II), R3, R4, R5 and R6 are each independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0038] m2 and n2 represent the number of hydroxyl groups, and m2 and n2 are each independently an integer of 1 to 5;

[0039] A is a linking group, p represents the number of repetitions of the linking group, and p is an integer from 1 to 4;

[0040] The connecting group is selected from any one of the following groups A1 to A5:

[0041]

[0042] Wherein, R7 is selected from hydrogen atom or C1-C4 alkyl; R8, R9, R 10 and R 11 Each is independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0043] m3 represents the number of hydroxyl groups, m3 is an integer from 1 to 5; m4 represents the number of hydroxyl groups, m4 is an integer from 1 to 4;

[0044] * indicates the attachment site;

[0045]

[0046] In the general formula (III), R 12 、R13 、R 14 and R 15 Each is independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group;

[0047] m5 and n5 represent the number of hydroxyl groups, and m5 and n5 are each independently an integer of 1 to 4;

[0048] The number of hydroxyl groups in each polyhydroxyphenyl group is independently selected from 2 to 6.

[0049] The photoresist composition of the present application, by adding an additive containing a polyhydroxyphenyl compound, on the one hand improves the dissolution rate of the non-exposed area, thereby solving the problem of residues on the surface of the photoresist pattern after development; on the other hand, due to the large number of cross-linkable hydroxyl groups in the structure of the photoresist composition and the high cross-linking density in the exposed area, the dissolution rate difference between the exposed area and the non-exposed area is further increased, thereby improving the contrast of the photoresist, thereby solving the problem of bridging defects in the spacing area of ​​the photoresist pattern after development.

[0050] Preferably, the polyhydroxyphenyl compound represented by general formula (I) is selected from the following compounds:

[0051] Preferably, the polyhydroxy polyphenyl compound represented by general formula (II) is selected from the following compounds:

[0052]

[0053]

[0054] Preferably, the polyhydroxy polyphenyl compound represented by general formula (III) is selected from the following compounds:

[0055]

[0056]

[0057] In one embodiment of the present application, the photoresist composition further comprises the following components: a polymer containing a p-hydroxystyrene structural unit, a photoacid generator, a cross-linking agent, a nitrogen-containing alkaline compound, and a surfactant. The mass ratio of the polymer containing a p-hydroxystyrene structural unit, the additive containing a polyhydroxyphenyl compound, the photoacid generator, the cross-linking agent, the nitrogen-containing alkaline compound, and the surfactant is 100:(1-20):(1-10):(1-10):(0.01-1):(0.005-0.5). The content of each of the above components is regulated within the above range to prepare the photoresist composition of the present application. On the one hand, the dissolution rate of the non-exposed area is improved, solving the problem of residues on the surface of the photoresist pattern after development. On the other hand, due to the large number of cross-linkable hydroxyl groups in the structure of the photoresist composition and the high cross-linking density of the exposed area, the dissolution rate difference between the exposed area and the non-exposed area is further increased, thereby improving the contrast of the photoresist, thereby solving the problem of bridging defects in the spacer area of ​​the photoresist pattern after development.

[0058] The present application does not impose any particular restrictions on the content of the solvent, as long as the objectives of the present application are achieved. For example, the mass percentage of the solvent based on the total mass of the photoresist composition is 70% to 95%. It is understood that the "total mass of the photoresist composition" herein can also be understood as the sum of the masses of the individual components, namely, the polymer containing p-hydroxystyrene structural units, the additive containing a polyhydroxyphenyl compound, the photoacid generator, the crosslinker, the nitrogen-containing basic compound, the surfactant, and the solvent.

[0059] In one embodiment of the present application, the polymer containing p-hydroxystyrene structural units comprises one or more of structural units IV-1, IV-2 and IV-3:

[0060]

[0061] Among them, the molar percentages of structural unit IV-1, structural unit IV-2 and structural unit IV-1 are (70 mol%~100 mol%):(0 mol%~30 mol%):(0 mol%~10 mol%), and the total molar percentages of structural unit IV-1, structural unit IV-2 and structural unit IV-3 are 100%.

[0062] The polymer containing p-hydroxystyrene structural units in the present application is a random polymer.

[0063] In one embodiment of the present application, the weight average molecular weight Mw of the polymer containing p-hydroxystyrene structural units is 1000 to 10000. Controlling the weight average molecular weight of the polymer containing p-hydroxystyrene structural units within the above range is more conducive to improving the film forming properties of the photoresist and reducing the development defects of the photoresist.

[0064] The present application does not particularly limit the type of photoacid generator, and it can be a well-known acid generator used in chemically amplified photoresist compositions in the prior art, as long as the purpose of the present application can be achieved. For example, the photoacid generator is selected from at least one of sulfonium salt-type acid generators, iodonium salt-type acid generators, N-imidosulfonate-type acid generators, diazomethane-type acid generators, and nitrobenzenesulfonate-type acid generators. The selection of the photoacid generator allows the photoresist composition to absorb light energy and decompose acid under KrF excited state laser irradiation. When baked after exposure, the acid-catalyzed crosslinking agent reacts with the hydroxyl groups on the polymer containing para-hydroxystyrene structural units and the hydroxyl groups on the additive containing polyhydroxyphenyl compounds to undergo cross-linking reactions. The present application does not particularly limit the type of sulfonium salt-type acid generator, as long as the purpose of the present application can be achieved. For example, the sulfonium salt-type acid generator is selected from at least one of the compounds represented by general formula (V):

[0065]

[0066] In the general formula (V), R 16 、R 17 、R 18 Each independently selected from hydrogen, C1-C4 alkyl or C1-C4 alkoxy groups; R 19 It is selected from trifluoromethyl, perfluorobutyl, perfluorooctyl, p-tolyl, p-trifluoromethylphenyl or camphenyl groups.

[0067] The present application does not particularly limit the type of iodonium salt-type acid generator, as long as it can achieve the purpose of the present application. For example, the iodonium salt-type acid generator is selected from at least one compound represented by general formula (VI):

[0068]

[0069] Among them, R 20 、R 21 Each independently selected from hydrogen, C1-C4 alkyl or C1-C4 alkoxy groups; R 22 It is selected from trifluoromethyl, perfluorobutyl, perfluorooctyl, p-tolyl, p-trifluoromethylphenyl or camphenyl groups.

[0070] The present application does not particularly limit the type of N-imidosulfonate acid generator, as long as it can achieve the purpose of the present application. For example, the N-imidosulfonate acid generator is selected from at least one of the compounds represented by general formula (VII) and the compounds represented by general formula (VIII):

[0071]

[0072] Among them, R 23 and R 24Each is independently selected from trifluoromethyl, perfluorobutyl, perfluorooctyl, p-tolyl, p-trifluoromethylphenyl or camphoryl groups.

[0073] The present application has no particular limitation on the types of diazomethane acid generators and nitrobenzene sulfonate acid generators, as long as the purpose of the present application can be achieved.

[0074] The present application does not particularly limit the type of crosslinking agent; it can be any known crosslinking agent used in chemically amplified photoresist compositions in the prior art, as long as it can achieve the objectives of the present application. For example, the crosslinking agent can be selected from at least one of an etherified amino crosslinking agent and an etherified polyphenyl crosslinking agent. During the post-exposure bake, the crosslinking agent undergoes a crosslinking reaction with the hydroxyl groups on the polymer containing p-hydroxystyrene structural units and the hydroxyl groups on the polyhydroxyphenyl compound additive under acid catalysis, thereby reducing the dissolution rate of the exposed area and rendering it insoluble in the developer. After development, a negative image that is the opposite of the mask pattern is obtained. The present application does not particularly limit the type of etherified amino crosslinking agent, as long as it can achieve the objectives of the present application. For example, the etherified amino crosslinking agent can be selected from an etherified melamine crosslinking agent or an etherified urea crosslinking agent. The etherified melamine crosslinking agent can be selected from Cymel 303LF (manufactured by Cymel Specialty Chemicals, USA) and Cymel 308 (manufactured by Cymel Specialty Chemicals, USA). The etherified urea crosslinker is selected from 1,3,4,6-tetrakis(methoxymethyl)glycoluril (TMMG), 1,3-dimethoxymethyl-4,5-dimethoxyethyleneurea, 1,3-dimethoxy-1,3-dimethylurea, and the like. The present application does not particularly limit the type of etherified polyphenyl crosslinker, as long as it can achieve the objectives of the present application. For example, the etherified polyphenyl crosslinker is selected from 4,4'-(2,2-dipropyl)bis(2,6-bis(methoxymethyl)phenol), 4,4',4"-(1,1,1-triethyl)tris(2,6-bis(methoxymethyl)phenol), and the like.

[0075] Preferably, the cross-linking agent is selected from cross-linking agents having more than 3 etherified groups in a single cross-linking molecule.

[0076] The present application does not particularly limit the type of nitrogen-containing alkaline compound, and it can be a well-known nitrogen-containing alkaline compound used in chemically amplified photoresist compositions in the prior art, as long as the purpose of the present application can be achieved. For example, the nitrogen-containing alkaline compound is selected from at least one of alkylamines, alkylolamines, hydroxyalkylamines, alkoxyalkylamines, cyclic amines, and polymeric amines. In the chemically amplified photoresist compositions of the prior art, the acid on the surface of the photoresist film will be neutralized by amine pollutants in the environment during the period from exposure to post-exposure baking (PEB), causing the surface layer to be insoluble during development, resulting in problems with post-exposure storage stability; in addition, excessive diffusion of acid during PEB will cause problems with the accuracy of image size. The addition of the nitrogen-containing alkaline compound to the photoresist composition of the present application, used as an acid quencher, can improve the storage stability after exposure, prevent excessive diffusion of acid, and improve the accuracy of image size.

[0077] The present application has no particular restrictions on the type of alkylamine, as long as the purpose of the present application can be achieved. For example, the alkylamine is selected from diethylamine, triethylamine, di-n-propylamine, tri-n-propylamine, tri-n-octylamine (also known as trioctylamine, abbreviated as TOA) or dioctylmethylamine, etc., and more preferably trialkyl tertiary amine. The present application has no particular restrictions on the type of alkylolamine, as long as the purpose of the present application can be achieved. For example, the alkylolamine is selected from diethanolamine, triethanolamine or triisopropanolamine, etc., and more preferably trialkylol tertiary amine. The present application has no particular restrictions on the type of alkylamine hydroxide, as long as the purpose of the present application can be achieved. For example, the alkylamine hydroxide is selected from tetraethylamine hydroxide, tetrabutylamine hydroxide or the lactate of tetrabutylamine hydroxide, more preferably tetrabutylamine hydroxide and its lactate. The present application has no particular restrictions on the type of alkoxyalkylamine, as long as the purpose of the present application can be achieved. For example, the alkoxyalkylamine is selected from tris-(2-methoxymethoxyethyl)amine, tris-2-(2-methoxy(ethoxy)ethylamine) or tris-(2-(2-methoxyethoxy)methoxyethoxyamine, more preferably tris-2-(2-methoxy(ethoxy)ethylamine). The present application has no particular limitation on the type of cyclic amine, as long as the purpose of the present application can be achieved. For example, the cyclic amine is selected from pyridine, picoline, ethylpyridine or 1,4-diazabicyclo[2,2,2]octane. The present application has no particular limitation on the type of polymer amine, as long as the purpose of the present application can be achieved. For example, the polymer amine is selected from polyethylpyridine or the Tetronic series polymer amines produced by BASF.

[0078] The present application does not particularly limit the type of surfactant; it can be any known surfactant used in prior art photoresist compositions, as long as it can achieve the objectives of the present application. For example, the surfactant can be selected from at least one of a siloxane-containing nonionic surfactant and a fluorine-containing nonionic surfactant. The selection of a surfactant can improve the leveling and film-forming uniformity of the photoresist composition, thereby reducing the risk of streaks and coating defects during photoresist coating.

[0079] The present application does not particularly limit the type of siloxane-containing nonionic surfactant, as long as the purpose of the present application can be achieved. For example, the siloxane-containing nonionic surfactant is selected from BYK series surfactants of BYK Chemical Company, Silwet series surfactants of Momentive High Performance Materials Company, etc. BYK series surfactants such as BYK-307, BYK-308, BYK-310, BYK-320, BYK-323, etc., Silwet series surfactants such as Silwet L-77, Silwet L-71, etc. The present application does not particularly limit the type of fluorine-containing nonionic surfactant, as long as the purpose of the present application can be achieved. For example, the fluorine-containing nonionic surfactant is selected from 3M's FC series surfactants and Chemours' FS series surfactants, etc. FC series surfactants such as FC-4430, FC-4432, etc., FS series surfactants such as FS-3000, FS-3100, etc.

[0080] The present application does not particularly limit the type of solvent, as long as it can dissolve the components of the photoresist composition of the present application to produce a uniform solution and achieve the purpose of the present application. For example, the solvent is selected from at least one of ketone solvents, polyol solvents and their derivatives, cyclic ether solvents, ester solvents, and aromatic hydrocarbon solvents. These solvents have good solubility and coating properties. By selecting these solvents, the polymer containing para-hydroxystyrene structural units, the additive containing a polyhydroxyphenyl compound, the photoacid generator, the crosslinking agent, the nitrogen-containing basic compound, and the surfactant in the photoresist composition can be more uniformly dissolved in the solvent.

[0081] The present application has no particular restrictions on the types of ketone solvents, as long as the purpose of the present application can be achieved. For example, ketone solvents are selected from acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, 2-heptanone, etc. The present application has no particular restrictions on the types of polyol solvents and their derivatives, as long as the purpose of the present application can be achieved. For example, polyol solvents and their derivatives are selected from 1,2-ethylene glycol, diethylene glycol, propylene glycol, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), etc. The present application has no particular restrictions on the types of cyclic ether solvents, as long as the purpose of the present application can be achieved. For example, cyclic ether solvents are selected from tetrahydrofuran, dioxane, etc. The present application has no particular restrictions on the types of ester solvents, as long as the purpose of the present application can be achieved. For example, the ester solvent is selected from methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, γ-butyrolactone, etc. The present application does not particularly limit the type of aromatic hydrocarbon solvent, as long as it can achieve the purpose of the present application. For example, the aromatic hydrocarbon solvent is selected from toluene, xylene, etc.

[0082] In the present application, there is no particular limitation on the preparation method of the photoresist composition, as long as the purpose of the present application can be achieved. For example, the preparation method of the photoresist composition of the present application may include the following steps: dissolving the polymer containing para-hydroxystyrene structural units, the additive containing polyhydroxyphenyl compound, the photoacid generator, the crosslinking agent, the nitrogen-containing basic compound, and the surfactant in a solvent according to a mass ratio of 100: (1-20): (1-10): (1-10): (0.01-1): (0.005-0.5) and mixing them uniformly to obtain the photoresist composition of the present application. The mass percentage of the solvent can be selected according to the actual required photoresist film thickness.

[0083] It should be noted that since natural light includes ultraviolet (UV) light, in order to prevent chemical reactions caused by UV light during the preparation of the photoresist composition, which could affect the chemical stability of the photoresist composition, in one embodiment of the present application, the photoresist composition is prepared under yellow light with a wavelength longer than UV light. For example, a polymer containing p-hydroxystyrene structural units, an additive containing a polyhydroxyphenyl compound, a photoacid generator, a crosslinker, a nitrogen-containing basic compound, and a surfactant are dissolved in a solvent under yellow light and mixed uniformly to obtain a photoresist composition.

[0084] In the present application, there is no particular restriction on the order of mixing the polymer containing para-hydroxystyrene structural units, the additive containing polyhydroxyphenyl compounds, the photoacid generator, the crosslinking agent, the nitrogen-containing basic compound, the surfactant and the solvent, as long as the purpose of the present application can be achieved.

[0085] The second aspect of the present application provides a use of the photoresist composition of the present application as a deep ultraviolet KrF negative photoresist. The photoresist composition of the present application is used as a deep ultraviolet KrF negative photoresist, and the exposure light source has a wavelength of 248nm.

[0086] When the photoresist composition of the present application is used as a deep ultraviolet KrF negative photoresist, on the one hand, the dissolution rate of the non-exposed areas is improved, solving the problem of residue on the surface of the photoresist pattern after development. On the other hand, due to the large number of cross-linkable hydroxyl groups in the structure of the photoresist composition and the high cross-linking density in the exposed areas, the dissolution rate difference between the exposed and non-exposed areas is further increased, thereby improving the contrast of the photoresist and solving the problem of bridging defects in the spacer areas of the photoresist pattern after development. As a result, the deep ultraviolet KrF negative photoresist of the present application has higher resolution and a better process window.

[0087] The following examples and comparative examples are given to further illustrate the embodiments of the present application. The experiments and evaluations of the examples and comparative examples were carried out according to the following methods.

[0088] Example 1

[0089] The types and masses of the components used to prepare the photoresist composition 1 are as follows:

[0090] Polymer containing p-hydroxystyrene structural units: poly (p-hydroxystyrene) (Mw = 4600, molecular weight distribution index (PDI) = 1.71, abbreviated as PHS, the molar percentages of structural unit IV-1, structural unit IV-2, and structural unit IV-1 are 100 mol %:0 mol %:0 mol %), 10.83 g;

[0091] Additive containing a polyhydroxyphenyl compound: compound 2-A4-2 0.70 g;

[0092] Photoacid generator: triphenylsulfonium perfluorobutanesulfonate (TPS-PFBS, structural formula shown below) 0.70 g;

[0093]

[0094] Cross-linking agent: TMMG 0.75 g;

[0095] Nitrogen-containing basic compound: TOA 0.06g;

[0096] Surfactant: BYK-307 (manufacturer: BYK) 0.005 g;

[0097] Solvent: PGMEA 60g.

[0098] The above components are weighed and mixed, and then stirred thoroughly to completely dissolve them. The mixture is then filtered through a polytetrafluoroethylene microporous filter membrane with a pore size of 0.1 μm to obtain a photoresist composition 1.

[0099] Example 2

[0100] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.65 g of compound 2-A4-1 to prepare a photoresist composition 2.

[0101] Example 3

[0102] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.50 g of Compound 1-2 to prepare Photoresist Composition 3.

[0103] Example 4

[0104] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.56 g of compound 2-A1-2 to prepare photoresist composition 4.

[0105] Example 5

[0106] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.60 g of compound 2-A2-2 to prepare photoresist composition 5.

[0107] Example 6

[0108] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.75 g of compound 2-A3-2 to prepare a photoresist composition 6.

[0109] Example 7

[0110] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.63 g of Compound 3-1 to prepare a photoresist composition 7.

[0111] Example 8

[0112] The process was the same as that of Example 1, except that the amount of the polyhydroxyphenyl compound-containing additive was adjusted to 0.68 g of compound 2-A5-1 to prepare a photoresist composition 8.

[0113] Example 9

[0114] The process was the same as that of Example 1 except that the mass of the cross-linking agent TMMG was adjusted to 0.60 g to prepare a photoresist composition 9.

[0115] Example 10

[0116] The process was the same as that of Example 1, except that the mass of the cross-linking agent TMMG was adjusted to 0.81 g to prepare a photoresist composition 10.

[0117] Example 11

[0118] The photoresist composition 11 is prepared in the same manner as in Example 1, except that PHS is replaced by (parahydroxystyrene-styrene) copolymer (English name: P(HS-co-styrene), with a weight-average molecular weight of Mw=3900, PDI=1.75, and the molar percentages of structural unit IV-1, structural unit IV-2, and structural unit IV-1 are 86.4 mol%:13.6 mol%:0 mol%), the mass of the additive compound 2-A4-2 containing a polyhydroxyphenyl compound is adjusted to 1.02 g, and the mass of the crosslinker TMMG is adjusted to 0.95 g.

[0119] Comparative Example 1

[0120] The photoresist composition 12 was prepared in the same manner as in Example 1, except that the additive containing the polyhydroxyphenyl compound was not included.

[0121] Comparative Example 2

[0122] Except that poly(p-hydroxystyrene) is replaced by (p-hydroxystyrene-styrene) copolymer (English name: P(HS-co-styrene), weight average molecular weight Mw=3900, PDI=1.75, molar percentages of structural unit IV-1, structural unit IV-2 and structural unit IV-1 are 86.4 mol%:13.6 mol%:0 mol%) to prepare photoresist composition 13, the rest is the same as comparative example 1.

[0123] Test methods and equipment:

[0124] The photoresist composition obtained in each embodiment and comparative example was coated on an 8-inch single crystal silicon wafer by spin coating. After the coating was completed, the substrate that was coated with the photoresist was pre-baked on a hot plate for 100° C. / 60s. The rotating speed was adjusted so that the dried film thickness was 0.58 μm. Subsequently, a DUV exposure machine was used to expose the substrate. The exposed substrate was post-baked on a hot plate for 115° C. / 60s. Finally, the substrate was spray-developed with 2.38wt% tetramethylammonium hydroxide for 60s. After the operation was completed, a scanning electron microscope (CD-SEM) (Hitachi S9220) was used to detect the pattern formed after the development.

[0125] If there is no development residue on the 0.25 μm isolated line (iso line), the evaluation result is marked as good. If there is development residue on the 0.25 μm iso line, the evaluation result is marked as poor.

[0126] If there is no bridging defect in the 0.21 μm iso space, the evaluation result is marked as good. If there is a bridging defect in the 0.21 μm iso space, the evaluation result is marked as poor.

[0127] The preparation parameters of the photoresist compositions prepared in various examples and comparative examples are shown in Table 1, and the test evaluation results are shown in Table 2.

[0128] Table 1

[0129]

[0130]

[0131] Note: N represents the mass ratio of the polymer containing p-hydroxystyrene structural units, the additive containing a polyhydroxyphenyl compound, the photoacid generator, the crosslinking agent, the nitrogen-containing basic compound, and the surfactant. The “\” in Table 1 indicates that there is no corresponding substance or parameter. The difference between Comparative Example 2 and Comparative Example 1 is the different types of polymers containing p-hydroxystyrene structural units.

[0132] Table 2

[0133]

[0134] As can be seen from Examples 1 to 11, Comparative Example 1, and Comparative Example 2 in Table 1, the photoresist composition of the present application, by adding an additive containing a polyhydroxyphenyl compound, improves the dissolution rate of the non-exposed area, thereby solving the problem of residues on the surface of the photoresist pattern after development. Furthermore, due to the large number of cross-linkable hydroxyl groups in the structure of the photoresist composition and the high cross-linking density in the exposed area, the dissolution rate difference between the exposed and non-exposed areas is further increased, thereby improving the contrast of the photoresist and solving the problem of bridging defects in the spacers of the photoresist pattern after development. However, the photoresist composition of Comparative Example 1 does not include an additive containing a polyhydroxyphenyl compound, and thus fails to solve the problem of bridging defects in the spacers of the photoresist pattern after development. The photoresist composition of Comparative Example 2 does not include an additive containing a polyhydroxyphenyl compound, and thus fails to solve the problem of residues on the surface of the photoresist pattern after development, nor does it solve the problem of bridging defects in the spacers of the photoresist pattern after development.

[0135] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0136] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A photoresist composition comprising an additive containing a polyhydroxyphenyl compound, wherein the additive containing a polyhydroxyphenyl compound is selected from the polyhydroxyphenyl compound represented by the general formula (III): In the general formula (III), R 12 、R 13 、R 14 and R 15 Each is independently selected from a hydrogen atom, a C1-C4 alkyl group, a hydroxymethyl group or a polyhydroxyphenyl group; m5 and n5 represent the number of hydroxyl groups, and m5 and n5 are each independently an integer of 1 to 4; The number of hydroxyl groups in each of the polyhydroxyphenyl groups is independently selected from 2 to 6; The photoresist composition further comprises the following components: a polymer containing a p-hydroxystyrene structural unit, a photoacid generator, a crosslinking agent, a nitrogen-containing basic compound, a surfactant, and a solvent; The mass ratio of the polymer containing p-hydroxystyrene structural units, the additive containing a polyhydroxyphenyl compound, the photoacid generator, the crosslinking agent, the nitrogen-containing basic compound, and the surfactant is 100:(1-20):(1-10):(1-10):(0.01-1):(0.005-0.5).

2. The photoresist composition according to claim 1, wherein The polyhydroxy polyphenyl compound represented by the general formula (III) is selected from the following compounds:

3. The photoresist composition according to claim 1, wherein The polymer containing p-hydroxystyrene structural units comprises one or more of structural units IV-1, IV-2 and IV-3: Among them, the molar percentages of the structural unit IV-1, the structural unit IV-2 and the structural unit IV-1 are (70mol%~100mol%):(0mol%~30mol%):(0mol%~10mol%), and the total molar percentages of the structural unit IV-1, the structural unit IV-2 and the structural unit IV-3 are 100%.

4. The photoresist composition according to claim 3, wherein The weight average molecular weight Mw of the polymer containing p-hydroxystyrene structural units is 1,000 to 10,000.

5. The photoresist composition according to claim 1, wherein The photoacid generator is selected from at least one of a sulfonium salt type acid generator, an iodonium salt type acid generator, an N-imidosulfonate type acid generator, a diazomethane type acid generator, and a nitrobenzenesulfonate type acid generator; The cross-linking agent is selected from at least one of an etherified amino cross-linking agent and an etherified polyphenyl cross-linking agent; The nitrogen-containing basic compound is at least one selected from alkylamines, alkylolamines, alkylamine hydroxides, alkoxyalkylamines, cyclic amines, and polymeric amines; The surfactant is selected from at least one of a silicone-containing nonionic surfactant and a fluorine-containing nonionic surfactant. 6 . Use of the photoresist composition according to claim 1 as a deep ultraviolet KrF negative photoresist.

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