A thick film photoresist composition, a preparation method thereof and an application thereof

Abstract

The present invention discloses a thick film photoresist composition, a preparation method and an application thereof. The photoresist composition of the present invention comprises the following components: a resin, a photoacid generator and a solvent. The film formed by the photoresist composition of the present invention has good performance and has good application prospects.

Description

Technical Field

[0001] The present invention relates to a thick film photoresist composition, a preparation method thereof and an application thereof. Background Art

[0002] Currently, in the field of semiconductor manufacturing, in the chip manufacturing processes such as LCD (Liquid Crystal Display) / BUMP bump / MEMS Micro-Electro-Mechanical System / 3D-NAND memory, KrF light source thick film photoresist is used. Such photoresist is neither the same as the conventional KrF thin film photoresist nor the photoresist of ArF light source, but has its own unique properties.

[0003] At present, although the integrated circuit semiconductor chip manufacturing technology is developing rapidly, the technology of such thick film photoresist of KrF light source supporting it is not completely mature, which is a hot field in the research of KrF type photoresist.

[0004] There are many problems existing in the KrF light source thick film photoresist currently. For example, film cracking, poor film thickness uniformity, many defects, poor resolution and sensitivity, poor film stripping property, poor shape, poor rectangularity, poor resolution, insufficient heat resistance, inability to suppress the fluctuation phenomenon, and serious impurities, etc.

[0005] Therefore, there is an urgent need in the art to develop a thick film photoresist that can comprehensively solve the above problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a thick film photoresist composition, a preparation method thereof and an application thereof in order to overcome the defects in the prior art such as easy cracking of the photoresist film, poor film thickness uniformity, many defects, poor resolution and sensitivity, poor film stripping property, poor shape, poor rectangularity, poor resolution, insufficient heat resistance, inability to suppress the fluctuation phenomenon or serious impurities, etc. The gel film formed by using this photoresist composition has at least any one of the following advantages: not easy to crack, uniform film thickness, few defects, high resolution and sensitivity, good film stripping property, excellent shape, good rectangularity, strong resolution, strong heat resistance, ability to suppress the fluctuation phenomenon and few impurities.

[0007] The present invention provides a photoresist composition, which comprises the following components: resin, photoacid generator and solvent;

[0008] The resin is prepared by the following preparation method, and the preparation method comprises the following steps:

[0009] In the presence of benzoyl peroxide, the monomers represented by formula A, the monomers represented by formula B, the monomers represented by formula C, the monomers represented by formula D, and the monomers represented by formula E are polymerized in ethyl acetate to obtain the resin; wherein, the number of parts by weight of the monomers represented by formula D is 1-10 parts, and the number of parts by weight of the monomers represented by formula E is 1-10 parts;

[0010] The temperature of the polymerization reaction is 75-80 °C;

[0011]

[0012] In formula A, R 1 is R 1a substituted 5-10 membered heteroalkyl or -CH 2 (C=O)OR 1b ;

[0013] R 1b is R 1b-1 substituted 5-10 membered heteroalkyl;

[0014] R 1a and R 1b-1 are independently oxo, cyano or C 1-4 alkyl;

[0015] The R 1a substituted 5-10 membered heteroalkane and the R 1b-1 substituted 5-10 membered heteroalkyl have heteroatoms as O, and the number is 1 or 2;

[0016] In formula B, R 2 is

[0017] n 1 is any integer from 1 to 4;

[0018] n 2 is any integer from 1 to 4;

[0019] Y is a straight bond or (CH 2 )n 3 ;

[0020] n 3 is any integer from 1 to 5;

[0021] R 2a and R 2b are independently C 1-4 alkyl, hydroxy-substituted C 1-4 alkyl, phenyl, R 2a-1 substituted phenyl, naphthyl, 5-6 membered cycloalkyl or adamantyl, and R2a and R 2b are independently not phenyl at the same time;

[0022] R 2a-1 is an alkyl group of C 1-4 or an alkoxy group of C 1-4 ;

[0023] Alternatively, R 2a and R 2b together with the nitrogen atom to which they are attached form a 5- or 6-membered heterocycloalkyl group or an R 2b-1 -substituted 5- or 6-membered heterocycloalkyl group, and the heteroatoms in the 5- or 6-membered heterocycloalkyl group and the R 2b-1 -substituted 5- or 6-membered heterocycloalkyl group are independently selected from O and N, and the number is 1 or 2;

[0024] R 2b-1 is an alkyl group of C 1-4 or an amino protecting group;

[0025] In formula C, is a single bond or a double bond;

[0026] R 3a 、R 3b and R 3c are independently H, a hydroxyl group, a cyano group, -(C=O)OR 3a-1 、-O(C=O)R 3a-2 、an alkyl group of C 1-4 or a hydroxyl-substituted alkyl group of C 1-4 ; and R 3a 、R 3b and R 3c are not H at the same time;

[0027] R 3a-1 is H, an alkyl group of C 1-5 、

[0028] R 3a-2 is an alkyl group of C 1-4 or a phenyl group;

[0029] Alternatively, any two of R 3a 、R 3b and R 3c together with the carbon atom to which they are attached form a phenyl group, a 5- to 7-membered cycloalkyl group, a 5- to 7-membered cycloalkenyl group,

[0030] In formula D, n 4 is 0 or 1;

[0031] R 4a and R 4b are independently H or C1-4 alkyl; and R 4a and R 4b are not simultaneously H;

[0032] In formula E, R 5 is H, cyano, C 1-4 alkyl, R 5a substituted C 1-4 alkyl or -(C=O)OR 5b ;

[0033] R 5a is hydroxyl or acetyl;

[0034] R 5b is C 1-4 alkyl;

[0035] The photoacid generator described above is PAG1 and / or PAG2, and its structure is shown as follows:

[0036]

[0037] In the present invention, when R 1 is a 5-10 membered heteroalkyl group substituted by R 1a , the 5-10 membered heteroalkyl group is preferably a 5, 6, 9 or 10 membered heteroalkyl group.

[0038] In the present invention, when R 1b is a 5-10 membered heteroalkyl group substituted by R 1b-1 , the 5-10 membered heteroalkyl group is preferably a 5, 9 or 10 membered heteroalkyl group.

[0039] In the present invention, when the said R 1a and R 1b-1 are independently C 1-4 alkyl, the C 1-4 alkyl is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably methyl.

[0040] In the present invention, when R 1 is a 5-10 membered heteroalkyl group substituted by R 1a , the 5-10 membered heteroalkyl group substituted by R 1a is preferably More preferably

[0041] In the present invention, when the said R 1b is a 5-10 membered heteroalkyl group substituted by R 1b-1 , the said R 1b-1The substituted 5- to 10-membered heterocycloalkyl is preferably more preferably

[0042] In the present invention, when R 2a and R 2b are independently an alkyl group of C 1-4 the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

[0043] In the present invention, when R 2a-1 is an alkyl group of C 1-4 the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably methyl or n-butoxy, sec-butoxy, isobutoxy or tert-butoxy.

[0044] In the present invention, when R 2a-1 is an alkoxy group of C 1-4 the alkoxy group of C 1-4 is preferably methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy or tert-butoxy, more preferably methoxy or n-butoxy, sec-butoxy, isobutoxy or tert-butoxy.

[0045] In the present invention, when R 2a and R 2b are independently a 5- to 6-membered cycloalkyl group, the 5- to 6-membered cycloalkyl group is preferably cyclopentyl or cyclohexyl.

[0046] In the present invention, when R 2a and R 2b together with the nitrogen atom to which they are attached form a 5- to 6-membered heterocycloalkyl group, the 5- to 6-membered heterocycloalkyl group is preferably

[0047] In the present invention, when R 2a and R 2b together with the carbon atom to which they are attached form an R 2b-1 substituted 5- to 6-membered heterocycloalkyl group, the heteroatom in the 5- to 6-membered heterocycloalkyl group is preferably N or O.

[0048] In the present invention, when R 2b-1 is an alkyl group of C 1-4 the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably methyl, n-butyl, sec-butyl, isobutyl or tert-butyl.

[0049] In the present invention, when R 2a and R 2b together with the carbon atom to which they are attached form an R 2b-1 -substituted 5- to 6-membered heteroalkyl group, the R 2b-1 -substituted 5- to 6-membered heteroalkyl group is preferably

[0050] In the present invention, when R 3a , R 3b and R 3c are independently an alkyl group of C 1-4 , the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably tert-butyl.

[0051] In the present invention, when R 3a , R 3b and R 3c are independently an alkyl group of C 1-4 substituted by a hydroxyl group, the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably methyl.

[0052] In the present invention, when R 3a-1 is an alkyl group of C 1-5 , the alkyl group of C 1-5 is preferably ethyl or

[0053] In the present invention, when R 3a-2 is an alkyl group of C 1-4 , the alkyl group of C 1-4 is preferably methyl.

[0054] In the present invention, when any two of the groups R 3a , R 3b and R 3c are attached to each other to form a 5- to 7-membered cycloalkyl group, the 5- to 7-membered cycloalkyl group is preferably cyclopentyl, cyclohexyl or

[0055] In the present invention, when any two of the groups R 3a , R 3b and R 3c are attached to each other to form a 5- to 7-membered cycloalkenyl group, the 5- to 7-membered cycloalkenyl group is preferably cyclopentenyl.

[0056] In the present invention, when R 4a and R 4b are independently H or an alkyl group of C 1-4 , the alkyl group of C 1-4The alkyl group is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably methyl, ethyl or n-propyl.

[0057] In the present invention, when R 5a is an alkyl group of C 1-4 the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably tert-butyl.

[0058] In the present invention, when R 5b is an alkyl group of C 1-4 the alkyl group of C 1-4 is preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert-butyl, more preferably methyl or ethyl.

[0059] In a preferred embodiment of the present invention, the composition further contains an additive, and the additive is selected from one or more of a leveling agent, a plasticizer, an organic base, a dissolution rate enhancer and a photosensitizer, and the weight parts of the additive are 5-10 parts.

[0060] In the present invention, the parts by weight of the resin can be the conventional parts in the art, preferably 10-45 parts, such as 10 parts, 20 parts, 25 parts, 30 parts, 35 parts or 45 parts.

[0061] In the present invention, the parts by weight of the photoacid generator can be the conventional parts in the art, preferably 0.6-5 parts, such as 0.6 parts, 3 parts, 5 parts or 5.5 parts.

[0062] In the present invention, the weight average molecular weight of the resin is preferably 3000-20000, such as 6000-19000.

[0063] In the present invention, the polydispersity index (PDI) of the resin is preferably 1.2-2.5, such as 1.5-2.3.

[0064] In the present invention, the parts by weight of the monomer represented by formula A can be the conventional parts in the art, preferably 35-65 parts, such as 35-48 parts, and also such as 35 parts, 40 parts, 45 parts or 48 parts.

[0065] In the present invention, the parts by weight of the monomer represented by formula B can be the conventional parts in the art, preferably 20-55 parts, such as 30-40 parts, and also such as 30 parts, 35 parts or 40 parts.

[0066] In the present invention, the parts by weight of the monomer represented by Formula C can be the conventional parts in the art, preferably 10 - 25 parts, such as 10 - 20 parts, and for another example, 10 parts, 15 parts or 20 parts.

[0067] In the present invention, the parts of the monomer represented by Formula D can be 5 - 10 parts, and for another example, 5 parts, 6 parts, 7 parts, 8 parts or 10 parts.

[0068] In the present invention, the parts of the monomer represented by Formula E can be 3 - 10 parts, and for another example, 3 parts, 4 parts, 5 parts, 7 parts or 10 parts.

[0069] In the present invention, the solvent is a conventional solvent in the art, such as at least one of cyclohexanone, diacetone alcohol, ethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate and dipropylene glycol monomethyl ether.

[0070] In the present invention, the parts by weight of the solvent can be the conventional parts in the art, preferably 60 - 85 parts, such as 50 - 85 parts, and for another example, 50 parts, 50 parts, 69.4 parts, 70 parts, 77 parts, 85 parts.

[0071] In the present invention, the monomer represented by Formula A is preferably any one of the following compounds:

[0072]

[0073] More preferably:

[0074]

[0075] In the present invention, the monomer represented by Formula B is preferably any one of the following compounds:

[0076]

[0077]

[0078] More preferably:

[0079]

[0080] In the present invention, the monomer represented by Formula C is preferably any one of the following compounds:

[0081]

[0082] More preferably:

[0083]

[0084] In the present invention, the monomer represented by Formula D is preferably any one of the following compounds:

[0085] In the present invention, the monomer represented by Formula E is preferably any one of the following compounds:

[0086]

[0087] More preferably:

[0088]

[0089] In the preparation method of the resin in the present invention, each monomer and its dosage are shown in any one of the following (1)-(10) groups, and Resin 1 to Resin 10 are obtained accordingly:

[0090] Resin 1: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 40:30:20:6:4;

[0091] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0092] Resin 2: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 45:35:10:7:3;

[0093] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0094] Resin 3: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 48:40:10:1:1;

[0095] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0096] Resin 4: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 40:30:15:8:7;

[0097] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0098] Resin 5: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 35:40:10:8:7;

[0099] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0100] Resin 6: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 40:30:20:5:5;

[0101] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0102] Resin 7: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 45:35:10:5:5;

[0103] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0104] Resin 8: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 40:40:10:5:5;

[0105] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0106] Resin 9: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 40:30:15:5:10;

[0107] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0108] Resin 10: The weight ratio of the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E is 35:45:10:10:5;

[0109] The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is

[0110] In the polymerization reaction, the mass ratio of benzoyl peroxide to "the monomer represented by Formula A, the monomer represented by Formula B, the monomer represented by Formula C, the monomer represented by Formula D, and the monomer represented by Formula E" can be a conventional mass ratio in the art, for example: 1:50.

[0111] In the polymerization reaction described above, the mass ratio of ethyl acetate to "the monomer represented by formula A, the monomer represented by formula B, the monomer represented by formula C, the monomer represented by formula D, and the monomer represented by formula E" can be a conventional mass ratio in the art, for example: 6:5.

[0112] The temperature of the polymerization reaction described above is preferably 77 °C.

[0113] The time of the polymerization reaction described above can be a conventional time in the art, for example 7 hours.

[0114] The post-treatment after the polymerization reaction described above preferably includes the following steps: cooling, precipitation, and drying.

[0115] Among them, the number of times of precipitation described above can be the conventional number of times of precipitation in the art, for example 3 times.

[0116] Among them, the solvent used in the precipitation described above can be an alcohol solvent, and further can be methanol.

[0117] Among them, the drying described above is preferably carried out in a vacuum drying oven.

[0118] In the present invention, the preparation method of the resin preferably includes the following steps:

[0119] Under nitrogen protection, the mixed solution 1 of "ethyl acetate and benzoyl peroxide" is added to the mixed solution 2 of "the monomer represented by formula A, the monomer represented by formula B, the monomer represented by formula C, the monomer represented by formula D, the monomer represented by formula E, and ethyl acetate";

[0120] Among them, the time of addition described above is preferably 10 min. In a preferred embodiment of the present invention, the resin is prepared by the method in the preparation of the resin in the specific embodiment.

[0121] In the present invention, the solvent described above can be a conventional solvent in the art, preferably one or more of a ketone solvent, an ester solvent, and an ether solvent. When the solvent is a ketone solvent, the ketone solvent can be cyclohexanone. The ester solvent can be ethyl acetate. The ether solvent can be ethylene glycol monomethyl ether and / or dipropylene glycol monomethyl ether.

[0122] In a preferred embodiment of the present invention, the photoresist composition is prepared from the following components: a photoacid generator, a resin, and a solvent; the type of the photoacid generator, the type and amount of the resin, and "the type and amount of the solvent" are the same as those described above.

[0123] In a preferred embodiment of the present invention, the photoresist composition consists of the following components: the photoacid generator, the resin, the solvent, and the additive; the number of parts of the photoacid generator, the type and number of parts of the resin, the type and number of parts of the solvent, and "the type and number of parts of the additive" are the same as those described above.

[0124] In a preferred embodiment of the present invention, the photoresist composition is any one of the following combinations:

[0125] Combination 1: "5 parts of PAG1, 25 parts of Resin 1, and 70 parts of cyclohexanone";

[0126] Combination 2: "5 parts of PAG2, 25 parts of Resin 2, and 70 parts of ethyl acetate";

[0127] Combination 3: "0.6 parts of PAG2, 30 parts of Resin 3, and 69.4 parts of ethylene glycol monomethyl ether";

[0128] Combination 4: "3 parts of PAG1, 20 parts of Resin 4, and 77 parts of cyclohexanone";

[0129] Combination 5: "5.5 parts of PAG2, 35 parts of Resin 5, and 59 parts of ethylene glycol monomethyl ether";

[0130] Combination 6: "5 parts of PAG1, 45 parts of Resin 6, and 50 parts of ethyl acetate";

[0131] Combination 7: "0.6 parts of PAG2, 30 parts of Resin 7, and 69.4 parts of dipropylene glycol monomethyl ether;

[0132] Combination 8: "5 parts of PAG1, 10 parts of Resin, and 85 parts of dipropylene glycol monomethyl ether";

[0133] Combination 9: "5.5 parts of PAG2, 35 parts of Resin 9, and 59 parts of ethyl acetate" and

[0134] Combination 10: "5 parts of PAG2, 45 parts of Resin 10, and 50 parts of ethylene glycol monomethyl ether".

[0135] The present invention also provides a method for preparing a photoresist, which includes the following steps: mixing the above components evenly.

[0136] In the preparation method, the mixing method can be a conventional mixing method in the art, preferably shaking.

[0137] In the preparation method, the mixing time can be a conventional mixing time in the art, preferably 18 - 30 hours, 24 hours.

[0138] After mixing, a filtration step may further be included. The filtration method may be a conventional method in the art, and preferably filtration is performed using a filter. The number of filtration times is preferably 2 - 3 times. The pore size of the filter membrane of the filter is preferably 20 - 50 nm or 2 - 20 nm. When the number of filtration times is 2 times, the pore size of the filter membrane of the first filter is larger than that of the second filter.

[0139] The pore size of the filter membrane of the first filter is preferably 20 - 50 nm. The pore size of the filter membrane of the first filter is preferably 2 - 20 nm.

[0140] The present invention also provides a method for forming a photolithography pattern, and the method includes the following steps:

[0141] Step 1: Coating the above-mentioned photoresist composition on the surface of a wafer substrate to form a photoresist layer;

[0142] Step 2: Baking the photoresist layer;

[0143] Step 3: Cooling the photoresist layer after baking in Step 2;

[0144] Step 4: Exposing the photoresist layer after cooling in Step 5;

[0145] Step 5: Baking the photoresist layer after exposure in Step 4;

[0146] Step 6: Developing and rinsing the photoresist layer after baking in Step 5.

[0147] In Step 1, the wafer is preferably pretreated. The pretreatment preferably deposits gaseous hexamethyldisilazane (HMDS) on the surface of the wafer substrate and cools it. The cooling temperature is preferably room temperature. The wafer is preferably 12 wafers.

[0148] In Step 1, the coating of the photoresist on the wafer is preferably performed in a spin coater.

[0149] In Step 1, the coating method is preferably spin coating.

[0150] In Step 1, the thickness of the photoresist layer is preferably 5 - 9 μm, such as 6 μm, 7 μm, or 8 μm.

[0151] In Step 2, the baking temperature is preferably 120 - 150 °C.

[0152] In Step 2, the baking time is preferably 80 - 150 seconds.

[0153] In Step 3, the cooling temperature of the photoresist layer is preferably room temperature.

[0154] In Step 4, the wavelength of the exposure is preferably 248 nm.

[0155] In Step 4, the intensity of the exposure is preferably 10 - 50 mJ / cm 2 .

[0156] In Step 5, the baking temperature is preferably 90 - 120 °C.

[0157] In Step 5, the baking time is preferably 90 - 130 seconds.

[0158] In Step 6, the developing instrument is a developing machine.

[0159] In Step 6, the developer for the developing is preferably an aqueous solution of tetramethylammonium hydroxide (TMAH), such as 2.38% TMAH.

[0160] In Step 6, the developing time is preferably 50 - 70 seconds, such as 60 seconds.

[0161] After the developing in Step 6, a rinsing step may further be included. The solvent used for the rinsing is water, such as pure water.

[0162] In the present invention, "alkyl" refers to a straight-chain or branched-chain alkyl having a specified number of carbon atoms.

[0163] In the present invention, "cycloalkyl" refers to a saturated monocyclic ring system (such as cyclopentyl, cyclohexyl) having a stable cyclic system or a saturated 2 - 4-membered bridged ring system (such as ).

[0164] In the present invention, "heterocycloalkyl" refers to a monocyclic ring (such as ) or a 2 - 4-membered bridged ring system (such as ) containing one or more heteroatoms of N, O, or S.

[0165] On the basis of not violating the common knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0166] The resin of the present invention is self-made, and other reagents and raw materials used are commercially available.

[0167] The positive and progressive effects of the present invention are as follows: The film formed by using the photoresist composition of the present invention has at least any one of the following advantages: not easily cracking, having uniform thickness, poor resolution and sensitivity, good film stripping property, good shape, good rectangularity, good resolution, good heat resistance, capable of suppressing fluctuation phenomena, and having few metal impurities. Detailed Description of the Invention

[0168] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0169] Preparation of Resin

[0170] The resins 1-15 used in the examples or comparative examples were prepared according to the following method. The respective monomers used are shown below:

[0171] Monomer A:

[0172]

[0173] Monomer B:

[0174]

[0175] Monomer C

[0176]

[0177] Monomer D:

[0178]

[0179] Monomer E:

[0180]

[0181] Step 1: Add the monomers A-E in the amounts shown in Table 1 into a reaction kettle filled with nitrogen, then add 100 g of ethyl acetate into the reaction kettle. After stirring evenly, heat the reaction kettle to 77 °C, and then dropwise add a mixed solution of ethyl acetate (20 g) and benzoyl peroxide (2 g) into the reaction kettle again. The dropping is completed in 10 min. React at 77 °C for 7 hours, stop the reaction, and cool the temperature of the reaction solution to room temperature;

[0182] Step 2: After the reaction solution is cooled to room temperature, add methanol (1000 g) into the reaction kettle to produce precipitation. After 1 h, drain the liquid in the reaction kettle, and add ethyl acetate into the reaction kettle until the precipitate dissolves (120 g);

[0183] Step 3: Add methanol (1000 g) into the reaction kettle in Step 2, repeat the operation in Step 2 three times to obtain a solid precipitate. Place the solid precipitate in a vacuum drying oven for drying to obtain 78 g of modified film-forming resin.

[0184] Measure the weight-average molecular weight and polydispersity index (PDI) of the modified film-forming resin using a gel permeation chromatography (GPC) device.

[0185] Table 1

[0186]

[0187] In the following Examples or Comparative Examples, the photoresist compositions were prepared according to the following method:

[0188] Examples 1-10 and Comparative Examples 1-10

[0189] Photoacid generator:

[0190]

[0191] The raw materials in Table 2 were added to a new clean 100 mL glass bottle. At room temperature, the mixture was shaken in the bottle for 24 hours to dissolve it completely, and then the photoresist solution was filtered successively through 0.22 μm and 0.02 μm filters to obtain the photoresist composition.

[0192] Table 2

[0193]

[0194]

[0195] Effect Examples

[0196] In the HMDS chamber of the spin coater, gaseous HMDS was deposited on the surface of the wafer substrate. The photoresists of Examples 1-10 and Comparative Examples 1-10 were spin-coated on the HMDS-pretreated 12" silicon wafers and spun into films at a speed of 1000-3000 revolutions per minute, baked on a hot plate at 120 °C for 90 seconds, cooled to room temperature in the cold plate chamber, and then exposed on an exposure machine. The wavelength of the exposure machine was 248 nm, and the exposure intensity was 10-50 mJ / cm 2 . After exposure, it was baked on a hot plate at 110 °C for 90 seconds, and finally developed in a 2.38% TMAH developer for 60 seconds, and then dried for inspection of the lithography results under an electron microscope.

[0197] The model of the exposure machine was 248 nm KrF stepper: Nikon S204B, 0.55 NA, 0.33 Sigma (NA: numerical aperture; Sigma: aperture).

[0198] 1. Crack resistance

[0199] The crack resistance of the photoresist film surface was observed using an SEM device (device name: "S8840"; manufactured by Hitachi Corporation).

[0200] 2. Viscosity test

[0201] The viscosity (at 25 °C) of the thick film photoresist was measured using an automatic viscosity measuring device VMC-252 (manufactured by Clutch Co., Ltd.).

[0202] 3. Film thickness measurement

[0203] The film thickness (nm) of the photoresist at 49 measurement points on the wafer was measured using a photoresist film thickness measuring device, Nano Tester (manufactured by Nanometrics, Inc.).

[0204] 4. In-plane uniformity evaluation of film thickness

[0205] 3σ is three times the standard error (σ) calculated from the 49 measurement results. The smaller the value of this 3σ, the smaller the in-plane non-uniformity of the film thickness, and a photoresist with high-quality in-plane uniformity can be obtained.

[0206] 5. Defect evaluation

[0207] Defects were measured using a surface defect measuring device KLA2132 (trade name) manufactured by KLA-TENCOR CORPORATION, and the number of defects on the substrate was evaluated.

[0208] 6. Resolution limit CD (Critical Dimension) (nm)

[0209] Observation was carried out using an electron microscope, and the space width at the substrate interface in the cross-section of the non-photoresist part (line / space = 4:1) in the photoresist pattern was evaluated as the resolution limit CD.

[0210] 7. Shape evaluation

[0211] From the results of the cross-sectional SEM of the developed wafer, it was possible to resolve down to the substrate. Those with good linearity of the pattern (rectangular shape) were evaluated as A, and those that could not be resolved down to the substrate but had poor linearity of the pattern (bottom protrusion) were evaluated as B.

[0212] 8. Rectangularity evaluation of the cross-sectional shape of the pattern

[0213] By observing the cross-sectional shape of the pattern using SEM, those with almost perpendicular side cuts were designated as A, those with a roughly conical shape were designated as B, those with wavy sides were designated as C, and those with wavy sides were designated as D.

[0214] 9. Evaluation of developability

[0215] Using a mask, the exposure amount was changed, and the space width of the photoresist pattern was observed. The smallest space width (unit: micrometer) in the space width was used as an index for the evaluation of developability.

[0216] 10. Evaluation of film peeling after vacuum treatment

[0217] The evaluation pattern wafer was placed in a pressure-resistant container and vacuum treatment was performed (left at 0.01 Torr for 15 minutes). The wafer after vacuum treatment was observed using an optical microscope (manufactured by Olympus Corporation) in the optical microscope mode with a scanning confocal laser microscope (model: LEXT OLS3100) to observe film peeling on the wafer surface. The case where the number of film peelings exceeded 100 was counted as D, the case where the number of film peelings was 6 to 100 was counted as C, the case where the number of film peelings was 2 to 5 was counted as B, the case where the number of film peelings was 1 was counted as A, and the case where the number of film peelings was 0 was counted as S.

[0218] 11. Sensitivity Evaluation

[0219] The exposure time required to form a pattern consisting of line-and-space width (L&S) components with each width of 1.5 μm (1:1) according to the aforementioned lithography method is expressed in milliseconds (ms) (Eop exposure amount).

[0220] 12. Evaluation of Fluctuation Phenomena

[0221] Using a critical dimension measurement SEM, the profile of the obtained resist pattern was observed by passing through the L&S resist pattern with a width of 1.5 μm from the right side. The case where the fluctuation phenomenon could not be recognized was designated as "A", and the case where the fluctuation phenomenon could be recognized was designated as "B".

[0222] 13. Measurement of Depth of Field (DOF)

[0223] The Eop exposure amount required for the specified dimensions of the mask pattern (line width: 1.5 μm, L&S resist pattern: 1:1) was used as the standard exposure amount. Then, cross-sectional SEM photos of the L&S (line width: 1.5 μm, L&S resist pattern: 1:1) profile were taken at the irradiation dose under the condition of moving the focus up and down using SEM, and then exposed and developed further. The maximum value (μm) of the focus deviation required to obtain a rectangular resist pattern with a width of 1.5 μm within the specified dimensions of ±10% in the SEM micrograph was considered as the depth of field.

[0224] 14. Heat Resistance Test

[0225] In the same manner as above, an L&S resist pattern with a width of 1.5 μm was formed at the exposure amount (Eop) obtained through the above sensitivity test and heat treatment at 140 °C for 300 seconds was performed. Then, the cross-sectional profile was observed by SEM. The case where almost no deformation of the resist pattern was observed was designated as "A", and the case where shrinkage of the resist pattern could be observed was designated as "B".

[0226] 15. Metal Impurities

[0227] The content of 25 metal impurity components (Na, K, Ca, Fe, Cu, Mg, Mn, Al, Li, Cr, Ni, Sn, Zn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, Mo, Zr) contained in each component was measured using the ICP-MS device (Inductively Coupled Plasma Mass Spectrometer) "Agilent 7500cs" manufactured by Agilent Technologies. When the content of the metal impurity with the highest content was greater than 10 ppb, it was denoted as B; when it was less than 10 ppb, it was denoted as A.

[0228] Table 3

[0229]

[0230] Table 4

[0231]

[0232] Note: " / " in Tables 3 and 4 indicates that the test was not conducted.

[0233] As can be seen from Table 3 above, the thick film formed by the photoresist composition of the present invention has no cracking, good film thickness uniformity (3σ is below 42), few defects, a resolution in the range of 514 - 681 nm, a rectangular cross-sectional shape, good developability (the space width of the resist pattern is in the range of 1.3 - 1.8 microns), less film peeling after treatment (SABC), high sensitivity (253 - 291 ms), strong heat resistance (the deformation of the resist pattern can hardly be observed), can suppress the fluctuation phenomenon, and few impurities (the minimum amount of impurities can be below 10 ppb).

[0234] Taking the evaluation of film peeling after vacuum treatment as an example, through the comparison of the evaluation of film peeling after vacuum treatment of "Example 1 and Comparative Examples 1 - 7", "Example 2 and Comparative Examples 8 - 9", and "Examples 1 - 10 and Comparative Example 10" in Tables 3 and 4, it can be seen that for the resist films formed by the photoresist compositions outside the resin range, photoacid generator range, and the range of "resin and photoacid generator" of the present invention, the film peeling parts are all higher than those of the resist film formed by the photoresist composition of the present invention. The resist film formed by the photoresist composition within the scope of the present invention has fewer film peeling parts. It can be seen that the photoresist composition within the scope of the present invention has good performance.

Claims

1. A photoresist composition, characterized in that it comprises the following components: a resin, a photoacid generator, and a solvent; the resin is prepared by the following preparation method, and the preparation method comprises the following steps: in the presence of benzoyl peroxide, polymerize the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E in ethyl acetate to obtain the resin; wherein, the number of parts by weight of the monomer shown in formula D is 1-10 parts, and the number of parts by weight of the monomer shown in formula E is 1-10 parts; the polymerization reaction temperature is 75-80 °C; the monomer shown in formula A is any one of the following compounds: the monomer shown in formula B is any one of the following compounds: the monomer shown in formula C is any one of the following compounds: the monomer shown in formula D is any one of the following compounds: the monomer shown in formula E is any one of the following compounds: the photoacid generator is PAG1 and / or PAG2, and its structure is shown as follows:

2. The photoresist composition according to claim 1, characterized in that the number of parts of the resin is 10-45 parts; and / or, the number of parts of the photoacid generator is 0.6-5 parts; and / or, the weight average molecular weight of the resin is 3000-20000; and / or, the polydispersity index of the resin is 1.2-2.5; and / or, the number of parts of the monomer shown in formula A is 35-65 parts; and / or, the number of parts of the monomer shown in formula B is 20-55 parts; and / or, the number of parts of the monomer shown in formula C is 10-25 parts; and / or, the number of parts of the monomer shown in formula D is 5-10 parts; and / or, the number of parts of the monomer shown in formula E is 3-10 parts; and / or, the solvent is at least one of cyclohexanone, diacetone alcohol, ethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether; and / or, the number of parts of the solvent is 60-85 parts.

3. The photoresist composition according to claim 2, characterized in that the number of parts of the resin is 10 parts, 20 parts, 25 parts, 30 parts, 35 parts or 45 parts; and / or, the number of parts of the photoacid generator is 0.6 parts, 3 parts, 5 parts or 5.5 parts; and / or, the weight average molecular weight of the resin is 6000-19000; and / or, the polydispersity index of the resin is 1.5-2.3; and / or, the number of parts of the monomer shown in formula A is 35-48 parts; and / or, the number of parts of the monomer shown in formula B is 30-40 parts; and / or, the number of parts of the monomer shown in formula C is 10-20 parts; and / or, the number of parts of the monomer shown in formula D is 1 part, 5 parts, 6 parts, 7 parts, 8 parts or 10 parts; and / or, the number of parts of the monomer shown in formula E is 1 part, 3 parts, 4 parts, 5 parts, 7 parts or 10 parts; and / or, the number of parts of the solvent is 50-85 parts.

4. The photoresist composition according to claim 1, It is characterized in that in the preparation method of the resin, the monomers and their dosages are shown in any one of the following (1)-(10), and resins 1 to 10 are obtained correspondingly in sequence: Resin 1: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 40:30:20:6:4; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 2: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 45:35:10:7:3; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 3: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 48:40:10:1:1; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 4: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 40:30:15:8:7; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 5: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 35:40:10:8:7; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 6: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 40:30:20:5:5; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 7: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 45:35:10:5:5; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 8: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 40:40:10:5:5; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 9: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 40:30:15:5:10; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is Resin 10: The weight ratio of the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, and the monomer shown in formula E is 35:45:10:10:5; The monomer represented by Formula A is The monomer represented by Formula B is The monomer represented by Formula C is The monomer represented by Formula D is The monomer represented by Formula E is 5. The photoresist composition according to claim 1, it is characterized in that the preparation method includes the following steps: Under nitrogen protection, add the mixed solution of "ethyl acetate and benzoyl peroxide" to the mixed solution of "the monomer shown in formula A, the monomer shown in formula B, the monomer shown in formula C, the monomer shown in formula D, the monomer shown in formula E, and ethyl acetate"; wherein, the addition time is 10 min.

6. The photoresist composition according to claim 1, wherein, the photoresist composition further contains an additive, and the additive is selected from at least one of a leveling agent, a plasticizer, an organic base, a dissolution rate enhancer, and a photosensitizer; the additive is in an amount of 5 - 10 parts by weight.

7. The photoresist composition according to any one of claims 1 - 5, wherein, the photoresist composition is composed of the following components: the photoacid generator, the resin, and the solvent.

8. The photoresist composition according to claim 4, wherein, the photoresist composition is any one of the following combinations: Combination 1: "5 parts of PAG1, 25 parts of Resin 1, and 70 parts of cyclohexanone"; Combination 2: "5 parts of PAG2, 25 parts of Resin 2, and 70 parts of ethyl acetate"; Combination 3: "0.6 part of PAG2, 30 parts of Resin 3, and 69.4 parts of ethylene glycol monomethyl ether"; Combination 4: "3 parts of PAG1, 20 parts of Resin 4, and 77 parts of cyclohexanone"; Combination 5: "5.5 parts of PAG2, 35 parts of Resin 5, and 59 parts of ethylene glycol monomethyl ether"; Combination 6: "5 parts of PAG1, 45 parts of Resin 6, and 50 parts of ethyl acetate"; Combination 7: "0.6 part of PAG2, 30 parts of Resin 7, and 69.4 parts of dipropylene glycol monomethyl ether; Combination 8: "5 parts of PAG1, 10 parts of Resin 8, and 85 parts of dipropylene glycol monomethyl ether"; Combination 9: "5.5 parts of PAG2, 35 parts of Resin 9, and 59 parts of ethyl acetate" and Combination 10: "5 parts of PAG2, 45 parts of Resin 10, and 50 parts of ethylene glycol monomethyl ether".

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