A positive photoresist composition and its preparation and use method

Abstract

The present invention relates to a positive photoresist composition and its preparation and use methods. The photoresist composition comprises the following components in percentage by mass: a polymer resin, which accounts for 15-25% of the total mass of the photoresist composition; a naphthalimide-type photoacid generator, which accounts for 1.0-6.0% of the polymer resin; an acid diffusion controller, which accounts for 8-40% of the naphthalimide-type photoacid generator; a leveling agent, which accounts for 0.1-0.5% of the total mass of the photoresist composition; and a solvent, which makes up 100% of the total mass. The polymer resin comprises a first polymer resin and a second polymer resin. The preparation method comprises the following steps: mixing the components of the positive photoresist composition. The use method comprises the following steps: coating the positive photoresist composition on a silicon wafer, and sequentially performing pre-baking, exposure, post-baking, and development to obtain a photoresist pattern. The positive photoresist composition provided by the present invention can effectively reduce the standing wave effect, increase the verticality of the sidewalls of the photoresist pattern, and improve the resolution of the photoresist imaging.

Description

Technical Field

[0001] The present invention relates to the technical field of photoresists, and in particular to a positive photoresist composition and a preparation and use method thereof. Background Art

[0002] Photoresist is a key material in the manufacture of integrated circuits, and its performance directly affects the integration, operating speed, power consumption and other performance of integrated circuit chips.

[0003] Photoresist, also known as photoresist, is a photosensitive polymer material with high sensitivity to light and radiation. Upon exposure to ultraviolet light, electron beams, excimer laser beams, ion beams, X-rays, and other materials, it undergoes a photochemical reaction, causing the film's solubility properties to change before and after exposure. Therefore, it can be categorized as either positive or negative photoresist. Photoresists primarily consist of film-forming resins, photoacid generators, acid diffusion controllers, and solvents.

[0004] When deep ultraviolet photoresist is exposed, light shines through the photoresist onto the silicon (Si) substrate. At the interface between the photoresist and the substrate, the light will be reflected. These reflected lights and the incident light will interfere with each other, causing the light intensity to be unevenly distributed along the depth of the photoresist, forming a standing wave effect. Summary of the Invention

[0005] The purpose of the present invention is to provide a positive photoresist composition and its preparation and use method to reduce the standing wave effect of the photoresist.

[0006] In order to achieve the purpose of the present invention, this application provides the following technical solutions.

[0007] In a first aspect, the present application provides a positive photoresist composition, comprising the following components in percentage by mass:

[0008]

[0009]

[0010] The polymer resin includes a first polymer resin and a second polymer resin; the first polymer resin is a copolymer of a hydroxystyrene compound, a styrene compound and a tert-butyl acrylate compound; the second polymer resin is a copolymer of a hydroxystyrene compound, an acetal-protected hydroxystyrene compound and a compound of formula I;

[0011] The structure of the compound of general formula I is as follows:

[0012]

[0013] In formula I, P1 is a hydrogen atom or a C1-C4 alkyl group; P2, P3 and P4 are each independently a C1-C 10 and at least one of P2, P3 and P4 is C4~C 10 The cycloalkyl group or any two of P2, P3 and P4 may be bonded to form a ring.

[0014] The present application uses a polymer resin containing a compound of formula 1, which undergoes a chemical reaction in the photoresist after exposure. The generated substance remains in the photoresist and can plasticize the polymer, thereby facilitating the diffusion of the photoacid generator in the exposed area, thereby reducing the standing wave effect of the photoresist.

[0015] In one embodiment of the first aspect, the compound of formula I is selected from at least one of the following structures:

[0016]

[0017]

[0018]

[0019] In one embodiment of the first aspect, the photoresist composition further comprises at least one of the following technical features:

[0020] a1) the mass ratio of the first polymer resin to the second polymer resin is (1:2) to (4:1);

[0021] a2) the weight average molecular weight of the first polymer resin is 8000 to 17000;

[0022] a3) the molecular weight distribution coefficient of the first polymer resin is PDI<2.5;

[0023] a4) The first polymer resin is obtained by polymerization of monomers having the following molar ratios:

[0024] Hydroxystyrene compounds 60-65%;

[0025] Styrene compounds 15-25%;

[0026] Tert-butyl acrylate compound 15-25%;

[0027] a5) the weight average molecular weight of the second polymer resin is 5000 to 15000;

[0028] a6) the molecular weight distribution coefficient of the second polymer resin is PDI<2.5;

[0029] a7) The second polymer resin is obtained by polymerization of monomers in the following molar ratios:

[0030] Hydroxystyrene compounds 60-70%;

[0031] 5-25% of acetal-protected hydroxystyrene compound;

[0032] 15-30% of the compound of formula I.

[0033] In one embodiment of the first aspect, the naphthalimide photoacid generator has a structure represented by the following general formula II:

[0034]

[0035] In formula II, R1 is selected from a hydrogen atom or a C1-C6 linear or branched aliphatic saturated hydrocarbon group, wherein the carbon atoms of the aliphatic saturated hydrocarbon group may be substituted by oxygen atoms or sulfur atoms;

[0036] R2 is selected from C1~C 10 Straight-chain aliphatic saturated hydrocarbon group or C6~C 10 aromatic group, the hydrogen atoms of the aliphatic saturated hydrocarbon group may be substituted by fluorine atoms, the C6~C 10 The hydrogen atom of the aromatic group may be substituted with a fluorine atom.

[0037] In one embodiment of the first aspect, the naphthalimide photoacid generator is selected from at least one of the following structures:

[0038]

[0039]

[0040]

[0041] In one embodiment of the first aspect, the photoresist composition further comprises at least one of the following technical features:

[0042] b1) the acid diffusion controller is selected from at least one of triethanolamine, tetrabutylammonium hydroxide, tri(3,6-dioxaheptyl)amine, trioctylamine, triisopropanolamine, triethylenediamine, 2-ethyl-N,N-bis(2-ethylhexyl)-1-hexylamine, 2,6-di-tert-butylpyridine, 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, 2-phenylbenzimidazole, and diphenylamine;

[0043] b2) the leveling agent is selected from at least one of 3M fluorocarbon surfactant FC-4430 and Troysol S366;

[0044] b3) the solvent is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, anisole, propylene glycol monoacetate, propylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ethyl ether, butyl acetate, neopentyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, diacetone alcohol, and gamma-butyrolactone.

[0045] In a second aspect, the present application also provides a method for preparing the positive photoresist composition as described above, the preparation method comprising the following steps: adding the polymer resin, the naphthalimide photoacid generator, the acid diffusion controller, and the leveling agent to a solvent in proportion and mixing, and filtering to obtain a photoresist.

[0046] In one embodiment of the second aspect, the pore size of the membrane used for filtration is a nylon membrane of 1.0 μm+1.0 μm+1.0 μm.

[0047] In a third aspect, the present application further provides a method for using the positive photoresist composition as described above, the method comprising the following steps:

[0048] The positive photoresist composition is coated on a silicon wafer, and sequentially subjected to pre-baking, exposure, post-baking and development to obtain a desired photolithographic pattern.

[0049] In one embodiment of the third aspect, the method of use further includes at least one of the following technical features:

[0050] c1) The pre-baking temperature is 90-130°C and the pre-baking time is 70-110s;

[0051] c2) The exposure energy is 20-25 mj / m 2 ;

[0052] c3) the post-baking temperature is 110-150°C and the post-baking time is 50-90s;

[0053] c4) The developer used in the development was 2.38% TMAH, and the development time was 20 to 40 seconds.

[0054] Compared with the prior art, the present invention can effectively reduce the standing wave effect, increase the verticality of the sidewalls of the photoresist pattern, and improve the resolution of photoresist imaging by mixing a first polymer resin and a second polymer resin containing a compound of general formula I and selecting an appropriate content. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 This is the photolithographic pattern after the photoresist prepared in Example 1 is used.

[0056] Figure 2This is the photolithographic pattern after the photoresist prepared in Example 2 is used.

[0057] Figure 3 This is the photolithographic pattern after using the photoresist prepared in Example 3.

[0058] Figure 4 This is the photolithographic pattern after using the photoresist prepared in Example 4.

[0059] Figure 5 This is the photolithographic pattern after using the photoresist prepared in Example 5.

[0060] Figure 6 This is the photolithographic pattern after using the photoresist prepared in Comparative Example 1.

[0061] Figure 7 This is the photolithographic pattern after using the photoresist prepared in Comparative Example 2.

[0062] Figure 8 This is the photolithographic pattern after using the photoresist prepared in Comparative Example 3. DETAILED DESCRIPTION

[0063] Unless otherwise indicated, implied from the context, or customary in the art, all parts and percentages in this application are based on weight, and the test and characterization methods used are current as of the filing date of this application. Where applicable, the contents of any patents, patent applications, or publications referred to in this application are incorporated herein by reference in their entirety, and their equivalent patent families are also incorporated by reference, especially with respect to definitions of synthetic techniques, product and processing designs, polymers, comonomers, initiators, or catalysts disclosed in these documents in the art. If the definition of a specific term disclosed in the prior art is inconsistent with any definition provided in this application, the definition of the term provided in this application shall prevail.

[0064] Numerical ranges in this application are approximate values, so unless otherwise indicated, they may include numerical values ​​outside the scope. Numerical ranges include all numerical values ​​from the lower limit to the upper limit increased by 1 unit, provided that there is an interval of at least 2 units between any lower value and any higher value. For example, if the description component, physical or other properties (such as molecular weight, melt index, etc.) is 100 to 1000, it means that all individual numerical values ​​are clearly enumerated, such as 100, 101, 102, and all subranges, such as 100 to 166, 155 to 170, 198 to 200, etc. For a numerical value less than 1 or a scope comprising a fraction greater than 1 (such as 1.1, 1.5, etc.), 1 unit is appropriately considered to be 0.0001, 0.001, 0.01 or 0.1. For ranges containing single-digit numbers less than 10 (e.g., 1 to 5), one unit is generally considered to be 0.1. These are merely specific examples of what is intended, and all possible combinations of numerical values ​​between the lowest value and the highest value enumerated are to be considered expressly stated in this application. The numerical ranges within this application provide, among other things, calcium-containing filler content, stirring temperature, and various characteristics and properties of these components.

[0065] When used with respect to chemical compounds, unless expressly stated otherwise, the singular includes all isomeric forms and vice versa (e.g., "hexane" includes all isomers of hexane, individually or collectively). In addition, nouns using "a," "an," or "the" also include their plural forms unless expressly stated otherwise.

[0066] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any other components, steps or processes and are irrelevant to whether these other components, steps or processes are disclosed in this application. To eliminate any doubt, all compositions using the terms "comprising", "including", or "having" in this application may include any additional additives, excipients or compounds unless expressly stated otherwise. In contrast, the term "essentially consisting of" excludes any other components, steps or processes from the scope of any description of the term below, except those necessary for operational performance. The term "consisting of" does not include any components, steps or processes that are not specifically described or listed. Unless expressly stated otherwise, the term "or" refers to the listed members alone or in any combination thereof.

[0067] The first aspect of the present invention provides a positive photoresist composition comprising the following components in percentage by mass:

[0068]

[0069] The polymer resin includes a first polymer resin and a second polymer resin; the first polymer resin is a copolymer of a hydroxystyrene compound, a styrene compound and a tert-butyl acrylate compound; the second polymer resin is a copolymer of a hydroxystyrene compound, an acetal-protected hydroxystyrene compound and a compound of formula I.

[0070] The structure of the compound of general formula I is as follows:

[0071]

[0072] In formula I, P1 is a hydrogen atom or a C1-C4 alkyl group; P2, P3 and P4 are each independently a C1-C 10 and at least one of P2, P3 and P4 is C4~C 10 The cycloalkyl group or any two of P2, P3 and P4 may be bonded to form a ring.

[0073] Preferably, P1 is a hydrogen atom or a methyl group, and C1 to C 10 The alkyl group is selected from methyl or ethyl, and at least one of P2, P3 and P4 is C4 to C 10 The cycloalkyl group is selected from cyclopentane, cyclohexane, cycloheptane or cyclooctane, or any two of P2, P3 and P4 can be bonded to form cyclopentane, cyclohexane, cycloheptane or cyclooctane.

[0074] Preferably, the compound of formula I is selected from at least one of the following structures:

[0075]

[0076]

[0077] Preferably, it also includes at least one of the following technical features:

[0078] a1) the mass ratio of the first polymer resin to the second polymer resin is (1:2) to (4:1), such as (1:2) to (3:2) or (3:2) to (4:1);

[0079] a2) the weight average molecular weight of the first polymer resin is 8000 to 17000, such as 8000 to 12400 or 12400 to 17000;

[0080] a3) the molecular weight distribution coefficient of the first polymer resin is PDI<2.5, such as 1.75 to 2.5;

[0081] a4) The first polymer resin is obtained by polymerization of monomers having the following molar ratios:

[0082] Hydroxystyrene compounds 60-65%;

[0083] 15-25% of styrene compound, such as 15-20% or 20-25%;

[0084] 15-25% of tert-butyl acrylate compound, such as 15-20% or 20-25%;

[0085] a5) the weight average molecular weight of the second polymer resin is 5000-15000, such as 5000-11600, 11600-11900, 11900-12600 or 12600-15000;

[0086] a6) the molecular weight distribution index of the second polymer resin is PDI<2.5, such as 1.81-1.84, 1.84-1.87 or 1.87-2.5;

[0087] a7) The second polymer resin is obtained by polymerization of monomers in the following molar ratios:

[0088] 60-70% of hydroxystyrene compound, such as 60-65% or 65-70%;

[0089] 5-25% of an acetal-protected hydroxystyrene compound, such as 5-10% or 10%-25%;

[0090] 15-30% of the compound of formula I, such as 15-25% or 25-30%.

[0091] Preferably, the naphthaleneimide photoacid generator has a structure represented by the following general formula:

[0092]

[0093] In the formula, R1 is selected from a hydrogen atom or a C1-C6 linear or branched aliphatic saturated hydrocarbon group, wherein the carbon atoms of the aliphatic saturated hydrocarbon group may be substituted by oxygen atoms or sulfur atoms;

[0094] R2 is selected from C1~C 10 Straight-chain aliphatic saturated hydrocarbon group or C6~C 10 aromatic group, the hydrogen atoms of the aliphatic saturated hydrocarbon group may be substituted by fluorine atoms, the C6~C 10 The hydrogen atom of the aromatic group may be substituted with a fluorine atom.

[0095] Preferably, R1 is selected from a hydrogen atom, isopropyl, n-butyl, methoxyethoxy, propoxy, isopropoxy, propylthio or isopropylthio;

[0096] R2 is selected from methyl, ethyl, propyl, n-butyl, trifluoromethyl, perfluoropropyl, perfluorobutyl, perfluorooctyl, phenyl, perfluorophenyl or methylphenyl.

[0097] Preferably, the naphthalimide photoacid generator is selected from at least one of the following structures:

[0098]

[0099]

[0100] Preferably, the photoresist composition further comprises at least one of the following technical features:

[0101] b1) the acid diffusion controller is selected from at least one of triethanolamine, tetrabutylammonium hydroxide, tri(3,6-dioxaheptyl)amine, trioctylamine, triisopropanolamine, triethylenediamine, 2-ethyl-N,N-bis(2-ethylhexyl)-1-hexylamine, 2,6-di-tert-butylpyridine, 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, 2-phenylbenzimidazole, and diphenylamine;

[0102] b2) the leveling agent is selected from at least one of 3M fluorocarbon surfactant FC-4430 and Troysol S366;

[0103] b3) the solvent is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, anisole, propylene glycol monoacetate, propylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ethyl ether, butyl acetate, neopentyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, diacetone alcohol, and gamma-butyrolactone.

[0104] The second aspect of the present invention provides a method for preparing the positive photoresist composition, comprising the following steps: adding the polymer resin, the naphthalimide photoacid generator, the acid diffusion controller and the leveling agent to a solvent in proportion, mixing, and filtering to obtain a photoresist.

[0105] Preferably, the filtration uses a nylon membrane of 1.0 μm+1.0 μm+1.0 μm.

[0106] The third aspect of the present invention provides a method for using the positive photoresist composition, comprising the following steps: coating the photoresist on a silicon wafer, and sequentially performing pre-baking, exposure, post-baking and development to obtain a desired photolithographic pattern.

[0107] Preferably, it also includes at least one of the following technical features:

[0108] c1) The pre-baking temperature is 90-130°C, such as 110°C, and the pre-baking time is 70-110s, such as 90s;

[0109] c2) The exposure energy is 20-25 mj / m 2 ;

[0110] c3) the post-baking temperature is 110-150° C., such as 130° C., and the post-baking time is 50-90 seconds, such as 60 seconds;

[0111] c4) The developer used in the development is 2.38% TMAH, and the development time is 20 to 40 seconds, such as 30 seconds.

[0112] In the present invention, the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following examples are all conventional methods in the art unless otherwise specified.

[0113] Preparation of polymer resins

[0114] The first polymer resin A-1 is obtained by the following synthesis method:

[0115]

[0116] In a 500ml dry four-necked flask protected by nitrogen equipped with a stirrer and a condenser, acetoxystyrene (90.0g, 0.555mol), styrene (19.3g, 0.185mol), tert-butyl acrylate (23.7g, 0.185mol) and solvent methanol (140g) were added. The reaction system was decompressed and evacuated, and nitrogen was replaced three times. The reaction solution was stirred and mixed, cooled to 0°C, and then initiator V601 (17g) was added and stirred for 10 minutes. The reaction system was then heated to 65°C and reacted for 18h. After the polymerization was complete, the reaction system was cooled to room temperature.

[0117] The system was converted into a distillation apparatus, methanol (150 g) was added to dilute the system, and triethylamine (15 g) and water (5 g) were added dropwise. The system was heated to 62-65°C and reacted for 8 hours (during this process, the acetyl group in the acetoxystyrene was removed to form a hydroxyl group). The mixed solution was slowly added dropwise to 5 L of deionized water to precipitate to obtain a solid compound. The solid compound was collected by 40# filter paper, and then the solid compound was dissolved to about 20% using tetrahydrofuran. The compound was precipitated in 5 L of deionized water again, and the above operation was repeated twice. The solid compound was collected and placed in a vacuum oven at 45°C and dried for 48 hours to obtain 4-hydroxystyrene-styrene-tert-butyl acrylate terpolymer A-1 (122.4 g, weight average molecular weight 12400, molecular weight distribution coefficient 1.75).

[0118] The second polymer resin B-1 was obtained by the following synthesis method:

[0119]

[0120] In a 500ml dry four-necked flask protected by nitrogen equipped with a stirrer and a condenser, acetoxystyrene (90.0g, 0.555mol), P-(1-ethoxyethoxy)styrene (16.4g, 0.085mol) and compound I-1 (35.9g, 0.213mol) and solvent methanol (140g) were added. The reaction system was decompressed and evacuated, and nitrogen was replaced three times. The reaction solution was stirred and mixed, cooled to 0°C, and then initiator V601 (17g) was added and stirred for 10 minutes. The reaction system was then heated to 65°C and reacted for 18h. After the polymerization was complete, the reaction system was cooled to room temperature.

[0121] The system was converted into a distillation apparatus, methanol (150 g) was added to dilute the system, and triethylamine (15 g) and water (5 g) were added dropwise. The system was heated to 62-65°C and reacted for 8 hours (during this process, the acetyl group in the acetoxystyrene was removed to form a hydroxyl group). The mixed solution was slowly added dropwise to 5 L of deionized water to precipitate to obtain a solid compound. The solid compound was collected by 40# filter paper, and then the solid compound was dissolved to about 20% using tetrahydrofuran. The compound was precipitated in 5 L of deionized water again, and the above operation was repeated twice. The solid compound was collected and placed in a vacuum oven at 45°C and dried for 48 hours to obtain 4-hydroxystyrene-P-(1-ethoxyethoxy)styrene-Compound I-1 terpolymer B-1 (113.57 g, weight average molecular weight 11600, molecular weight distribution coefficient 1.84).

[0122] The second polymer resin B-2 was obtained by the following synthesis method:

[0123] The synthesis method of the second polymer resin B-2 is the same as the synthesis method of the first polymer resin B-1 and the relevant process parameters are the same, except that the monomers used are acetoxystyrene (90.0 g, 0.555 mol), P-(1-ethoxyethoxy)styrene (16.4 g, 0.085 mol) and compound I-2 (44.8 g, 0.213 mol). The reaction scheme is as follows:

[0124]

[0125] The final obtained second polymer resin B-2 (117.33 g, weight average molecular weight 12100, molecular weight distribution coefficient 1.87) was obtained.

[0126] The second polymer resin B-3 was obtained by the following synthesis method:

[0127] The synthesis method of the second polymer resin B-3 is the same as the synthesis method of the second polymer resin B-1 and the related process parameters are the same, except that the monomers used are acetoxystyrene (90.0 g, 0.555 mol), P-(1-ethoxyethoxy)styrene (16.4 g, 0.085 mol) and compound I-3 (41.8 g, 0.213 mol). The reaction scheme is as follows:

[0128]

[0129] The final obtained second polymer resin B-3 (113.94 g, weight average molecular weight 12600, molecular weight distribution coefficient 1.81) was obtained.

[0130] Comparative Example polymer resin B-4 was obtained by the following synthesis method:

[0131]

[0132]

[0133] In a 500ml dry four-necked flask protected by nitrogen equipped with a stirrer and a condenser, acetoxystyrene (90.0g, 0.555mol), P-(1-ethoxyethoxy)styrene (45.7g, 0.238mol) and solvent methanol (140g) were added. The reaction system was decompressed and evacuated, and nitrogen was replaced three times. The reaction solution was stirred and mixed, cooled to 0°C, and then initiator V601 (17g) was added. After stirring for 10 minutes, the reaction system was heated to 65°C and reacted for 18h. After the polymerization was complete, the reaction system was cooled to room temperature.

[0134] The system was converted into a distillation apparatus, methanol (150 g) was added to dilute the system, and triethylamine (15 g) and water (5 g) were added dropwise. The system was heated to 62-65°C and reacted for 8 h (during this process, the acetyl group in the acetoxystyrene was removed to form a hydroxyl group). The mixed solution was slowly added dropwise to 5 L of deionized water to precipitate to obtain a solid compound. The solid compound was collected by 40# filter paper, and then the solid compound was dissolved to about 20% in tetrahydrofuran. The compound was precipitated in 5 L of deionized water again, and the above operation was repeated twice. The solid compound was collected and placed in a vacuum oven at 45°C for 48 h to obtain 4-hydroxystyrene-P-(1-ethoxyethoxy)styrene copolymer A-2 (111.15 g, weight average molecular weight 11900, molecular weight distribution coefficient 1.72).

[0135] Example

[0136] The embodiments of the present invention will be described in detail below. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0137] The structures of the photoacid generators used in the Examples and Comparative Examples are as follows:

[0138]

[0139] Example 1

[0140] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0141]

[0142] The preparation process of the positive photoresist composition is as follows: add the components according to the formula, mix and stir evenly, and then filter through a 1.0 μm+1.0 μm+1.0 μm nylon membrane to complete the photoresist preparation.

[0143] The prepared positive photoresist composition is used as follows:

[0144] The positive photoresist composition prepared as above was spin-coated at 1000-3000 rpm on an 8-inch bare silicon wafer provided with HMDS primer to form a 1.4 μm film. The film was pre-baked on a 110°C hot plate for 90 seconds, then selectively exposed (400nm Line / Space) using a KrF exposure machine XT860M (Conventional: NA 0.57Sigma 0.66), and then post-baked on a 130°C hot plate for 60 seconds. After the wafer cooled to room temperature, it was developed with 2.38% TMAH developer for 30 seconds, and finally rinsed with deionized water for 30 seconds to form the desired photolithographic pattern. The photolithographic pattern obtained is as follows: Figure 1 As shown, the sidewalls of the photoresist pattern are vertical and do not show a standing wave effect.

[0145] Example 2

[0146] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0147]

[0148] The preparation method of the positive photoresist composition is the same as that of Example 1, and the use method of the positive photoresist composition is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 2 As shown, the sidewalls of the photoresist pattern are vertical and do not show a standing wave effect.

[0149] Example 3

[0150] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0151]

[0152] The preparation method of the positive photoresist composition is the same as that of Example 1, and the use method of the positive photoresist composition is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 3 As shown, the sidewalls of the photoresist pattern are vertical and do not show a standing wave effect.

[0153] Example 4

[0154] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0155]

[0156] The preparation method of the positive photoresist composition is the same as that of Example 1, and the use method of the positive photoresist composition is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 4 As shown, the sidewalls of the photoresist pattern are vertical and do not show a standing wave effect.

[0157] Example 5

[0158] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0159]

[0160] The preparation method of the positive photoresist composition is the same as that of Example 1, and the use method of the positive photoresist composition is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 5 As shown, the sidewalls of the photoresist pattern are vertical and do not show a standing wave effect.

[0161] Comparative Example 1

[0162] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0163]

[0164] The preparation method of the above-mentioned photoresist is the same as that of Example 1, and the use method of the above-mentioned photoresist is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 6 As shown, a standing wave effect occurs in the photolithographic pattern.

[0165] Comparative Example 2

[0166] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0167]

[0168] The preparation method of the above-mentioned photoresist is the same as that of Example 1, and the use method of the above-mentioned photoresist is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 7 As shown, a standing wave effect occurs in the photolithographic pattern.

[0169] Comparative Example 3

[0170] A positive photoresist composition comprises the following components in parts by weight (total 100 parts):

[0171]

[0172] The preparation method of the above-mentioned photoresist is the same as that of Example 1, and the use method of the above-mentioned photoresist is the same as that of Example 1. The obtained photoresist pattern is as follows Figure 8 As shown, a standing wave effect occurs in the photolithographic pattern.

[0173] The specific compositions of Examples 1-5 and Comparative Examples 1-3 are shown in the following table:

[0174] Table 1 Photoresist composition

[0175]

[0176]

[0177] The photoresist patterns of the above-mentioned embodiments 1 to 5 and comparative examples 1 to 3 are as follows: Figures 1 to 8 As shown. Figures 1 to 8 It can be seen that the standing wave effect and the verticality of the sidewalls of Examples 1 to 5 of the present application are better than those of the patterns of Comparative Examples 1 to 3.

[0178] In Examples 1 to 5, a first polymer resin and a second polymer resin containing a compound of formula I are used, and the photolithographic patterns have a small standing wave effect and good sidewall verticality.

[0179] Comparative Example 1 used only the first polymer resin, and its photolithographic pattern showed a standing wave effect.

[0180] Comparative Example 2 used a first polymer resin and a second polymer resin B-1 containing a compound of Formula I, but the mass percentage of the second polymer resin B-1 was too low, and its photolithographic pattern showed a standing wave effect.

[0181] Comparative Example 3 used the first polymer resin and polymer resin B-4 without the compound of formula I, and its photolithographic pattern showed a standing wave effect.

[0182] The above results indicate that when a photoresist comprising a first polymer resin and a second polymer resin containing a compound of formula I is used, and the first polymer resin and the second polymer resin containing a compound of formula I have appropriate contents, the standing wave effect of the photolithographic pattern can be effectively reduced, the verticality of the sidewalls of the photoresist pattern can be increased, and the resolution of the photoresist imaging can be improved.

[0183] The above description of the embodiments is intended to facilitate understanding and application of the present application by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without expending any creative effort. Therefore, the present application is not limited to the embodiments described herein, and improvements and modifications made by those skilled in the art based on the disclosure of this application without departing from the scope and spirit of this application are within the scope of this application.

Claims

1. A positive photoresist composition, characterized in that The photoresist composition comprises the following components in percentage by mass: The polymer resin includes a first polymer resin and a second polymer resin; the first polymer resin is a copolymer of a hydroxystyrene compound, a styrene compound and a tert-butyl acrylate compound; the second polymer resin is a copolymer of a hydroxystyrene compound, an acetal-protected hydroxystyrene compound and a compound of formula I; The structure of the compound of formula I is as follows: In formula I, P1 is a hydrogen atom or a C1-C4 alkyl group; P2, P3 and P4 are each independently a C1-C 10 and at least one of P2, P3 and P4 is C4~C 10 The cycloalkyl group or any two of P2, P3 and P4 can be bonded to form a ring; The compound of formula I is selected from at least one of the following structures:

2. The positive photoresist composition according to claim 1, wherein The photoresist composition further comprises at least one of the following technical features: a1) the mass ratio of the first polymer resin to the second polymer resin is (1:2) to (4:1); a2) the weight average molecular weight of the first polymer resin is 8000 to 17000; a3) the molecular weight distribution coefficient of the first polymer resin is PDI<2.5; a4) The first polymer resin is obtained by polymerization of monomers having the following molar ratios: Hydroxystyrene compounds 60-65%; Styrene compounds 15-25%; Tert-butyl acrylate compound 15-25%; a5) the weight average molecular weight of the second polymer resin is 5 to 15k; a6) the molecular weight distribution coefficient of the second polymer resin is PDI<2.5; a7) The second polymer resin is obtained by polymerization of monomers in the following molar ratios: Hydroxystyrene compounds 60-70%; 5-25% of acetal-protected hydroxystyrene compound; 15-30% of the compound of formula I.

3. The positive photoresist composition according to claim 1, wherein The naphthaleneimide photoacid generator has a structure shown in the following general formula II: In formula II, R1 is selected from a hydrogen atom or a C1-C6 linear or branched aliphatic saturated hydrocarbon group, wherein the carbon atoms of the aliphatic saturated hydrocarbon group may be substituted by oxygen atoms or sulfur atoms; R2 is selected from C1~C 10 Straight-chain aliphatic saturated hydrocarbon group or C6~C 10 aromatic group, the hydrogen atoms of the aliphatic saturated hydrocarbon group may be substituted by fluorine atoms, the C6~C 10 The hydrogen atom of the aromatic group may be substituted with a fluorine atom.

4. The positive photoresist composition according to claim 3, wherein The naphthaleneimide photoacid generator is selected from at least one of the following structures:

5. The positive photoresist composition according to claim 1, wherein The photoresist composition further comprises at least one of the following technical features: b1) the acid diffusion controller is selected from at least one of triethanolamine, tetrabutylammonium hydroxide, tri(3,6-dioxaheptyl)amine, trioctylamine, triisopropanolamine, triethylenediamine, 2-ethyl-N,N-bis(2-ethylhexyl)-1-hexylamine, 2,6-di-tert-butylpyridine, 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, 2-phenylbenzimidazole, and diphenylamine; b2) the leveling agent is selected from at least one of 3M fluorocarbon surfactant FC-4430 and Troysol S366; b3) the solvent is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, anisole, propylene glycol monoacetate, propylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol methyl ethyl ether, butyl acetate, neopentyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, diacetone alcohol, and gamma-butyrolactone.

6. A method for preparing a positive photoresist composition according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: adding the polymer resin, the naphthalimide photoacid generator, the acid diffusion controller and the leveling agent into a solvent in proportion, mixing, and filtering to obtain a photoresist.

7. The method for preparing the positive photoresist composition according to claim 6, wherein: The pore size of the membrane used for the filtration is a nylon membrane of 1.0 μm+1.0 μm+1.0 μm.

8. A method for using the positive photoresist composition according to any one of claims 1 to 5, characterized in that: The method of use comprises the following steps: The positive photoresist composition is coated on a silicon wafer, and sequentially subjected to pre-baking, exposure, post-baking and development to obtain a photolithographic pattern.

9. The method for using the positive photoresist composition according to claim 8, wherein: The method of use also includes at least one of the following technical features: c1) The pre-baking temperature is 90-130°C and the pre-baking time is 70-110s; c2) The exposure energy is 20-25 mj / m 2 ; c3) the post-baking temperature is 110-150°C and the post-baking time is 50-90s; c4) The developer used in the development was 2.38% TMAH, and the development time was 20 to 40 seconds.

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