Polymer resin and preparation method thereof, method for improving cracking of electron beam photoresist, electron beam photoresist and preparation and use thereof
阅读说明：本技术 聚合物树脂及其制备方法、改善电子束光刻胶开裂的方法、电子束光刻胶及其制备与使用 (Polymer resin and preparation method thereof, method for improving cracking of electron beam photoresist, electron beam photoresist and preparation and use thereof ) 是由 傅志伟 梅崇余 潘新刚 冉瑞成 于 2021-09-03 设计创作，主要内容包括：本发明涉及一种聚合物树脂及其制备方法、改善电子束光刻胶开裂的方法、电子束光刻胶及其制备与使用。聚合物树脂的制备方法包括如下步骤：1)包含芳香族乙烯基单体和α-卤代丙烯酸酯单体的单体组合物聚合；2)将得到的混合物在包括酮类溶剂/和烷基类溶剂的溶液中沉降、过滤和干燥。电子束光刻胶采用该制备方法获得的聚合物树脂,改善电子束光刻胶开裂。电子束光刻胶的制备方法：将电子束光刻胶的各组分混合。使用方法：将电子束光刻胶涂布在硅片上,依次经过前烘、曝光和显影。本发明将单体组合物聚合得到的混合物在包括酮类溶剂/和烷基类溶剂的溶液中沉降,能够改善电子束光刻胶的开裂,提高电子束光刻胶曝光的可靠性。(The invention relates to a polymer resin and a preparation method thereof, a method for improving cracking of an electron beam photoresist, the electron beam photoresist and preparation and use thereof. The preparation method of the polymer resin comprises the following steps: 1) polymerizing a monomer composition comprising an aromatic vinyl monomer and an α -haloacrylate monomer; 2) the resulting mixture is settled, filtered and dried in a solution comprising ketone solvent/and alkyl solvent. The electron beam photoresist adopts the polymer resin obtained by the preparation method, and the cracking of the electron beam photoresist is improved. The preparation method of the electron beam photoresist comprises the following steps: the components of the electron beam resist are mixed. The using method comprises the following steps: coating the electron beam photoresist on a silicon wafer, and sequentially carrying out prebaking, exposure and development. The mixture obtained by polymerizing the monomer composition is settled in the solution containing the ketone solvent and/or the alkyl solvent, so that the cracking of the electron beam photoresist can be improved, and the exposure reliability of the electron beam photoresist can be improved.)
1. A method for preparing a polymer resin, comprising the steps of:
1) polymerizing a monomer composition comprising an aromatic vinyl monomer and an α -haloacrylate monomer;
2) settling, filtering and drying the mixture obtained in the step 1) in a solution containing ketone solvent/alkyl solvent to obtain the polymer resin.
2. The method of claim 1, further comprising at least one of the following technical features:
a1) the aromatic vinyl monomer is selected from at least one of alpha-methyl styrene monomer and 4-fluoro-alpha-methyl styrene monomer;
a2) the alpha-halogenated acrylate monomer is selected from alpha-methyl chloroacrylate monomer, alpha-ethyl chloroacrylate monomer, alpha-benzyl chloroacrylate monomer, alpha-1-adamantyl chloroacrylate monomer, alpha-2, 2,3,3, 3-pentafluoropropyl chloroacrylate monomer, alpha-2, 2,3,3,4,4, 4-heptafluorobutyl chloroacrylate monomer, alpha-methyl fluoroacrylate monomer, alpha-ethyl fluoroacrylate monomer, alpha-benzyl fluoroacrylate monomer, alpha-1-adamantyl fluoroacrylate monomer, alpha-2, 2,3,3, 3-pentafluoropropyl fluoroacrylate monomer, and alpha-2 chloroacrylate monomer, at least one of 2,3,3,4,4, 4-heptafluorobutyl ester monomers;
a3) the molar ratio of the aromatic vinyl monomer to the alpha-halogenated acrylate monomer is 2: 1-1: 1;
a4) the ketone solvent is selected from at least one of acetone, cyclohexanone and methyl isobutyl ketone;
a5) the alkyl solvent is selected from at least one of n-pentane, n-hexane, cyclohexane and n-heptane;
a6) the volume ratio of the mixture obtained in the step 1) to the solution containing the ketone solvent/alkyl solvent is 1: 5-1: 2;
a7) the volume ratio of the ketone solvent to the alkyl solvent is 6: 1-1: 2;
a8) the drying temperature is 40-60 ℃.
3. A polymer resin obtained by the production method according to claim 1 or 2.
4. The polymer resin of claim 3, further comprising at least one of the following technical features:
b1) the weight average molecular weight of the polymer resin is 35000-70000;
b2) the molecular weight distribution coefficient of the polymer resin is less than 3.
5. A method for improving the cracking of an electron beam resist, wherein the polymer resin of claim 3 or 4 is added to the electron beam resist.
6. An electron beam resist comprising the polymer resin according to claim 3 or 4.
7. The electron beam resist of claim 6, comprising the following components in mass percent:
3-15% of the polymer resin;
85-97% of a solvent.
8. The electron beam resist of claim 7, further comprising at least one of the following features:
c1) the solvent is at least one selected from anisole, toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, propylene glycol monoacetate, propylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol monomethyl ether, diethylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, butyl acetate, neopentyl acetate, gamma-butyrolactone and ethyl lactate;
c2) the electron beam photoresist also comprises an auxiliary agent, wherein the auxiliary agent is selected from at least one of a photoacid generator, a viscosity control agent, a stabilizing agent and a leveling agent; preferably, the electron beam photoresist comprises the following components in percentage by mass:
3-15% of the polymer resin;
84.95-96.998% of a solvent;
0.002-0.05% of an auxiliary agent.
9. A method for preparing an electron beam resist according to any one of claims 6 to 8, comprising the steps of: and mixing the components of the electron beam photoresist to obtain the electron beam photoresist.
10. A method of using the electron beam resist according to any one of claims 6 to 8, comprising the steps of: and coating the electron beam photoresist on a silicon wafer, and sequentially carrying out prebaking, exposure, development and fixation to obtain a photoetching pattern.
11. The method of using an electron beam resist according to claim 10, further comprising at least one of the following technical features:
d1) the pre-drying temperature is 160-180 ℃;
d2) the pre-drying time is 160-200 s;
d3) the exposure energy is 1-10C/m2；
d4) The developing solution used for developing is amyl acetate or a mixed solution containing amyl acetate and isopropanol;
d5) the developing time is 50-70 s;
d6) the fixing solution used for fixing is isopropanol;
d7) the fixing time is 30-50 s.
Technical Field
The invention relates to the technical field of electron beam photoresist, in particular to polymer resin and a preparation method thereof, a method for improving cracking of electron beam photoresist, electron beam photoresist and preparation and use thereof.
Background
Electron Beam Lithography (EBL) is one of the most promising Lithography technologies under the 22 nm node, with its high resolution and stable performance, and its progress is often inseparable from the development of Lithography materials. In recent years, electron beams have been more demanding for lithographic materials as a nano-scale lithographic technique. The electron beam photoresist is a photoetching material coated on the surface of a substrate and used for realizing pattern transfer through electron beam exposure, and can be divided into positive photoresist and negative photoresist according to the crosslinking or chemical bond breakage before and after polymer irradiation.
After the photoresist is exposed by electron beams, chemical bonds of polymers of the photoresist are broken, and broken polymer fragments are easily dissolved in a developing solution to form the positive photoresist. On the contrary, after exposure, the photoresist is cross-linked and polymerized into macromolecules by micromolecules, and the exposed photoresist is insoluble in a developing solution and is a negative photoresist. Alpha-methyl chloroacrylate and alpha-methylstyrene copolymers and polymethylmethacrylate are two commonly used polymeric resins for electron beam resists. The former photoresist has the characteristics of high resolution, high sensitivity and etching resistance, but the problem of cracking frequently occurs. US5087551A solves the cracking problem of electron beam resists by optimizing the resist solvent, CN1815369A optimizes the coating process. The method solves the problem of cracking of the electron beam photoresist from a polymer synthesis treatment process.
Disclosure of Invention
The present invention aims to overcome the defects of the prior art and provide a polymer resin and a preparation method thereof, a method for improving the cracking of an electron beam photoresist, the electron beam photoresist and preparation and use thereof.
The present application also aims to provide an electron beam resist with high sensitivity, and a preparation method and a use method thereof.
In order to achieve the object of the present invention, the present application provides the following technical solutions.
In a first aspect, the present application provides a method of preparing a polymer resin, comprising the steps of:
1) polymerizing a monomer composition comprising an aromatic vinyl monomer and an α -haloacrylate monomer;
2) settling, filtering and drying the mixture obtained in the step 1) in a solution containing ketone solvent/alkyl solvent to obtain the polymer resin.
In a preferred mode of the first aspect, at least one of the following technical features is further included:
a1) the aromatic vinyl monomer is selected from at least one of alpha-methyl styrene monomer and 4-fluoro-alpha-methyl styrene monomer;
a2) the alpha-halogenated acrylate monomer is selected from alpha-methyl chloroacrylate monomer, alpha-ethyl chloroacrylate monomer, alpha-benzyl chloroacrylate monomer, alpha-1-adamantyl chloroacrylate monomer, alpha-2, 2,3,3, 3-pentafluoropropyl chloroacrylate monomer, alpha-2, 2,3,3,4,4, 4-heptafluorobutyl chloroacrylate monomer, alpha-methyl fluoroacrylate monomer, alpha-ethyl fluoroacrylate monomer, alpha-benzyl fluoroacrylate monomer, alpha-1-adamantyl fluoroacrylate monomer, alpha-2, 2,3,3, 3-pentafluoropropyl fluoroacrylate monomer, and alpha-2 chloroacrylate monomer, at least one of 2,3,3,4,4, 4-heptafluorobutyl ester monomers;
a3) the molar ratio of the aromatic vinyl monomer to the alpha-halogenated acrylate monomer is 2: 1-1: 1, as 2: 1-5.2: 4. 5.2: 4-1.1: 1 or 1.1: 1-1: 1;
a4) the ketone solvent is at least one selected from acetone, cyclohexanone and methyl isobutyl ketone; preferably acetone;
a5) the alkyl solvent is selected from at least one of n-pentane, n-hexane, cyclohexane and n-heptane;
a6) the volume ratio of the mixture obtained in the step 1) to the solution containing the ketone solvent/alkyl solvent is 1: 5-1: 2, as shown in 1: 5-1: 3 or 1: 3-1: 2;
a7) the volume ratio of the ketone solvent to the alkyl solvent is 6: 1-1: 2, as shown in 6: 1-4: 1. 4: 1-3: 2 or 3: 2-1: 2;
a8) the drying temperature is 40-60 deg.C, such as 40-50 deg.C, 50-55 deg.C or 55-60 deg.C.
In a second aspect, the present application provides a polymer resin obtained by the above-described production method.
In a preferred mode of the second aspect, at least one of the following technical features is further included:
b1) the weight average molecular weight of the polymer resin is 35000-70000, such as 35000-54100, 54100-57200, 57200-59500, 59500-61200 or 61200-70000;
b2) the molecular weight distribution coefficient of the polymer resin is less than 3, such as 1.62-1.74, 1.74-1.78, 1.78-1.81.
In a third aspect, the present application also provides a method for improving cracking of an electron beam resist to which the above polymer resin is added. Namely, the electron beam photoresist contains the polymer resin.
In a fourth aspect, the present application also provides an electron beam resist comprising the above polymer resin.
In a preferred mode of the fourth aspect, the composition comprises the following components in percentage by mass:
3-15% of the polymer resin, such as 3-10% or 10-15%;
85-97% of solvent, such as 85-90% or 90-97%.
In a preferred mode of the fourth aspect, at least one of the following technical features is further included:
c1) the solvent is at least one selected from anisole, toluene, xylene, trimethylbenzene, chlorobenzene, dichlorobenzene, propylene glycol monoacetate, propylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol monomethyl ether, diethylene glycol methyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, butyl acetate, neopentyl acetate, gamma-butyrolactone and ethyl lactate;
c2) the auxiliary agent is selected from at least one of a photoacid generator, a viscosity control agent, and a stabilizer and a leveling agent. The photoacid generator is selected from the group consisting of N-hydroxynaphthalimide trifluoromethanesulfonic acid, (4, 8-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate, (4, 7-dihydroxy-1-naphthyl) dimethylsulfonium trifluoromethanesulfonate, (4-methoxynaphthyl) diphenylsulfonium trifluoromethanesulfonate, (4-phenylthiophenyl) diphenylsulfonium trifluoromethanesulfonate, 2- (benzo [ d ] [1,3] dioxolan-5-yl) -4, 6-bis (trichloromethyl) -1,3, 5-triazine, 2- (2, 4-dimethoxystyryl) -4, 6-bis (trichloromethyl) -1,3, 5-triazine and 2- [4- (4-methoxyphenyl) phenyl ] -4, at least one of 6-bis (trichloromethyl) -1,3, 5-triazine, the viscosity control agent is selected from butanol, chloroform, ethanol, water, acetonitrile, hexane and isopropanol, and the stabilizer is selected from at least one of p-benzoquinone, methyl hydroquinone, p-hydroxyanisole, 2-tert-butylhydroquinone and 2, 5-di-tert-butylhydroquinone. The leveling agent is selected from one or more of acrylic leveling agent, silicon-containing leveling agent and fluorine-containing leveling agent, such as Dow Corning DC-7, MEGAFACE F-563 (available from DIC corporation), polymethylphenylsiloxane, polydimethylsiloxane, ETA-706, etc. Preferably, the electron beam photoresist comprises the following components in percentage by mass:
3-15% of the polymer resin, such as 3-7% or 7-15%;
84.95-96.998% of solvent, such as 84.95-92.98% or 92.98-96.998%;
0.002-0.05% of assistant, such as 0.002-0.02% or 0.02-0.05%.
In a fifth aspect, the present invention also provides a method for preparing an electron beam resist as described above, comprising the steps of: and mixing the components of the electron beam photoresist to obtain the electron beam photoresist.
In a sixth aspect, the present invention also provides a method for using the electron beam resist, comprising the following steps: and coating the electron beam photoresist on a silicon wafer, and sequentially carrying out prebaking, exposure, development and fixation to obtain a photoetching pattern.
In a preferred mode of the sixth aspect, at least one of the following technical features is further included:
d1) the temperature of the pre-drying is 160-180 ℃, such as 160-170 ℃ or 170-180 ℃;
d2) the pre-drying time is 160-200 s, such as 160-180 s or 180-200 s;
d3) the exposure energy is 1-10C/m2E.g. 1 to 2C/m2、2～3C/m2、3～4C/m2Or 4 to 10C/m2；
d4) The developing solution used for developing is amyl acetate or a mixed solution containing amyl acetate and isopropanol; preferably amyl acetate;
d5) the developing time is 50-70 s, such as 50-60 s or 60-70 s;
d6) the fixing solution used for fixing is isopropanol;
c7) the fixing time is 30-50 s, such as 30-40 s or 40-50 s.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a method for settling a mixture obtained by polymerizing a monomer composition containing an aromatic vinyl monomer and an alpha-halogenated acrylate monomer in a solution containing a ketone solvent and/or an alkyl solvent, which can improve the cracking of an electron beam photoresist and improve the exposure reliability of the electron beam photoresist, and is simple to operate, convenient and reliable.
Drawings
FIG. 1 is a scanning electron micrograph of the electron beam resist of example 1.
FIG. 2 is a scanning electron micrograph of the electron beam resist of example 2.
FIG. 3 is a scanning electron micrograph of the electron beam resist of example 3.
FIG. 4 is a scanning electron micrograph of the electron beam resist of example 4.
FIG. 5 is a scanning electron micrograph of the electron beam resist of comparative example 1.
Detailed Description
Unless otherwise indicated, implied from the context, or customary in the art, all parts and percentages herein are by weight and the testing and characterization methods used are synchronized with the filing date of the present application. Where applicable, the contents of any patent, patent application, or publication referred to in this application are incorporated herein by reference in their entirety and their equivalent family patents are also incorporated by reference, especially as they disclose definitions relating to synthetic techniques, products and process designs, polymers, comonomers, initiators or catalysts, and the like, in the art. To the extent that a definition of a particular term disclosed in the prior art is inconsistent with any definitions provided herein, the definition of the term provided herein controls.
The numerical ranges in this application are approximations, and thus may include values outside of the ranges unless otherwise specified. A numerical range includes all numbers from the lower value to the upper value, in increments of 1 unit, provided that there is a separation of at least 2 units between any lower value and any higher value. For example, if a compositional, physical, or other property (e.g., molecular weight, melt index, etc.) is recited as 100 to 1000, it is intended that all individual values, e.g., 100, 101,102, etc., and all subranges, e.g., 100 to 166,155 to 170,198 to 200, etc., are explicitly recited. For ranges containing a numerical value less than 1 or containing a fraction greater than 1 (e.g., 1.1, 1.5, etc.), then 1 unit is considered appropriate 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), 1 unit is typically considered 0.1. these are merely specific examples of what is intended to be expressed and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application. The numerical ranges within this application provide, among other things, the calcium-containing filler content, the stirring temperature, and various characteristics and properties of these components.
When used with respect to chemical compounds, the singular includes all isomeric forms and vice versa (e.g., "hexane" includes all isomers of hexane, individually or collectively) unless expressly specified otherwise. In addition, unless explicitly stated otherwise, the use of the terms "a", "an" or "the" are intended to include the plural forms thereof.
The terms "comprising," "including," "having," and derivatives thereof do not exclude the presence of any other component, step or procedure, and are not intended to exclude the presence of other elements, steps or procedures not expressly disclosed herein. To the extent that any doubt is eliminated, all compositions herein containing, including, or having the term "comprise" may contain any additional additive, adjuvant, or compound, unless expressly stated otherwise. Rather, the term "consisting essentially of … …" excludes any other components, steps or processes from the scope of any of the terms hereinafter recited, except those necessary for performance. The term "consisting of … …" does not include any components, steps or processes not specifically described or listed. Unless explicitly stated otherwise, the term "or" refers to the listed individual members or any combination thereof.
Examples
The following will describe in detail the embodiments of the present invention, which are implemented on the premise of the technical solution of the present invention, and the detailed embodiments and the specific operation procedures are given, but the scope of the present invention is not limited to the following embodiments.
Example 1
A method of preparing a polymer resin comprising the steps of:
1) 482.1g (4.0mol) of methyl α -chloroacrylate and 614.51g (5.2mol) of α -methylstyrene were dissolved in 1253.5g of dioxane, and the temperature was raised to 85 ℃. Then, a dioxane solution containing 0.50g of azobisisobutyronitrile was added. After further reaction for 18 hours, it was cooled to room temperature. The dichloromethane was diluted to twice the original volume.
2) The system is settled into 5 times volume of mixed solution containing acetone and n-heptane, and is filtered and dried, wherein the volume ratio of the acetone to the n-heptane is 4: 1, the drying temperature is 60 ℃. GPC test data: the weight-average molecular weight Mw was 59.5K, and the molecular weight distribution coefficient D was 1.74.
An electron beam photoresist comprises the following components in percentage by mass:
7% of a polymer resin obtained by the above preparation method;
solvent anisole 92.98%;
0.02 percent of isopropanol serving as an auxiliary agent.
The preparation method of the electron beam photoresist comprises the following steps: the components are added according to the formula and stirred to be completely dissolved.
The prepared electron beam photoresist is used according to the following method:
spin-coating the electron beam photoresist on a 4-inch silicon wafer at the rotating speed of 3000rpm, wherein the coating thickness of the electron beam photoresist is 1200A; pre-baking at 180 deg.C for 180 s; exposing in an electron beam lithography machine at an electron beam lithography voltage of 100KeV and a current of 500pA and an exposure energy of 2C/m2(ii) a And developing in a developing solution, wherein the developing solution is amyl acetate, the developing time is 60s, the isopropanol is fixed for 40s, the pattern morphology is observed by a scanning electron microscope, and the pattern of the square single-end line combined groove is not cracked, as shown in figure 1.
Example 2
A method of preparing a polymer resin comprising the steps of:
1) 482.1g (4.0mol) of methyl α -chloroacrylate and 614.51g (5.2mol) of α -methylstyrene were dissolved in 1253.5g of dioxane, and the temperature was raised to 85 ℃. Then, a dioxane solution containing 0.50g of azobisisobutyronitrile was added. After further reaction for 18 hours, it was cooled to room temperature. The dichloromethane was diluted to twice the original volume.
2) The system was settled to 5 volumes of acetone solution, filtered and dried at 40 ℃. GPC test data: the weight-average molecular weight Mw was 57.2K and the molecular weight distribution coefficient D was 1.78.
An electron beam photoresist comprises the following components in percentage by mass:
10% of a polymer resin obtained by the above preparation method;
90% of propylene glycol monomethyl ether acetate serving as a solvent.
The preparation method of the electron beam photoresist comprises the following steps: the components are added according to the formula and stirred to be completely dissolved.
The prepared electron beam photoresist is used according to the following method:
spin-coating the electron beam photoresist on a 4-inch silicon wafer at the rotating speed of 3000rpm, wherein the coating thickness of the electron beam photoresist is 1200A; pre-baking at 180 deg.C for 180 s; exposing in an electron beam lithography machine at an electron beam lithography voltage of 100KeV and a current of 500pA and an exposure energy of 3C/m2(ii) a And developing in a developing solution, wherein the developing solution is amyl acetate, the developing time is 60s, the isopropanol is fixed for 40s, the pattern morphology is observed by a scanning electron microscope, and the pattern of the square single-end line combined groove is not cracked, as shown in figure 2.
Example 3
A method of preparing a polymer resin comprising the steps of:
1) 241.1g (2.0mol) of methyl α -chloroacrylate and 472.7g (4.0mol) of α -methylstyrene were dissolved in 620g of dioxane, and the temperature was raised to 80 ℃. Then, a dioxane solution containing 0.28g of azobisisobutyronitrile was added. After further reaction for 20 hours, it was cooled to room temperature. The dichloromethane was diluted to twice the original volume.
2) The system was settled to 2 times volume of a mixed solution comprising acetone and n-heptane, and filtered to dry, wherein the volume ratio of acetone to n-heptane was 6: 1, the drying temperature is 50 ℃. GPC test data: the weight-average molecular weight Mw was 61.2K and the molecular weight distribution coefficient D was 1.81.
An electron beam photoresist comprises the following components in percentage by mass:
15% of a polymer resin obtained by the above preparation method;
solvent propylene glycol monomethyl ether 84.95%;
the assistant Dow Corning DC-70.05%.
The preparation method of the electron beam photoresist comprises the following steps: the components are added according to the formula and stirred to be completely dissolved.
The prepared electron beam photoresist is used according to the following method:
spin-coating the electron beam photoresist on a 4-inch silicon wafer at the rotating speed of 3000rpm, wherein the coating thickness of the electron beam photoresist is 1200A; pre-baking at 160 deg.C for 200 s; exposing in an electron beam lithography machine at an electron beam lithography voltage of 100KeV and a current of 500pA and an exposure energy of 4C/m2(ii) a And developing in a developing solution, wherein the developing solution is amyl acetate, the developing time is 70s, the isopropanol is fixed for 50s, the shape of the graph is observed by a scanning electron microscope, and the pattern of the line combination groove at the two ends of the square is not cracked, as shown in figure 3.
Example 4
A method of preparing a polymer resin comprising the steps of:
1) 238.54g (1mol) of 2,2,3,3, 3-pentafluoropropyl α -chloroacrylate and 149.79g (1.1mol) of 4-fluoro- α -methylstyrene were dissolved in 350g of dioxane, and the temperature was raised to 85 ℃. Then, a dioxane solution containing 0.15g of azobisisobutyronitrile was added. After further reaction for 16 hours, it was cooled to room temperature. The dichloromethane was diluted to 3 times its original volume.
2) And (2) settling the system into a mixed solution containing cyclohexanone and cyclohexane in a volume ratio of 3 times, filtering and drying, wherein the volume ratio of the cyclohexanone to the cyclohexane is 1: 2, the temperature for drying is 55 ℃. GPC test data: the weight-average molecular weight Mw was 54.1K, and the molecular weight distribution coefficient D was 1.62.
An electron beam photoresist comprises the following components in percentage by mass:
3% of a polymer resin obtained by the above preparation method;
solvent anisole 96.998%;
0.002% of auxiliary agent p-hydroxyanisole.
The preparation method of the electron beam photoresist comprises the following steps: the components are added according to the formula and stirred to be completely dissolved.
The prepared electron beam photoresist is used according to the following method:
spin-coating the electron beam photoresist on a 4-inch silicon wafer at the rotating speed of 3000rpm, wherein the coating thickness of the electron beam photoresist is 1200A; pre-baking at 170 ℃ for 160 s; exposing in an electron beam lithography machine at an electron beam lithography voltage of 100KeV and a current of 500pA and an exposure energy of 4C/m2(ii) a And developing in a developing solution, wherein the developing solution is amyl acetate, the developing time is 50s, the isopropanol is fixed for 30s, the shape of the graph is observed by a scanning electron microscope, and the pattern of the line combination groove at the two ends of the square is not cracked, as shown in figure 4.
Comparative example 1
A method of preparing a polymer resin comprising the steps of:
1) 482.1g (4.0mol) of methyl α -chloroacrylate and 614.51g (5.2mol) of α -methylstyrene were dissolved in 1253.5g of dioxane, and the temperature was raised to 85 ℃. Then, a dioxane solution containing 0.50g of azobisisobutyronitrile was added. After further reaction for 18 hours, it was cooled to room temperature. The dichloromethane was diluted to twice the original volume.
2) The system was precipitated into 5 volumes of n-heptane, filtered and dried at 60 ℃. GPC test data: the weight-average molecular weight Mw was 39.3K and the molecular weight distribution coefficient D was 1.81.
An electron beam photoresist comprises the following components in percentage by mass:
10% of a polymer resin obtained by the above preparation method;
89.98% of anisole as a solvent;
0.02 percent of isopropanol serving as an auxiliary agent.
The preparation method of the electron beam photoresist comprises the following steps: the components are added according to the formula and stirred to be completely dissolved.
The prepared electron beam photoresist is used according to the following method:
spin-coating the electron beam photoresist on a 4-inch silicon wafer at the rotating speed of 3000rpm, wherein the coating thickness of the electron beam photoresist is 1200A; pre-baking at 180 deg.C for 180 s; exposing in an electron beam lithography machine with an electron beam lithography voltage of 100KeV, a current of 500pA,the exposure energy is 2C/m2(ii) a And developing in a developing solution, wherein the developing solution is amyl acetate, the developing time is 60s, the isopropanol is fixed for 40s, the shape of the graph is observed by a scanning electron microscope, and a cracking pattern is arranged at the corner of the square single-end line combined groove pattern, as shown in figure 5.
Therefore, the mixture obtained by polymerizing the monomer composition containing the aromatic vinyl monomer and the alpha-halogenated acrylate monomer is settled in the solution containing the ketone solvent/alkyl solvent, so that the cracking of the electron beam photoresist can be improved, the exposure reliability of the electron beam photoresist can be improved, and the operation is simple, convenient and reliable.
The embodiments described above are intended to facilitate the understanding and appreciation of the application by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present application is not limited to the embodiments herein, and those skilled in the art who have the benefit of this disclosure will appreciate that many modifications and variations are possible within the scope of the present application without departing from the scope and spirit of the present application.