阅读说明：本技术 一种感光性聚合物及其制备方法和应用 (Photosensitive polymer and preparation method and application thereof ) 是由 邓云祥 钟春燕 于 2021-08-27 设计创作，主要内容包括：本发明属于高分子材料领域,公开了一种感光性聚合物及其制备方法和应用。该感光性聚合物,包含下列结构单元：(1A)：具有至少一个能够通过酸水解产生酸性基团的结构单元；(1B)：具有至少一个烯烃、乙烯基醚或(甲基)丙烯酸酯能够通过作用力配对的单体结构单元；(1C)：具有至少一个环状基团的结构单元。本发明通过对感光性聚合物结构的优化,使其具有良好的浸润性,利用其制备的光刻胶,与涂布材料的相容性好,能够应用于193nm浸没式光刻,满足45nm以下的半导体制程的分辨率。(The invention belongs to the field of high molecular materials, and discloses a photosensitive polymer, and a preparation method and application thereof. The photosensitive polymer comprises the following structural units: (1A) the method comprises the following steps Having at least one building block capable of generating an acidic group by acid hydrolysis; (1B) the method comprises the following steps Monomer building blocks having at least one olefin, vinyl ether or (meth) acrylate capable of pairing by force; (1C) the method comprises the following steps A structural unit having at least one cyclic group. The invention optimizes the structure of the photosensitive polymer to ensure that the photosensitive polymer has good wettability, and the photoresist prepared by the photosensitive polymer has good compatibility with coating materials, can be applied to 193nm immersion lithography, and meets the resolution of a semiconductor process below 45 nm.)

1. A photosensitive polymer comprising the following structural units:

(1A) the method comprises the following steps Having at least one building block capable of generating an acidic group by acid hydrolysis;

(1B) the method comprises the following steps Monomer building blocks having at least one olefin, vinyl ether or (meth) acrylate capable of pairing by force;

(1C) the method comprises the following steps A structural unit having at least one cyclic group.

2. The photosensitive polymer according to claim 1, wherein the structural unit (1A) contains an ester group or an ether group.

3. The photosensitive polymer according to claim 2, wherein the structural unit (1A) has a structure represented by the formula a1 and/or the formula a2,

wherein, Ra₁、Ra₁' each independently represents at least one substituent selected from the following classes: c being unsubstituted, unsubstituted or halogen-substituted₁-C₆Straight-chain alkyl, unsubstituted or halogen-substituted C₁-C₆Branched alkyl, unsubstituted or halogen-substituted C₆-C₂₀A cyclic alkyl group;

Ra₂、Ra₂' each independently represents at least one substituent selected from the following classes: hydroxy, carboxy, unsubstituted, hydroxy-or halogen-substituted C₁-C₆Straight-chain alkyl, unsubstituted, hydroxy-or halogen-substituted C₁-C₆Branched alkyl, unsubstituted or hydroxy-or halogen-substituted C₆-C₁₀An aryl group;

Ra₃、Ra₃' each independently represents at least one substituent selected from the following classes: no, halogen atom, substituted or unsubstituted C₁-C₆Straight chain alkyl, substituted or unsubstituted C₁-C₆A branched alkyl group; the substitution of the alkyl is selected from one of halogen atom, hydroxyl, carboxyl, amido, nitryl, nitroso or acyloxy or amido.

4. The photosensitive polymer according to claim 1, wherein the structural unit (1B) has a structure represented by the formula B1,

in formula b1, Rb₁、Rb₂And Rb₃Each independently represents a substituent; wherein, Rb is₁Represents at least one substituent selected from the following classes: none, C₁-C₁₀Straight chain alkyl, C₁-C₁₀Branched alkyl or C₃-C₃₀A cyclic alkyl group;

Rb₂represents at least one substituent selected from the following classes: a hydrogen atom or a methyl group;

Rb₃represents at least one substituent selected from the following classes: none, C₁-C₃₀Straight-chain or branched alkyl or C₁-C₃₀An alkoxy group;

L₁、L₂represents a structure of the formula:

wherein X may be a carbon atom or a silicon atom;

Rb₄、Rb₅each independently represents at least one substituent selected from the following classes: c unsubstituted, substituted by hydroxy or halogen₁-C₆Straight-chain alkyl, unsubstituted, hydroxy-or halogen-substituted C₁-C₆Branched alkyl, unsubstituted, hydroxy-or halogen-substituted C₆-C₂₀And (4) an aryl group.

5. The photosensitive polymer according to claim 4, wherein the structural unit (1B) comprises an acrylate structure and an olefin structure; preferably, the acrylate structure accounts for 50-90% of the total structure number; the olefin structure accounts for 10-50% of the total structure number.

6. The photosensitive polymer according to claim 1, wherein in the structural unit (1C), the cyclic group is selected from one or more of adamantane, styrene or α -pinene.

7. A photoresist, comprising the following components: a photosensitive polymer, a photoacid generator, an acid diffusion terminator, a surfactant, and a solvent as described in any one of claims 1 to 6.

8. The photoresist of claim 7, comprising the following components in parts by weight:

9. the method for preparing the photoresist according to claim 7 or 8, comprising the steps of:

and dissolving the photosensitive polymer, the photosensitive acid generator, the acid diffusion terminator and the surfactant in a solvent, stirring, filtering, taking filtrate and standing to obtain the ArFi photoresist.

10. A lithographic film comprising the photoresist of claim 7 or 8.

Technical Field

The invention belongs to the field of high molecular materials, and particularly relates to a photosensitive polymer, and a preparation method and application thereof.

Background

Integrated Circuits (ICs) are one of the most critical technologies in the information age, and photolithography (photolithography) is one of the critical technologies in the manufacture of ICs. The improvement of the functions of the chip cannot be separated from the development of the photoetching materials and the process.

Photolithography is a process of transferring a predetermined pattern on a mask (mask) onto a substrate (substrate) using a photochemical reaction. In the photolithography process, photoresist (photo-resist) is the most critical material. Incident light passes through the mask plate, so that patterns on the mask plate are projected onto photoresist coated on a substrate, photochemical reaction is excited, baking and development are carried out, and photoresist patterns are formed and then serve as blocking layers for selectively blocking subsequent etching or ion implantation and the like.

The current mainstream process is an ArF photoetching process using a light source with the wavelength of 193nm, the used light source is 193nm laser excited by ArF, and the ArFi photoresist is an ArF immersion photoresist. 193nm lithography can be divided into 193nm dry lithography and 193nm wet lithography according to the difference of media between a wafer and a lens in an exposure system, wherein air is arranged between the wafer subjected to 193nm dry lithography and the lens, the light flux (NA) is less than 1.0, and the 193nm dry lithography can only meet the resolution of 90nm and 65nm semiconductor manufacturing processes; in the semiconductor process with the resolution of below 45nm, water is used to replace air to obtain a high-resolution photoetching process with the light flux of 1.07-1.35NA, so that 193nm wet photoresist, namely ArFi photoresist, is used in the semiconductor process for manufacturing higher-end semiconductors such as 45nm and 32 nm. The current photoresist formula can not be applied to 193nm immersion lithography, and the resolution of a semiconductor process below 45nm is met. In addition, the wettability of the photosensitive polymer in the existing photoresist is poor, and the wettability cannot be adjusted according to needs, so that the photoresist has poor compatibility with a coating material in application, and the application range is narrow.

Therefore, it is desirable to provide a photosensitive polymer which has good wettability, good compatibility between the prepared photoresist and the coating material, can be applied to 193nm immersion lithography, and satisfies the resolution of a semiconductor process below 45 nm.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art described above. Therefore, the invention provides a photosensitive polymer which has good wettability, and the prepared photoresist has good compatibility with coating materials, can be applied to 193nm immersion lithography, and meets the resolution of a semiconductor process below 45 nm.

The present invention provides, in a first aspect, a photosensitive polymer.

Specifically, the photosensitive polymer comprises the following structural units:

(1A) the method comprises the following steps Having at least one building block capable of generating an acidic group by acid hydrolysis;

(1B) the method comprises the following steps Monomer building blocks having at least one olefin, vinyl ether or (meth) acrylate capable of pairing by force;

(1C) the method comprises the following steps A structural unit having at least one cyclic group.

Preferably, the structural unit (1A) contains an ester group or an ether group.

Preferably, the structural unit (1A) contains a structure represented by formula a1 and/or formula a2,

wherein, Ra₁、Ra₁' each independently represents at least one substituent selected from the following classes: c being unsubstituted, unsubstituted or halogen-substituted₁-C₆Straight-chain alkyl, unsubstituted or halogen-substituted C₁-C₆Branched alkyl, unsubstituted or halogen-substituted C₆-C₂₀A cyclic alkyl group;

Ra₂、Ra₂' each independently represents at least one substituent selected from the following classes: hydroxy, carboxy, unsubstituted, hydroxy-or halogen-substituted C₁-C₆Straight-chain alkyl, unsubstituted, hydroxy-or halogen-substituted C₁-C₆Branched alkyl, unsubstituted or hydroxy-or halogen-substituted C₆-C₁₀An aryl group;

Ra₃、Ra₃' each independently represents at least one substituent selected from the following classes: no, halogen atom, substituted or unsubstituted C₁-C₆Straight chain alkyl, substituted or unsubstituted C₁-C₆A branched alkyl group; the substitution of the alkyl is selected from one of halogen atom, hydroxyl, carboxyl, amido, nitryl, nitroso or acyloxy or amido.

Preferably, the structural unit (1B) has a structure represented by the formula B1,

in formula b1, Rb₁、Rb₂And Rb₃Each independently represents a substituent; wherein, Rb is₁Represents at least one substituent selected from the following classes: none, C₁-C₁₀Straight chain alkyl, C₁-C₁₀Branched alkyl or C₃-C₃₀A cyclic alkyl group;

Rb₂represents at least one substituent selected from the following classes: a hydrogen atom or a methyl group;

Rb₃represents at least one substituent selected from the following classes: none, C₁-C₃₀Straight-chain or branched alkyl or C₁-C₃₀An alkoxy group;

L₁、L₂represents a structure that can be linked by covalent bonds, or bound by intermolecular forces, and may be specifically:

wherein X may be a carbon atom or a silicon atom;

Rb₄、Rb₅each independently represents at least one substituent selected from the following classes: c unsubstituted, substituted by hydroxy or halogen₁-C₆Straight-chain alkyl, unsubstituted, hydroxy-or halogen-substituted C₁-C₆Branched alkyl, unsubstituted, hydroxy-or halogen-substituted C₆-C₂₀And (4) an aryl group.

Preferably, the structural unit (1B) includes an acrylate structure and an olefin structure. The main chain of the polymer can form different sequence structures according to the proportion of two structures of acrylate and olefin.

Preferably, the acrylate structure accounts for 50-90% of the total structure number; the olefin structure accounts for 10-50% of the total structure number. The Tg of the resin and the wettability of the prepared ArFi photoresist can be adjusted by adjusting the proportion of the acrylate structure to the olefin structure on the main chain of the photosensitive polymer.

When the acrylate structure accounts for 85% and the olefin structure accounts for 15%, the main chain of the polymer can form the following sequence: -M- (O-M-O-M) -M-;

wherein M represents an acrylate structure and O represents an olefin structure.

When the acrylate structure accounts for 75%, and the olefin structure accounts for 25%, the main chain of the polymer can form the following sequence: -O- (M-O-M-O-M) -O-;

wherein M represents an acrylate structure and O represents an olefin structure.

When the acrylate structure accounts for 65% and the olefin structure accounts for 35%, the main chain of the polymer can form the following sequence: -O-M-O-;

wherein M represents an acrylate structure and O represents an olefin structure.

Or by partially or totally interrupting L in the structural unit (1B)₁、L₂Adjusting the wettability of the ArFi photoresist and the Tg of the resin by the connected covalent bond:

preferably, in the structural unit (1C), the cyclic group is selected from one or more of adamantane, styrene or α -pinene.

More preferably, the structural unit (1C) contains at least one of the formula C1, the formula C2 or the formula C3,

in the general formulae (c1), (c2) and (c3), Rc₁、Rc₁' and Rc₁"each independently represents one or more of the following substituents: free, substituted or unsubstituted C₁-C₁₀Straight chain alkyl, substituted or unsubstituted C₁-C₁₀Branched alkyl, substituted or unsubstituted C₃-C₃₀A cyclic alkyl group; if present, the substituent of the alkyl group is selected from at least one of a halogen atom (preferably a fluorine atom), a hydroxyl group, or a carboxyl group;

Rc₂、Rc₂' and Rc₂"each independently represents one or more of the following substituents: hydrogen, halogen, substituted or unsubstituted C₁-C₃₀Linear alkyl of (3), substituted or unsubstituted C₁-C₃₀Branched alkyl of, substituted or unsubstituted C₁-C₃₀Alkoxy, substituted or unsubstituted C₆-C₃₀An aryl group; the substituent(s) in the alkyl group, alkoxy group or aryl group, if any, is (are) at least one selected from the group consisting of a halogen atom (preferably a fluorine atom), a hydroxyl group and a carboxyl group.

In a second aspect, the invention provides an ArFi photoresist.

Specifically, the ArFi photoresist comprises the following components: the photosensitive polymer, the photosensitive acid generator, the acid diffusion terminator, the surfactant and the solvent.

Preferably, the photoresist comprises the following components in parts by weight:

preferably, the photosensitive acid generator comprises the following structure:

wherein, Rd₁、Rd₂、Rd₃Each independently represents a substituent; the substituent group is selected from C₁-C₂₀Straight chain alkyl group of (1), C₁-C₂₀Branched alkyl or C₁-C₂₀Aryl of (a); x-represents a non-nucleophilic anion.

Preferably, two of Rd1, Rd2, Rd3 may be linked to form a ring via a single bond or a linking group selected from an ester bond, an amide bond, a carbonyl group, a methylene group, an ethylene group, or an ether bond.

Preferably, X-represents a non-nucleophilic anion and is selected from one of a sulfonate anion, a bis-sulfonyl amide anion, or a trisulfonylmethyl anion; further preferably, X-is selected from anions represented by the following formulae:

wherein, Re₁、Re₁’、Re₂’、Re₁”、Re₂”、Re₃Each independently represents C₁-C₁₀Alkyl derivative of (5) or C₆-C₂₀An aryl derivative of (1).

Preferably, said C₁-C₁₀The alkyl derivative of (A) is C substituted at the alpha-position with a fluorine atom or a fluoroalkyl group₁-C₁₀Alkyl group of (1).

Preferably, said C₆-C₂₀The aryl derivative of (A) is C substituted by fluorine atom or fluoroalkyl group₆-C₂₀Aryl group of (1).

Preferably, the acid diffusion terminator is selected from at least one of a tertiary amine compound, an amide compound, a quaternary ammonium hydroxide compound, or a nitrogen-containing heterocyclic compound.

Preferably, the surfactant comprises the following structure:

rc1, Rc2, R in the structural units (3A) and (3B)C1' each independently represents an organic group, wherein Rc1, Rc2 are selected from C₁-C₈The linear alkyl group of (1); rc 1' is selected from one or more of the following substituents: substituted or unsubstituted C₁-C₃₀Linear alkyl of (3), substituted or unsubstituted C₁-C₃₀Branched alkyl of, substituted or unsubstituted C₁-C₃₀Alkoxy, substituted or unsubstituted C₆-C₃₀An aryl group;

n represents the number average polymerization degree of molecules, and the value range of n is 5-200; preferably, n ranges from 10 to 100.

The third aspect of the invention provides a preparation method of an ArFi photoresist.

Specifically, the preparation method of the ArFi photoresist comprises the following steps:

and dissolving the photosensitive polymer, the photosensitive acid generator, the acid diffusion terminator and the surfactant in a solvent, stirring, filtering, taking filtrate and standing to obtain the ArFi photoresist.

The fourth aspect of the invention provides an application of an ArFi photoresist in preparation of a photolithographic film.

The invention provides a photoetching film comprising the ArFi photoresist.

A method for producing a photolithographic film, comprising the steps of:

and coating the ArFi photoresist on a substrate, baking for the first time, coating a waterproof coating, exposing, baking for the second time, and developing to obtain the photoetching film.

Compared with the prior art, the invention has the following beneficial effects:

(1) the photosensitive polymer provided by the invention comprises a structural unit capable of generating an acid group by acid hydrolysis, a monomer structural unit capable of pairing olefin, vinyl ether or (methyl) acrylate by acting force and a structural unit with a cyclic group, has good wettability by optimizing the structure of the photosensitive polymer, and the photoresist prepared by using the photosensitive polymer has good compatibility with a coating material, can be applied to 193nm immersion lithography and meets the resolution of a semiconductor process below 45 nm.

(2) The photosensitive polymer provided by the invention can regulate and control wettability and Tg (glass transition temperature); the water contact angle of the ArFi photoresist prepared by the method can be adjusted within the range of 36-87 degrees, and the Tg of the ArFi photoresist can be adjusted within the range of 0-240 ℃.

Drawings

FIG. 1 is a graph showing a molecular weight distribution curve of a photosensitive polymer obtained in example 1;

FIG. 2 is a nuclear magnetic resonance hydrogen spectrum of the photosensitive polymer obtained in example 1;

FIG. 3 is a nuclear magnetic resonance carbon spectrum graph of the photosensitive polymer obtained in example 1;

FIG. 4 is a line pattern of a photoresist prepared in example 2;

FIG. 5 is a DOF plot of a photoresist made in example 2;

FIG. 6 is a line pattern of a photoresist prepared in example 3;

FIG. 7 is a line pattern obtained by using the photoresist prepared in example 3 at different focal lengths and different energies;

FIG. 8 is a graph showing a molecular weight distribution curve of a photosensitive polymer obtained in example 4;

FIG. 9 is a line pattern of a photoresist prepared in example 5;

FIG. 10 is a line pattern of a photoresist prepared in comparative example 1;

FIG. 11 shows the line patterns obtained by the photoresist prepared in comparative example 1 at different focal lengths and different energies;

fig. 12 is a line pattern of the photoresist prepared in comparative example 2.

Detailed Description

In order to make the technical solutions of the present invention more apparent to those skilled in the art, the following examples are given for illustration. It should be noted that the following examples are not intended to limit the scope of the claimed invention.

The starting materials, reagents or apparatuses used in the following examples are conventionally commercially available or can be obtained by conventionally known methods, unless otherwise specified.

Example 1

A photosensitive polymer prepared from monomers represented by the following formula:

the preparation process of the photosensitive polymer is as follows: 30g of monomer M1, 15g of monomer M2 and 15g of monomer M3 are dissolved in 70mL of acetonitrile and transferred to a reaction bottle, the temperature of the mixed solution system is increased to 90 ℃, 0.20g of Dibenzoyl peroxide (BPO) is added and uniformly mixed, the temperature of the reaction system is increased to 100 ℃, the reaction is continued for 8 hours, 5mL of ethanol is added to stop the reaction, the mixed solution after the reaction is stopped is precipitated in ethanol, and the obtained solid is heated and dried in an oven at 100 ℃ for 8 hours to obtain white powdery photosensitive polymer Q152.1g.

The number average molecular weight of the photosensitive polymer Q1 was 27890 and the weight average molecular weight was 53498, as measured by Gel Permeation Chromatography (GPC), and the molecular weight distribution of the photosensitive polymer Q1 is shown in fig. 1.

After acid treatment, the photosensitive polymer Q1 was subjected to Nuclear magnetic resonance hydrogen spectroscopy (H-NMR) and Nuclear magnetic resonance carbon spectroscopy (C-NMR) to determine the ratio of methacrylate units to olefin units in the resin backbone structure and the specific arrangement structure, respectively, at 85% and 15%, and the arrangement structure was as follows: -M-M-M-M-M-M- (O-M-O-M-O-M) -M-.

The measured hydrogen and carbon spectra of NMR are shown in FIGS. 2 and 3. FIG. 2 is a nuclear magnetic resonance hydrogen spectrum showing the structure of M2 after deprotection by acid treatment in the resin, and the continuation symbol "-" in FIG. 2 indicates the omission of the subsequent structure; FIG. 3 is a nuclear magnetic resonance carbon spectrum formed by carbon atoms with regular change of chemical environment in a sequence after a resin molecular chain forms a sequence structure.

By adjusting the feed ratio of M2, a series of polymers with different ratios of methacrylate units to olefin units can be obtained, as shown in Table 1.

TABLE 1

20g of the photosensitive polymer Q1 obtained in example 1 was dissolved in 25mL of THF (tetrahydrofuran), 1mL of trifluoroacetic acid was added dropwise at room temperature, followed by stirring for 12 hours to carry out acid treatment, the acid-treated solution was precipitated by adding 100mL of ethanol, and the obtained solid was dried by heating in an oven at 100 ℃ for 8 hours to obtain 19g of a pale yellow powdery solid, namely, an acidified photosensitive polymer Q1, which was designated as Q1'.

The photosensitive polymers Q2-Q5 were treated with acidification in the same manner to obtain Q2 ', Q3', Q3 ', and Q5'.

1g of the photosensitive polymers Q1-Q5 and the acidified polymers Q1 '-Q5' were dissolved in 10mL of PGMEA (propylene glycol methyl ether acetate), spin-coated on a 1cm by 1cm silicon wafer and dried, and 1 drop of clean water was added dropwise to measure the contact angle, and the results of the contact angle measurement are shown in Table 2.

Table 2 contact angle test results

Sample number	Before treatment	After acidification treatment
			Q1	87°	24°
Q2	95°	29°
			Q3	102°	33°
Q4	114°	36°
			Q5	133°	40°

As is clear from table 2, the wettability of the photosensitive polymer to water can be adjusted by the acid treatment, and the wettability of the photosensitive polymer to water is stronger after the acid treatment. By adjusting the wettability of the photosensitive polymer to water, the photoresist containing the photosensitive polymer can be compatible with more coating materials, the compatibility of the photoresist and the coating materials is increased, and the uniformity of the coating and the permeation behavior among the coatings are improved; meanwhile, by adjusting the wettability of the photosensitive polymer to water, the process window of the application of the photosensitive polymer can be widened, so that the photosensitive polymer can be used in more diversified environments to prepare a pattern meeting the resolution of a semiconductor process below 45 nm.

Tests show that the water contact angle of the photoresist prepared from the photosensitive polymer can be adjusted within the range of 36-87 degrees by adjusting the wettability of the ArFi photoresist.

15mg of Q1 and Q1 'were taken, respectively, and Tg was measured by DSC (Q2000 calorimeter) at a temperature rise/fall rate of 10 ℃/min, and Tg was measured for Q1 and Q1' at 33 ℃ and 40 ℃, respectively. Tests show that the Tg of the photoresist can be adjusted within the range of 20-140 ℃ by adjusting the wettability of the ArFi photoresist when the photoresist is prepared by adopting the photosensitive polymer provided by the invention.

Example 2

An ArFi photoresist comprises 25g of the photosensitive polymer Q1 prepared in example 1, 0.2g of a photosensitive acid generator P2, 0.05g of an acid diffusion terminator P3 and 0.01g of a surfactant P4, wherein the P2 comprises the components of 0.02g P2a, 0.05g P2b, 0.03gP2c and 0.1g P2d, and the P3 comprises the components of 0.01g P3a, 0.05g P3b and 0.04g P3 c.

The structural formula of P2a-P2d is as follows:

the structural formula of P3a-P3c is as follows:

the structural formula of P4 is as follows:

the preparation method of the ArFi photoresist comprises the following specific operation steps:

25g of the photosensitive polymer Q1 prepared in example 1 was taken, and the contact angle thereof was adjusted from 87 ℃ to 24 ℃ by acid treatment, and the resultant was dissolved in Ethyl Lactate (EL) until the polymer concentration became about 5% by mass, and then 0.2g of a photosensitive acid generator P2, 0.05g of an acid diffusion terminator P3 and 0.01g of a surfactant P4 were added thereto, and filtration was performed by using a polytetrafluoroethylene filter having a pore diameter of 0.2 μm, to obtain a resist.

A photolithographic film is prepared from the ArFi photoresist.

A method for preparing a photolithographic film comprises the following specific operations:

hexamethyldisilazane (HDMS) was spin-coated on a 12-inch silicon plate, and then the photoresist was spin-coated on the hexamethyldisilazane film, and a 100-150nm thick photoresist layer was obtained by baking at 90 ℃/120 s.

After obtaining the photoresist layer, spin-coating an Imaging Top Coating (ITC) layer with a thickness of 20-50nm on the photoresist layer using 193 Immersion lightAn exposure machine (ArFi eximer scanner, ASML XT1900) for exposing L/S pattern with exposure energy ranging from 15-35mJ/cm²。

After the exposure is completed, post-exposure baking (PEB) is performed on a hot stage at a temperature of 120 ℃/60s, an alkaline aqueous developing solution (2.38% by mass of Tetramethylammonium hydroxide (TMAH) aqueous solution) is used to perform 60s of development on the exposed photoresist layer, and then the photoresist pattern is obtained by rinsing with ultrapure water.

The size of the image of the obtained pattern was measured by a macro scanning electron Microscope (Critical Dimension Scan Electronic Microscope, CD-SEM, Hitachi). The measurement results are shown in table 3 below.

TABLE 3

The photoresist prepared by the embodiment can obtain very regular 45nm photoresist lines, and the obtained 45nm photoresist line pattern is measured by using a CD-SEM (Hitachi), as shown in FIG. 4, and FIG. 4 is the line pattern of the photoresist. The parameters in the measurement process are 45nm/45nm L/S FEM. Under the energy of 23mj, the photoresist can obtain a 160nm Depth of focus (DOF) map on an ASML1900 machine, and the Depth of focus map is shown in fig. 5. In fig. 5, the abscissa represents the depth of focus in μm, and the ordinate represents the figure size. As can be seen from FIG. 5, the photoresist can obtain a pattern with a dimension requirement (160 + -10 nm) within a focus depth variation range of 160nm at 23 mj.

Example 3

An ArFi photoresist comprising 25g of the photopolymer Q4 prepared in example 1, 0.15g of the photoacid generator P2 ', 0.05g of the acid diffusion terminator P3 ', and 0.01g of the surfactant P4 '. Wherein, P2 comprises components of 0.02g P2a ', 0.05g P2 b', 0.03g P2c 'and P3 comprises components of 0.01g P3 a', 0.01g P3b 'and 0.03g P3 c'.

The structural formula of P2a '-P2 c' is as follows:

the structural formula of P3a '-P3 c' is as follows:

the structural formula of P4' is as follows:

the preparation method of the ArFi photoresist comprises the following specific operation steps:

25g of the photosensitive polymer Q4 prepared in example 1 was taken, and the contact angle thereof was adjusted from 114 ℃ to 36 ℃ by acid treatment, and dissolved in Ethyl Lactate (EL) until the polymer concentration became about 5% by mass, and then 0.15g of a photosensitive acid generator P2 ', 0.05g of an acid diffusion terminator P3 ' and 0.01g of a surfactant P4 ' were added thereto, and the mixture was stirred at room temperature for 24 hours and filtered through a polytetrafluoroethylene filter having a bore diameter of 0.2. mu.m, to obtain an ArFi resist.

A photolithographic film is prepared from the ArFi photoresist.

A method for preparing a photolithographic film comprises the following specific operations:

hexamethyldisilazane (HDMS) was spin-coated on a 12-inch silicon plate, and then the photoresist obtained above was spin-coated on the hexamethyldisilazane film, and a 100 nm thick 150nm photoresist layer was obtained by baking at 90 ℃/120 s.

After obtaining the photoresist layer, an Imaging Top Coating (ITC) with a thickness of 20-50nm was spin-coated on the photoresist layer using 193 Immersion lithography machine (ArFi exposure scanner, manufactured by ASML, XT1900), and the likeExposing the line L/S pattern with exposure energy ranging from 15 to 35mJ/cm²。

After the exposure is completed, post-exposure baking (PEB) is performed on a hot stage at a temperature of 120 ℃/60s, an alkaline aqueous developing solution (2.38% by mass of Tetramethylammonium hydroxide (TMAH) aqueous solution) is used to perform 60s of development on the exposed photoresist layer, and then the photoresist pattern is obtained by rinsing with ultrapure water.

The size of the image of the obtained pattern was measured by a macro scanning electron Microscope (Critical Dimension Scan Electronic Microscope, CD-SEM, Hitachi). The measurement results are shown in table 4 below.

TABLE 4

According to the test results, the photoresist is exposed on ASML1900 to obtain images with the line width ranging from 45nm to 92 nm. The obtained line pattern of the 43nm photoresist was measured by CD-sem (hitachi), and the result is shown in fig. 6, where fig. 6 is the line pattern of the photoresist, and the image line is straight and smooth as can be seen from fig. 6. FIG. 7 is a line pattern obtained by photoresist at different focal lengths and different energies, corresponding to Table 4. The photosensitive resin provided by the invention can be applied to 193 immersion type photoresist and can obtain higher resolution. The parameters in the measurement process are 150nm/1500nm L/P FEM.

Example 4

A photosensitive polymer prepared from monomers represented by the following formula:

the preparation process of the photosensitive polymer is as follows: dissolving 25g of monomer M4, 15g of monomer M5 and 20g of monomer M6 with 70mL of acetonitrile, transferring the mixture into a reaction bottle, raising the temperature of the mixed solution system to 90 ℃, adding 0.20g of Dibenzoyl peroxide (BPO), uniformly mixing, raising the temperature of the reaction system to 100 ℃, continuing to react for 8 hours, adding 5mL of ethanol to terminate the reaction, precipitating the mixed solution after terminating the reaction in ethanol, and heating and drying the obtained solid in an oven at 100 ℃ for 8 hours to obtain white powdery photosensitive polymer Q652.1g.

The number average molecular weight of the photosensitive polymer Q6 was 24783 and the weight average molecular weight was 48997, as determined by Gel Permeation Chromatography (GPC), and the molecular weight distribution of the photosensitive polymer Q6 is shown in fig. 8.

Example 5

An ArFi photoresist comprises 25g of the photosensitive polymer Q6 prepared in example 4 and 0.15g of the photosensitive acid generator P2 ', 0.05g of the acid diffusion terminator P3 ' and 0.01g of the surfactant P4 ' used in example 3.

The preparation method of the ArFi photoresist comprises the following specific operation steps:

25g of the photosensitive polymer Q6 prepared in example 1 was dissolved in Ethyl Lactate (EL) until the polymer concentration became about 5% by mass, and then 0.15g of a photosensitive acid generator P2 ', 0.05g of an acid diffusion terminator P3 ' and 0.01g of a surfactant P4 ' were added thereto, and the mixture was stirred at room temperature for 24 hours and filtered through a polytetrafluoroethylene filter having a pore size of 0.2 μm to obtain an ArFi resist.

A photolithographic film is prepared from the ArFi photoresist.

A method for preparing a photolithographic film comprises the following specific operations:

hexamethyldisilazane (HDMS) was spin-coated on a 12-inch silicon plate, and then the photoresist obtained above was spin-coated on the hexamethyldisilazane film, and a 100 nm thick 150nm photoresist layer was obtained by baking at 90 ℃/120 s.

After obtaining the photoresist layer, spin-coating an Immersion top water-repellent coating (ITC) with a thickness of 20-50nm on the photoresist layer, and exposing the photoresist layer to an L/S pattern using a 193 Immersion lithography machine (ArFi exposure scanner, ASML XT1900) with an exposure energy range of 15-35mJ/cm²。

After the exposure is completed, post-exposure baking (PEB) is performed on a hot stage at a temperature of 120 ℃/60s, an alkaline aqueous developing solution (2.38% by mass of Tetramethylammonium hydroxide (TMAH) aqueous solution) is used to perform 60s of development on the exposed photoresist layer, and then the photoresist pattern is obtained by rinsing with ultrapure water.

The size of the image of the obtained pattern was measured by a macro scanning electron Microscope (Critical Dimension Scan Electronic Microscope, CD-SEM, Hitachi). The photoetching film layer is 30 mJ/cm²Regular 40nm photoetching lines can be obtained under the condition, and the line pattern is shown in figure 9.

Comparative example 1

An ArFi photoresist comprising the following components: 25g of photosensitive polymer P1 (24957 for number average molecular weight and 67647 for weight average molecular weight), 0.15g of photosensitive acid generator P2 ', 0.05g of acid diffusion terminator P3 ' and 0.01g of surfactant P4 ' prepared in example 1 of patent 201910388389.4.

The preparation method of the ArFi photoresist comprises the following specific operation steps:

25g of photosensitive polymer P1 (having a number average molecular weight of 24957 and a weight average molecular weight of 67647) prepared in example 1 of patent 201910388389.4 was dissolved in Ethyl Lactate (EL) until the polymer concentration became about 5% by mass, and 0.15g of a photosensitive acid generator P2 ', 0.05g of an acid diffusion terminator P3 ' and 0.01g of a surfactant P4 ' were filtered through a filter made of polytetrafluoroethylene having a pore size of 0.2 μm to obtain an ArFi resist.

A photolithographic film is prepared from the ArFi photoresist.

A method for preparing a photolithographic film comprises the following specific operations:

hexamethyldisilazane (HDMS) was spin-coated on a 12-inch silicon plate, and then the photoresist was spin-coated on the hexamethyldisilazane film, and a 100-150nm thick photoresist layer was obtained by baking at 90 ℃/120 s.

After obtaining the resist layer, an Image Top Coating (ITC) was applied to the resist layer in a thickness of 20 to 50nm by using a 193 Immersion lithography machine (ArFi exposure scanner, manufactured by ASML, XT1900)Performing exposure of L/S pattern with exposure energy range of 15-35mJ/cm²。

After the exposure is completed, post-exposure baking (PEB) is performed on a hot stage at a temperature of 120 ℃/60s, an alkaline aqueous developing solution (2.38% by mass of Tetramethylammonium hydroxide (TMAH) aqueous solution) is used to perform 60s of development on the exposed photoresist layer, and then the photoresist pattern is obtained by rinsing with ultrapure water.

The obtained pattern was measured by CD-SEM (under 40nm/40nm L/S FEM) including image size, image Line Width Roughness (LWR), and the test results are shown in fig. 10, where fig. 10 is a line pattern of the photoresist. FIG. 11 shows the CD-SEM images of lines obtained at different focal lengths and at different energies, but with poor image contrast, uneven line shape and bridging defects between lines.

Comparative example 2

An ArFi photoresist comprising the following components: 25g of photosensitive polymer P1 (number average molecular weight 21349, weight average molecular weight 39875) prepared in example 2 of patent 201910388389.4, 0.15g of photosensitive acid generator P2 ', 0.05g of acid diffusion terminator P3 ' and 0.01g of surfactant P4 '.

The preparation method of the ArFi photoresist comprises the following specific operation steps:

25g of the photosensitive polymer P1 (number average molecular weight 21349, weight average molecular weight 39875) prepared in example 2 of patent 201910388389.4 was dissolved in Ethyl Lactate (EL) until the polymer concentration became about 5% by mass, and 0.15g of a photosensitive acid generator P2 ', 0.05g of an acid diffusion terminator P3 ' and 0.01g of a surfactant P4 ' were filtered through a filter made of polytetrafluoroethylene having a pore size of 0.2 μm to obtain an ArFi resist.

A photolithographic film is prepared from the ArFi photoresist.

A method for preparing a photolithographic film comprises the following specific operations:

hexamethyldisilazane (HDMS) was spin-coated on a 12-inch silicon plate, and then the photoresist obtained above was spin-coated on the hexamethyldisilazane film, and a 100 nm thick 150nm photoresist layer was obtained by baking at 90 ℃/120 s.

After obtaining the photoresist layer, spin-coating an Immersion top water-repellent coating (ITC) with a thickness of 20-50nm on the photoresist layer, and exposing the photoresist layer to an L/S pattern using a 193 Immersion lithography machine (ArFi exposure scanner, ASML XT1900) with an exposure energy range of 15-35mJ/cm²。

After the exposure is completed, post-exposure baking (PEB) is performed on a hot stage at a temperature of 120 ℃/60s, an alkaline aqueous developing solution (2.38% by mass of Tetramethylammonium hydroxide (TMAH) aqueous solution) is used to perform 60s of development on the exposed photoresist layer, and then the photoresist pattern is obtained by rinsing with ultrapure water.

The obtained pattern was measured by CD-SEM, and the measurement results include image size, Line Width Roughness (LWR), and fig. 12 shows the line pattern of the photoresist at 90nm/110nm L/S FEM, where the line pattern of the entire image is smooth and uniform in shape, but bridging defects appear between lines.