A composition for forming an anti-corrosion agent underlayer film, and its preparation method and application

Abstract

The present invention belongs to the technical field of photolithography materials, and specifically relates to a composition for forming a resist underlayer film, and a preparation method and application thereof. The resist underlayer film forming composition comprises a polymer and an organic solvent I; the polymer is obtained by polymerizing a compound A having a structure represented by formula (1) with a compound B having a structure represented by formula (2). The key to the present invention is to introduce a polymer obtained by a polymerization reaction between a specific compound A and a compound B into the resist underlayer film forming composition. Since the polymer has a condensed ring aromatic group, an ether bond, and an ester group structure, these group structures cooperate with each other to improve the storage stability of the resist underlayer film forming composition containing the polymer at room temperature, thereby facilitating the improvement of the quality and performance stability of semiconductor product preparation. #imgabs0#

Description

Technical Field

[0001] The invention belongs to the technical field of photolithography materials, and in particular relates to a composition for forming an anti-etching agent underlayer film, a preparation method and an application thereof. Background Art

[0002] In the manufacture of semiconductor products, a thin film of a photoresist composition is formed on a semiconductor substrate such as a silicon wafer, and a photolithography pattern is obtained on the semiconductor substrate after a series of treatments such as photolithography and development. In order to reduce the adverse effects of the semiconductor substrate on the formed photolithography pattern, a resist lower film is usually set between the resist and the semiconductor substrate. In recent years, with the development of the high integration of semiconductor devices and devices, semiconductor process materials such as resist lower film (BARC) compositions are increasingly required to be high-quality. The quality and performance stability of semiconductor devices are closely related to the storage stability of the resist lower film forming composition, that is, if the resist lower film forming composition deteriorates or performance degrades during storage or use, the semiconductor device performance manufactured will be inconsistent, affecting the reliability and stability of the product. However, the storage stability of the existing resist lower film forming composition still needs to be further improved to meet the high requirements of producing semiconductor products. Summary of the invention

[0003] The purpose of the present invention is to address the problem that the storage stability of existing resist underlayer film forming compositions is poor and needs to be further improved, and to provide a resist underlayer film forming composition and its preparation method and application, which can significantly improve the storage stability of the resist underlayer film forming composition and is expected to meet the high requirements for the production of semiconductor products.

[0004] In a first aspect, the present invention provides a composition for forming a resist underlayer film, the composition for forming a resist underlayer film comprising a polymer and an organic solvent I; the polymer is obtained by polymerizing a compound A having a structure represented by formula (1) and a compound B having a structure represented by formula (2);

[0005]

[0006] In formula (1) and formula (2), Ph represents a divalent phenyl group or a C 10 ~C 20 A divalent fused-ring aromatic group, R 1 and R 2 Each independently represents C 1 ~C 3 The alkylene group, R 3 and R 4 Each independently represents C 0 ~C 5wherein R represents a single bond, an ether bond, a peroxide bond, a monosulfide bond or a disulfide bond.

[0007] In a preferred embodiment, the polymer has a structure as shown in formula (3),

[0008]

[0009] In formula (3), Ph represents a divalent phenyl group or a C 10 ~C 20 A divalent fused-ring aromatic group, R 1 and R 2 Each independently represents C 1 ~C 3 The alkylene group, R 3 and R 4 Each independently represents C 0 ~C 5 wherein R represents a single bond, an ether bond, a peroxide bond, a monosulfide bond or a disulfide bond, and n is an integer of 1 to 50.

[0010] In a preferred embodiment, the weight average molecular weight of the polymer is 4000-8000 g / mol, and the PDI is 1.4-3.

[0011] In a preferred embodiment, the Ph is selected from at least one of the following structures:

[0012]

[0013] In a preferred embodiment, the molar ratio of compound A to compound B is 1:(1-1.8).

[0014] In a preferred embodiment, the polymerization reaction conditions include: temperature of 100-150° C. and time of 5-15 h.

[0015] In a preferred embodiment, the polymerization reaction is further carried out in the presence of a catalyst.

[0016] In a preferred embodiment, the catalyst is selected from an organophosphorus catalyst and / or a pyridine catalyst.

[0017] In a preferred embodiment, the organophosphorus catalyst is at least one selected from ethyltriphenylphosphonium bromide, tetrabutylphosphonium bromide, and benzyltriethylammonium chloride.

[0018] In a preferred embodiment, the polymerization reaction is further carried out in the presence of an organic solvent II.

[0019] In a preferred embodiment, the organic solvent II is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, toluene, xylene, cyclopentanone, cyclohexanone, ethyl lactate, butyl lactate, tetrahydrofuran, methyl ethyl ketone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0020] In a preferred embodiment, the organic solvent I is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, toluene, xylene, cyclopentanone, cyclohexanone, ethyl lactate, butyl lactate, tetrahydrofuran, methyl ethyl ketone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0021] In a preferred embodiment, based on the total weight of the resist underlayer film forming composition, the content of the polymer is 10 to 40 wt %, and the content of the organic solvent I is 60 to 90 wt %.

[0022] In a preferred embodiment, the resist underlayer film-forming composition further comprises at least one of a cross-linking agent, an acid generator, and a surfactant.

[0023] In a second aspect, the present invention provides a method for preparing the above-mentioned composition for forming an anti-etching agent underlayer film, the preparation method comprising: mixing a polymer with an organic solvent I to obtain a solution which is the composition for forming an anti-etching agent underlayer film.

[0024] In a third aspect, the present invention provides use of the resist underlayer film forming composition in the field of photolithography.

[0025] The key to the present invention is to introduce a polymer obtained by polymerization reaction of a specific compound A and a compound B into a resist underlayer film forming composition. Since the polymer has a condensed ring aromatic group, an ether bond, and an ester group structure, these group structures cooperate with each other to improve the storage stability of the resist underlayer film forming composition containing the polymer at room temperature, thereby facilitating improving the quality and performance stability of semiconductor product preparation. DETAILED DESCRIPTION

[0026] The composition for forming an anti-corrosion agent underlayer film provided by the present invention comprises a polymer and an organic solvent I. The polymer is obtained by polymerizing a compound A having a structure represented by formula (1) and a compound B having a structure represented by formula (2). The polymer can be any one of an alternating copolymer, a block copolymer, and a random copolymer.

[0027]

[0028] In formula (1) and formula (2), Ph represents a divalent phenyl group or a C 10 ~C 20 A divalent fused-ring aromatic group, R 1 and R 2 Each independently represents C 1 ~C 3 The alkylene group, R 3 and R 4 Each independently represents C 0 ~C 5 wherein R represents a single bond (-), an ether bond (-O-), a peroxide bond (-OO-), a monosulfide bond (-S-) or a disulfide bond (-SS-). The divalent phenyl group refers to a benzene ring structure having two bonding sites, and the C 10 ~C 20 The divalent fused-ring aromatic group refers to a fused-ring aromatic group with two bonding sites. When R is a single bond (-), R 3 and R 4 Cannot be C at the same time 0 Specific examples of the fused ring aromatic group include, but are not limited to, naphthalene ring, anthracene ring, phenanthrene ring, pyrene ring, One of a ring and a perylene ring. 1 ~C 3 Specific examples of the alkylene group include, but are not limited to, one of methylene, ethylene, n-propylene, and isopropylene. 0 ~C 5 Specific examples of the alkylene group include, but are not limited to, none, methylene (-CH 2 -), ethylene (-CH 2 CH 2 -), n-propylene (-CH 2 CH 2 CH 2 -), isopropylidene (-CH(CH 3 )CH 2 -), n-butylene (-CH 2 CH 2 CH 2 CH 2 -), isobutylene (-CH 2 CH(CH 3 )CH 2 -), sec-butylene (-CH(CH 3 )CH 2 CH 2 -), tert-butyl (-C(CH 3 ) 2 CH 2 -), n-pentylene (-CH2 CH 2 CH 2 CH 2 CH 2 -)

[0029] In the present invention, the polymer preferably has a structure as shown in formula (3):

[0030]

[0031] In formula (3), Ph represents a divalent phenyl group or a C 10 ~C 20 A divalent fused-ring aromatic group, R 1 and R 2 Each independently represents C 1 ~C 3 The alkylene group, R 3 and R 4 Each independently represents C 0 ~C 5 wherein R represents a single bond (-), an ether bond (-O-), a peroxide bond (-OO-), a monosulfide bond (-S-) or a disulfide bond (-SS-), and n is an integer from 1 to 50, such as 1, 2, 5, 8, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50 or any integer therebetween. 10 ~C 20 A divalent fused-ring aromatic group or C 1 ~C 3 Alkylene or C 0 ~C 5 Specific examples of the alkylene group are as described above and will not be repeated here one by one.

[0032] In the present invention, the weight average molecular weight (Mw) of the polymer is preferably 4000-8000 g / mol, such as 4000 g / mol, 4500 g / mol, 5000 g / mol, 5500 g / mol, 6000 g / mol, 6500 g / mol, 7000 g / mol, 8000 g / mol or any value therebetween; PDI is preferably 1.4-3, such as 1.4, 1.5, 1.8, 2, 2.2, 2.5, 2.8, 3 or any value therebetween.

[0033] In the present invention, the Ph can be selected from at least one of the following structures. Wherein, * represents the position where Ph is bonded to O in formula (1), and this bonding site can be a divalent phenyl group or a C 10 ~C 20 Any two sites on the divalent fused-ring aromatic structure.

[0034]

[0035] In the present invention, the compound A can be any compound having a structure as shown in formula (1), and can be commercially available or prepared based on existing technology or principles. The compound A is preferably selected from at least one of the compounds having the following structures:

[0036]

[0037] In the present invention, the compound B can be any compound having a structure as shown in formula (2), and can be commercially available or prepared based on existing technology or principles. The compound B is preferably selected from at least one of the compounds having the following structures:

[0038]

[0039] In the present invention, the molar ratio of compound A to compound B is preferably 1:(1-1.8), such as 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.5, 1:1.6, 1:1.8 or any value therebetween. The conditions of the polymerization reaction may include: the temperature is preferably 100-150°C, such as 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or any value therebetween; the time is preferably 5-15h, such as 5h, 6h, 8h, 10h, 12h, 15h or any value therebetween.

[0040] In the present invention, the polymerization reaction is preferably carried out in the presence of a catalyst. The catalyst can be any of various existing compounds that can catalyze the polymerization reaction between the compound A having an epoxy group and the compound B having a carboxyl group, preferably an organophosphorus catalyst and / or a pyridine catalyst. The organophosphorus catalyst is preferably at least one selected from ethyltriphenylphosphonium bromide, tetrabutylphosphonium bromide, and benzyltriethylammonium chloride.

[0041] In the present invention, the polymerization reaction is preferably carried out in the presence of an organic solvent II, and the presence of organic solvent II can provide a better reaction environment for the polymerization reaction between compound A and compound B. Specific examples of the organic solvent II include, but are not limited to, at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, toluene, xylene, cyclopentanone, cyclohexanone, ethyl lactate, butyl lactate, tetrahydrofuran, methyl ethyl ketone, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0042] In the present invention, the polymerization reaction may further include a purification process after completion. The purification process may include the following steps: mixing the reaction solution obtained from the polymerization reaction with water or aliphatic lower alcohol, and performing solid-liquid separation to obtain a precipitate, wherein the precipitate is a polymer having a structure shown in formula (1). The aliphatic lower alcohol may be methanol, ethanol, etc.

[0043] In the present invention, the organic solvent I can be any of the existing organic solvents used in the anti-etching agent underlayer film forming composition, and specific examples include but are not limited to: propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, toluene, xylene, cyclopentanone, cyclohexanone, ethyl lactate, butyl lactate, tetrahydrofuran, methyl ethyl ketone, N,N-dimethylformamide, and at least one of N,N-dimethylacetamide.

[0044] In the present invention, based on the total mass of the anti-etching agent underlayer film forming composition, the content of the polymer is preferably 10 to 40wt%, such as 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt% or any value therebetween; the content of the organic solvent I is preferably 60 to 90wt%, such as 60wt%, 65wt%, 70wt%, 75wt%, 80wt%, 85wt%, 90wt% or any value therebetween.

[0045] In the present invention, the resist underlayer film forming composition preferably further comprises at least one of a crosslinking agent, an acid generator, and a surfactant, which can be conventionally selected in the art.

[0046] The method for preparing the anti-etching agent underlayer film forming composition provided by the present invention comprises: mixing a polymer with an organic solvent I to obtain a solution which is the anti-etching agent underlayer film forming composition.

[0047] In addition, the terms "Ⅰ" and "Ⅱ" are only for the purpose of convenience of description and should not be understood as special limitations on the type or quantity of technical features.

[0048] The present invention will be described in detail below through specific embodiments.

[0049] Example 1 Preparation of a composition for forming an anti-etching agent underlayer film

[0050] In a 200 mL reaction flask were placed 22.20 g (0.1 mol) of compound A1, 10.40 g (0.1 mol) of compound B1, 1.30 g of ethyltriphenylphosphonium bromide catalyst, 0.36 g of pyridine catalyst and 60.00 g of propylene glycol monomethyl ether. The raw material solution was obtained after mixing evenly. The solution was heated to reflux at 120° C. for 6 h. The reaction process is shown below. After the reaction, GPC analysis revealed that the polymer C1 had Mw=5600 g / mol and PDI=2.56.

[0051] The reaction liquid obtained above was added dropwise into 300 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C1 was obtained. 5 g of polymer C1 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D1 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D1 had Mw = 5708 g / mol and PDI = 2.47.

[0052]

[0053] Example 2 Preparation of a composition for forming an anti-etching agent underlayer film

[0054] In a 200 mL reaction flask were placed 17.10 g (0.06 mol) of compound A2, 13.40 g (0.1 mol) of compound B2, 1.22 g of ethyltriphenylphosphonium bromide catalyst, 0.33 g of pyridine catalyst and 60.00 g of propylene glycol monomethyl ether. The raw material solution was obtained after mixing evenly. The solution was heated to reflux at 120° C. for 8 h. The reaction process is shown below. After the reaction, GPC analysis revealed that the polymer C2 had Mw = 6400 g / mol and PDI = 2.05.

[0055] The reaction liquid obtained above was added dropwise into 300.00 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C2 was obtained. 5 g of polymer C2 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D2 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D2 had Mw = 6513 g / mol and PDI = 1.97.

[0056]

[0057] Example 3 Preparation of a composition for forming an anti-etching agent underlayer film

[0058] In a 200 mL reaction flask were placed 34.80 g (0.1 mol) of compound A3, 21.00 g (0.1 mol) of compound B3, 1.67 g of ethyltriphenylphosphonium bromide catalyst and 60.00 g of propylene glycol monomethyl ether. The raw material solution was obtained after mixing evenly. The solution was heated to reflux at 120° C. for 12 h. The reaction process is shown below. After the reaction, GPC analysis revealed that the polymer C3 had Mw=6400 g / mol and PDI=2.05.

[0059] The reaction liquid obtained above was added dropwise into 300.00 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C3 was obtained. 5 g of polymer C3 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D3 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D3 had Mw = 6890 g / mol and PDI = 2.07.

[0060]

[0061] Example 4 Preparation of a composition for forming an anti-etching agent underlayer film

[0062] The polymer was prepared according to the method of Example 1, except that the same molar number of compound B4 was used instead of compound B1. The other conditions were the same as in Example 1. The reaction process was shown below, and polymer C4 was prepared. GPC analysis showed that Mw of polymer C4 was 4120 g / mol and PDI was 1.72.

[0063] The reaction liquid obtained above was added dropwise into 300.00 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C4 was obtained. 5 g of polymer C4 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D4 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D4 had Mw = 4340 g / mol and PDI = 1.70.

[0064]

[0065] Example 5 Preparation of a composition for forming an anti-etching agent underlayer film

[0066] The polymer was prepared according to the method of Example 2, except that the same molar number of compound B5 was used instead of compound B2. The other conditions were the same as in Example 2. The reaction process was shown below, and polymer C5 was prepared. GPC analysis showed that Mw of polymer C5 was 4830 g / mol and PDI was 1.45.

[0067] The reaction liquid obtained above was added dropwise into 300.00 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C5 was obtained. 5 g of polymer C5 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D5 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D5 had Mw = 4980 g / mol and PDI = 1.42.

[0068]

[0069] Example 6 Preparation of a composition for forming an anti-etching agent underlayer film

[0070] A polymer was prepared according to the method of Example 1, except that 0.05 mol of compound B1 and 0.05 mol of compound B2 were used instead of 0.1 mol of compound B1. The other conditions were the same as those in Example 1. The reaction process was shown below, and polymer C6 was prepared. GPC analysis showed that Mw of polymer C6 was 4890 g / mol and PDI was 1.87.

[0071] The reaction liquid obtained above was added dropwise into 300.00 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C6 was obtained. 5 g of polymer C6 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D6 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D6 had Mw = 4990 g / mol and PDI = 1.84.

[0072]

[0073] Comparative Example 1 Preparation of a reference composition for forming an anti-etching agent underlayer film

[0074] A reference polymer was prepared according to the method of Example 1, except that the same molar number of compound A7 was used instead of compound A1. The other conditions were the same as in Example 1. The reaction process is shown below, thereby preparing a reference polymer C7. GPC analysis showed that the reference polymer had Mw = 4320 g / mol and PDI = 2.23.

[0075] The reaction liquid obtained above was added dropwise into 300.00 g of methanol solution, and a large amount of white resin precipitated. After filtering the solid-liquid mixture, polymer C7 was obtained. 5 g of polymer C7 was weighed and dissolved in 20 g of propylene glycol monomethyl ether acetate (PGMEA). The obtained mixed solution was the composition D7 for forming the anti-etching agent underlayer film. GPC analysis showed that the composition D7 had Mw = 4410 g / mol and PDI = 2.21.

[0076]

[0077] Test Case

[0078] The compositions for forming an anti-etching agent underlayer film prepared in the above examples and comparative examples were subjected to an aging test at room temperature (20° C.): the samples were stored in a constant temperature incubator, and the temperature in the incubator was set to be constant at 20° C. The Mw and PDI at 0d, 7d, 30d, and 180d were tested respectively, and the results are shown in Table 1.

[0079] Table 1

[0080]

[0081] It can be seen from the results in Table 1 that at the same temperature, compared with Comparative Example 1, the compositions for forming an anti-etching agent underlayer film provided by Examples 1 to 6 of the present invention still have stable, almost unchanged Mw and PDI over time, and have higher storage stability.

[0082] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A resist underlayer film-forming composition, characterized in that: The resist underlayer film forming composition comprises a polymer and an organic solvent I; the polymer is obtained by polymerizing a compound A having a structure represented by formula (1) and a compound B having a structure represented by formula (2); In formula (1) and formula (2), Ph represents a divalent phenyl group or a C 10 ~C 20 R1 and R2 each independently represent a C1-C3 alkylene group, R3 and R4 each independently represent a C0-C5 alkylene group, and R represents a single bond, an ether bond, a peroxide bond, a monosulfide bond or a disulfide bond.

2. The resist underlayer film forming composition according to claim 1, wherein The polymer has a structure as shown in formula (3), In formula (3), Ph represents a divalent phenyl group or a C 10 ~C 20 R1 and R2 each independently represent a C1-C3 alkylene group, R3 and R4 each independently represent a C0-C5 alkylene group, R represents a single bond, an ether bond, a peroxide bond, a monosulfide bond or a disulfide bond, and n is an integer of 1 to 50; Preferably, the weight average molecular weight of the polymer is 4000-8000 g / mol, and the PDI is 1.4-3.

3. The resist underlayer film forming composition according to claim 1, wherein The Ph is selected from at least one of the following structures:

4. The resist underlayer film forming composition according to claim 1, wherein The molar ratio of compound A to compound B is 1:(1-1.8); Preferably, the polymerization reaction conditions include: temperature of 100-150° C. and time of 5-15 h.

5. The resist underlayer film forming composition according to claim 1, wherein The polymerization reaction also includes being carried out in the presence of a catalyst; Preferably, the catalyst is selected from an organophosphorus catalyst and / or a pyridine catalyst; Preferably, the organophosphorus catalyst is selected from at least one of ethyltriphenylphosphonium bromide, tetrabutylphosphonium bromide and benzyltriethylammonium chloride.

6. The resist underlayer film forming composition according to claim 1, wherein The polymerization reaction further comprises being carried out in the presence of an organic solvent II; Preferably, the organic solvent II is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, toluene, xylene, cyclopentanone, cyclohexanone, ethyl lactate, butyl lactate, tetrahydrofuran, methyl ethyl ketone, N,N-dimethylformamide and N,N-dimethylacetamide.

7. The resist underlayer film forming composition according to claim 1, wherein The organic solvent I is selected from at least one of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, toluene, xylene, cyclopentanone, cyclohexanone, ethyl lactate, butyl lactate, tetrahydrofuran, methyl ethyl ketone, N,N-dimethylformamide, and N,N-dimethylacetamide.

8. The resist underlayer film forming composition according to claim 1, wherein Based on the total weight of the resist underlayer film-forming composition, the content of the polymer is 10 to 40 wt %, and the content of the organic solvent I is 60 to 90 wt %; Preferably, the resist underlayer film-forming composition further comprises at least one of a cross-linking agent, an acid generator, and a surfactant.

9. The method for preparing the resist underlayer film forming composition according to any one of claims 1 to 8, characterized in that: The preparation method comprises: mixing the polymer with the organic solvent I to obtain a solution which is a composition for forming an anti-etching agent lower layer film.

10. Use of the resist underlayer film forming composition according to any one of claims 1 to 8 in the field of photolithography.

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