Resist bottom layer composition and method for forming pattern using the composition

Abstract

The present invention relates to a resist bottom layer composition and a method for forming a pattern using the composition. According to an embodiment, the resist bottom layer composition comprises: a polymer including a structure represented by Chemical Formula 1 at the end and a structural unit represented by Chemical Formula 2 and a structural unit represented by Chemical Formula 3 in the main chain; and a solvent. The definitions of Chemical Formulas 1 to 3 are the same as those described in the detailed description.

Description

Technical Field

[0001] The present invention relates to a resist bottom layer composition and a method for forming a pattern using the composition. More specifically, the present invention relates to a photoresist bottom layer composition for a bottom layer formed between a semiconductor substrate and a photoresist layer and a method for forming a photoresist pattern using the bottom layer. Background Art

[0002] Recently, the semiconductor industry has developed an ultra-fine technique having a pattern size of several nanometers to several tens of nanometers. This ultra-fine technique essentially requires an effective lithographic technique.

[0003] The lithography technology includes coating a photoresist layer on a semiconductor substrate such as a silicon wafer, exposing and developing it to form a thin layer, irradiating activating radiation such as ultraviolet (UV) while setting a mask pattern having a device pattern, developing the resultant to obtain a photoresist pattern, and etching the substrate using the photoresist pattern as a protective layer to form a fine pattern corresponding to the photoresist pattern on the surface of the substrate.

[0004] Since a technique for manufacturing ultra-fine patterns is required, activating radiation with a short wavelength, such as i-line (365 nanometers), KrF excimer laser (wavelength of 248 nanometers), ArF excimer laser (wavelength of 193 nanometers), etc., is used to expose the photoresist. Therefore, research has been conducted to solve the problem of activating radiation caused by diffuse reflection, standing wave, etc. from the semiconductor substrate by sandwiching a resist bottom layer with optimal reflectivity between the photoresist and the semiconductor substrate.

[0005] On the other hand, in addition to activating radiation, high-energy rays such as extreme ultraviolet (EUV; wavelength of 13.5 nanometers), electron beam (E-beam), etc. have been used as light sources for producing fine patterns, and the light sources do not have reflection from the substrate, but extensive research has been conducted on improving the adhesion of the resist to the underlying layer to improve the collapse of the pattern. In addition, in addition to reducing the problems caused by the light source, extensive research has also been conducted on improving the etching selectivity and chemical resistance of the resist bottom layer. Summary of the invention

[0006] Technical issues

[0007] The embodiment provides a resist base layer composition having coating properties, adhesion and chemical resistance.

[0008] Another embodiment provides a method of forming a pattern using a resist underlying composition.

[0009] Solution to the problem

[0010] According to an embodiment, a resist underlayer composition includes: a polymer including a structure represented by Chemical Formula 1 at a terminal and a structural unit represented by Chemical Formula 2 and a structural unit represented by Chemical Formula 3 in a main chain; and a solvent.

[0011] [Chemical formula 1]

[0012]

[0013] [Chemical formula 2]

[0014]

[0015] [Chemical formula 3]

[0016]

[0017] In Chemical Formulae 1 to 3,

[0018] L 1 To L 7 are independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C1 to C30 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C1 to C30 heteroalkenylene group, a substituted or unsubstituted C2 to C30 heteroarylene group, a substituted or unsubstituted C1 to C30 alkenylene group, a substituted or unsubstituted C1 to C30 alkynylene group, or a combination thereof,

[0019] A, B, C and D are independently O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b ,

[0020] At least one of B, C and D is S,

[0021] n1, n2, n3 and n4 are independently an integer from 0 to 3, with the proviso that at least one of n2, n3 and n4 is an integer of 1 or greater than 1,

[0022] R a , R b and R 1 To R 3 are independently hydrogen, deuterium, hydroxyl, thiol, halogen, carboxyl, acetyl, amine, cyano, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C30 acyl, or a combination thereof, and

[0023] * indicates the connection point.

[0024] According to another embodiment, a method for forming a pattern includes: forming an etching object layer on a substrate; coating an etching resist bottom layer composition on the etching object layer to form a resist bottom layer; forming a photoresist pattern on the resist bottom layer; and using the photoresist pattern as an etching mask to sequentially etch the resist bottom layer and the etching object layer.

[0025] Effects of the Invention

[0026] A resist underlayer having improved coating properties, adhesion and chemical resistance can be provided. DETAILED DESCRIPTION

[0027] Exemplary embodiments of the present disclosure will be described in detail below, and those skilled in the art can easily perform exemplary embodiments of the present disclosure. However, the present disclosure can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0028] It should be understood that when an element (e.g., a layer, film, region, or substrate) is referred to as being "on" another element, the element can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0029] As used herein, when no definition is otherwise provided, "substituted" means that a hydrogen atom of the compound is replaced by a substituent selected from the group consisting of a halogen atom (F, Br, Cl or I), a hydroxyl group, a nitro group, a cyano group, an amine group, an azide group, an amidine group, a hydrazine group, a hydrazone group, a carbonyl group, a carbamoyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a vinyl group, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C6 to C30 allyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C3 to C30 heterocycloalkyl group, and combinations thereof.

[0030] As used herein, when a definition is not otherwise provided, "hetero" means including 1 to 10 heteroatoms selected from N, O, S and P.

[0031] As used herein, when no definition is otherwise provided, "*" indicates a point of attachment for a compound or moiety of a compound.

[0032] Hereinafter, a resist underlayer composition according to an embodiment is described.

[0033] The resist underlayer composition according to the embodiment includes: a polymer including a structure represented by Chemical Formula 1 at a terminal and a structural unit represented by Chemical Formula 2 and a structural unit represented by Chemical Formula 3 in a main chain; and a solvent.

[0034] [Chemical formula 1]

[0035]

[0036] [Chemical formula 2]

[0037]

[0038] [Chemical formula 3]

[0039]

[0040] In Chemical Formulae 1 to 3,

[0041] L 1 To L 7 are independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C1 to C30 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C1 to C30 heteroalkenylene group, a substituted or unsubstituted C2 to C30 heteroarylene group, a substituted or unsubstituted C1 to C30 alkenylene group, a substituted or unsubstituted C1 to C30 alkynylene group, or a combination thereof,

[0042] A, B, C and D are independently O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b ,

[0043] At least one of B, C and D is S,

[0044] n1, n2, n3 and n4 are independently an integer from 0 to 3, with the proviso that at least one of n2, n3 and n4 is an integer of 1 or greater than 1,

[0045] R a , R b and R 1 To R 3 are independently hydrogen, deuterium, hydroxyl, thiol, halogen, carboxyl, acetyl, amine, cyano, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C30 acyl, or a combination thereof, and

[0046] * indicates the connection point.

[0047] The structure represented by Chemical Formula 1 present at the terminal of the polymer is a structure in which substituted or unsubstituted benzene is linked to the main chain of the polymer through a thioether bond.

[0048] In this way, by introducing a substituted or unsubstituted benzene as a functional group connected to the terminal of the polymer via thioether, the polarity of the composition can be controlled, and thus, when the composition is used as a photoresist underlying material, improved surface properties such as high film density, coating uniformity and improved adhesion can be achieved.

[0049] The polarity of the composition can be adjusted according to the benzene functional group as the terminal substituent, and for example, R 1 To R 3 It may independently be hydrogen, hydroxyl, thiol, halogen, carboxyl, amine, cyano, nitro, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C2 to C30 alkenyl, substituted or unsubstituted C6 to C30 aryl, substituted or unsubstituted C1 to C10 alkoxy, substituted or unsubstituted C1 to C30 acyl, or a combination thereof.

[0050] In an embodiment, R 1 To R 3 They may independently be hydrogen, hydroxy, halogen, carboxyl, carboxymethyl, acetyl or a combination thereof.

[0051] For example, Chemical Formula 1 may be represented by Chemical Formula 1-1.

[0052] [Chemical formula 1-1]

[0053]

[0054] In Chemical Formula 1-1, R 1 and R 2 Same as above, L 1 is a single bond or a substituted or unsubstituted C1 to C30 alkylene group, A is O, S, S(O2), C(O), C(O)O, NR aor C(O)NR b , and n1 is an integer from 0 to 3.

[0055] Meanwhile, the thioether bond of the polymer may be formed by polymerization via a thiol-ene reaction.

[0056] Thiol-ene reaction means any reaction that can form a thioether bond by an addition reaction between a carbon-carbon double bond and a thiol functional group. The reaction can proceed not only by a free radical initiated mechanism but also by a nucleophilic addition reaction.

[0057] For example, it is performed under photo-initiated free radical conditions, and can be performed through a typical chain growth reaction consisting of an initiation step, a propagation step, and a termination step.

[0058] As an example, the end-forming compound used to synthesize the polymer may include a substituted or unsubstituted benzene comprising a thiol functional group and a substituted or unsubstituted benzene comprising an olefin functional group.

[0059] For example, the terminal-forming compound used for synthesizing the polymer may be selected from the compounds of Group I, but is not limited thereto.

[0060] [Group I]

[0061]

[0062] The structural unit represented by Chemical Formula 2 has a structure in which a heterocycloalkylene skeleton exists in the core and three oxygen atoms are connected to the heterocycloalkylene group. By having such a structure, it can have a high etching selectivity for a photoresist layer in an etching process and can provide excellent flatness.

[0063] The structural unit represented by Chemical Formula 2 may include at least one hydroxyl group, and due to such a structure, the uniformity of the coating layer may be further ensured.

[0064] In addition, sulfur (S) may be included in the main chain of the polymer by including the structural unit represented by Chemical Formula 3. In this case, it may have a faster etching rate.

[0065] For example, the polymer may include at least one of the structural units represented by Chemical Formula 4 to Chemical Formula 6.

[0066] [Chemical formula 4]

[0067]

[0068] [Chemical formula 5]

[0069]

[0070] [Chemical formula 6]

[0071]

[0072] In Chemical Formulae 4 to 6,

[0073] L 8 To L 22 are independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C1 to C30 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C1 to C30 heteroalkenylene group, a substituted or unsubstituted C2 to C30 heteroarylene group, a substituted or unsubstituted C1 to C30 alkenylene group, a substituted or unsubstituted C1 to C30 alkynylene group, or a combination thereof,

[0074] E, F, G, H, I, J and K are independently O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b ,

[0075] At least one of E and F is S,

[0076] At least one of G and H is S,

[0077] At least one of I, J and K is S,

[0078] n5 to n11 are independently an integer from 0 to 3,

[0079] At least one of n5 and n6 is an integer of 1 or greater,

[0080] At least one of n7 and n8 is an integer of 1 or greater,

[0081] At least one of n9 to n11 is an integer of 1 or greater, and

[0082] * indicates the connection point.

[0083] For example, the polymer may include a moiety represented by one of Chemical Formula 7 to Chemical Formula 11.

[0084] [Chemical formula 7]

[0085]

[0086] [Chemical formula 8]

[0087]

[0088] [Chemical formula 9]

[0089]

[0090] [Chemical formula 10]

[0091]

[0092] [Chemical formula 11]

[0093]

[0094] In Chemical Formula 7 to Chemical Formula 11,

[0095] L 1 is a single bond or a substituted or unsubstituted C1 to C30 alkylene group,

[0096] A is O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b ,and

[0097] nl is an integer from 0 to 3, and

[0098] R 1 and R 2 are independently hydrogen, hydroxy, halogen, carboxymethyl, acetyl or a combination thereof.

[0099] In an embodiment, the polymer may include a portion represented by one of Chemical Formulae 12 to 16, but is not limited thereto.

[0100] [Chemical formula 12]

[0101]

[0102] [Chemical formula 13]

[0103]

[0104] [Chemical formula 14]

[0105]

[0106] [Chemical formula 15]

[0107]

[0108] [Chemical formula 16]

[0109]

[0110] By L 1 To L 22The represented linking group may be unsubstituted, or at least one of the hydrogen atoms constituting the linking group may be replaced by at least one of the group including a C1 to C5 alkyl group, a halogen, a hydroxyl group (-OH), an amine group (-NH2), a carboxyl group (-COOH), an amide group (-CONH2) or a thiol group (-SH).

[0111] The polymer has improved solubility and thus can form a resist base layer with excellent coating uniformity. When the polymer is used as a material for the resist base layer, not only can a uniform thin layer be obtained during a baking process without forming pinholes or voids and without deteriorating the thickness distribution, but also excellent gap filling and planarization characteristics can be obtained when the lower substrate (or layer) has a step or is patterned.

[0112] The polymer may have a weight average molecular weight of 1,000 to 100,000. Specifically, the polymer may have a weight average molecular weight of 1,000 to 50,000 and more specifically 1,000 to 20,000. When the polymer has a weight average molecular weight within this range, the resist underlying composition including the polymer may be optimized by adjusting the carbon content and solubility in a solvent.

[0113] The polymer may be included in an amount of 0.1 wt % to 50 wt %, 0.1 wt % to 30 wt % or 0.1 wt % to 10 wt % based on the total amount of the resist bottom layer composition. When the polymer is included in this range, the thickness, surface roughness and planarization of the resist bottom layer can be controlled.

[0114] The solvent may be any solvent having sufficient solubility or dispersion for the polymer without particular limitation, and may be, for example, at least one selected from the group consisting of propylene glycol, propylene glycol diacetate, methoxypropylene glycol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl α-hydroxyisobutyrate, ethyl α-hydroxyisobutyrate, methyl 3-methoxypropionate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methylpyrrolidinone, acetylacetone, and ethyl 3-ethoxypropionate.

[0115] In addition to the polymers, the resist base layer composition may further include at least one other polymer selected from acrylic resin, epoxy resin, novolac resin, glycoluril resin and melamine resin, but is not limited thereto.

[0116] The resist base layer composition may further include at least one additive selected from the group consisting of a surfactant, a thermal acid generator, a plasticizer, and combinations thereof.

[0117] The surfactant may include, for example, alkylbenzene sulfonate, alkylpyridinium salt, polyethylene glycol, or quaternary ammonium salt, but is not limited thereto.

[0118] The thermal acid generator may be, for example, an acidic compound, such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthoic acid, etc. and / or 2,4,4,6-tetrabromocyclohexadienonone, benzoin toluenesulfonate, 2-nitrobenzyl toluenesulfonate, other organic alkyl sulfonates, etc., but is not limited thereto.

[0119] The additive may be present in an amount of 0.001 to 40 parts by weight based on 100 parts by weight of the resist bottom layer composition. Within this range, the solubility may be increased while the optical properties of the resist bottom layer composition are not changed.

[0120] According to another embodiment, a resist bottom layer manufactured using the resist bottom layer composition is provided. The resist bottom layer can be formed by coating the resist bottom layer composition and curing it by heat treatment, and the heat treatment can be performed at a temperature of about 100° C. to 500° C. For example, the resist bottom layer may include an organic thin layer used in electronic devices, such as a planarization layer, an anti-reflective coating, a sacrificial layer, or a filler.

[0121] Hereinafter, the present disclosure is described in more detail by way of examples of synthesizing a polymer and preparing a resist bottom layer composition comprising the polymer. However, the present disclosure is not technically limited to the following examples.

[0122] Synthetic polymers

[0123] Synthesis example 1:

[0124] 10 g of 1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate, 3.35 g of 1,2-ethanedithiol, 0.52 g of 2,2-azobisisobutyronitrile (AIBN) and 10 g of N,N-dimethylformamide (DMF) were placed in a 100 ml round-bottom flask equipped with a condenser, and then heated while stirring with a magnetic bar to perform a polymerization reaction at 60° C. After the reaction was performed for 3 hours, 1.9 g of 3,4-difluorobenzyl mercaptan was added thereto and reacted for another 1 hour, and then the temperature was lowered to room temperature (23° C. to 25° C.) to complete the reaction. Then, tetrahydrofuran (THF) was placed in the reactor in which the polymerization was completed for dilution, and purification was performed using toluene, isopropyl alcohol (IPA) and heptane to obtain a polymer (Mw=3,100) including a moiety represented by Chemical Formula 12a, wherein n is an integer greater than 0.

[0125] [Chemical formula 12a]

[0126]

[0127] Synthesis example 2:

[0128] 6 g of 1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate, 6.1 g of 1,3-bis(3-mercaptopropyl)-5-(2-hydroxyethyl)-isocyanurate, 0.22 g of v-601 and 20 g of N,N-dimethylformamide (DMF) were placed in a 100 ml round-bottom flask equipped with a condenser, and then heated while stirring with a magnetic bar to perform a polymerization reaction at 75° C. After the reaction was performed for 3 hours, 1.2 g of 3,4-difluorobenzyl mercaptan was added thereto and reacted for another 1 hour, and the temperature was lowered to room temperature (23° C. to 25° C.) to complete the reaction. Then, tetrahydrofuran (THF) was placed in the reactor in which the polymerization was completed for dilution, and purified using toluene, isopropyl alcohol (IPA) and heptane to obtain a polymer (Mw=3,500) containing a portion represented by Chemical Formula 13a, wherein n is an integer greater than 0.

[0129] [Chemical formula 13a]

[0130]

[0131] Synthesis example 3:

[0132] 10 g of 1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate, 4.4 g of 2,3-dimercapto-1-propanol, 0.52 g of AIBN and 20 g of N,N-dimethylformamide (DMF) were placed in a 100 ml round-bottom flask equipped with a condenser, and then heated while stirring with a magnetic bar to perform a polymerization reaction at 55° C. After the reaction was performed for 3 hours, 2 g of 4-mercaptophenylacetic acid was added thereto, and then reacted for another 5 hours, and the temperature was lowered to room temperature (23° C. to 25° C.) to complete the reaction. Then, tetrahydrofuran (THF) was placed in the reactor in which the polymerization was completed for dilution, and purified using toluene, isopropyl alcohol (IPA) and heptane to obtain a polymer (Mw=4,500) containing a portion represented by Chemical Formula 14a, wherein n is an integer greater than 0.

[0133] [Chemical formula 14a]

[0134]

[0135] Synthesis example 4:

[0136] 15 g of 1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate, 7 g of bis(2-mercaptoethyl)ether, 0.7 g of AIBN and 15 g of N,N-dimethylformamide (DMF) were placed in a 100 ml round-bottom flask equipped with a condenser to perform a polymerization reaction at 55° C. After the reaction was performed for 10 hours, 2 g of 1-phenylethylthiol was added thereto and reacted for another 5 hours, and the temperature was lowered to room temperature (23° C. to 25° C.) to complete the reaction. In the reactor in which the polymerization was completed, tetrahydrofuran (THF) was placed for dilution, and toluene, isopropyl alcohol (IPA) and heptane were used for purification to obtain a polymer (Mw=7,000) containing a portion represented by Chemical Formula 15a, wherein n is an integer greater than 0.

[0137] [Chemical Formula 15a]

[0138]

[0139] Synthesis example 5:

[0140] 10 g of 1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate, 4.1 g of 1,2-ethanedithiol, 0.36 g of v-601 and 22 g of N,N-dimethylformamide (DMF) were placed in a 100 ml round-bottom flask equipped with a condenser to perform a polymerization reaction at 60°C. After the reaction was carried out for 5 hours, 1.4 g of 3-(allyloxy)benzoic acid was added thereto and reacted for another 2 hours, and the temperature was lowered to room temperature (23°C to 25°C) to complete the reaction. In the reactor in which the polymerization was completed, tetrahydrofuran (THF) was placed for dilution, and toluene, isopropanol (IPA) and heptane were used for purification to obtain a polymer (Mw=3,300) containing a portion represented by Chemical Formula 16a, wherein n is an integer greater than 0.

[0141] [Chemical formula 16a]

[0142]

[0143] Comparative Synthesis Example 1

[0144] 15 g of 1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate, 7.5 g of bis(2-mercaptoethyl)ether, 0.7 g of AIBN and 15 g of N,N-dimethylformamide (DMF) were placed in a 100 ml round-bottom flask equipped with a condenser to perform a polymerization reaction at 55°C. After the reaction was carried out for 10 hours, the temperature was lowered to room temperature (23°C to 25°C) to complete the reaction. In the reactor where the polymerization was completed, tetrahydrofuran (THF) was placed for dilution, and toluene, isopropanol (IPA) and heptane were used for purification to obtain a polymer (Mw=5,800) containing a portion represented by Chemical Formula 17a, wherein n is an integer greater than 0.

[0145] [Chemical Formula 17a]

[0146]

[0147] Preparation of resist bottom layer composition

[0148] Examples 1 to 5 and Comparative Example 1

[0149] Example 1

[0150] Based on 100 parts by weight of the polymer according to Synthesis Example 1, 20 parts by weight of PD1174 (TCI; curing agent) and 2 parts by weight of pyridinium p-toluenesulfonate were dissolved in a mixed solvent of propylene glycol monomethyl ether, ethyl lactate and cyclohexanone (mixing weight ratio = 3:6:1), and then stirred for 12 hours to prepare an anti-etching agent base layer composition.

[0151] The amount of the mixed solvent may be adjusted according to the evaluation method so that the polymer solid content may be 0.2 wt % to 1 wt % based on the total amount of the resist underlying layer composition.

[0152] Example 2 to Example 5

[0153] Each resist underlayer composition was prepared according to the same method as in Example 1, except that each polymer according to Synthesis Examples 2 to 5 was used.

[0154] Comparative Example 1

[0155] A resist underlayer composition was prepared according to the same method as in Example 1, except that the polymer according to Comparative Synthesis Example 1 was used.

[0156] Evaluation 1: Film density

[0157] 5 ml of the composition according to Examples 1 to 5 and Comparative Example 1 were taken respectively to form a thickness of 100 angstroms and coated on an 8-inch wafer, and then spin-coated at 1,500 rpm using an automatic track ACT8 (TEL Company). Subsequently, the spin-coated composition was cured at 205°C for 50 seconds to form a 100 angstrom thick resist bottom layer. Each resist bottom layer was measured for density based on the critical angle by an X-ray Reflection (XRR) method. Measured by using X'pert PRO MPD (Panalytical Company).

[0158] The results are shown in Table 1.

[0159] [Table 1]

[0160] <![CDATA[Film density (dyne / cm 2 )]]> Example 1 1.37 Example 2 1.37 Example 3 1.44 Example 4 1.32 Example 5 1.35 Comparative Example 1 1.22

[0161] Referring to Table 1, when the compositions according to Examples 1 to 5 were respectively formed as resist underlayers, the densities thereof were improved compared to the resist underlayer formed of the composition according to Comparative Example 1.

[0162] Evaluation 2: Coating uniformity

[0163] 5 ml of the composition according to Examples 1 to 5 and Comparative Example 1 were taken to form a thickness of 100 angstroms and coated on an 8-inch wafer, and then spin-coated at 1,500 rpm using an automatic track ACT8 (TEL). Subsequently, the spin-coated composition was cured at 205°C for 50 seconds to form a 100 angstrom thick resist bottom layer, and the thickness at 51 points in the horizontal axis was measured to compare the coating uniformity. The thickness was measured by Opti-2600 (Thermawave) using ellipsometry, and the results are shown in Table 2.

[0164] In Table 2, the smaller the coating uniformity (%) is, the more excellent the coating uniformity is.

[0165] [Table 2]

[0166] Coating uniformity (%) Example 1 1.7％ Example 2 1.2％ Example 3 1.5％ Example 4 0.9％ Example 5 2.1％ Comparative Example 1 4.8％

[0167] Referring to Table 2, the resist underlying layer compositions according to Examples 1 to 5 show coating uniformity compared to the resist underlying layer composition according to Comparative Example 1.

[0168] Evaluation 3: Pinhole Evaluation

[0169] 5 ml of the compositions according to Examples 1 to 5 and Comparative Example 1 were respectively taken to form a thickness of 100 angstroms and coated on an 8-inch wafer, and then spin-coated at 1,500 rpm by using an automatic track ACT8 (TEL Corporation). Subsequently, the spin-coated compositions were cured at 205° C. for 50 seconds to form a 50 angstrom thick resist bottom layer, and then selected 10 points in the horizontal axis of the surface of the resist bottom layer were inspected by an optical microscope.

[0170] [Table 3]

[0171] Pinhole Example 1 no Example 2 no Example 3 no Example 4 no Example 5 no

[0172] Referring to Table 3, even when the film is 50 angstroms thick and ultra-thin, the resist underlayer compositions according to Examples 1 to 5 are very uniformly coated into a pinhole-free film.

[0173] While the invention has been described in conjunction with what are presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A resist bottom layer composition comprising A polymer including a structure represented by Chemical Formula 1 at a terminal and a structural unit represented by Chemical Formula 2 and a structural unit represented by Chemical Formula 3 in a main chain; and Solvent: [Chemical formula 1] [Chemical formula 2] [Chemical formula 3] in, In Chemical Formulae 1 to 3, L 1 To L 7 are independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C1 to C30 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C1 to C30 heteroalkenylene group, a substituted or unsubstituted C2 to C30 heteroarylene group, a substituted or unsubstituted C1 to C30 alkenylene group, a substituted or unsubstituted C1 to C30 alkynylene group, or a combination thereof, A is O, S, C(O), C(O)O, NR a or C(O)NR b , B, C and D are independently O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b , At least one of B, C and D is S, n1, n2, n3 and n4 are independently an integer from 0 to 3, with the proviso that at least one of n2, n3 and n4 is an integer of 1 or greater than 1, R a , R b and R 1 To R 3 are independently hydrogen, deuterium, hydroxyl, thiol, halogen, carboxyl, acetyl, amine, cyano, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C30 acyl, or a combination thereof, and * indicates the connection point.

2. The resist base composition according to claim 1, wherein R 1 To R 3 and independently hydrogen, hydroxyl, thiol, halogen, carboxyl, amine, cyano, nitro, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C30 acyl, or a combination thereof.

3. The resist base composition according to claim 1, wherein R 1 To R 3 are independently hydrogen, hydroxy, halogen, carboxyl, carboxymethyl, acetyl or a combination thereof.

4. The resist base layer composition according to claim 1, wherein the chemical formula 1 is a structure represented by chemical formula 1-1: [Chemical formula 1-1] in, In Chemical Formula 1-1, L 1 is a single bond or a substituted or unsubstituted C1 to C30 alkylene group, A is O, S, C(O), C(O)O, NR a or C(O)NR b ,and nl is an integer from 0 to 3, and R 1 and R 2 are independently hydrogen, hydroxy, halogen, carboxyl, carboxymethyl, acetyl or a combination thereof.

5. The resist base layer composition according to claim 1, wherein the polymer comprises at least one of the structural units represented by Chemical Formula 4 to Chemical Formula 6: [Chemical formula 4] [Chemical formula 5] [Chemical formula 6] in, In Chemical Formulae 4 to 6, L 8 To L 22 are independently a single bond, a substituted or unsubstituted C1 to C30 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, a substituted or unsubstituted C1 to C30 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C1 to C30 heteroalkenylene group, a substituted or unsubstituted C2 to C30 heteroarylene group, a substituted or unsubstituted C1 to C30 alkenylene group, a substituted or unsubstituted C1 to C30 alkynylene group, or a combination thereof, E, F, G, H, I, J and K are independently O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b , At least one of E and F is S, At least one of G and H is S, At least one of I, J and K is S, n5 to n11 are independently an integer from 0 to 3, At least one of n5 and n6 is an integer of 1 or greater, At least one of n7 and n8 is an integer of 1 or greater, At least one of n9 to n11 is an integer of 1 or greater, and * indicates the connection point. 6 . The resist underlayer composition according to claim 1 , wherein the polymer has a weight average molecular weight of 1,000 to 100,000. 7 . The resist underlayer composition according to claim 1 , wherein the polymer is contained in an amount of 0.1 wt % to 50 wt % based on the total weight of the composition.

8. The resist base layer composition according to claim 1, further comprising at least one polymer selected from the group consisting of acrylic resin, epoxy resin, novolac resin, glycoluril resin and melamine resin. 9 . The resist base layer composition according to claim 1 , further comprising at least one additive selected from the group consisting of a surfactant, a thermal acid generator, a plasticizer, and combinations thereof.

10. A resist bottom layer composition comprising A polymer including a moiety represented by one of Chemical Formula 7 to Chemical Formula 11; and Solvent: [Chemical Formula 7] [Chemical formula 8] [Chemical formula 9] [Chemical formula 10] [Chemical formula 11] in, In Chemical Formula 7 to Chemical Formula 11, L 1 is a single bond or a substituted or unsubstituted C1 to C30 alkylene group, A is O, S, S(O2), C(O), C(O)O, NR a or C(O)NR b ,and nl is an integer from 0 to 3, and R 1 and R 2 are independently hydrogen, hydroxy, halogen, carboxyl, carboxymethyl, acetyl or a combination thereof.

11. A resist bottom layer composition comprising A polymer including a moiety represented by one of Chemical Formula 12 to Chemical Formula 16; and Solvent: [Chemical formula 12] [Chemical formula 13] [Chemical formula 14] [Chemical formula 15] [Chemical formula 16] in, In Chemical Formulae 12 to 16, * is a connection point.

12. A method for forming a pattern, comprising: forming an etching target layer on a substrate; The resist base layer composition according to any one of claims 1 to 11 is applied on the etching target layer to form a resist base layer, forming a photoresist pattern on the resist bottom layer, and The resist bottom layer and the etching target layer are sequentially etched using the photoresist pattern as an etching mask.

13. The method for forming a pattern according to claim 12, wherein forming the photoresist pattern comprises forming a photoresist layer on the resist base layer, exposing the photoresist layer, and The photoresist layer is developed. 14 . The method for forming a pattern according to claim 12 , wherein after coating the resist base layer composition, forming the resist base layer further comprises heat treating the resist base layer composition at a temperature of 100° C. to 500° C.

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