Patent Application
20240255849
This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 of Korean Patent Application No. 10-2022-0186255, filed on Dec. 27, 2022, the entire contents of which are hereby incorporated by reference.
The present disclosure herein relates to a resist compound for photolithography used for the manufacture of semiconductor devices, a method for forming the same, and a method for manufacturing semiconductor devices using the same.
Photolithography may include an exposing process and a developing process. The exposing process may include exposing a resist layer to a specific wavelength of light to induce the change of the chemical structure of the resist layer. The developing process may include selectively removing of the exposed part or the unexposed part of the resist layer by using a solubility difference between the exposed part and the unexposed part.
Recently, as semiconductor devices are highly integrated and downsized, line widths of patterns in semiconductor devices are miniaturized. In order to form minute patterns, various studies are conducted to improve resolution and sensitivity of resist patterns formed by photolithography and to restrain the collapse of resist patterns. Further, a desire for a resist pattern having excellent etching resistance to an etching process is being increased.
The technical task for accomplishing of the present disclosure is to provide a resist compound which may improve the resolution and sensitivity of a photoresist pattern and increasing the etching resistance of the photoresist pattern, a method for forming the same, and a method for manufacturing a semiconductor device using the same.
Another technical task for accomplishing of the present disclosure is to provide a resist compound which may restrain the collapse of a photoresist pattern, a method for forming the same, and a method for manufacturing a semiconductor device using the same.
The task for solving of the present disclosure is not limited to the aforementioned tasks, and unreferred other tasks may be clearly understood by a person skilled in the art from the description below.
According to an embodiment of the inventive concept, there is provided a resist compound for photolithography, represented by Formula 1.
In Formula 1, R1 and R5 are each independently an alkylene group of 1 to 4 carbon atoms, R2 and R6 are each independently a single bond or an alkylene group of 1 to 4 carbon atoms, R3 and R7 are each independently a fluoroalkyl group of 1 to 20 carbon atoms, a fluoroalkyl ether fluoroalkyl group of 2 to 20 carbon atoms, a fluoroalkyl ether fluoroalkylene ether fluoroalkyl group of 3 to 20 carbon atoms or a fluoroaryl group of 6 to 20 carbon atoms, R4 and R8 are each independently hydrogen, deuterium, or a vinyl silyl group, and A1 and A2 are hydrogen or an aryl group of 6 to 20 carbon atoms.
According to another embodiment of the inventive concept, there is provided a method for forming a resist compound for photolithography, including: providing a single molecule having a core structure including at least six benzene rings; and combining a functional group with the core structure. The combining of the functional group with the core structure includes combining a preliminary functional group including a fluorine-containing group and a hydroxyl group (—OH) with the core structure. The combining of the preliminary functional group with the core structure includes performing SN2 type ring-opening reaction using the single molecule having the core structure, and an oxygen-containing heterocyclic compound of 2 to 5 carbon atoms, having the fluorine-containing functional group. The preliminary functional group is combined with any one among the benzene rings of the core structure.
According to another embodiment of the inventive concept, there is provided a method for manufacturing a semiconductor device, including: forming a lower layer on a substrate; and forming a photoresist layer on the lower layer. The photoresist layer includes a resist compound having an organic single molecular structure. The resist compound includes a core structure including at least six benzene rings, and a functional group combined with at least one of the benzene rings of the core structure. The functional group includes at least one among a fluoroalkyl group of 1 to 20 carbon atoms, a fluoroalkyl ether fluoroalkyl group of 2 to 20 carbon atoms, a fluoroalkyl ether fluoroalkylene ether fluoroalkyl group of 3 to 20 carbon atoms, a fluoroaryl group of 6 to 20 carbon atoms, and a vinyl silyl group.
The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification. The drawings illustrate example embodiments of the inventive concept and, together with the description, serve to explain principles of the inventive concept. In the drawings:
Preferred embodiments of the inventive concept will be explained with reference to the accompany drawings for sufficient understanding of the configurations and effects of the inventive concept. The inventive concept may, however, be embodied in various forms, have various modifications and should not be construed as limited to the embodiments set forth herein. The embodiments are provided to complete the disclosure of the inventive concept through the explanation of the embodiments and to completely inform a person having ordinary knowledge in this technical field to which the inventive concept belongs of the scope of the inventive concept. A person having ordinary skill in this technical field may understand which environment is suitable for performing the inventive concept.
The terminology used herein is for the purpose of describing example embodiments and is not intended to limit the inventive concept. In the description, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated materials, constituent elements, steps, operations and/or devices, but do not preclude the presence or addition of one or more other stated materials, constituent elements, steps, operations and/or devices.
In the present description, an alkyl group includes a monovalent saturated hydrocarbon group of a linear chain, branched chain or cyclic chain, unless otherwise indicated.
In the present description, an alkylene group includes a divalent saturated hydrocarbon group of a linear chain, branched chain or cyclic chain, unless otherwise indicated.
In the present description, fluoroalkyl is an alkyl group of which at least one hydrogen is substituted with fluorine, fluoroalkylene is an alkylene group of which at least one hydrogen is substituted with fluorine, fluoroaryl is an aryl group of which at least one hydrogen is substituted with fluorine, and alkoxy fluoride is an alkoxy group of which at least one hydrogen is substituted with fluorine.
In the description, a hydrocarbon group “having a substituent” means that at least a portion of the hydrogen atoms of the hydrocarbon group are substituted with functional groups or atoms, other than hydrogen atoms.
In the description, a case of not drawing a chemical bond at a position where a chemical bond is required may mean that a hydrogen atom is bonded at the position, unless otherwise defined.
Hereinafter, embodiments of the inventive concept will be explained in detail with reference to attached drawings. The same reference numerals are used for the same constituent elements on the drawings, and repeated explanation thereon will be omitted.
The resist compound according to embodiments of the inventive concept may be used for the manufacture of a semiconductor device and may be used in a photolithography process for the manufacture of a semiconductor device. The resist compound may be used, for example, in an extreme ultraviolet or e-beam lithography process. The extreme ultraviolet may mean ultraviolet having a wavelength of about 10 nm to about 124 nm, in detail, a wavelength of about 13.0 nm to about 13.9 nm, in more detail, a wavelength of about 13.4 nm to about 13.6 nm.
The resist compound may include an organic single molecular structure. The resist compound may include a core structure and a functional group combined with the core structure. The core structure may be a single molecule or a dendrimer type. In an embodiment, the core structure may include a compound of at least six hydrocarbon rings, in detail, at least six benzene rings. The functional group may be combined with any one among the benzene rings. The functional group may include at least one among a fluoroalkyl group of 1 to 20 carbon atoms, a fluoroalkyl ether fluoroalkyl group of 2 to 20 carbon atoms, a fluoroalkyl ether fluoroalkylene ether fluoroalkyl group of 3 to 20 carbon atoms, a fluoroaryl group of 6 to 20 carbon atoms, or a vinyl silyl group.
The resist compound may be represented by Formula 1.
In Formula 1, R1 and R5 are each independently an alkylene group of 1 to 4 carbon atoms, and R2 and R6 are each independently a single bond or an alkylene group of 1 to 4 carbon atoms. R3 and R7 are each independently a fluoroalkyl group of 1 to 20 carbon atoms, a fluoroalkyl ether fluoroalkyl group of 2 to 20 carbon atoms, a fluoroalkyl ether fluoroalkylene ether fluoroalkyl group of 3 to 20 carbon atoms or a fluoroaryl group of 6 to 20 carbon atoms. R4 and R8 are each independently hydrogen, deuterium, or a vinyl silyl group, and A1 and A2 are hydrogen or an aryl group of 6 to 20 carbon atoms.
R1, R2, R5 and R6 may each independently have a structure of —CnH2n—, and “n” may be an integer of 1 to 4.
R3 and R7 may be each independently a functional group represented by Formula 2-1, Formula 2-2, Formula 2-3, or Formula 2-4.
In Formula 2-1, “a” is an integer of 1 to 19.
In Formula 2-1 to Formula 2-4, * is a part bonded to the carbon of Formula 1.
R4 and R8 may be each independently a functional group represented by Formula 3.
In Formula 3, R9, R10, R11, R12 and R13 are each independently hydrogen, deuterium, or an alkyl group of 1 to 3 carbon atoms, and * is a part bonded to the oxygen of Formula 1.
The functional group represented by Formula 3 may include a functional group represented by Formula 3-1.
In Formula 3-1, * is a part bonded to the oxygen of Formula 1.
A1 and A2 may be each independently a phenyl group or a phenyl group having a substituent. The phenyl group having the substituent means that at least a portion of the hydrogen atoms of the phenyl group are substituted with functional groups or atoms other than the hydrogen atom. The substituent may be an alkyl group (—R) of 1 to 20 carbon atoms, a fluoroalkyl group of 1 to 20 carbon atoms, a hydroxyl group (—OH), an alkoxy group (—OR) of 1 to 20 carbon atoms, a fluoroalkoxy group of 1 to 20 carbon atoms, a thiol group (—SH), an alkoxythiol group (—SOR) of 1 to 20 carbon atoms, a fluoroalkoxy thiol group of 1 to 20 carbon atoms, a carboxyl group (—COOH), an alkylcarbonyl group (—COR) of 1 to 20 carbon atoms, a fluoroalkyl carbonyl group of 1 to 20 carbon atoms, an alkyl ester group (—COOR) of 1 to 20 carbon atoms, a fluoroalkyl ester group of 1 to 20 carbon atoms, an amino group (NH2), an alkylamino group (—NR2) of 1 to 20 carbon atoms, a fluoroalkyl amino group of 1 to 20 carbon atoms, a nitro group (—NO2), or a halogen atom (—F, —Cl, —Br or —I). In an embodiment, the substituent may be *—CF3, *—OCH3 or *—O(CF2)5CF3, where * is a part bonded to the carbon of the phenyl group.
According to some embodiments, the resist compound represented by Formula 1 may include a material represented by Formula 4 or Formula 5.
In Formula 4 and Formula 5, R1, R2, R3, R5, R6, R7, A1 and A2 are the same as defined in Formula 1.
The resist compound represented by Formula 4 may include a material represented by Formula 4-1, Formula 4-2, Formula 4-3 or Formula 4-4.
The resist compound represented by Formula 5 may include a material represented by Formula 5-1, Formula 5-2, Formula 5-3 or Formula 5-4.
The method for forming the resist compound may include providing a single molecule having a core structure and combining a functional group with the core structure.
The core structure may have a dendrimer type and may include, for example, a compound of at least six hydrocarbon rings, in detail, at least six benzene rings. The functional group may be combined with any one among the benzene rings of the core structure.
The single molecule having the core structure may include a material represented by Formula 6-1 or Formula 6-2.
The combination of the functional group with the core structure may include combining a preliminary functional group including a fluorine-containing functional group and a hydroxyl group (—OH) with the core structure. The fluorine-containing functional group may be a fluoroalkyl group of 1 to 20 carbon atoms, a fluoroalkyl ether fluoroalkyl group of 2 to 20 carbon atoms, a fluoroalkyl ether fluoroalkylene ether fluoroalkyl group of 3 to 20 carbon atoms, or a fluoroaryl group of 6 to 20 carbon atoms. The fluorine-containing functional group may be represented by Formula 2-1, Formula 2-2, Formula 2-3 or Formula 2-4.
The combination of the preliminary functional group with the core structure may include performing SN2 (bimolecular nucleophilic substitution) type ring-opening reaction using the single molecule having the core structure and an oxygen-containing heterocyclic compound of 2 to 5 carbon atoms, having the fluorine-containing functional group. For example, the oxygen-containing heterocyclic compound may be an epoxide.
Particularly, the combination of the preliminary functional group with the core structure may include preparing an epoxide having the fluorine-containing functional group according to Reaction 1, and performing SN2 type ring-opening reaction using the single molecule having the core structure and the epoxide having the fluorine-containing functional group according to Reaction 2-1 and Reaction 2-2.
In Reaction 1, Reaction 2-1 and Reaction 2-2, X1, R3 and R7 are the fluorine-containing functional groups. X1 is a fluoroalkyl group of 1 to 20 carbon atoms, a fluoroalkyl ether fluoroalkyl group of 2 to 20 carbon atoms, a fluoroalkyl ether fluoroalkylene ether fluoroalkyl group of 3 to 20 carbon atoms, or a fluoroaryl group of 6 to 20 carbon atoms. X1 may be a functional group represented by Formula 2-1, Formula 2-2, Formula 2-3 or Formula 2-4. X2 may be a single bond or an alkylene group of 1 to 4 carbon atoms. R2, R3, R6 and R7 are the same as defined in Formula 1. In Reaction 1, AIBN is azobis-isobutyronitrile. In Reaction 2-1 and Reaction 2-2, DMAP is 4-dimethylaminopyridine, and EtOH is ethanol.
Reaction 1 may include Reaction 1-1 or Reaction 1-2.
In Reaction 1, IPA is isopropyl alcohol.
Reaction 2-1 may include Reaction 2-1A or Reaction 2-1B.
By Reaction 2-1A, the resist compound represented by Formula 4-1 may be produced.
By Reaction 2-1B, the resist compound represented by Formula 4-2 may be produced.
Reaction 2-2 may include Reaction 2-2A or Reaction 2-2B.
By Reaction 2-2A, the resist compound represented by Formula 4-3 may be produced.
By Reaction 2-2B, the resist compound represented by Formula 4-4 may be produced.
The combination of the functional group with the core structure, may further include substituting the hydroxyl group (—OH) of the preliminary functional group with a vinyl silyl group. The vinyl silyl group may be represented by Formula 3. The substitution of the hydroxyl group (—OH) of the preliminary functional group with the vinyl silyl group may be performed according to Reaction 3-1 or Reaction 3-2.
In Reaction 3-1 and Reaction 3-2. R2, R3, R6 and R7 are the same as defined in Reaction 1. THF is tetrahydrofuran.
Reaction 3-1 may include Reaction 3-1A or Reaction 3-1B.
By Reaction 3-1A, the resist compound represented by Formula 5-1 may be produced.
By Reaction 3-1B, the resist compound represented by Formula 5-2 may be produced.
Reaction 3-2 may include Reaction 3-2A or Reaction 3-2B.
By Reaction 3-2A, the resist compound represented by Formula 5-3 may be produced.
By Reaction 3-2B, the resist compound represented by Formula 5-4 may be produced.
To a 100 cm3 round flask, 9,9-bis(6-hydroxy-2-naphthyl)fluorene (3.00 g, 6.66 mmol), 3-(perfluoro-n-hexyl)propenoxide (6.26 g, 16.7 mmol) and 4-dimethylaminopyridine (DMAP, 0.0200 g, 0.170 mmol) were injected, and a mixture was prepared using ethanol (30 cm3) as a solvent. The mixture was stirred at a temperature of about 90° C. for about 12 hours to produce a reaction solution. After finishing the reaction, the reaction solution was diluted using ethyl acetate (150 cm3). The organic solvent layer of the diluted reaction solution was separated and recovered, washed with water twice, and further washed once using a saturated sodium chloride aqueous solution (150 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of ethyl acetate and chloroform (ethyl acetate:chloroform=1:9) as a mobile phase, and then concentrated under a reduced pressure. The concentrated product was diluted again in ethyl acetate (20 cm3) and purified by re-precipitating in hexane (350 cm3) to obtain a final product (white solid, HNF-OH, 2.00 g, yield 25%).
1H NMR (400 MHZ, CDCl3): δ=7.83 (d, J=7.5 Hz, 2H, Ar—H), 7.63 (d, J=9.0 Hz, 2H, Ar—H), 7.59-7.53 (m, 4H, Ar—H), 7.50 (d, J=7.5 Hz, 2H, Ar—H), 7.44-7.36 (m, 4H, Ar—H), 7.29 (td, J=7.5, 1.0 Hz, 2H, Ar—H), 7.12-7.07 (m, 4H, Ar—H), 4.61-4.52 (m, 2H, —CH(OH)—), 4.21-4.07 (m, 4H, —OCH2—), 2.58-2.41 (m, 6H, —CH2CF2—, —OH); (ESI-TOF-MS): m/z Calc for (M+CHOO)−, 1225.1784; found, 1225.1792 (Here, Ar means a benzene ring).
To a 50 cm3 seal tube, 9,9-bis(6-hydroxy-2-naphthyl)fluorene (0.760 g, 1.69 mmol), 3-(perfluoro-n-butyl)propenoxide (1.08 g, 3.72 mmol) and 4-dimethylaminopyridine (DMAP, 0.0051 g, 0.0422 mmol) were injected, and a mixture was prepared using ethanol (7 cm3) as a solvent. The mixture was stirred at a temperature of about 90° ° C. for about 12 hours to produce a reaction solution. After finishing the reaction, the reaction solution was diluted using ethyl acetate (100 cm3). The organic solvent layer of the diluted reaction solution was separated and recovered, washed with water twice, and further washed once using a saturated sodium chloride aqueous solution (100 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of ethyl acetate and chloroform (ethyl acetate:chloroform=1:15) as a mobile phase. The product was concentrated under a reduced pressure to obtain a final product (white solid, HNF-OH(s), 0.66 g, yield 39%).
1H NMR (400 MHZ, CDCl3): δ=7.82 (d, J=7.0 Hz, 2H, Ar—H), 7.63 (d, J=9.0 Hz, 2H, Ar—H), 7.60-7.52 (m, 4H, Ar—H), 7.50 (d, J=7.5 Hz, 2H, Ar—H), 7.40 (t, J=9.0 Hz, 4H, Ar—H), 7.30 (d, J=7.0 Hz, 2H, Ar—H), 7.09 (d, J=8.0 Hz, 4H, Ar—H), 4.60-4.52 (m, 2H, —CH(OH)—), 4.20-4.03 (m, 4H, —OCH2—), 2.57-2.40 (m, 6H, —CH2CF2—, —OH) (Here, Ar means a benzene ring).
To a 250 cm3 Schlenk tube, 2,7-dibromo-9-fluorenone (2.40 g, 7.10 mmol), phenylboronic acid (2.16 g, 17.8 mmol), and tetrakis(triphenylphosphine)palladium(0) (0.0821 g, 0.0710 mmol) were injected and sealed. The inside of the tube was changed to a N2 atmosphere using a vacuum pump. Toluene (80 cm3) and ethanol (20 cm3) were bubbled and injected into the tube, and a 2 M potassium carbonate aqueous solution (2.21 g, 16.0 mmol) was injected into the tube to produce a reaction solution. The reaction solution was stirred at a temperature of about 80ºC for about 12 hours. After finishing the reaction, the solvent of the reaction solution was vaporized using a rotary evaporator, and a preliminary product was obtained. The preliminary product was diluted using dichloromethane (250 cm3), and the organic solvent layer of the diluted preliminary product was washed with water twice and washed once more using a saturated sodium chloride aqueous solution (250 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the moisture-removed organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using chloroform as a mobile phase, and the product was concentrated under a reduced pressure. The concentrated product was purified through recrystallization using dichloromethane to obtain a final product (yellow solid, 2,7-diphenyl-9H-fluoren-9-one (DPF), 1.90 g, yield 80%).
1H NMR (400 MHZ, CDCl3): δ=7.94 (dd, J=2.0, 0.5 Hz, 2H, Ar—H), 7.75 (dd, J=8.0, 2.0 Hz, 2H, Ar—H), 7.66-7.59 (m, 6H, Ar—H), 7.51-7.44 (m, 4H, Ar—H), 7.42-7.36 (m, 2H, Ar—H)
To a 100 cm3 round flask, 2,7-diphenyl-9H-fluoren-9-one (DPF, 1.40 g, 4.21 mmol), 2-naphthol (1.46 g, 10.1 mmol), 3-mercaptopropionic acid (0.0447 g, 0.421 mmol) and methanesulfonic acid (1.62 g, 16.8 mmol) were injected, and a reaction solution was produced using toluene (8.4 cm3) as a solvent. The reaction solution was stirred at a temperature of about 50° C. for about 12 hours. The reaction solution was neutralized using a 2 M NaOH aqueous solution and diluted using ethyl acetate (100 cm3). The organic solvent layer of the diluted reaction solution was washed with water twice and washed once more using a saturated sodium chloride aqueous solution (100 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the moisture-removed organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of dichloromethane and ethyl acetate (dichloromethane:ethyl acetate=15:1) as a mobile phase, and the product was concentrated under a reduced pressure. As a result, a final product (brown solid, 2,7-diphenyl-9,9-bis(6-hydroxy-2-naphthyl)fluorene (DPNF), 0.9 g, yield 35%) was obtained.
1H NMR (400 MHZ, CDCl3): δ=7.90 (d, J=8.0 Hz, 2H, Ar—H), 7.73 (d, J=1.0 Hz, 2H, Ar—H), 7.65 (dd, J=8.0, 1.5 Hz, 2H, Ar—H), 7.61 (d, J=9.0 Hz, 4H, Ar—H), 7.59-5.52 (m, 6H, Ar—H), 7.48 (dd, J=9.0, 2.0 Hz, 2H, Ar—H), 7.42-7.36 (m, 4H, Ar—H), 7.33-7.27 (m, 2H, Ar—H), 7.10 (d, J=2.5 Hz, 2H, Ar—H), 7.02 (dd, J=9.0, 2.5 Hz, 2H, Ar—H), 4.91 (s, 2H, —OH) (Here, Ar means a benzene ring).
To a 100 cm3 round flask, 2,7-diphenyl-9,9-bis(6-hydroxy-2-naphthyl)fluorene (DPNF, 0.770 g, 1.28 mmol), perfluoroalkyl epoxide (1.20 g, 3.19 mmol) and 4-dimethylaminopyridine (DMAP, 0.00390 g, 0.0319 mmol) were injected, and a mixture was prepared using ethanol (10 cm3) as a solvent. The mixture was stirred at a temperature of about 90° ° C. for about 12 hours to produce a reaction solution. After finishing the reaction, the reaction solution was diluted using ethyl acetate (100 cm3). The organic solvent layer of the diluted reaction solution was separated and recovered, washed with water twice, and further washed once using a saturated sodium chloride aqueous solution (100 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of ethyl acetate and hexane (ethyl acetate:hexane=1:2) as a mobile phase, and then concentrated under a reduced pressure. The concentrated product was diluted again in ethyl acetate (3 cm3) and re-precipitated in hexane (200 cm3) to obtain a final product (white solid, DPNF-OH, 0.700 g, yield 40%).
1H NMR (400 MHz, CDCl3): δ=7.91 (d, J=9.0 Hz, 2H, Ar—H), 7.73 (d, J=1.5 Hz, 2H, Ar—H), 7.67 (t, J=1.5 Hz, 2H, Ar—H), 7.65 (d, J=2.0 Hz, 2H, Ar—H), 7.64 (d, J=1.5 Hz, 2H, Ar—H), 7.61-7.53 (m, 6H, Ar—H), 7.51 (dd, J=9.0, 2.0 Hz, 2H, Ar—H), 7.42-7.37 (m, 4H, Ar—H), 7.34-7.28 (m, 2H, Ar—H), 7.12-7.08 (m, 4H, Ar—H), 4.60-4.51 (m, 2H, —CH(OH)—), 4.18-4.04 (m, 4H, —OCH2—), 2.57-2.41 (m, 6H, —CH2CF2—, —OH) (Here, Ar means a benzene ring).
To a 50 cm3 seal tube, HNF-OH (1.00 g, 0.830 mmol), 1,3-divinyl-1,1,3,3-tetramethyldisilazane (0.340 g, 1.83 mmol) and saccharin (1.70 mg, 0.00910 mmol) were injected, and a mixture was prepared using tetrahydrofuran (THF, 20 cm3) as a solvent. The mixture was stirred at a temperature of about 60° ° C. for about 2 hours to produce a reaction solution. After finishing the reaction, the reaction solution was diluted using ethyl acetate (100 cm3). The organic solvent layer of the diluted reaction solution was washed with water twice, and further washed once using a saturated sodium chloride aqueous solution (100 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of ethyl acetate and hexane (ethyl acetate:hexane=1:9) as a mobile phase. The product was concentrated under reduced pressure conditions to obtain a final product (white solid, HNF-DVS, 0.800 g, yield 71%).
1H NMR (400 MHZ, CDCl3): δ=7.83 (d, J=7.0 Hz, 2H, Ar—H), 7.63 (d, J=9.0 Hz, 2H, Ar—H), 7.55 (d, J=9.0 Hz, 4H, Ar—H), 7.51 (d, J=7.5 Hz, 2H, Ar—H), 7.40 (t, J=7.5 Hz, 4H, Ar—H), 7.29 (t, J=7.5 Hz, 2H, Ar—H), 7.12-7.02 (m, 4H, Ar—H), 6.18 (dd, J=20.0, 15.0 Hz, 2H, —CHCH2), 6.04 (dd, J=20.0, 3.5 Hz, 2H, —CHCH2), 5.82 (dd, J=20.0, 3.5 Hz, 2H, —SiCH—), 4.61-4.52 (m, 2H, —CH(OSi—)—), 4.07-3.93 (m, 4H, —OCH2—), 2.61-2.30 (m, 4H, —CH2CF2—), 0.25 (s, 12H, —CH3); (ESI-TOF-MS): m/z Calc for (M+CHOO)−, 1415.2643; found, 1415.2682 (Here, Ar means a benzene ring).
To a 50 cm3 seal tube, HNF-OH(s) (0.80 g, 0.798 mmol), 1,3-divinyl-1,1,3,3-tetramethyldisilazane (0.325 g, 1.83 mmol) and saccharin (1.60 mg, 0.00878 mmol) were injected, and a mixture was prepared using tetrahydrofuran (THF, 10 cm3) as a solvent. The mixture was stirred at a temperature of about 60° C. for about 2 hours to produce a reaction solution. After finishing the reaction, the reaction solution was diluted using ethyl acetate (100 cm3). The organic solvent layer of the diluted reaction solution was washed with water twice, and further washed once using a saturated sodium chloride aqueous solution (100 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of ethyl acetate and hexane (ethyl acetate:hexane=1:9) as a mobile phase. The product was concentrated under a reduced pressure to obtain a final product (white solid, HNF-DVS(s), 0.700 g, yield 75%).
1H NMR (400 MHZ, CDCl3): δ=7.82 (d, J=7.0 Hz, 2H, Ar—H), 7.62 (d, J=9.0 Hz, 2H, Ar—H), 7.55 (d, J=9.0 Hz, 4H, Ar—H), 7.50 (d, J=7.5 Hz, 2H, Ar—H), 7.39 (t, J=8.0 Hz, 4H, Ar—H), 7.29 (d, J=7.5 Hz, 2H, Ar—H), 7.07 (d, J=11.5 Hz, 4H, Ar—H), 6.18 (dd, J=19.5, 15.0 Hz, 2H, —CHCH2), 6.03 (d, J=13.0 Hz, 2H, —CHCH2), 5.82 (d, J=20.5 Hz, 2H, —SiCH—), 4.60-4.51 (m, 2H, —CH(OSi—)—), 4.06-3.92 (m, 4H, —OCH2—), 2.60-2.31 (m, 4H, —CH2CF2—), 0.25 (s, 12H, —CH3) (Here, Ar means a benzene ring).
To a 25 cm3 seal tube, DPNF-OH (0.60 g. 0.44 mmol), 1,3-divinyl-1,1,3,3-tetramethyldisilazane (0.16 g, 0.89 mmol) and saccharin (0.80 mg, 0.0044 mmol) were injected, and a mixture was prepared using tetrahydrofuran (THF, 6 cm3) as a solvent. The mixture was stirred at a temperature of about 60° C. for about 2 hours to produce a reaction solution. After finishing the reaction, the reaction solution was diluted using ethyl acetate (100 cm3). The organic solvent layer of the diluted reaction solution was washed with water twice, and further washed once using a saturated sodium chloride aqueous solution (100 cm3). Then, moisture contained in the organic solvent layer was removed using anhydrous MgSO4, and the organic solvent layer was concentrated under reduced pressure conditions to produce a product. The product was purified by column chromatography using a mixture of chloroform and hexane (chloroform:hexane=3:1) as a mobile phase, and the product was concentrated under a reduced pressure. The concentrated product was diluted again in ethyl acetate (3 cm3) and purified through re-precipitation using methanol (150 cm3). As a result, a final product (white solid, DPNF-DVS, 0.42 g, yield 62%) was obtained.
1H NMR (400 MHZ, CDCl3): δ=7.90 (d, J=8.0 Hz, 2H, Ar—H), 7.73 (d, J=1.5 Hz, 2H, Ar—H), 7.67 (d, J=1.0 Hz, 2H, Ar—H), 7.65 (d, J=1.5 Hz, 2H, Ar—H), 7.63 (d, J=1.5 Hz, 2H, Ar—H), 7.59-7.53 (m, 6H, Ar—H), 7.50 (dd, J=9.0, 2.0 Hz, 2H, Ar—H), 7.39 (t, J=7.5 Hz, 4H, Ar—H), 7.33-7.27 (m, 2H, Ar—H), 7.10-7.04 (m, 4H, Ar—H), 6.17 (dd, J=20.0, 15.0 Hz, 2H, —CHCH2), 6.03 (dd, J=15.0, 4.0 Hz, 2H, —CHCH2), 5.81 (dd, J=20.0, 4.0 Hz, 2H, —SiCH—), 4.60-4.50 (m, 2H, —CH(OSi—)—), 4.06-3.93 (m, 4H, —OCH2—), 2.60-2.29 (m, 4H, —CH2CF2—), 0.24 (d, J=2.0 Hz, 12H, —CH3) (Here, Ar means a benzene ring).
Referring to
The photoresist layer 120 may include the resist compound according to embodiments of the inventive concept. The resist compound may be represented by Formula 1. The formation of the photoresist layer 120 may include applying the resist compound on the lower layer 110 using a fluorine-based solvent. The fluorine-based solvent may include, for example, hydrofluoroether (HFE) and/or perfluorocarbon (PFC). The applying of the resist compound on the lower layer 110 may be performed by, for example, a spin coating method. The formation of the photoresist layer 120 may further include performing heating process (for example, a soft baking process) on the resist compound applied.
Referring to
The resist compound may include radicals produced by the irradiation of the light 140. A C—F bond in the resist compound may be broken by secondary electrons produced by the irradiation of the light 140, and accordingly, carbon radicals may be formed. The carbon radicals may be chemically combined with the vinyl silyl group of the resist compound. In an embodiment, double bonds between the carbon atoms of the vinyl silyl group may be broken, and the vinyl silyl group and the carbon radicals may be combined. Through the combination reaction of the vinyl silyl group and the carbon radicals, the resist compound may include a combined (crosslinked) structure of the molecules represented by Formula 1 from each other.
In the first part 122 of the photoresist layer 120, the resist compound may include the carbon radicals produced by the irradiation of the light 140. Through the combination reaction of the vinyl silyl group and the carbon radicals, the resist compound may include a combined (crosslinked) structure of the molecules represented by Formula 1 from each other. In the second part 124 of the photoresist layer 120, the chemical structure of the resist compound may not change, and the resist compound may include a single molecular structure represented by Formula 1. By the exposing process, the first part 122 and the second part 124 of the photoresist layer 120 may have different chemical structures from each other.
Referring to
According to embodiments of the inventive concept, the resist compound may have an organic single molecular structure represented by Formula 1. Since the resist compound has the organic single molecular structure having a small molecular weight in contrast to a polymer, the resist compound may be purified so as to have high purity through a sublimation process under a low pressure.
The photoresist layer 120 may include the resist compound of the organic single molecular structure represented by Formula 1. By the exposing process, the resist compound in the exposed part (i.e., the first part 122) of the photoresist layer 120 may include a combined (or crosslinked) structure of the molecules represented by Formula 1 from each other, and the resist compound in the unexposed part (i.e., the second part 124) of the photoresist layer 120 may include the single molecular structure represented by Formula 1.
Since the resist compound includes a fluorine atom having high absorbance of the light 140 (for example, extreme ultraviolet), the production of the carbon radicals in the first part 122 of the photoresist layer 120 may increase. Further, the resist compound may include a vinyl silyl group which may undergo the combination reaction with the carbon radicals, and accordingly, the crosslinking bond between the molecules represented by Formula 1 in the first part 122 of the photoresist layer 120 may be easy. In the second part 124 of the photoresist layer 120, the resist compound may have a single molecular structure having a small size (or molecular weight) and narrow polydispersity index in contrast to a polymer, and accordingly, the second part 124 may have a high and uniform solubility with respect to the developing solution used in the developing process. Accordingly, the sensitivity and resolution of the photoresist pattern 122 having a negative tone may be improved.
Further, the developing process may be performed using the fluorine-based solvent as a developing solution. The fluorine-based solvent has no flammability, low toxicity, chemical stability and relatively low surface tension. Since the developing process is performed using the fluorine-based solvent having relatively low surface tension, the pattern collapse of the photoresist pattern 122 may be minimized.
Referring to
According to embodiments of the inventive concept, the resist compound may have an organic single molecular structure represented by Formula 1 and may have high etching resistance due to the core structure constituting the organic single molecular structure. Accordingly, during the etching process of the lower layer 110, the etching resistance of the photoresist pattern 122 may increase, and thus, the formation of the lower pattern 110P may be easy. Further, the resist compound may not include a metal element, and accordingly, the contamination by the metal element may be prevented during the manufacturing process of a semiconductor device.
According to the inventive concept, the resist compound may have an organic single molecular structure represented by Formula 1, and the photoresist layer 120 may include the resist compound. By performing the exposing process and the developing process on the photoresist layer 120, the photoresist pattern 122 may be formed. Since the resist compound has the organic single molecular structure represented by Formula 1, the sensitivity and resolution of the photoresist pattern 122 may be improved, and the etching resistance of the photoresist pattern 122 may be increased. Further, the developing process may be performed using the fluorine-based solvent, and accordingly, the pattern collapse of the photoresist pattern 122 may be minimized.
Accordingly, a resist compound which may improve the resolution and sensitivity of a photoresist pattern, increase the etching resistance of the photoresist pattern, and may restrain the collapse of the photoresist pattern, a method for forming the same and a method for manufacturing a semiconductor device using the same may be provided.
A HNF-OH solution (about 3 wt/vol %) in which the resist compound (HNF-OH) synthesized in Experimental Example 1-1 was dissolved in PF-7600 (3M Co.) was applied on a silicon substrate at about 3000 rpm for about 60 seconds by a spin coating method, and heated at about 80° C. for about 1 minute to form a first photoresist thin layer (a thickness of about 100 nm). On the photoresist thin layer, e-beam of about 50 to about 1,500 μC/cm2 was irradiated under an acceleration voltage of about 80 keV, and then, a developing process was performed using a fluorine-based developing solution (HFE-7300 (3M Co.): PF-7600 (3M Co.)=1:1) for about 35 seconds to form a negative tone first photoresist pattern.
A HNF-DVS solution (about 2.2 wt/vol %) in which the resist compound (HNF-DVS) synthesized in Experimental Example 2-1 was dissolved in PF-7600 (3M Co.) was applied on a silicon substrate at about 3000 rpm for about 60 seconds by a spin coating method, and heated at about 80° C. for about 1 minute to form a second photoresist thin layer (a thickness of about 100 nm). On the second photoresist thin layer, e-beam of about 50 to about 1,500 μC/cm2 was irradiated under an acceleration voltage of about 80 keV, and then, a developing process was performed using a fluorine-based developing solution (HFE-7300: FC-3283(3M Co.)=1:1) for about 35 seconds to form a negative tone second photoresist pattern.
A HNF-DVS(s) solution (about 2.3 wt/vol %) in which the resist compound (HNF-DVS(s)) synthesized in Experimental Example 2-2 was dissolved in PF-7600 (3M Co.) was applied on a silicon substrate at about 4000 rpm for about 60 seconds by a spin coating method, and heated at about 80° ° C. for about 1 minute to form a third photoresist thin layer (a thickness of about 90 nm). On the third photoresist thin layer, e-beam of about 50 to about 1,500 μC/cm2 was irradiated under an acceleration voltage of about 80 keV, and then, a developing process was performed using a fluorine-based developing solution (HFE-7300) for about 30 seconds to form a negative tone third photoresist pattern.
A HNF-DVS solution (about 2.5 wt/vol %) obtained by dissolving the resist compound (HNF-DVS) synthesized in Experimental Example 2-1 in PF-7600 (3M Co.) was applied on a silicon substrate at about 3000 rpm for about 60 seconds by a spin coating method, and heated at about 80ºC for about 1 minute to form a photoresist thin layer (a thickness of about 120 nm). Extreme ultraviolet of about 2 to about 45 mJ/cm2 was irradiated on the photoresist thin layer using a stepper installed in a 4A beam line of Pohang Accelerator Laboratory, and then, a developing process was performed using a fluorine-based developing solution (HFE-7300: FC-3283=1:1) for about 90 seconds to form a negative tone photoresist pattern. The thickness of the photoresist pattern was measured using Alpha-Step® D-300 stylus profiler manufactured by Kla-Tencor Co., and the solubility change properties of the photoresist thin layer were evaluated.
A HNF-DVS solution (about 0.85 wt/vol %) obtained by dissolving the resist compound (HNF-DVS) synthesized in Experimental Example 2-1 in PF-7600 was applied on a silicon substrate coated with 1,3-divinyl-1,1,3,3-tetramethyldisilazane (DVS) at about 805 rpm for about 60 seconds by a spin coating method, and heated at about 80° C. for about 1 minute to form a photoresist thin layer (a thickness of about 35 nm). Extreme ultraviolet (EUV) was irradiated on the photoresist thin layer using a MET5 stepper possessed by Lawrence Berkeley National Laboratory, and then, a developing process was performed using a fluorine-based developing solution (HFE-7300: FC-3283=2:3) for about 30 seconds to form a negative tone photoresist pattern having a line width of about 30 nm or less.
Experiments on comparing etching rates of the resist compound (HNF-OH) synthesized in Experimental Example 1-1, the resist compound (HNF-DVS) synthesized in Experimental Example 2-1, a resist (L6) disclosed in Korean Registration Patent No. 10-2215511, and a commercially available KrF resist were conducted.
1) A HNF-OH solution (about 10 wt/vol %) obtained by dissolving the resist compound (HNF-OH) synthesized in Experimental Example 1-1 in PF-7600 was applied on a silicon substrate at about 1500 rpm for about 60 seconds by a spin coating method, and heated at about 80° C. for about 1 minute to form a first photoresist thin layer (a thickness of about 610 nm).
2) A HNF-DVS solution (about 10 wt/vol %) obtained by dissolving the resist compound (HNF-DVS) synthesized in Experimental Example 2-1 in PF-7600 was applied on a silicon substrate at about 2000 rpm for about 60 seconds by a spin coating method, and heated at about 80° C. for about 1 minute to form a second photoresist thin layer (a thickness of about 500 nm).
3) (Comparative Example 1) A solution of L6 (about 20 wt/vol %) obtained by dissolving a resist (L6) disclosed in Korean Registration Patent No. 10-2215511 in HFE-7500 was applied on a silicon substrate at about 1000 rpm for about 60 seconds by a spin coating method, and heated at about 80° ° C. for about 1 minute to form a third photoresist thin layer (a thickness of about 1 μm).
4) (Comparative Example 2) A commercially available KrF resist solution (purchased from Dongjin Semichem) was applied on a silicon substrate at about 2000 rpm for about 60 seconds by a spin coating method, and heated at about 80ºC for about 1 minute to form a fourth photoresist thin layer (a thickness of about 630 nm).
5) An etching process was performed on the first to fourth photoresist thin layers. The etching process is a dry etching process using a reactive ion etching (RIE) method, and a mixture gas of O2 and CF4 was used as an etching gas. The etching process was performed by about 100 W, about 100 kHz, and flow conditions of about 2 sccm of O2 and about 18 sccm CF4. The thickness of a remaining thin film according to the etching time (0 seconds, 25 seconds, 50 seconds and 75 seconds) of the etching process was measured using ellipsometry.
The first and second photoresist thin layers formed in Experimental Example 6 were thin layers not undergone an exposing process. If an exposing process is performed on the first and second photoresist thin layers, the first and second photoresist thin layers may include a combined structure of single molecules represented by Formula 1. In this case, the resist compounds (HNF-OH and HNF-DVS) according to the Examples of the inventive concept are expected to achieved better etching resistance than Comparative Example 2 (KrF resist).
In Experimental Example 6, the resist (L6) disclosed in Korean Registration Patent No. 10-2215511 of Comparative Example 1 includes a material represented by Formula 7.
In Formula 7, R is a functional group represented by Formula 8.
In Formula 8, * is a part bonded to the oxygen of Formula 7.
According to the inventive concept, the resist compound may have an organic single molecular structure represented by Formula 1, and a photoresist layer may include the resist compound. By performing an exposing process and a developing process on the photoresist layer, a photoresist pattern may be formed. Since the resist compound includes the organic single molecular structure represented by Formula 1, the sensitivity and resolution of the photoresist pattern may be improved, and the etching resistance of the photoresist pattern may be increased. Further, the developing process may be performed using a fluorine-based solvent as a developing solution, and accordingly, the pattern collapse of the photoresist pattern may be minimized.
Accordingly, a resist compound capable of improving the resolution and sensitivity of a photoresist pattern, increasing the etching resistance of a photoresist pattern, and restraining the collapse of a photoresist pattern, a method for forming the same, and a method for manufacturing a semiconductor device using the same, may be provided.
Although the embodiments of the present invention have been described, it is understood that the present invention should not be limited to the embodiments, but various changes and modifications can be made by one ordinary skilled in the art within the spirit and scope of the present invention as hereinafter claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0186255 | Dec 2022 | KR | national |
