Monomolecular resin based on modification of multiple metallocene groups and photoresist thereof

Abstract

The invention provides a series of novel monomolecular resin based on the metallocene compound, the monomolecular resin is used as a single-component non-chemical amplification photoresist, the problems of non-uniform distribution of an acid generator and an anti-acid diffusion agent, non-uniform acid diffusion and the like in a chemical amplification photoresist are avoided, and an obtained pattern has high resolution and low line width roughness. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of material technology, and in particular relates to a type of single-molecule resin modified based on multiple metallocene groups and a photoresist thereof. Background Art

[0002] With the rapid development of the semiconductor industry, the integration of semiconductor devices is getting higher and higher, and the resolution required to be achieved by photolithography technology is also getting higher and higher. The quality of high-resolution photolithography patterns also puts forward higher requirements, especially the line width roughness (LWR) and line edge roughness (LER) of the patterns are becoming more and more stringent. Photoresist is a key material for the transfer of photolithography patterns during the processing of semiconductor devices. The photoresist is coated on different substrates, and after being irradiated with energy such as light beams, electron beams, ion beams or x-rays, the solubility changes, and then the corresponding pattern is transferred to the substrate through development and etching processes. The resolution that can be achieved by the pattern formed by the photoresist has a decisive influence on the integration of the device. The comprehensive performance of the photoresist needs to match the development of current photolithography technology.

[0003] Traditionally used chemically amplified photoresists (CARs) rely on mixed or polymer-bonded photoacid generators (PAGs) to achieve solubility differences. This chemically amplified photoresist system has a series of problems, such as high line edge roughness (LER) and line width roughness (LWR), instability after exposure, etc. In order to solve these problems, the research on new non-chemically amplified photoresists (n-CARs) is receiving increasing attention. n-CARs are materials that are directly sensitive to radiation. In their formulations, they do not require the addition of PAGs and only contain one component, the host material. Therefore, they can effectively solve the compatibility problem between the host material and the additive, as well as the problem of uneven acid diffusion after exposure, thereby reducing the LER value. However, compared with the number of CARs reported so far, the number of n-CARs is very limited, especially those based on single-molecule resins. Therefore, it is of great significance to develop single-molecule resin n-CARs with strong lithography potential, especially for sub-20nm patterning applications with low LER / LWR characteristics. Summary of the invention

[0004] In order to improve the above technical problems, the present invention first provides a compound represented by the following formula (I):

[0005]

[0006] Wherein, Ra, Rc, Rd are the same or different and are independently selected from H, the following groups which are unsubstituted or optionally substituted by one, two or more Rs: 1-12 Alkyl, C 1-12 Alkoxy, C 3-20 Cycloalkyl, 3-20 membered heterocyclic group;

[0007] Rs is selected from nitro, cyano, halogen, C 1-12 Alkyl, C 1-12 Alkoxy or halogenated C 1-12 alkyl;

[0008] Z is selected from divalent metals such as Fe, Zn, Ru, Os, Cd, Hg, Ni, Co, Rh, Pd, Pt, Sn, and Pb;

[0009] X is selected from halide, C 2-6 Alkylsulfonate, trifluoromethanesulfonate, perfluoropropylsulfonate, perfluorobutylsulfonate, p-toluenesulfonate, tetrafluoroborate, hexafluorophosphate or bistrifluoromethanesulfonyl imide ion;

[0010] s, m, and n are the same or different and are independently 1, 2, 3 or 4.

[0011] In some embodiments of the present invention, Ra, Rc, and Rd are the same or different and are independently selected from H, C unsubstituted or optionally substituted with one, two or more Rs. 1-6 Alkyl; Rs is selected from halogen.

[0012] In some embodiments of the present invention, Ra is methyl, ethyl or propyl; Rc, Rd are H;

[0013] In some embodiments of the present invention, Ra is ortho-methyl, ethyl or propyl; Rc, Rd are H;

[0014] In some embodiments of the present invention, X is selected from the group consisting of halide ions (eg, chloride ions), perfluorobutanesulfonate, and p-toluenesulfonate ions.

[0015] As an example, the compound represented by formula (I) is selected from the following compounds:

[0016]

[0017] In one embodiment of the present invention, the compound wherein X is a chloride ion is ion-exchanged with other anions to obtain a compound of formula (I) having different anions.

[0018] The present invention also provides a method for preparing the compound represented by formula (I), comprising the following steps:

[0019]

[0020] Compound Ia reacts with Ib to obtain a compound of formula I;

[0021] wherein Ra, Rc, Rd, s, m, n, and X have the same definitions as above.

[0022] In some embodiments, compound Ia is prepared by the following method:

[0023]

[0024] Compound Ia1 reacts with thionyl chloride to obtain a compound represented by formula Ia;

[0025] wherein Ra, s, and X have the same definitions as above.

[0026] When X is not a chloride ion, the compound Ia in which X is a chloride ion is ion-exchanged with other anions to obtain a compound Ia with a different anion.

[0027] The present invention also provides the use of the compound represented by the above formula (I), which is used as a photoresist, especially as a single-component photoresist.

[0028] The present invention also provides a photoresist composition, which comprises the compound represented by formula (I) as described above.

[0029] According to an embodiment of the present invention, the photoresist composition also includes a solvent, which is selected from one, two or more of the following substances: propylene glycol methyl ether acetate (PGMEA), N,N-dimethylformamide (DMF), cyclohexanone, ethyl n-amyl ketone, ethyl isoamyl ketone, ethanol, acetonitrile, isopropanol, acetone, methyl n-amyl ketone, and methyl isoamyl ketone.

[0030] According to an embodiment of the present invention, the photoresist composition is a positive or negative photoresist composition.

[0031] In one embodiment of the present invention, the photoresist composition is a single-component photoresist, which is composed of the compound represented by formula (I) and a solvent, that is, the photoresist composition includes only one photoresist component except the solvent, that is, it does not contain an acid generator except the compound represented by formula (I).

[0032] The present invention also provides a photoresist coating, which comprises the compound represented by formula (I) as described above.

[0033] The present invention also provides a method for preparing the above-mentioned photoresist coating, comprising: applying the above-mentioned photoresist composition on a substrate to prepare the coating.

[0034] In one embodiment, the applying method is spin coating.

[0035] In one embodiment, the substrate is a silicon wafer substrate.

[0036] Preferably, the photoresist coating is a thin film.

[0037] The present invention also provides the use of the compound represented by formula (I), the photoresist composition or the photoresist coating in photolithography.

[0038] According to the present invention, the photoresist coating is used in modern lithography techniques such as 248 nm lithography, 254 nm lithography, 193 nm lithography, extreme ultraviolet (EUV) lithography, nanoimprint lithography or electron beam lithography.

[0039] Beneficial Effects

[0040] (1) The present invention provides a series of novel single-molecule resins based on metallocene compounds, namely, compounds represented by formula (I), the raw materials of which are cheap and readily available, and the synthesis process is simple;

[0041] (2) The compound represented by formula (I) of the present invention can be used as a single-component non-chemically amplified photoresist, thereby avoiding the problems of uneven distribution of acid generators and acid diffusion inhibitors and uneven acid diffusion in chemically amplified photoresists, and the resulting pattern has high resolution and low line width roughness.

[0042] (3) The metallocene compound-based single-molecule resin of the present invention has a definite molecular structure and a single molecular size, and can well meet the requirements of high-resolution lithography.

[0043] (4) The metallocene compound-based single-molecule resin of the present invention introduces a metallocene structure into the photoresist. The addition of metal elements can improve the etching resistance of the photoresist and improve the sensitivity of the photoresist in electron beam lithography and EUV lithography. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is an AFM image of the compound I-2 film in Example 2 of the present invention.

[0045] Figure 2 This is the UV exposure pattern of the photoresist containing compound I-2 in Example 2 of the present invention.

[0046] Figure 3 This is the electron beam lithography exposure pattern of the photoresist containing compound I-2 in Example 2 of the present invention.

[0047] Definition and explanation of terms

[0048] Unless otherwise defined, all technical and scientific terms herein have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter belongs.

[0049] "More" means three or more.

[0050] The term "halogen" includes F, Cl, Br or I.

[0051] The term "C1-12 "Alkyl" is understood to mean a straight-chain or branched saturated monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably C 1-6 Alkyl. "C 1-6 The term “alkyl” is understood as meaning preferably a linear or branched, saturated, monovalent hydrocarbon radical having 1, 2, 3, 4, 5 or 6 carbon atoms. The alkyl radical is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, etc. or their isomers. In particular, the radical has 1, 2 or 3 carbon atoms (“C 1-3 "alkyl"), for example methyl, ethyl, n-propyl or isopropyl.

[0052] The term "C 3-20 "Cycloalkyl" is understood to mean a saturated monovalent monocyclic or bicyclic hydrocarbon ring having 3 to 20 carbon atoms, preferably "C 3-12 The term "Cycloalkyl" 3-12 "Cycloalkyl" is understood to mean a saturated, monovalent, monocyclic or bicyclic hydrocarbon ring having 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms. 3-12 The cycloalkyl group may be a monocyclic hydrocarbon group such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, or a bicyclic hydrocarbon group such as a decalin ring.

[0053] The term "3-20 membered heterocyclyl" means a saturated monovalent monocyclic or bicyclic hydrocarbon ring containing 1-5 heteroatoms independently selected from N, O and S, preferably a "3-12 membered heterocyclyl". The term "3-12 membered heterocyclyl" means a saturated monovalent monocyclic or bicyclic hydrocarbon ring containing 1-5, preferably 1-3 heteroatoms selected from N, O and S. The heterocyclyl may be attached to the rest of the molecule via any one of the carbon atoms or the nitrogen atom, if present. In particular, the heterocyclyl includes, but is not limited to, a 4-membered ring such as azetidinyl, oxetanyl; a 5-membered ring such as tetrahydrofuranyl, dioxolyl, pyrrolidinyl, imidazolidinyl, pyrazolidinyl, pyrrolinyl; or a 6-membered ring such as tetrahydropyranyl, piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl or trithianyl; or a 7-membered ring such as diazepanyl. Optionally, the heterocyclic group may be benzo-fused. The heterocyclic group may be bicyclic, for example, but not limited to, a 5,5-membered ring, such as a hexahydrocyclopenta[c]pyrrole-2(1H)-yl ring, or a 5,6-membered bicyclic ring, such as a hexahydropyrrolo[1,2-a]pyrazine-2(1H)-yl ring. The ring containing nitrogen atoms may be partially unsaturated, i.e., it may contain one or more double bonds, for example, but not limited to, 2,5-dihydro-1H-pyrrolyl, 4H-[1,3,4]thiadiazinyl, 4,5-dihydrooxazolyl or 4H-[1,4]thiazinyl, or it may be benzo-fused, for example, but not limited to, dihydroisoquinolinyl. According to the present invention, the heterocyclic group is non-aromatic.

[0054] The above term “C 1-12 The definition of "alkyl" also applies to compounds containing "C 1-12 Other terms for "alkyl", such as the term "C 1-12 Alkoxy", "halogenated C 1-12 Alkyl" and so on. DETAILED DESCRIPTION

[0055] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0056] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0057] Example 1

[0058] The synthesis route of compound I-1 is as follows:

[0059]

[0060] Synthesis of Compound A:

[0061] Specific steps: Compound A can be prepared according to the method reported previously. 1 eq. (15 g) of 2,6-dimethylphenol is dissolved in 35 ml of CS dried over molecular sieves in an ice bath. 2 Stir until completely dissolved, then add 10.98 g of AlCl 3 Then slowly add 3 ml of SOCl 2 , stirred for 40 minutes, the solution turned green first and then blue-purple, and after 1 hour of reaction, no raw material remained on the plate, so the reaction was stopped, 120 g of water and a small amount of HCl were added to quench the reaction, and the solid was filtered out and recrystallized from ethanol and ether. 1 H NMR(400MHz,1H-NMR(400MHz,DMSO-d 6 )δ(ppm)9.75(3H,s),7.37(6H,s),2.21(18H,s).

[0062] Synthesis of compound B:

[0063] Specific steps: 5g of ferrocenecarboxylic acid is added to 100ml of ultra-dry dichloromethane under an ice bath, and after stirring evenly, 5.5ml of oxalyl chloride and 1ml of DMF are added thereto, and the mixture is reacted under reflux for 2h. After the reaction, a solid is obtained by rotary evaporation, and the product is extracted with hot petroleum ether, and the solid ferrocenecarboxylic acid is obtained by rotary drying to obtain solid ferrocenecarboxylic acid chloride. After drying, 3.5g of the product is obtained. 1 H NMR (400 MHz, DMSO-d 6 )δ(ppm)4.92(2H),4.64(2H),4.34(5H).

[0064] Synthesis of compound I-1:

[0065] Specific steps: 1 eq. of compound A is completely dissolved in 8 ml of ultra-dry DMF to form a clear transparent solution, 0.53 g of monoferrocenyl chloride is added thereto, the solution turns red, 0.5 ml of Et 3 N, a small amount of smoke was generated, and then 0.02g of DMAP was added thereto, the ice bath was removed, and the reaction was monitored on a reaction point plate in a 60°C oil bath. After the reaction was completed, the reaction solution was dropped into 80ml of water for precipitation, and a yellow solid was obtained by suction filtration. The product was dissolved in DCM and separated by column chromatography (developing agent V DCM:CH3OH =20:1), and rotary evaporation gave an orange-yellow solid. 1 H NMR (400 MHz, DMSO-d 6)δ(ppm)7.79(s,6H),4.99(s,6H),4.70(s,6H),4.39(s,15H),2.29(s,18H);MS(ESI):m / z=1031.14,calculated value C 57 H 51 Fe 3 O 6 S + m / z=1031.14([M] + ); m / z = 1031.14, calculated value Cl - m / z=35.5([M] - ).

[0066] Example 2

[0067] Compound I-2 was prepared by the following synthetic route:

[0068]

[0069] Synthesis of compound C:

[0070] Specific steps: 1 eq. (0.84 g) of compound A was added to 10 ml of ethanol and stirred in an oil bath at 77°C. 2 eq. (0.74 g) of NaOTs was stirred in 5 ml of water at room temperature. After it was completely dissolved, it was added to the solution of compound A. The solution changed from turbid to clear and then to turbid. After 1 hour of reaction, the plate was spotted (developing agent V DCM:CH3OH =10:1), the reaction was observed to be completed. After the reaction was completed, 30 ml of deionized water was added to the reaction bottle, filtered, and the obtained solid was washed with (60 ml × 3 times) water, filtered, and placed in a vacuum drying oven to dry to obtain 0.83 g of product compound C. 1 H NMR (400 MHz, DMSO-d 6 )δ7.47(d,2H),7.35(s,6H),7.12(d,2H),2.28(s,3H),2.20(s,18H).

[0071] Synthesis of compound I-2:

[0072] Specific steps: 1 eq. (0.2 g) of compound C was completely dissolved in 8 ml of ultra-dry DMF to form a clear transparent solution, 0.53 g of monoferrocenyl chloride was added thereto, the solution turned red, and 0.5 ml of Et 3 N, a small amount of smoke was generated, and then 0.02g of DMAP was added thereto, the ice bath was removed, and the reaction was carried out in a 60℃ oil bath pot. The reaction was detected by spot plate. After the reaction was completed, the reaction solution was dropped into 80ml of water for precipitation, and a yellow solid was obtained by suction filtration. The product was dissolved in DCM and then passed through a column (developing agent VDCM:甲醇 =20:1), rotary evaporation to obtain an orange-yellow solid, dissolve it in ethanol, then dissolve sodium p-toluenesulfonate in deionized water, mix in a 70°C oil bath, and monitor the reaction with a plate. After the reaction is completed, the reaction solution is dropped into a large amount of water for precipitation, filtered, and washed with water three times to obtain the final product. 1 H NMR (400 MHz, DMSO-d 6 )δ7.47(d,2H),7.35(s,6H),7.12(d,2H),2.28(s,3H),2.20(s,18H);MS(ESI):m / z=1031.14,calculated value C 57 H 51 Fe 3 O 6 S + m / z=1031.14([M] + ); m / z = 1031.14, calculated value C 7 H 7 O 3 S - m / z=171.01([M] - ).

[0073] Example 3

[0074] Compound I-2 in Example 2 was dissolved in acetonitrile to obtain a solution with a concentration of 20 mg / ml. The solution was then filtered through a microporous filter with a pore size of 0.22 μm to obtain a spin coating solution. The spin coating solution was spin coated on a silicon substrate to form a film, and the uniformity and flatness of the film were analyzed using AFM. The results are shown in the attached Figure 1 It can be seen from the figure that the obtained film is very uniform and has no crystallization phenomenon, which is conducive to the preparation of a smooth surface lithography pattern.

[0075] Example 4

[0076] A negative photoresist formulation and its use in UV lithography: Compound I-2 of Example 2 was dissolved in acetonitrile to obtain a solution with a concentration of 20 mg / ml. The solution was filtered through a microporous filter with a pore size of 0.22 μm to obtain a spin coating solution. The spin coating solution was spin-coated on a silicon substrate to form a film, and baked at 80°C for 3 minutes. The prepared film was exposed to an exposure experiment (254 nm UV lamp) for 1 minute, and then developed with a volume ratio of water: isopropanol = 2:1 to obtain very clear stripes, as shown in FIG. Figure 2 .Depend on Figure 2 It can be seen that the width of the photolithography stripe is 1.29 microns.

[0077] Example 5

[0078] A negative photoresist formulation and its use in electron beam lithography: Compound I-2 of Example 2 was dissolved in acetonitrile to obtain a solution with a concentration of 15 mg / ml. The solution was filtered through a microporous filter with a pore size of 0.22 μm to obtain a spin coating solution. The spin coating solution was spin-coated on a silicon substrate and baked at 80°C for 3 minutes. The prepared film was subjected to an exposure experiment (electron beam lithography) with an exposure dose of 3200 uC / cm 2 Then use water: ethanol = 1:1.5 volume ratio to develop for 1 min, and get very clear stripes. Figure 3 .Depend on Figure 3 It can be seen that the minimum width of the photolithography stripe is 50nm.

[0079] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Compound represented by formula (I): in, Ra, Rc, Rd are the same or different and are independently selected from H, the following groups which are unsubstituted or optionally substituted by one, two or more Rs: 1-12 Alkyl, C 1-12 Alkoxy, C 3-20 Cycloalkyl, 3-20 membered heterocyclic group; Rs is selected from nitro, cyano, halogen, C 1-12 Alkyl, C 1-12 Alkoxy or halogenated C 1-12 alkyl; Z is selected from divalent metals such as Fe, Zn, Ru, Os, Cd, Hg, Ni, Co, Rh, Pd, Pt, Sn, and Pb; X is selected from halide ions, C 2-6 Alkylsulfonate, trifluoromethanesulfonate, perfluoropropylsulfonate, perfluorobutylsulfonate, p-toluenesulfonate, tetrafluoroborate, hexafluorophosphate or bistrifluoromethanesulfonyl imide ion; s, m, and n are the same or different and are independently 1, 2, 3 or 4.

2. The compound according to claim 1, characterized in that Ra, Rc, Rd are the same or different and are independently selected from H, C which is unsubstituted or optionally substituted with one, two or more Rs 1-6 Alkyl; Rs is selected from halogen; Preferably, Ra is methyl, ethyl or propyl; Rc, Rd are H; Preferably, Ra is an ortho-methyl, ethyl or propyl group; Rc, Rd are H; Preferably, X is selected from halide ions, perfluorobutanesulfonate ions, and p-toluenesulfonate ions.

3. The compound according to claim 1 or 2, characterized in that The compound represented by formula (I) is selected from the following compounds:

4. A method for preparing a compound of formula (I) according to any one of claims 1 to 3, characterized in that: The steps include: Compound Ia reacts with Ib to obtain a compound of formula I; Wherein, Ra, Rc, Rd, s, m, n, and X have the definitions as described in any one of claims 1 to 3.

5. Use of the compound according to any one of claims 1 to 3 as a photoresist.

6. A photoresist composition, characterized in that: The invention comprises the compound according to any one of claims 1 to 3.

7. The photoresist composition according to claim 6, characterized in that The photoresist composition also includes a solvent, which is selected from one, two or more of the following substances: propylene glycol methyl ether acetate, dimethylformamide, cyclohexanone, ethyl n-amyl ketone, ethyl isoamyl ketone, ethanol, acetonitrile, isopropanol, acetone, methyl n-amyl ketone, and methyl isoamyl ketone.

8. The photoresist composition according to claim 6 or 7, characterized in that: The photoresist composition is a positive or negative photoresist composition.

9. Use of the compound represented by formula (I) according to any one of claims 1 to 3 or the photoresist composition according to any one of claims 6 to 8 in photolithography.

10. The use according to claim 9, characterized in that: The photolithography is 248nm photolithography, 254nm photolithography, 193nm photolithography, extreme ultraviolet photolithography, nanoimprint photolithography or electron beam photolithography.

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