Pentaphenyl derivative as well as preparation method and application thereof in photoetching

Abstract

The invention belongs to the technical field of photoetching, and relates to a pentaphenyl derivative as well as a preparation method and application thereof in photoetching. The photoresist composition containing the pentaphenyl derivative can be used for preparing a uniform thin film, the thin film has good resolution, photosensitivity and adhesion and is easy to store, and molecular glass serving as a matrix component is not separated out in the film preparation process. The photoresist composition prepared by the invention has the advantages of better film-forming property, higher thermal stability, low possibility of denaturation in storage and low viscosity, and does not need to be diluted by an additional solvent in the use process. After electron beam exposure and development, an exposed pattern has relatively high contrast, excellent resolution and relatively good sensitivity, and can reach a photoetching line width of 40nm. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of photolithography, and in particular relates to a pentphenyl derivative and a preparation method thereof and application in photolithography. Background Art

[0002] Microelectronics technology has developed along with integrated circuits, especially ultra-large-scale integrated circuits. It is one of the core technologies of the information industry and has a profound impact on the national economy. In the late 1950s, scientists invented germanium integrated circuits and silicon integrated circuits. The emergence of integrated circuits promoted the rapid development of semiconductor technology. Modern electronic devices require that the size of integrated circuits (chips) is getting smaller and smaller, and the integration is getting higher and higher. Since the 1980s, photolithography technology has gone through the development process from G-line (436nm), I-line (365nm) lithography, to deep ultraviolet (248nm, 193nm) lithography, and then to the next generation of photolithography technology, extreme ultraviolet lithography (EUVL), nanoimprinting, and electron beam lithography. The corresponding photoresist (photoresist) has also changed accordingly. Advanced photolithography technology has made the integration higher and higher, and the size has been continuously reduced. The minimum feature size of integrated circuits has entered the nanometer level from the micron level and submicron level.

[0003] Photolithography and its related processes are the backbone of the nanotechnology revolution. The feature size of microelectronic circuit components manufactured by current optical lithography processes is limited by the wavelength of exposure radiation. Researchers are developing new lithography techniques and photoresist materials to meet the growing demand for higher resolution and better sensitivity. Among them, extreme ultraviolet (EUV) lithography and electron beam lithography can obtain nanoscale patterns with minimum feature sizes below 10nm. In the process of developing faster and smaller semiconductor devices, new photoresist materials and lithography processes are currently being jointly explored by industry and academia.

[0004] With the transition of exposure wavelength from ultraviolet (UV) to deep ultraviolet (DUV) and then to extreme ultraviolet (EUV), the feature size formed on the photoresist is getting smaller and smaller. In order to avoid the collapse of the photoresist under small feature size, the thickness of the photoresist film is also reduced. Therefore, the etching resistance of the photoresist itself needs to be improved urgently to meet the subsequent chip processing. Summary of the invention

[0005] The object of the present invention is to provide a pentphenyl derivative and a preparation method thereof.

[0006] Another object of the present invention is to provide a positive photoresist composition containing the above-mentioned pentphenyl derivative.

[0007] The present invention provides a compound represented by formula (I):

[0008]

[0009] Wherein, R is one of the following groups: -OC 1-12 Alkyl-COO-C 1-12 Alkyl, -OCOO-C 1-12 Alkyl, -OCOO-C 3-20 Cycloalkyl;

[0010] n is 1, 2, 3, 4 or 5;

[0011] m is 1, 2, 3 or 4;

[0012] R' and R1 are the same or different and are independently selected from H, C 1-12 Alkyl, C 1-12 Alkoxy, halogenated C 1-12 Alkyl, halogenated C 1-12 Alkoxy, -OC 1-12 Alkyl-COO-C 1-12 Alkyl, -OCOO-C 1-12 Alkyl or -OCOO-C 3-20 Cycloalkyl.

[0013] According to an embodiment of the present invention, R is one of the following groups: -OC 1-6 Alkyl-COO-C 1-6 Alkyl, -OCOO-C 1-6 Alkyl or -OCOO-C 3-12 Cycloalkyl;

[0014] n is 1, 2, 3, 4 or 5;

[0015] R' and R1 are selected from H.

[0016] According to a preferred embodiment of the present invention, R is selected from the following groups:

[0017]

[0018] In the above groups, * is the connection site; n is 1, 2 or 3.

[0019] In one embodiment, n is 3, and the R is substituted at any consecutive adjacent or non-adjacent positions of the benzene ring.

[0020] In one embodiment, n is 2, and the R are all substituted at the meta position of the benzene ring, or are all substituted at two ortho positions, or at any two positions of the ortho, meta or para positions.

[0021] In one embodiment, n is 1, and R is substituted at the ortho, meta or para position of the benzene ring.

[0022] As an example, the compound represented by formula I is selected from the following:

[0023]

[0024] The present invention also provides a method for synthesizing the compound represented by formula (I) as described above, comprising the following steps:

[0025]

[0026] Compound I' reacts with compound RL to obtain a compound of formula I; wherein L is halogen or OR; R, m and n have the definitions as described above;

[0027] Wherein, when R1 and R' in Formula I are -OC 1-12 Alkyl-COO-C 1-12 Alkyl, -OCOO-C 1-12 Alkyl or -OCOO-C 3-12 In the case of cycloalkane, R'1 and R" in formula I' are OH;

[0028] Wherein, when R1 and R' in Formula I are H, C 1-12 Alkyl, C 1-12 Alkoxy, halogenated C 1-12 Alkyl, halogenated C 1-12 In the case of an alkoxy group, R'1 and R" in Formula I' do not participate in the reaction and are equivalent to R1 and R' in Formula I.

[0029] According to an embodiment of the present invention, as described above, the reaction is carried out under the action of a base, and the base is preferably at least one of 4-dimethylaminopyridine (DMAP) or potassium carbonate, and the reaction temperature is preferably 20 to 80° C.; the reaction solvent is preferably at least one of tetrahydrofuran and 1-methyl-2-pyrrolidone.

[0030] According to an embodiment of the present invention, the compound represented by formula I' is obtained by reacting the following two compounds:

[0031]

[0032] wherein R'1, R", m and n are as defined above; L1 is -B(OH)2 or -B(OC 1-12 Alkyl)2.

[0033] According to an embodiment of the present invention, in the reaction for preparing formula I', the reaction is carried out under the action of a palladium-containing catalyst, and the catalyst is preferably at least one of tetrakis(triphenylphosphine)palladium(0), [1,1'-bis(diphenylphosphine)ferrocene]dichloropalladium, tetrakis(triphenylphosphine)palladium(0), tetrakis(tri-tert-butylphosphine)palladium(0), tetrakis(trimethoxyphosphine)palladium(0), bis(1,2-bis(diphenylphosphine)ethane)palladium(0), and bis(1,3-bis(diphenylphosphine)propane)palladium(0); the reaction is preferably carried out under the action of a base, and the base is preferably at least one of sodium carbonate, cesium carbonate, potassium acetate, potassium phosphate, tetrabutylammonium fluoride, cesium fluoride or potassium fluoride; the solvent of the reaction is preferably at least one of acetone, toluene, 1,4-dioxane, tetrahydrofuran, and anisole; the reaction temperature can be 60°C to 150°C, preferably 80°C to 120°C.

[0034] The present invention also provides the use of the compound represented by formula (I) in preparing photoresist.

[0035] The present invention also provides a photoresist composition, which comprises the compound of formula (I).

[0036] According to an embodiment of the present invention, the photoresist composition is a positive photoresist composition.

[0037] According to an embodiment of the present invention, the photoresist composition includes a compound of formula (I), a photoresist solvent and a photoacid generator.

[0038] Preferably, the photoresist composition contains, by mass fraction, 0.1% wt to 10% wt of the compound of formula (I) and 0.01% wt to 1% wt of the photoacid generator.

[0039] According to an embodiment of the present invention, the photoresist composition may further contain other photoresists and acid diffusion inhibitors, etc.

[0040] Preferably, the photoresist composition contains 0%wt to 0.1%wt of the acid diffusion inhibitor by mass fraction.

[0041] According to an embodiment of the present invention, in the photoresist composition, the compound represented by formula (I) is a compound represented by formula (Ia), that is, in the compound represented by formula (I), R is n is 3.

[0042] According to an embodiment of the present invention, in the photoresist composition, the compound represented by formula (I) is a compound represented by formula (Ib), that is, in the compound represented by formula (I), R is n is 2,

[0043] According to an embodiment of the present invention, in the photoresist composition, the compound represented by formula (I) is a compound represented by formula (Ic), that is, in the compound represented by formula (I), R is n is 1.

[0044] According to an embodiment of the present invention, the photoacid generator may be ionic or non-ionic, such as at least one selected from triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluorobutylsulfonate (perfluorobutylsulfonic acid triphenylsulfonium salt), di(4-tert-butylphenyl)iodonium p-toluenesulfonate, N-hydroxynaphthalimide trifluoromethanesulfonic acid, 2-phenyl-(4-phenylsulfide)phenylsulfide hexafluoroantimonate, benzyl(4-hydroxyphenyl)methylsulfonium hexafluoroantimonate, and the like.

[0045] According to an embodiment of the present invention, the photoresist solvent may be selected from at least one of propylene glycol methyl ether acetate (PGMEA), ethyl lactate, ethylene glycol monomethyl ether, cyclohexanone, and the like.

[0046] According to an embodiment of the present invention, the acid diffusion inhibitor may be selected from n-octylamine, tri-n-octylamine, N-methyldi-n-octylamine, tert-octylamine and the like.

[0047] According to an embodiment of the present invention, the photoresist composition may further include other additives, such as a sensitizer, a surfactant, a dye, a stabilizer, a cosolvent, and the like.

[0048] The present invention also provides the use of the photoresist composition described above in lithography processes such as 365nm lithography, 248nm lithography, 193nm lithography, extreme ultraviolet lithography (EUVL) and electron beam lithography (EBL).

[0049] The invention also provides a photoresist coating, comprising the compound shown in formula (I).

[0050] The invention also provides a method for preparing the photoresist coating, which comprises spin coating the photoresist composition on a substrate.

[0051] Preferably, the coating method is to perform spin coating on the substrate by a coating machine.

[0052] Preferably, the substrate may be a silicon wafer, a silicon dioxide wafer, or a compound semiconductor wafer. The silicon wafer is preferably a silicon wafer that has been hydrophobically treated.

[0053] Beneficial Effects

[0054] 1. The compound represented by formula (I) of the present invention is a stereosymmetrical amorphous small molecule compound with a simple molecular structure, controllable molecular weight, simple synthesis steps, high thermal stability, no precipitation during baking, and not easy to denature during photolithography, which can meet the requirements of photolithography technology, and the film structure does not change during high-temperature baking.

[0055] 2. Compared with conventional polymer photoresists, the compound represented by formula (I) of the present invention has a larger proportion of phenyl groups and thus a higher carbon-hydrogen ratio, thereby obtaining a photoresist material with high etching resistance.

[0056] 3. The photoresist composition of the present invention can be used to prepare a uniform film having good resolution and photosensitivity (the photoresist sensitivity can reach 70 μC / cm 2 ), adhesion (film-forming property), easy to store, and in the film-making process, the molecular glass as a matrix component does not precipitate. The photoresist composition prepared by the present invention has good film-forming property, high thermal stability, is not easy to denature during storage, and has low viscosity, and does not need to be additionally diluted with solvent during use. After electron beam exposure and development, the exposure pattern has high contrast, excellent resolution, good sensitivity, can reach a photolithography line width of 40nm, and has high etching resistance, and has a higher etching ratio compared with silicon.

[0057] Definition and explanation of terms

[0058] 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.

[0059] In the present application, some substituents marked with "*" represent the connection site.

[0060] "More" means three or more.

[0061] The term "halogen" includes F, Cl, Br or I.

[0062] The term "C 1-12 "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.

[0063] 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 decahydronaphthalene ring; it may also be C 7-12 Bridged ring cycloalkyl, such as norbornane, adamantane, bicyclo[2,2,2]octane.

[0064] The above term “C 1-12 The definition of "alkyl" also applies to groups containing "C 1-12 Other terms for "alkyl", such as the term "C 1-12 Alkoxy", "halogenated C 1-12 Alkyl" and so on. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 A photoresist film spin-coated on a silicon wafer with the positive photoresist composition B-1 prepared in Example 2;

[0066] Figure 2 This is the SEM image of 365nm UV exposure in Example 4;

[0067] Figure 3 is the SEM image of electron beam exposure in Example 5;

[0068] Figure 4 This is a SEM image of the cross section of the silicon wafer after etching in Example 6. DETAILED DESCRIPTION

[0069] 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.

[0070] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0071] Example 1 Synthesis and preparation of compound (Ib)

[0072]

[0073] 3.88g (10mmol) of compound (II), 0.19g (1mmol) of cuprous iodide, 1.2g (10mmol) of benzaldehyde oxime and 6.52g of cesium carbonate (20mmol) were weighed and added into a 150ml three-necked flask in sequence, and then 80ml of dimethyl sulfoxide was added, and refluxed and stirred at 80°C for 18-24h. After the reaction was completed, the reaction solution was extracted with ethyl acetate and water, and the obtained organic phase was dried with anhydrous sodium sulfate, and then column chromatography was performed using ethyl acetate: tetrahydrofuran (v:v) 1:1. The obtained organic phase was spun out of the solvent, and the obtained solid was dried at 60°C in vacuum to obtain 2.12g of compound (III) with a yield of 81%. MALDI-TOF (C 18 H 14 O2), m / z:262.10.

[0074] 2.62 g (10 mmol) of compound (III) obtained in the previous step was placed in a 150 ml three-necked flask, and 100 ml of acetonitrile solution containing 8 g (50 mmol) of bromine was added, and stirred at 25°C for 5 h. After the reaction was completed, the remaining bromine was neutralized with an aqueous solution of sodium thiosulfate, and the acetonitrile in the system was removed by rotation. The reaction solution was then extracted with ethyl acetate, and the obtained organic phase was dried with anhydrous sodium sulfate. The solvent was removed from the obtained organic phase, and the obtained solid was dried at 60°C in vacuum to obtain 4.85 g of compound (IV) with a yield of 84%. MALDI-TOF (C 18 H 10 Br4O2), m / z:573.74.

[0075] 5.72 g (10 mmol) of compound (Ⅳ) obtained in the previous step was placed in a 250 ml three-necked flask, and 9.24 g (60 mmol) of 3.5-dihydroxyphenylboronic acid, 0.116 g of tetrakis(triphenylphosphine)palladium (0.1 mmol) and 100 ml of 1,4-dioxane solvent were added. Then 5.52 g (40 mmol) of potassium carbonate was dissolved in 50 ml of water and added to the reaction flask, and the reaction was carried out at 90-100 ° C for 16 hours. After the reaction was completed, the system was separated into layers, and the organic phase was dried with anhydrous magnesium sulfate and evaporated to obtain a crude product. The obtained crude product was washed three times with n-hexane, filtered to obtain compound (V-b), which weighed 5.75 g after drying, with a yield of 83%. MALDI-TOF (C 42 H 30 O 10 ),m / z:694.18.

[0076] Finally, 6.94 g (10 mmol) of the compound (V-b) obtained in the previous step was placed in a 250 ml three-necked flask, and 26.2 g (120 mmol) of di-tert-butyl dicarbonate was added, followed by 150 ml of tetrahydrofuran and 0.122 g (1 mmol) of 4-dimethylaminopyridine, and the mixture was reacted at 25°C for 10 h. After the reaction, 300 ml of ethyl acetate and 300 ml of water were added to the reaction solution, and the yellow organic phase was separated by extraction. The obtained organic phase was dried over anhydrous magnesium sulfate and then rotary evaporated to an oily viscous substance. 500 ml of n-hexane was added to the oily viscous substance, heated to 75°C, refluxed and boiled for 8 h, and cooled and filtered to obtain 15.23 g of a white product I-b, with a yield of 90%. MALDI-TOF (C 92 H 110 O 30 ),m / z:1694.71.

[0077] Example 2 Preparation of positive photoresist composition B-1

[0078] Weigh 300 mg of the compound (Ib) prepared in Example 1, 22.5 mg of the photoacid generator N-hydroxynaphthaleneimide trifluoromethanesulfonic acid, and 10 ml of the photoresist solvent propylene glycol monomethyl ether acetate (PGMEA) to prepare a photoresist solution. After ultrasonic treatment for half an hour, filter it three times with a 0.20 μm polytetrafluoroethylene film to prepare a positive photoresist composition B-1. Spin-coat the photoresist composition B-1 on a silicon wafer to obtain a uniform and complete film. Figure 1 shown.

[0079] Example 3 Preparation of positive photoresist composition B-2

[0080] Weigh 300 mg of the compound (Ib) prepared in Example 1, 15 mg of the photoacid generator triphenylsulfonium perfluorobutanesulfonate, and 10 ml of the photoresist solvent propylene glycol monomethyl ether acetate (PGMEA) to prepare a photoresist solution, which is ultrasonically treated for half an hour and then filtered three times with a 0.20 μm polytetrafluoroethylene film to prepare a positive photoresist composition.

[0081] Example 4 365 nm UV Lithography Performance of Positive Photoresist Composition B-1

[0082] A photoresist composition with a concentration of 30 mg / ml of compound (Ib) was prepared according to Example 2. A silicon wafer treated with HMDS was selected. The spin coating parameters were set to 3000 rpm / 90 s, and the pre-bake parameters were set to 100°C / 120 s. The film thickness was measured by ellipsometer and was about 50 nm. I-line (365 nm) photolithography 30 mj / cm 2The post-baking parameters are 70℃ / 20s, the developing parameters are 0.26N TMAH aqueous solution / 60s, and the rinsing parameters are deionized water / 60s. After exposure, a Hitachi 8230 scanning electron microscope was used to collect SEM images. The specific lithography results are shown in the figure. Figure 2 As shown, the stripe width is 2 μm.

[0083] Example 5 Electron beam lithography performance of positive photoresist composition B-2

[0084] A photoresist composition with a concentration of 30 mg / ml of compound (Ib) was prepared according to Example 3. A silicon wafer treated with HMDS was selected. The spin coating parameters were set to 3000 rpm / 90 s, the pre-bake parameters were set to 100°C / 120 s, and the film thickness was measured by ellipsometer to be about 50 nm. An electron beam with an accelerating voltage of 100 kV was used for exposure at 70 μC / cm 2 The post-baking parameters are 70℃ / 20s, the developing parameters are 0.26N TMAH aqueous solution / 60s, and the rinsing parameters are deionized water / 60s. After exposure, a Hitachi 8230 scanning electron microscope was used to collect SEM images. The specific lithography results are shown in the figure. Figure 3 As shown, the stripe width is 40nm.

[0085] Example 6 Anti-etching performance of positive photoresist composition B-1

[0086] The silicon wafer after photolithography development in Example 5 was etched in a SF6 / O2 atmosphere to obtain a silicon wafer cross section with an etching ratio of 7:1. The specific etching results are as follows: Figure 4 It is shown that the obtained photoresist composition has high etching resistance, a higher etching ratio compared with silicon, and good photosensitivity.

[0087] 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. The compound represented by formula (I): in, R is one of the following groups: -OC 1-12 Alkyl-COO-C 1-12 Alkyl, -OCOO-C 1-12 Alkyl, -OCOO-C 3-20 Cycloalkyl; n is 1, 2, 3, 4 or 5; m is 1, 2, 3 or 4; R' and R1 are the same or different and are independently selected from H, C 1-12 Alkyl, C 1-12 Alkoxy, halogenated C 1-12 Alkyl, halogenated C 1-12 Alkoxy, -OC 1-12 Alkyl-COO-C 1-12 Alkyl, -OCOO-C 1-12 Alkyl or -OCOO-C 3-20 Cycloalkyl.

2. The compound according to claim 1, wherein R is one of the following groups: -OC 1-6 Alkyl-COO-C 1-6 Alkyl, -OCOO-C 1-6 Alkyl or -OCOO-C 3-12 Cycloalkyl; n is 1, 2, 3, 4 or 5; R' and R1 are selected from H.

3. The compound according to claim 1, wherein R is selected from the following groups: In the above groups, * is the connection site; n is 1, 2 or 3.

4. The compound according to any one of claims 1 to 3, wherein The compound shown in formula I is selected from the following:

5. A method for synthesizing a compound of formula (I) according to any one of claims 1 to 4, wherein: The steps include: Compound I' reacts with compound RL to obtain a compound of formula (I); wherein L is halogen or OR; R, m and n have the definitions as described in any one of claims 1 to 4; Wherein, when R1 and R' in Formula I are -OC 1-12 Alkyl-COO-C 1-12 Alkyl, -OCOO-C 1-12 Alkyl or -OCOO-C 3-12 In the case of cycloalkane, R'1 and R" in formula I' are OH; Wherein, when R1 and R' in Formula I are H, C 1-12 Alkyl, C 1-12 Alkoxy, halogenated C 1-12 Alkyl, halogenated C 1-12 In the case of an alkoxy group, R'1 and R" in Formula I' do not participate in the reaction and are equivalent to R1 and R' in Formula I.

6. The method according to claim 5, wherein: The compound represented by formula I' is obtained by reacting the following two compounds: wherein R'1, R", m and n have the meanings as defined in any one of claims 1 to 4; L1 is -B(OH)2 or -B(OC 1-12 Alkyl)2.

7. Use of the compound represented by formula (I) according to any one of claims 1 to 4 in preparing photoresist.

8. A photoresist composition comprising the compound represented by formula (I) according to any one of claims 1 to 4.

9. Use of the photoresist composition according to claim 8 in lithography processes such as 365nm lithography, 248nm lithography, 193nm lithography, extreme ultraviolet lithography (EUVL) and electron beam lithography (EBL).

10. A photoresist coating comprising the compound of formula (I) according to any one of claims 1 to 4.

Images