Pyrene side group-containing polymer, hard mask composition and pattern forming method
阅读说明：本技术 含芘侧基聚合物和硬掩膜组合物及图案形成方法 (Pyrene side group-containing polymer, hard mask composition and pattern forming method ) 是由 王静 肖楠 于 2019-07-10 设计创作，主要内容包括：本发明属于光刻领域,公开了一种含芘侧基聚合物和硬掩膜组合物及图案形成方法。所述硬掩膜组合物含有含芘侧基聚合物和溶剂以及任选的交联剂、催化剂和表面活性剂,所述含芘侧基聚合物具有式(1)和/或式(2)所示的结构。本发明通过对苯酚聚合物的侧基采用含芘基团进行修饰改性而获得含芘侧基聚合物,该含芘侧基聚合物具有较高的碳含量,能够提高硬掩膜组合物的耐刻蚀性和耐热性,并且该含芘侧基聚合物中高碳含量的芘基位于侧链,不会因为碳含量高而影响聚合物的溶解性,从而确保了硬掩膜组合物具有良好的溶解性,容易通过旋涂方式涂布于基板上,进而可获得平坦化特征和填隙特征均良好的硬掩膜。<Image he="280" wi="700" file="DDA0002125110120000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The invention belongs to the field of photoetching, and discloses a composition containing a pyrene side group polymer and a hard mask and a pattern forming method. The hard mask composition contains a pyrene side group-containing polymer and a solvent, and optionally a cross-linking agent, a catalyst and a surfactant, wherein the pyrene side group-containing polymer has a structure shown in a formula (1) and/or a formula (2). The side group of the phenol polymer is modified by the pyrene-containing group to obtain the pyrene side group-containing polymer, the pyrene side group-containing polymer has higher carbon content and can improve the etching resistance and the heat resistance of the hard mask composition, and the pyrene group with the high carbon content in the pyrene side group-containing polymer is positioned on the side chain and cannot influence the solubility of the polymer due to the high carbon content, so that the hard mask composition is ensured to have good solubility, and the pyrene side group-containing polymer is easily coated on a substrate in a spin coating mode, and further the hard mask with good planarization characteristics and gap filling characteristics can be obtained.)
1. A pyrene side group-containing polymer is characterized in that the pyrene side group-containing polymer has a structure represented by formula (1) and/or formula (2):
wherein R is1Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R2Is hydrogen atom, alkyl group with 1-10 carbon atoms or substituted or unsubstituted aryl group with 6-30 carbon atoms, R3Is a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, Ar1Is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and m is an integer of 1 to 500.
2. The pyrene-side group-containing polymer of claim 1, wherein R is R1Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2Is hydrogen atom, alkyl group with 1-6 carbon atoms or substituted or unsubstituted aryl group with 6-10 carbon atoms, R3Is a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, Ar1Is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and m is an integer of 5 to 20.
3. The pyrene side group-containing polymer according to claim 1 or 2, wherein the weight average molecular weight of the pyrene side group-containing polymer is 500-10000.
4. A hardmask composition comprising a polymer and a solvent, wherein the polymer is the pyrene-containing pendant polymer of any of claims 1-3.
5. The hardmask composition according to claim 4, wherein the solvent is at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclohexanone, and ethyl lactate.
6. The hardmask composition according to claim 4 or 5, further comprising at least one of a crosslinker, a catalyst, and a surfactant.
7. The hardmask composition according to claim 6, wherein the hardmask composition comprises 3 to 20 wt% of the pyrene-containing pendant polymer, 0.4 to 3 wt% of the crosslinking agent, 0.004 to 0.1 wt% of the catalyst, 0.001 to 1 wt% of the surfactant, and 76 to 95.6 wt% of the solvent.
8. A pattern forming method, characterized by comprising the steps of:
forming a material layer on a substrate;
applying the hardmask composition according to any one of claims 4 to 7 to the material layer and performing a heat treatment to form a hardmask;
forming a silicon-containing thin layer on the hard mask;
forming a photoresist resist layer on the thin silicon-containing layer;
exposing and developing the photoresist resist layer to form a photoresist pattern;
selectively removing portions of the thin silicon-containing layer and the hard mask using the photoresist pattern to expose a portion of the material layer;
the exposed portions of the material layer are etched.
9. The pattern forming method according to claim 8, wherein the hard mask composition is applied on the material layer by a spin coating method.
Technical Field
The invention belongs to the field of photoetching, and particularly relates to a composition containing a pyrene side group polymer and a hard mask and a pattern forming method.
Background
Conventionally, in the manufacture of semiconductor devices, patterning has been performed by photolithography of a photoresist. Typical lithographic processes include: the method includes forming a material layer on a semiconductor substrate, coating a photoresist on the material layer, exposing and developing the photoresist layer to provide a photoresist pattern, and etching the material layer using the photoresist pattern as a mask.
In recent years, with the high integration and high speed of semiconductor devices, the shorter wavelength of KrF excimer laser (248nm) has been advancing to ArF excimer laser (193nm) as a lithography light source used for forming a photoresist pattern. In order to ensure light transmittance, the resin used in the ArF photoresist is preferably a polymer containing no aromatic ring, resulting in poor etching resistance of the ArF photoresist, and therefore, in order to obtain a fine pattern, a three-layer resist method is proposed, which comprises the steps of: a material layer is formed on a semiconductor substrate, a thick amorphous carbon layer is formed on the material layer by chemical vapor deposition, the middle layer is a thin silicon-rich layer, and the upper layer is an ArF photoresist layer capable of realizing patterns. The ArF photoresist layer is sufficient to pattern the silicon rich layer; the silicon-rich layer is sequentially used as a hard mask to realize the patterning of the lower layer carbon; and finally obtaining a refined pattern on the material layer by using the patterned carbon layer as a hard mask.
In addition, in order to reduce equipment investment and improve the quality of a hard mask layer, recently, a spin coating method rather than a chemical vapor deposition method is more suggested when forming the hard mask layer. Spin coating requires the use of a hardmask composition having both good etch resistance and solubility. However, there is a constraint relationship between the etching resistance and the solubility of the hardmask composition, and generally, a polymer having a high carbon content has good etching resistance, but has poor solubility, which may affect the planarization characteristics and gap-filling characteristics of the hardmask, so that there is a need for continuous research and development of hardmask compositions that satisfy both of these properties.
Disclosure of Invention
The invention aims to overcome the defect that the existing hard mask material cannot simultaneously have excellent etching resistance and solubility, and provides a novel pyrene side group-containing polymer, a hard mask composition and a pattern forming method.
Specifically, the invention provides a pyrene side group-containing polymer, wherein the pyrene side group-containing polymer has a structure shown in a formula (1) and/or a formula (2):
wherein R is1Is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R2Is hydrogen atom, alkyl group with 1-10 carbon atoms or substituted or unsubstituted aryl group with 6-30 carbon atoms, R3Is a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, Ar1Is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and m is an integer of 1 to 500.
Further, R1Is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2Is hydrogen atom, alkyl group with 1-6 carbon atoms or substituted or unsubstituted aryl group with 6-10 carbon atoms, R3Is a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, Ar1Is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and m is an integer of 5 to 20.
Further, the weight average molecular weight of the pyrene side group-containing polymer is 500-10000.
The invention also provides a hard mask composition, wherein the hard mask composition contains the pyrene side group-containing polymer and a solvent.
Further, the solvent is at least one selected from propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, cyclohexanone and ethyl lactate.
Further, the hard mask composition further comprises at least one of a cross-linking agent, a catalyst and a surfactant.
Further, the hard mask composition contains 3-20 wt% of pyrene-containing side group polymer, 0.4-3 wt% of cross-linking agent, 0.004-0.1 wt% of catalyst, 0.001-1 wt% of surfactant and 76-95.6 wt% of solvent.
The invention also provides a pattern forming method, wherein the pattern forming method comprises the following steps: forming a material layer on a substrate; applying the hard mask composition on the material layer and carrying out heat treatment to form a hard mask; forming a silicon-containing thin layer on the hard mask; forming a photoresist resist layer on the thin silicon-containing layer; exposing and developing the photoresist resist layer to form a photoresist pattern; selectively removing portions of the thin silicon-containing layer and the hard mask using the photoresist pattern to expose a portion of the material layer; the exposed portions of the material layer are etched.
Further, the manner of applying the hardmask composition to the material layer is spin coating.
The invention has the following beneficial effects:
the side group of the phenol polymer is modified by the pyrene-containing group to obtain the pyrene side group-containing polymer, the pyrene side group-containing polymer has higher carbon content and can improve the etching resistance and the heat resistance of the hard mask composition, and the pyrene group with the high carbon content in the pyrene side group-containing polymer is positioned on the side chain and cannot influence the solubility of the polymer due to the high carbon content, so that the hard mask composition is ensured to have good solubility, and the pyrene side group-containing polymer is easily coated on a substrate in a spin coating mode, and further the hard mask with good planarization characteristics and gap filling characteristics can be obtained.
Detailed Description
The present invention is described in detail below.
The term "substituted" as used herein means, when not additionally defined, substitution with at least one substituent selected from at least one of halogen, hydroxyl, nitro, cyano, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an aralkyl group having 7 to 30 carbon atoms, and the like.
In the present invention, the term "carbon content" refers to the ratio of the mass number of carbon atoms in a compound to the total mass number.
The hard mask composition provided by the invention contains a pyrene side group-containing polymer and a solvent, and can also contain at least one of a cross-linking agent, a catalyst and a surfactant according to needs. According to a specific embodiment of the present invention, the hardmask composition comprises 3 to 20 wt% of a pyrene-containing pendant group-containing polymer, 0.4 to 3 wt% of a crosslinking agent, 0.004 to 0.1 wt% of a catalyst, 0.001 to 1 wt% of a surfactant, and 76 to 95.6 wt% of a solvent.
Polymer and method of making same
The pyrene side group-containing polymer provided by the invention has a structure shown in a formula (1) and/or a formula (2):
wherein R is1、R2、R3、Ar1M is as defined above.
According to one embodiment of the present invention, the pyrene side group-containing polymer having the structure represented by formula (1) is produced by condensation polymerization of a pyrene side group-containing phenol and its derivatives with an aldehyde compound or its synthetic equivalents (e.g., hemiacetal, acetal compounds). The aldehyde compound may be an aliphatic aldehyde and/or an aromatic aldehyde. Specific examples of the fatty aldehyde include, but are not limited to: at least one of formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, and the like. Specific examples of the aromatic aldehyde include, but are not limited to; at least one of benzaldehyde, naphthaldehyde, anthracene formaldehyde, pyrene formaldehyde, p-hydroxybenzaldehyde, etc.
According to one embodiment of the invention, the pyrene side group-containing polymer having the structure represented by formula (2) is formed by condensation polymerization of pyrene side group-containing phenol and derivatives thereof and a compound having the structure represented by formula (3).
In the formula (3), Ar1Is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, R6And R7Each independently represents a hydrogen atom, a methyl group or an ethyl group. Examples of the compound having the structure represented by formula (3) include compounds represented by the following chemical formula 3-1 or chemical formula 3-2.
Chemical formula 3-1
Chemical formula 3-2
In the invention, the phenol derivative containing the pyrene side group refers to a compound in which a hydrogen atom on a phenolic hydroxyl group in phenol containing the pyrene side group is substituted by an alkyl group having 1-6 carbon atoms. In the present invention, examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a cyclopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a 1-methyl-cyclopropyl group, a 2-methyl-cyclopropyl group, an n-pentyl group, a 1-methyl-n-butyl group, a 2-methyl-n-butyl group, a 3-methyl-n-butyl group, a 1, 1-dimethyl-n-propyl group, a 1, 2-dimethyl-n-propyl group, a 2, 2-dimethyl-n-propyl group, a 1-ethyl-n-propyl group, a cyclopentyl group, a 1-methyl-cyclobutyl group, a 2-methyl-cyclobutyl group, a 3-methyl-cyclobutyl group, a 1, 2-dimethyl-cyclopropyl group, a 2, 3-dimethyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1-dimethyl-n-butyl, 1, 2-dimethyl-n-butyl, 1, 3-dimethyl-n-butyl, 2, 2-dimethyl-n-butyl, 2, 3-dimethyl-n-butyl, 3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1, 2-trimethyl-n-propyl, 1,2, 2-trimethyl-n-propyl, 1-methyl-1-ethyl-n-propyl, n-pentyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1, 2-dimethyl-cyclobutyl, 1, 3-dimethyl-cyclobutyl, 2-dimethyl-cyclobutyl, 2, 3-dimethyl-cyclobutyl, 2, 4-dimethyl-cyclobutyl, 3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl-cyclopropyl, 1,2, 2-trimethyl-cyclopropyl, 1,2, 3-trimethyl-cyclopropyl, 2, 3-trimethyl-cyclopropyl, 1-ethyl-2 methyl-cyclopropyl, 2-ethyl-3 methyl-cyclopropyl, and the like.
The polycondensation reaction generally needs to be carried out in the presence of an acid catalyst. The acid catalyst may be an inorganic acid and/or an organic acid. Specific examples of the inorganic acid include, but are not limited to: at least one of sulfuric acid, phosphoric acid, perchloric acid, and the like. Specific examples of the organic acid include, but are not limited to: at least one of p-toluenesulfonic acid, formic acid, oxalic acid and the like. In addition, the acid catalyst may be used in an amount of 0.1 to 100 parts by mass, based on 100 parts by weight of the total weight of the phenol having a pyrene side group and the phenol derivative having a pyrene side group.
The polycondensation reaction is generally carried out in a solvent. The kind of the solvent is not particularly limited as long as it does not hinder the reaction, and specific examples thereof include, but are not limited to: at least one of tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, and the like. In addition, if the acid catalyst used is a liquid substance such as formic acid, it may also serve as a solvent, and in this case, it is not necessary to add a solvent additionally.
The temperature of the polycondensation reaction can be 40-200 ℃, and the reaction time is selected according to the reaction temperature and the molecular weight requirement of the target polymer, and can be 30min-50 h.
Crosslinking agent
The hardmask composition may further comprise a crosslinking agent. The crosslinking agent may be at least one selected from the group consisting of a glycoluril compound represented by formula (4), an epoxy compound represented by formula (5), melamine represented by formula (6), and a melamine derivative.
Catalyst and process for preparing same
The hardmask composition may further comprise a catalyst. The catalyst is typically an acidic compound and acts to promote the crosslinking reaction. The catalyst may be at least one selected from the group consisting of compounds represented by formula (7) to formula (12).
Surface active agent
The hardmask composition may further comprise a surfactant. Specific examples of the surfactant include, but are not limited to: polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether and polyoxyethylene oleyl ether, polyoxyethylene alkylaryl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether, sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan monolinoleate and sorbitan tristearate, at least one polyoxyethylene sorbitan fatty acid ester such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monolaurate, and polyoxyethylene sorbitan tristearate.
Solvent(s)
The kind of the solvent is not particularly limited as long as it has sufficient solubility or dispersibility for the pyrene side group-containing polymer as well as the crosslinking agent, the catalyst and the surfactant. For example, the solvent may be selected from at least one of Propylene Glycol Monomethyl Ether Acetate (PGMEA), Propylene Glycol Monomethyl Ether (PGME), cyclohexanone, and ethyl lactate.
Pattern forming method
The pattern forming method provided by the invention comprises the following steps: forming a material layer on a substrate; applying the hard mask composition on the material layer and carrying out heat treatment to form a hard mask; forming a silicon-containing thin layer on the hard mask; forming a photoresist resist layer on the thin layer containing silicon; exposing and developing the photoresist resist layer to form a photoresist pattern; selectively removing portions of the thin silicon-containing layer and the hard mask using the photoresist pattern to expose a portion of the material layer; the exposed portions of the material layer are etched.
The substrate may be a silicon wafer, a glass substrate, or a polymer substrate.
The material layer is a material to be finally patterned, and may be, for example, a metal layer such as an aluminum layer or a copper layer, a semiconductor layer such as a silicon layer, or an insulating layer such as silicon dioxide or silicon nitride.
The hardmask composition is coated on the material layer in the form of a solution and preferably by a spin coating method, and specifically, the hardmask composition may be spin-coated to a thickness of
The thin layer containing silicon may be formed of, for example, silicon nitride, silicon oxide, or silicon oxynitride.
The photoresist resist layer may be formed of, for example, ArF type, KrF type, or EUV type photoresist.
The method of exposing the photoresist resist layer may be ArF, KrF, or EUV, for example.
The main improvement of the pattern forming method provided by the present invention is to use a new hard mask composition to form a hard mask, and the remaining steps and conditions, such as selectively removing a portion of the silicon-containing thin layer and the exposed portion of the hard mask, etching the material layer, etc., may be the same as those in the prior art, which will be known to those skilled in the art and will not be described herein again.
The present invention will be described in detail below by way of examples.
Synthesis example
Synthesis of monomer 1
(1) Placing 20mmol (3.04g) of p-methoxyphenylboronic acid, 20mmol (5.62g) of 1-bromopyrene, 0.6mmol (0.69g) of tetrakis (triphenylphosphine) palladium, 40mmol (5.53g) of potassium carbonate, 60ml of toluene and 20ml of water in a three-neck flask, carrying out reflux reaction under the protection of nitrogen, carrying out HPLC monitoring until the p-methoxyphenylboronic acid is reacted completely, stopping the reaction, cooling, standing, separating liquid, washing the organic phase with water for a plurality of times, drying the organic phase with anhydrous magnesium sulfate, filtering and spin-drying the solvent to obtain a crude product. And dissolving the crude product in tetrahydrofuran, and removing the palladium catalyst by adopting a column chromatography method to obtain the 1- (4-methoxyphenyl) pyrene.
(2) 10mmol (3.08g) of 1- (4-methoxyphenyl) pyrene and 80ml of dichloromethane are added into a 250ml three-neck flask, evenly stirred and then BBr is slowly dropped at the temperature of 0 DEG C3In a dichloromethane solution (preparation ratio: 50mmol (12.5g) of BBr3Dissolved in 50ml of dichloromethane) and reacted for 24h after completion of the dropwise addition. After completion of the reaction, the reaction mixture was poured into ice water and NaHCO was used3Adjusting the pH value to about 7, and filtering to obtain a monomer 1. The theoretical carbon content of monomer 1 is 89.77%. The specific synthesis process of monomer 1 is shown in the reaction formula 1:
reaction scheme 1
Synthesis of monomer 2
(1) Synthesis of monomer 1, step 1, was repeated except that 20mmol (7.14g) of 6-bromo-1-phenylpyrene was used instead of 20mmol (5.62g) of 1-bromopyrene to give 1- (4-methoxybenzene) -6-phenylpyrene.
(2) Synthesis step 2 of monomer 1 was repeated except that 10mmol (3.84g) of 1- (4-methoxybenzene) -6-phenylpyrene was used in place of 10mmol (3.08g) of 1- (4-methoxyphenyl) pyrene to give monomer 2. The theoretical carbon content of monomer 2 was 90.78%. The specific synthesis process of monomer 2 is shown in equation 2:
reaction formula 2
Synthesis of polymers
Synthesis of Polymer 1-1
A100 ml three-necked flask was charged with 2.94g (0.01mol) of monomer 1, 0.3g (0.01mol) of paraformaldehyde and 50ml of propylene glycol monomethyl ether acetate, and after mixing the mixture uniformly, 0.19g (0.001mol) of p-toluenesulfonic acid was added to the mixture to react at 100 ℃ for 10 hours under nitrogen protection. After the reaction was completed, the reaction solution was cooled, and then poured into methanol to remove unreacted monomers and low molecular weight polymers, the mixed solution was filtered, and the cake was further washed with methanol 2 times and then dried in a vacuum oven at 50 ℃ for 12 hours to obtain a polymer represented by chemical formula 1-1 (Mw 6500, polydispersity 2.1, m 11).
Chemical formula 1-1
Synthesis of Polymer 1-2
The procedure for synthesizing polymer 1-1 was repeated except that 3.70g (0.01mol) of monomer 2 was used instead of 2.94g (0.01mol) of monomer 1 to obtain a polymer represented by chemical formula 1-2 (Mw 6800, polydispersity 1.9, m 10).
Chemical formula 1-2
Synthesis of Polymer 2-1
The procedure for synthesizing the polymer 1-2 was repeated, except that 1.66g (0.01mol) of p-dimethoxymethylbenzene was used instead of 0.3g (0.01mol) of paraformaldehyde, to obtain a polymer represented by chemical formula 2-1 (Mw-6800, polydispersity-1.9, m-8).
Chemical formula 2-1
Synthesis of Polymer 2-2
The procedure for synthesizing the polymer 1-1 was repeated, except that 2.42g (0.01mol) of 4.4' -dimethoxymethylbiphenyl was used instead of 0.3g (0.01mol) of paraformaldehyde, to obtain a polymer represented by chemical formula 2-2 (Mw 6100, polydispersity 2.5, m 5).
Chemical formula 2-2
Comparative Synthesis example
The procedure of synthesizing polymer 1-1 was repeated except that 2.18g (0.01mol) of 1-pyrenyl alcohol was used instead of 2.94g (0.01mol) of monomer 1 to obtain a polymer represented by chemical formula 3-1 (Mw ═ 6100, polydispersity ═ 2.5).
Chemical formula 3-1
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