JP3568599B2 - Radiation-sensitive material and pattern forming method - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a radiation-sensitive material and a pattern forming method using the radiation-sensitive material.
In recent years, integration of semiconductor integrated circuits has progressed, and LSIs and VLSIs have been put to practical use. With this, the minimum pattern has been extended to a submicron region and tends to be further miniaturized. To form a fine pattern, the target substrate on which the thin film has been formed is coated with a resist, and after performing selective exposure, development is performed to form a resist pattern. Using this as a mask, dry etching is performed, and then the resist is removed. Therefore, it is essential to use a lithography (photolithography) technique for obtaining a desired pattern. Ultraviolet rays were initially used as an exposure light source for this purpose, but with the miniaturization of patterns, far ultraviolet rays with short wavelengths, electron beams, X-rays, and the like have come to be used as light sources.
[0002]
Accordingly, a resist material having high resolution, high sensitivity, and excellent dry etching resistance has been demanded, particularly corresponding to the lithography technique using an excimer laser (KrF laser having a wavelength of 248 nm, ArF laser having a wavelength of 193 nm). I have.
[0003]
[Prior art]
Many conventional resists based on phenolic resins or novolak resins have been developed, but these materials contain aromatic rings and have excellent dry etching resistance, but are not suitable for KrF laser wavelengths. On the other hand, transparency is low. In particular, it is completely opaque to the wavelength of the ArF laser. For this reason, it has not been possible to obtain a pattern accuracy that can cope with miniaturization.
[0004]
On the other hand, t-butyl methacrylate polymer has been proposed as a resist transparent to excimer light, but this resist lacks dry etching resistance.
Therefore, the present inventors have developed a chemically amplified resist using an alicyclic group as one having a dry etching resistance comparable to that of an aromatic ring and being transparent to the wavelengths of a KrF laser and an ArF laser. presentation. In addition, as alicyclic, norbornene, perhydroanthracene, cyclohexane, tricyclo [5.2.1.0^2,6Desirable are decane and adamantane (see JP-A-4-39665).
[0005]
[Problems to be solved by the invention]
However, in the chemically amplified resist using the above alicyclic copolymer, the alicyclic group imparting dry etching resistance increases the hydrophobicity and rigidity of the polymer as its composition ratio increases. To go.
Therefore, in a composition ratio where a dry etching resistance comparable to that of a resist based on a phenol resin or a novolak resin is obtained, for example, in a region where the unit structure having an alicyclic group is 50 mol% or more, in addition to high hydrophobicity, the hardness is increased. For this reason, there is a problem that diffusion of the protonic acid as a catalyst is hindered, the amplification rate decreases, the amount of carboxylic acid generated decreases, and the solubility in an aqueous alkali solution as a developer decreases.
[0006]
In addition, these resists have poor adhesion, and the introduction of alicyclic groups hardens the resist film, so that the strain applied to the resist film increases and the resist film is easily peeled off. Therefore, there is a problem that stable pattern characteristics cannot be obtained.
Also, a problem specific to the chemically amplified resist is that during the period from exposure to post-exposure bake (PEB), the acid generated by exposure is neutralized and deactivated by atmospheric contaminants (amine components, etc.). A phenomenon that a desired pattern cannot be formed occurs. It is known that a pattern forming method of applying a protective film on a resist film is effective as an improvement method. This method has been very effective for resists based on phenol, which make up the majority of conventional resists. However, when a protective film is applied to a resist based on a non-phenolic, low-polarity polymer, especially a hydrophobic polymer containing an alicyclic group, the polarities of the two are similar, so that a conventional coating solvent for the protective film is used. When an aromatic hydrocarbon solvent that has been used is used, the resist film itself dissolves, and there is a problem that it is difficult to apply a protective film.
[0007]
For this reason, there has been a problem that the pattern cannot be resolved due to the influence of the contaminants, or the pattern size largely deviates from a desired pattern size.
An object of the present invention is to use not only excellent transparency and etching resistance but also high sensitivity and excellent adhesion to a radiation-sensitive material and a pattern using the radiation-sensitive material, which are used in lithography using an excimer laser as an exposure source. It is to provide a forming method.
[0008]
Another object of the present invention is to provide a pattern forming method capable of forming a protective film even with a non-phenol-based low-polarity polymer and obtaining stable pattern characteristics.
[0009]
[Means for Solving the Problems]
The above problem is based on the general formula
[0010]
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And a substance which generates an acid upon irradiation with radiation.
In the above radiation-sensitive material, the unit structure having an alicyclic group in the copolymer is preferably 40 to 70 mol%.
[0015]
In addition, the above-mentioned problem is solved by the general formula
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Hydroxyethyl methacrylate represented by, Unit structure containing alicyclic groupAnd a polymer having a unit structure that generates an alkali-soluble group by an acid, and a substance that generates an acid by irradiation.
In addition, the above-mentioned problem is solved by the general formula
[0016]
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And a substance which generates an acid upon irradiation with radiation.
Here, as the case where an alkali-soluble group is generated by an acid, any of ester groups such as a t-butyl group, a terahydropyranyl group, an α, α-dimethylbenzyl group, a 3-oxocyclohexyl group, etc. Can be used. However, those containing no benzene ring are suitable because they are transparent to excimer light. Therefore, a t-butyl group, a terahydropyranyl group, and a 3-oxocyclohexyl group are more preferable.
[0017]
In the above radiation-sensitive material, it is preferable that the content of the hydroxyethyl methacrylate in the copolymer is 5 mol% or more.
[0022]
In addition, the above-mentioned problem is solved by the general formula
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A polymer comprising a unit structure represented by the formula and a unit structure capable of forming an alkali-soluble group by an acid and a substance generating an acid upon irradiationThe polymer has an alicyclic groupThis is achieved by a radiation-sensitive material.
Further, in the above radiation-sensitive material, it is preferable that the copolymer has a t-butyl group.
[0023]
Further, in the above radiation sensitive material, the general formula
[0024]
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Is preferably acrylonitrile or methacrylonitrile.
In the above radiation-sensitive material, the acrylonitrile or methacrylonitrile in the copolymer is desirably 10 to 70 mol%.
[0032]
Also, the general formula
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An anhydrous itacone represented byA unit structure containing an acid or an alicyclic group;Polymerization involving a unit structure generating an alkali-soluble group by an acidBodyThis is achieved by a radiation-sensitive material comprising a copolymer contained in the unit structure and a substance that generates an acid upon irradiation.
In the above radiation-sensitive material, the copolymer has a general formula
[0033]
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It is desirable to be shown by.
[0036]
In the radiation-sensitive material described above, it is preferable that the copolymer contains a unit structure composed of the itaconic anhydride at a ratio of 5 to 50 mol%.
Further, the object is to form a resist using the radiation-sensitive material, apply the resist on a substrate to be processed, perform a pre-bake of the substrate to be processed, and then apply the resist to the resist on the substrate to be processed. This is achieved by a pattern forming method comprising selectively exposing to radiation, performing post-baking of the substrate to be processed, and then developing the resist on the substrate to be processed to form a predetermined resist pattern. Is done.
[0037]
In addition, the above problemsIncluding alicyclic structureA resist is formed using a radiation-sensitive material, the resist is applied on a substrate to be processed, the substrate to be processed is pre-baked, and the resist on the substrate to be processed is selectively exposed to radiation. In a pattern forming method for performing post-baking of a processing substrate and developing the resist on the processing target substrate to form a predetermined resist pattern, a mixed solution of an organic alkali aqueous solution and isopropyl alcohol is used as a developing solution. This is achieved by the following pattern formation method.
[0038]
The radiation-sensitive material at this time is composed of a polymer containing a unit structure containing an alicyclic group such as an adamantyl group or a nobornyl group and a unit structure generating an alkali-soluble group by an acid, and a substance generating an acid by irradiation. Desirably.
In the above-described pattern forming method, it is preferable that the developer contains the isopropyl alcohol in an amount of 5 vol% to 95 vol%.
[0039]
In addition, an acrylate unit having an alicyclic group in the ester portion or a methacrylate unit having an alicyclic group in the ester portion, and an acrylate unit having a polar structure in the ester portion or a polar structure in the ester portion After forming a resist using a polymer containing a methacrylate unit and applying the resist on a substrate to be processed, a pre-baking of the substrate to be processed is performed, and carbonization transparent to far ultraviolet light on the resist is performed. After applying a protective film made of a hydrogen-based polymer, heat treatment is performed, and after selectively exposing the resist on the substrate to radiation with radiation, post-baking of the substrate to be processed is performed, and the protective film is peeled off. Then, in a pattern forming method of developing the resist on the substrate to be processed to form a predetermined resist pattern, Coating solvent of the hydrocarbon-based polymer in the protective film, a non-aromatic hydrocarbon or formula
[0040]
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This is achieved by a pattern forming method characterized by being an aromatic hydrocarbon represented by the formula:
Further, a resist is formed using the radiation-sensitive material described above, and after applying the resist on a substrate to be processed, a pre-bake of the substrate to be processed is performed, and a hydrocarbon transparent to far ultraviolet light is formed on the resist. After applying a protective film made of a system polymer, a heat treatment was performed, and after selectively exposing the resist on the processed substrate to radiation, post-baking of the processed substrate was performed, and the protective film was peeled off. Thereafter, the pattern is formed by developing the resist on the substrate to be processed to form a predetermined resist pattern.
[0041]
In the above pattern forming method, the coating solvent for the hydrocarbon polymer in the protective film is limonene, 1,5-cyclooctadiene, 1-decene, t-butylcyclohexane, p-cymene, or dodecylbenzene. Desirably.
In the above-described pattern forming method, it is preferable that the hydrocarbon polymer is an olefin polymer or a diene polymer.
[0042]
In the above pattern formation method, the substance having a polar structure is a ketone, an alcohol, an ether, an ester, a carboxylic acid, an acid anhydride structure, or a structure in which some atoms of these structures are sulfur, nitrogen, or It is desirable to have a structure substituted with halogen.
The substance that generates an acid upon irradiation with radiation used in the above radiation-sensitive material, that is, the acid generator is represented by a general formula
[0043]
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An oxaazole derivative represented by the general formula
[0044]
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An s-triazine derivative represented by the formula:
[0045]
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An iodonium salt represented by the general formula
[0046]
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A sulfonium salt represented by the general formula
[0047]
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A disulfone derivative represented by the general formula
[0048]
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An imide sulfonate derivative represented by the general formula
[0049]
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It is possible to use a diazonium salt represented by However, it is not limited to these.
[0050]
[Action]
General formula
[0051]
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In the radiation-sensitive material comprising the copolymer represented by the formula (1) and a substance which generates an acid upon irradiation, one of the α-positions R1 and R2 is not a bulky and strongly hydrophobic methyl group, but has a small size. Further, since the proton is weaker in hydrophobicity, the copolymer becomes less hydrophobic and its hardness is reduced. For this reason, familiarity with the developing solution is increased, and the developer easily penetrates, and the diffusion of the protonic acid as the catalyst is also facilitated, so that a large amount of carboxylic acid is generated. For these reasons, development is facilitated, sensitivity is improved, and stable patterning characteristics can be obtained.
[0052]
Here, it is preferable that the unit structure having an alicyclic group in the copolymer is 40 to 70 mol%. If the composition is less than 40 mol%, sufficient dry etching resistance cannot be obtained and more than 70 mol% This is because patterning becomes difficult because there are few t-butyl units as photosensitive groups.
[0057]
Also, the general formula
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Hydroxyethyl methacrylate represented by, Unit structure containing alicyclic groupRadiation-sensitive materials composed of a polymer having a unit structure that generates an alkali-soluble group by an acid and a substance that generates an acid upon irradiation with radiation, the hydroxyethyl methacrylate is introduced into the polymer as a hydrophilic group, and the As in the case where an acid is introduced, the hydrophilicity of the polymer is increased, the polymer is easily compatible with the developer, the penetration is facilitated, and the solubility is increased.
[0058]
Also, the general formula
[0059]
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In a radiation-sensitive material comprising a tercopolymer represented by and a substance that generates an acid upon irradiation, hydroxyethyl methacrylate is used as a hydrophilic group because the copolymer contains a strongly alicyclic group. The effect of being introduced into the polymer is significant.
[0060]
Here, the reason why the content of hydroxyethyl methacrylate in the copolymer is desirably at least 5 mol% is that no effect is seen at less than 5 mol%.
[0066]
Further, in order to obtain more stable patterning characteristics, it is effective to improve the adhesion. In particular, when there is an adamantyl group or a t-butyl group which is a hydrocarbon, the adhesion is significantly reduced. It is considered that this is because the polarity of the hydrocarbon group is small and there is no interaction with the substrate.
[0067]
Therefore, the general formula
[0068]
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A polymer comprising a unit structure represented by the formula and a unit structure capable of forming an alkali-soluble group by an acid and a substance generating an acid upon irradiationThe polymer has an alicyclic groupSince the radiation-sensitive material has a highly polar nitrile group, the adhesiveness is improved and stable patterning characteristics can be obtained.
[0069]
For example, when the unit structure containing a nitrile group is acrylonitrile or methacrylonitrile, it is considered that the introduction amount is desirably 10 to 70 mol%. If the introduction amount is less than 10 mol%, sufficient adhesion cannot be obtained, and 70 mol% This is because if it exceeds, sensitivity cannot be obtained.
[0079]
Also, the general formula
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Itaconic anhydride represented by, Unit structure containing alicyclic groupA resist having excellent adhesion is formed by using a radiation-sensitive material comprising a copolymer having, as a unit structure, a polymer containing a unit structure that generates an alkali-soluble group by an acid, and a substance that generates an acid upon irradiation. be able to. That is, due to the strong polarity of itaconic anhydride, the adhesion to the substrate is significantly improved.
[0080]
In addition, since itaconic anhydride itself shows solubility in alkali, it is necessary to introduce an appropriate amount thereof in order to use it without impairing the patterning characteristics. The amount to be introduced varies depending on the polymer composition and structure, but is preferably 5 to 50 mol%. If the amount is less than 5 mol%, the adhesion cannot be sufficiently improved, and if the amount exceeds 50 mol%, the resist itself becomes alkali-soluble and unexposed portions are dissolved, so that patterning cannot be formed.
[0081]
The introduction of such an alkali-soluble group has a remarkable effect of improving the pattern removability, particularly in an alicyclic-based resist, and can improve the patterning characteristics.
The specific structure of the copolymer containing itaconic anhydride has a general formula
[0082]
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Etc.
Here, examples of the so-called alicyclic group include, but are not limited to, a structure partially having an adamantyl, norbornyl, cyclohexyl, tricyclo [5.2.1.0] decane skeleton, or the like.
[0086]
Examples of the group that generates an alkali-soluble group by an acid include t-butyl ester, t-amyl ester, t-butyl ether, t-BOC, tetrahydropyranyl ester, tetrahydropyranyl ether, 3-oxocyclohexyl ester, and dimethylbenzyl ester. But not limited thereto.
[0087]
That is, a resist is formed using the above-described radiation-sensitive material, and a fine pattern can be stably formed by applying the resist on a substrate to be processed, pre-baking, exposing, post-baking, and developing. it can.
Furthermore, in order to obtain more stable patterning characteristics, it is necessary to improve the developer. The chemically amplified resist has a specific problem that the proton acid is deactivated in the surface layer portion due to contamination of the amine and the like in the environment and becomes insoluble in a developing solution. For this reason, a difference in solubility between the surface layer portion and the inside occurs, which is a major factor in preventing a stable pattern. Particularly, a highly hydrophobic group such as an adamantyl group or a t-butyl group, which is a hydrocarbon, has an effect of inhibiting dissolution in a developing solution, and has a large influence of surface insolubilization.
[0088]
Therefore, by using a mixed solution of an organic alkali aqueous solution and isopropyl alcohol as a developer, the solubility is remarkably increased, and the difference in solubility between the surface layer portion and the inside is reduced, so that stable patterning can be performed. As the alcohol to be added, isopropyl alcohol was the most effective. In the case of methanol or ethanol, cracks occurred and peeling was conspicuous. Further, by using this mixed developer, the sensitivity was increased by one digit or more, and the distortion applied during the development was reduced, so that the adhesion was greatly improved.
[0089]
Further, the reason that the developer preferably contains 5 vol% to 95 vol% of isopropyl alcohol is that sensitivity is not improved if the content is less than 5 mol%, and if it exceeds 95 mol%, cracks and cracks are liable to occur. .
In addition, a material having an alicyclic acrylate structure or a methacrylate structure, and an acrylate structure having a highly polar unit in the ester portion or a methacrylate structure having a highly polar unit in the ester portion Since the polymer containing the material increases the polarity of the base polymer, the very strong hydrophobicity due to the alicyclic group can be reduced. As a result, a difference in polarity occurs between the protective film and the hydrocarbon-based protective film, so that the protective film can be applied without dissolving the resist film. Accordingly, a pattern having a desired size can be formed.
[0090]
Examples of a highly polar structure to be introduced include ketones, alcohols, ethers, esters, carboxylic acids, acid anhydride compounds, and structures in which some atoms of these structures are substituted with sulfur, nitrogen, or halogen. However, the present invention is not limited to these.
The ratio of introducing a material having a polar structure needs to be at least about 1 to 50 mol%, and preferably 20% or more.
[0091]
In addition, in the resist containing itaconic anhydride, a hydrocarbon-based polymer which has not been able to be used as a protective film is conventionally formed on the resist because of the strong polarity of itaconic anhydride. It is possible to apply.
By forming such a protective film on the resist, it becomes possible to prevent PED (Post Exposure Delay) which is a problem peculiar to the chemically amplified resist.
[0092]
Further, by using a hydrocarbon-based solvent having a large molecular weight as a coating solvent for the protective film, it became possible to more reliably apply the protective film. If the coating solvent has a very low boiling point, it is difficult to uniformly apply the protective film on the wafer. Therefore, those having a boiling point of 100 ° C. or higher are preferred. Specific examples include, but are not limited to, limonene, 1,5-cyclooctadiene, 1-decene, t-butylcyclohexane, p-cymene, dodecylbenzene, and the like.
[0093]
Examples of the hydrocarbon polymer include olefins and dienes, but are not limited thereto as long as they are transparent to the exposure wavelength and are soluble in the above-mentioned coating solvent.
Examples of the alicyclic group include a structure having a skeleton of cyclohexane, norbornane, adamantane, and tricyclo [5.2.1.0] decane, but are not limited thereto.
[0094]
【Example】
[Example 1]
An adamantyl methacrylate monomer and a t-butyl acrylate monomer are charged at a ratio of 1: 1 to obtain a 5 mol / l toluene solution.
[0095]
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AIBN (azoisobutyronitrile) of 20 mol% was added. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0096]
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A copolymer having a composition ratio of 58:42, a weight average molecular weight (Mw) of 5100, and a degree of dispersion (Mw / Mn) of 1.43 was obtained. The glass transition temperature of this polymer was 126 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0097]
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15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0098]
The resist film on the wafer thus obtained was exposed with a KrF excimer stepper (manufactured by Nikon, NA = 0.45), and then subjected to PEB (Post Exposure Bake) at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed for 60 seconds using NMD-3 (manufactured by Tokyo Ohka), which was an alkaline aqueous solution, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 50 mJ / cm.²Met. The resolution is 130 mJ / cm.²Shows an L & S (line and space) pattern having a width of 0.45 μm.
[Example 2]
Adamantyl acrylate monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0099]
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A copolymer having a composition ratio of 50:50, a weight average molecular weight of 4180, and a dispersity of 1.59 was obtained. The glass transition temperature of this polymer was 94 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0100]
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15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0101]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 81 mJ / cm.²Met. The resolution was an L & S pattern having a width of 0.50 μm.
[Example 3]
After adamantyl acrylate monomer and t-butyl acrylate monomer were charged at a ratio of 1: 1 to obtain a 5 mol / l toluene solution, 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0102]
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A copolymer having a composition ratio of 47:53, a weight average molecular weight of 4610, and a degree of dispersion of 1.83 was obtained. The glass transition temperature of this polymer was 72 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0103]
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15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0104]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 37 mJ / cm.²And the resolution was an L & S pattern having a width of 0.50 μm.
[Comparative Example 1]
Adamantyl methacrylate monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0105]
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A copolymer having a composition ratio of 59:41, a weight average molecular weight of 3351 and a dispersity of 1.31 was obtained. The glass transition temperature of this polymer could not be detected by thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0106]
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15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0107]
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, development did not proceed, and no pattern could be obtained at all.
[Comparative Example 2]
Adamantyl methacrylate monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 5 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0108]
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And a copolymer having a composition ratio of 47:53, a weight average molecular weight of 19000, and a dispersity of 1.51 was obtained. The glass transition temperature of this polymer could not be detected by thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0109]
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15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0110]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the irradiation dose was 102 mJ / cm.²Although the residual film was reduced to about 10% by the test, the residual film was not completely eliminated even when a higher exposure amount was given.
[Example 4]
Dimethyl adamantyl acrylate monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0111]
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A copolymer having a composition ratio of 47:53, a weight average molecular weight of 3650, and a dispersity of 1.64 was obtained. The glass transition temperature of this polymer was 66 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0112]
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15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0113]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 81 mJ / cm.²Met. The obtained minimum resolution pattern was L & S having a width of 0.35 μm.
[Example 5]
Dimethyl adamantyl acrylate monomer and t-butyl acrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0114]
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A copolymer having a composition ratio of 50:50, a weight average molecular weight of 4050, and a dispersity of 1.71 was obtained. The glass transition temperature of this polymer was 47 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0115]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0116]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 81 mJ / cm.²Met. The obtained minimum resolution pattern was L & S having a width of 0.30 μm.
[Comparative Example 3]
Adamantyl methacrylate monomer and t-butyl methacrylate monomer were charged in a ratio of 3: 7 to obtain a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0117]
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A copolymer having a composition ratio of 30:70, a weight average molecular weight of 8,400, and a degree of dispersion of 1.61 was obtained. The glass transition temperature of this polymer could not be detected by thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0118]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0119]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 81 mJ / cm.²Met. At this time, the remaining minimum resolution pattern was an L & S having a width of 0.50 μm, and the lower pattern was not peeled off.
[Example 6]
Adamantyl methacrylate monomer, t-butyl methacrylate monomer and methacrylic acid were charged at a ratio of 2: 1: 1 to obtain a 0.5 mol / l 1,4-dioxane (1,4-dioxane) solution, which was used as a polymerization initiator. AIBN was added at 20 mol%. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, the precipitate was purified by n-hexane (n-hexane). As a result, the structural formula
[0120]
Embedded image
And a terpolymer having a composition ratio of 59:27:14, a weight average molecular weight of 6242, and a dispersity of 2.14 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0121]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied in a thickness of 0.7 μm on a wafer coated with a hard-baked novolak resin by a spin coating method, and prebaked on a hot plate for 100 seconds.
[0122]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 100 mJ / cm.²And the resolution was an L & S pattern having a width of 0.45 μm.
[Example 7]
As a result of observing the profile of the hole pattern having a size of 1 μm obtained in Example 6, no surface insolubilized layer was found. In addition, the pattern was also formed when PEB was performed by leaving it for 45 minutes after exposure.
[Comparative Example 4]
Adamantyl methacrylate monomer and t-butyl acrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0123]
Embedded image
And a copolymer having a composition ratio of 58:42, a weight average molecular weight of 5100, and a degree of dispersion of 1.43, was obtained. The glass transition temperature of this polymer was 126 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0124]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0125]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 50 mJ / cm.²And an L & S pattern having a width of 0.45 μm is converted to 130 mJ / cm.²Resolved. The 1 μm hole pattern profile resulted in “eaves” due to the surface insolubilized layer.
[Comparative Example 5]
In Comparative Example 4 above, when PEB was performed by standing for 45 minutes after the exposure, about half of the upper part of the pattern was covered with the surface insolubilized layer. As a result, the pattern cannot be formed.
[Example 8]
Adamantyl methacrylate monomer, t-butyl methacrylate monomer, and methacrylic acid were charged at a ratio of 2: 1: 2 to prepare a 0.5 mol / l 1,4-dioxane solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After the completion of the polymerization, the precipitate was purified with n-hexane. As a result, the structural formula
[0126]
Embedded image
A terpolymer having a composition ratio of 53:27:20, a weight average molecular weight of 4523, and a dispersity of 1.92 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0127]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a hard-baked novolak resin by spin coating at a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 130 ° C. for 100 seconds.
[0128]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, NMD-3, which is an alkaline aqueous solution, was immersed in a solution diluted with a 20-fold amount of pure water for 90 seconds, developed, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 57 mJ / cm.²And the resolution was an L & S pattern having a width of 0.30 μm.
[Comparative Example 6]
Adamantyl methacrylate monomer, t-butyl methacrylate monomer, and methacrylic acid were charged at a ratio of 2: 1: 4 to prepare a 0.5 mol / l 1,4-dioxane solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After the completion of the polymerization, the precipitate was purified with n-hexane. As a result, the structural formula
[0129]
Embedded image
And a terpolymer having a composition ratio of 43:31:36, a weight average molecular weight of 4115, and a dispersity of 1.95 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0130]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a hard-baked novolak resin by spin coating at a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 130 ° C. for 100 seconds.
[0131]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, when NMD-3, which is an alkaline aqueous solution, was immersed in a solution diluted with a 20-fold amount of pure water for 90 seconds, the resist film disappeared in 30 seconds.
[Example 9]
Structural formula
[0132]
Embedded image
Adamantyl methacrylate-t-butyl methacrylate-hydroxyethyl methacrylate copolymer having a composition ratio of 53: 44: 4, a weight average molecular weight of 8,800 and a dispersity of 1.84, represented by the following formula:
[0133]
Embedded image
The cyclohexanone solvent was adjusted by adding 15 wt% of triphenylsulfonium hexafluoroantimony represented by the following formula. This was applied on a HMDS (hexamethyldisilane) -treated Si wafer and baked on a hot plate at a temperature of 60 ° C. for 20 minutes to form a 0.65 μm thick resist film.
[0134]
After exposing the thus obtained resist film with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% aqueous solution of TMAH (tetramethylammonium hydroxide). At this time, the irradiation dose was 110 mJ / cm²The L & S pattern having a width of 0.4 μm was resolved.
[Example 10]
Structural formula
[0135]
Embedded image
Adamantyl methacrylate-t-butyl methacrylate-hydroxyethyl methacrylate copolymer having a composition ratio of 48:40:12, a weight average molecular weight of 8400 and a dispersity of 1.94 represented by the following formula:
[0136]
Embedded image
The cyclohexanone solvent was adjusted by adding 15 wt% of triphenylsulfonium hexafluoroantimony represented by the following formula. This was applied on a HMDS-treated Si wafer, and baked on a hot plate at a temperature of 60 ° C. for 20 minutes to form a resist film having a thickness of 0.65 μm.
[0137]
After exposing the thus obtained resist film with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute. At this time, the irradiation dose was 40 mJ / cm.²The L & S pattern having a width of 0.4 μm was resolved.
[Comparative Example 7]
Structural formula
[0138]
Embedded image
Adamantyl methacrylate-t-butyl methacrylate copolymer having a composition ratio of 61:39, a weight average molecular weight of 7,900, and a dispersity of 1.82, represented by the following formula:
[0139]
Embedded image
The cyclohexanone solvent was adjusted by adding 15 wt% of triphenylsulfonium hexafluoroantimony represented by the following formula. This was applied on a wafer coated with a hard-baked novolak resin by spin coating, and baked on a hot plate at a temperature of 60 ° C. for 20 minutes to form a resist film having a thickness of 0.65 μm.
[0140]
After exposing the thus obtained resist film with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute. At this time, the irradiation dose was 380 mJ / cm²The L & S pattern having a width of 0.4 μm was resolved. However, there was no reproducibility.
[Example 11]
The adamantyl methacrylate monomer and the di-t-butyl itaconate monomer were charged at a ratio of 1: 3, and the polymerization formula
[0141]
Embedded image
20 mol% of MAIB (dimethyl 2,2-azoisobisbutyrate) represented by the formula was added. Thereafter, bulk polymerization was carried out at a temperature of 80 ° C. for about 3 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0142]
Embedded image
And a copolymer having a composition ratio of 59:41, a weight average molecular weight of 9357, and a dispersity of 2.44, was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0143]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on an HMDS-treated Si wafer by a spin coating method to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0144]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 5.6 mJ / cm.²Met. The resolution is 7 mJ / cm²Indicates an L & S pattern having a width of 0.45 μm.
[Comparative Example 8]
An adamantyl methacrylate monomer and a di-t-butyl methacrylate monomer were charged at a ratio of 1: 1 and a structural formula was used as a polymerization initiator.
[0145]
Embedded image
Was added in an amount of 20 mol%. Thereafter, bulk polymerization was carried out at a temperature of 80 ° C. for about 8 hours using toluene as a reaction solvent. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0146]
Embedded image
And a copolymer having a composition ratio of 59:41, a weight average molecular weight of 6061, and a dispersity of 1.24.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0147]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on an HMDS-treated Si wafer by a spin coating method to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0148]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 25.1 mJ / cm.²Met. The resolution is 41 mJ / cm²Indicates an L & S pattern having a width of 0.5 μm.
[Example 12]
Di-t-butyl itaconate monomer has a structural formula as a polymerization initiator
[0149]
Embedded image
Was added in an amount of 20 mol%. Thereafter, bulk polymerization was performed at a temperature of 80 ° C. for about 9.5 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0150]
Embedded image
And a polymer having a weight average molecular weight of 6061 and a dispersity of 1.24.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0151]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on an HMDS-treated Si wafer by a spin coating method to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0152]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 7 mJ / cm.²Met. The resolution is 11 mJ / cm²Indicates an L & S pattern having a width of 0.5 μm.
[Example 13]
An adamantyl methacrylate monomer and a di-t-butyl fumarate monomer were charged at a ratio of 1: 3, and a structural formula was used as a polymerization initiator.
[0153]
Embedded image
Was added in an amount of 20 mol%. Thereafter, bulk polymerization was carried out at a temperature of 80 ° C. for about 2.5 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0154]
Embedded image
And a copolymer having a composition ratio of 36:64, a weight average molecular weight of 22645, and a dispersity of 2.44.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0155]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on an HMDS-treated Si wafer by a spin coating method to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0156]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 5 mJ / cm.²Met. The resolution is 9 mJ / cm²Indicates an L & S pattern having a width of 0.5 μm.
[Comparative Example 9]
Structural formula
[0157]
Embedded image
Adamantyl methacrylate-t-butyl methacrylate copolymer having a composition ratio of 30:70, a weight average molecular weight of 8,400, and a dispersity of 1.61, represented by the following structural formula:
[0158]
Embedded image
The cyclohexanone solvent was adjusted by adding 15 wt% of triphenylsulfonium hexafluoroantimony represented by the following formula. This solution was applied on a wafer coated with a hard-baked novolak resin by a spin coating method, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds to form a resist film having a thickness of 0.7 μm.
[0159]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution. At this time, the threshold energy Eth of the irradiation dose is 15 mJ / cm.²Met. Also, 42mJ / cm²Resolved an L & S pattern having a width of 0.4 μm, but no reproducibility was obtained.
[Example 14]
After methacrylonitrile monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 and 5 mol / l of a solvent 1,4-dioxane and 1 mol% of a polymerization initiator AIBN were added, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. . After completion of the polymerization, precipitation and purification were performed using a solution of methanol and water (methanol: water = 2: 1). As a result, the structural formula
[0160]
Embedded image
A copolymer having a composition ratio of 41:59, a weight average molecular weight of 16,400, and a dispersity of 1.77 was obtained. The transmittance of the copolymer was 98% at a KrF laser wavelength when the film thickness was 1 μm.
Next, this copolymer was made into a 13% by weight cyclohexanone solution.
[0161]
Embedded image
A triphenylsulfonium hexafluoroantimony represented by the following formula was added to the polymer in an amount of 15 wt% to obtain a resist solution. This solution was applied on a HMDS-treated Si wafer by spin coating, and baked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a 0.7 μm-thick resist film.
[0162]
After exposing the thus obtained resist film with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, the film was immersed in a 2.38% TMAH aqueous solution for 60 seconds for development. As a result, the irradiation dose was 70 mJ / cm²The L & S pattern having a width of 0.3 μm was resolved.
[Example 15]
After methacrylonitrile monomer and t-butyl methacrylate monomer were charged at a ratio of 3: 7, 5 mol / l of a solvent 1,4-dioxane and 1 mol% of a polymerization initiator AIBN were added, and the mixture was polymerized at a temperature of 80 ° C. for about 8 hours. . After completion of the polymerization, precipitation and purification were performed using a solution of methanol and water (methanol: water = 2: 1). As a result, the structural formula
[0163]
Embedded image
And a copolymer having a composition ratio of 25:75, a weight average molecular weight of 18,800, and a dispersity of 1.73 was obtained. The transmittance of the copolymer was 98% at a KrF laser wavelength when the film thickness was 1 μm.
Next, using this copolymer, a pattern was formed in the same procedure as in Example 14 above. As a result, an L & S pattern having a width of 0.35 μm was resolved.
[Example 16]
After methacrylonitrile monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 and 5 mol / l of a solvent 1,4-dioxane and 1 mol% of a polymerization initiator AIBN were added, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. . After completion of the polymerization, precipitation and purification were performed using a solution of methanol and water (methanol: water = 2: 1). As a result, a structural formula having a composition ratio of 43:57, a weight average molecular weight of 31,800, and a dispersity of 1.53 was obtained.
[0164]
Embedded image
A copolymer having a composition ratio of 43:57, a weight average molecular weight of 31,800, and a degree of dispersion of 1.53 was obtained.
Next, using this copolymer, a pattern was formed in the same procedure as in Example 14 above. As a result, an L & S pattern having a width of 0.35 μm was resolved.
[Comparative Example 10]
After adding 5 mol / l of a solvent 1,4-dioxane and 1 mol% of a polymerization initiator AIBN, t-butyl methacrylate monomer was polymerized at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation and purification were performed using a solution of methanol and water (methanol: water = 2: 1). As a result, the structural formula
[0165]
Embedded image
And a homopolymer having a weight average molecular weight of 36000 and a dispersity of 1.82 was obtained.
Next, using this copolymer, a pattern was formed in the same procedure as in Example 14 above. As a result, the L & S pattern having a width of 1 μm or less peeled off.
[Example 17]
Methacrylonitrile, t-butyl methacrylate, and three monomers of adamantyl methacrylate were further added at a ratio of 1: 2: 1, and 1 mol / l of a solvent 1,4-dioxane and 1 mol% of a polymerization initiator AIBN were added. Thereafter, polymerization was performed at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation and purification were performed using a solution of methanol and water (methanol: water = 2: 1). As a result, the structural formula
[0166]
Embedded image
A terpolymer having a composition ratio of 10:54:36, a weight average molecular weight of 5750, and a dispersity of 1.21 was obtained.
Next, using this copolymer, a pattern was formed in the same procedure as in Example 14 above. As a result, the irradiation dose was 250 mJ / cm²The L & S pattern having a width of 0.7 μm was resolved.
[Comparative Example 11]
Using a copolymer of t-butyl methacrylate and adamantyl methacrylate having a composition ratio of 70:30, pattern formation was performed in the same procedure as in Example 14 above. As a result, the pattern was completely peeled off and did not remain at all.
[Example 18]
Structural formula
[0167]
Embedded image
A copolymer of adamantyl methacrylate and 3-oxocyclohexyl methacrylate having a composition ratio of 41:59, a weight average molecular weight of 13,900, and a dispersity of 1.51, represented by the following formula was used as a 15 wt% cyclohexanone solution. Structural formula as agent
[0168]
Embedded image
A triphenylsulfonium hexafluoroantimony represented by the following formula was added to the polymer in an amount of 15 wt% to obtain a resist solution. This solution was applied on a wafer coated with a hard-baked novolak resin by a spin coating method, and baked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a resist film having a thickness of 0.7 μm.
[0169]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, the film was immersed in a mixture of a 2.38% aqueous solution of TMAH and isopropyl alcohol at a volume ratio of 1: 1 for 60 seconds for development. As a result, the irradiation dose was 26 mJ / cm²In this way, an L & S pattern having a width of 0.25 μm was resolved.
[Comparative Example 12]
When the wafer subjected to PEB in the same process as in Example 18 was immersed in a 2.38% TMAH aqueous solution for 60 seconds and developed, the minimum resolution pattern was 0.45 μm L & S.
[Example 19]
Structural formula
[0170]
Embedded image
A copolymer of adamantyl methacrylate and 3-oxocyclohexyl methacrylate having a composition ratio of 41:59, a weight average molecular weight of 13,900, and a dispersity of 1.51, represented by the following formula was used as a 15 wt% cyclohexanone solution. Structural formula as agent
[0171]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by the following formula was added to the polymer in an amount of 10 wt% to obtain a resist solution. This solution was applied on a HMDS (hexamethyldisilane) -treated Si wafer by spin coating, and baked on a hot plate at 100 ° C. for 100 seconds to form a 0.7 μm thick resist film. .
[0172]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, the film was developed by immersing it in a mixed solution obtained by mixing a 2.38% TMAH aqueous solution and isopropyl alcohol at a volume ratio of 4: 1 for 60 seconds. As a result, the irradiation dose was 32 mJ / cm²In this way, an L & S pattern having a width of 0.30 μm was resolved.
[Comparative Example 13]
When the wafer subjected to PEB in the same process as in Example 19 was immersed in a 2.38% TMAH aqueous solution for 60 seconds and developed, all the patterns of 1 μm or less were peeled off.
[Example 20]
Dimethyl adamantyl methacrylate monomer and t-butyl methacrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, and 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0173]
Embedded image
A copolymer having a composition ratio of 59:41, a weight average molecular weight of 3351 and a dispersity of 1.31 was obtained. The glass transition temperature of this polymer could not be detected by thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0174]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0175]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed for 60 seconds using a mixed solution of NMD-3 and isopropyl alcohol, which are alkaline aqueous solutions, mixed at a volume ratio of 1: 1 and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 8 mJ / cm.²Met. The obtained minimum resolution pattern was L & S having a width of 0.30 μm.
[Example 21]
When a mixture of NMD-3 and isopropyl alcohol mixed at a volume ratio of 3: 1 was used as the developer instead of the mixture used in Example 20, the irradiation dose was 42 mJ / cm.²In this way, an L & S pattern having a width of 0.40 μm was resolved.
[Example 22]
When a mixture of NMD-3 and isopropyl alcohol mixed at a volume ratio of 9: 1 is used as the developer instead of the mixture used in Example 20, the irradiation dose is 98 mJ / cm.²In this way, an L & S pattern having a width of 0.40 μm was resolved.
[Comparative Example 14]
When isopropyl alcohol was used in place of the mixed solution used in Example 20 as the developing solution, the pattern was peeled off and did not remain at all.
[Example 23]
Structural formula
[0176]
Embedded image
A copolymer of adamantyl methacrylate and 3-oxocyclohexyl methacrylate having a composition ratio of 41:59, a weight average molecular weight of 13,900, and a dispersity of 1.51, represented by the following formula was used as a 15 wt% cyclohexanone solution. Structural formula as agent
[0177]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by the formula (1) was added at 1 wt% to the polymer to prepare a resist solution. This solution was applied on a wafer coated with a hard-baked novolak resin by a spin coating method, and baked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a resist film having a thickness of 0.7 μm.
[0178]
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 150 ° C. for 60 seconds. Subsequently, the film was immersed in a mixture of a 2.38% aqueous solution of TMAH and isopropyl alcohol at a volume ratio of 1: 1 for 60 seconds for development. As a result, the irradiation dose was 88 mJ / cm.²In this way, an L & S pattern having a width of 0.35 μm was resolved.
[Comparative Example 15]
Structural formula
[0179]
Embedded image
When a pattern was formed using the adamantyl methacrylate-t-butyl methacrylate copolymer represented by the following procedure in the same manner as in Example 23, no pattern was obtained.
[Example 24]
Structural formula
[0180]
Embedded image
A copolymer of adamantyl methacrylate and 3-oxocyclohexyl methacrylate having a composition ratio of 41:59, a weight average molecular weight of 13,900, and a dispersity of 1.51, represented by the following formula was used as a 15 wt% cyclohexanone solution. Structural formula as agent
[0181]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by the formula (1) was added at 1 wt% to the polymer to prepare a resist solution. This solution was applied onto a wafer coated with a hard-baked novolak resin by spin coating, and baked on a hot plate at 100 ° C. for 100 seconds to form a 0.7 μm-thick resist film.
[0182]
After the resist film on the wafer thus obtained was exposed with an ArF excimer stepper (NA = 0.55), PEB was performed at a temperature of 150 ° C. for 60 seconds. Subsequently, the film was immersed in a mixture of a 2.38% aqueous solution of TMAH and isopropyl alcohol at a volume ratio of 1: 1 for 60 seconds for development. As a result, the irradiation dose was 25 mJ / cm²In this way, an L & S pattern having a width of 0.2 μm was resolved.
[Example 25]
Structural formula
[0183]
Embedded image
A copolymer of adamantyl methacrylate and 3-oxocyclohexyl methacrylate having a composition ratio of 41:59, a weight average molecular weight of 13,900, and a dispersity of 1.51, represented by the following formula was used as a 15 wt% cyclohexanone solution. Structural formula as agent
[0184]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by (2) was added to the polymer at 2 wt% to obtain a resist solution. This solution was applied onto a wafer coated with a hard-baked novolak resin by spin coating, and baked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a resist film having a thickness of 0.4 μm.
[0185]
After the resist film on the wafer thus obtained was exposed with an ArF excimer stepper (NA = 0.55), PEB was performed at a temperature of 150 ° C. for 60 seconds. Subsequently, the film was immersed in a mixture of a 2.38% aqueous solution of TMAH and isopropyl alcohol at a volume ratio of 1: 1 for 60 seconds for development. As a result, the irradiation dose was 12 mJ / cm²In this way, an L & S pattern having a width of 0.2 μm was resolved.
[Example 26]
2-Norbornyl methacrylate monomer, t-butyl methacrylate monomer, and methacrylic acid were charged in a ratio of 2: 1: 1. After the addition, polymerization was carried out at a temperature of 80 ° C. for about 9 hours. After the completion of the polymerization, the precipitate was purified with n-hexane. As a result, the structural formula
[0186]
Embedded image
A terpolymer having a composition ratio of 56:31:13, a weight average molecular weight of 5833, and a dispersity of 2.34 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0187]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied to a wafer coated with a novolak resin hard baked by spin coating to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0188]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 63 mJ / cm.²Met. In addition, the resolution showed an L & S pattern having a width of 0.35 μm.
[Example 27]
Di-t-butyl itaconate monomer and cyclohexyl methacrylate monomer were charged at a ratio of 3: 1, and 20 mol% of MAIB was added. Thereafter, bulk polymerization was carried out at a temperature of 80 ° C. for about 10.5 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0189]
Embedded image
A copolymer having a composition ratio of 52:48, a weight average molecular weight of 6923, and a dispersity of 2.12 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0190]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on an HMDS-treated Si wafer by a spin coating method to a thickness of 0.7 μm, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0191]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 9.52 mJ / cm.²Met. Further, the resolution showed an L & S pattern having a width of 0.5 μm.
[Example 28]
Structural formula
[0192]
Embedded image
The tricyclo [5.2.1.0 methacrylate having a composition ratio of 50:50, a weight average molecular weight of 13,900, and a dispersity of 1.41 is shown.^2,6] A copolymer of decanyl and 3-oxocyclohexyl methacrylate was made into a 15 wt% cyclohexanone solution, and this solution was added with a structural formula
[0193]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by the following formula was added to the polymer in an amount of 10 wt% to obtain a resist solution. This solution was applied on a HMDS-treated Si wafer by spin coating, and baked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a 0.7 μm-thick resist film.
[0194]
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 150 ° C. for 60 seconds. Subsequently, the film was immersed in a mixed solution obtained by mixing a 2.38% aqueous solution of TMAH and isopropyl alcohol at a volume ratio of 3: 1 and developed. As a result, the irradiation dose was 23 mJ / cm²In this way, an L & S pattern having a width of 0.45 μm was resolved.
[Example 29]
Structural formula
[0195]
Embedded image
A terpolymer of vinylphenol, adamantyloxycarbonylmethylated styrene and tertbutyl methacrylate having a composition ratio of 50:20:30 represented by the following formula:
[0196]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula was added to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0197]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 26 mJ / cm.²In this way, an L & S pattern having a width of 0.275 μm was resolved. Even when PEB was performed after being left for 30 minutes after exposure, an L & S pattern having a width of 0.275 μm was resolved at the same irradiation dose.
[Example 30]
Structural formula
[0198]
Embedded image
A ternary copolymer of vinylphenol, norbornyloxycarbonylmethylated styrene and tertbutyl methacrylate having a composition ratio of 50:30:30 represented by the following formula:
[0199]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula was added to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0200]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 22 mJ / cm²In this way, an L & S pattern having a width of 0.275 μm was resolved. Even when PEB was performed after being left for 30 minutes after exposure, an L & S pattern having a width of 0.275 μm was resolved at the same irradiation dose.
[Example 31]
Structural formula
[0201]
Embedded image
A copolymer of vinylphenol having a composition ratio of 60:40 and tert-butyl methacrylate (manufactured by Maruzen Petroleum) represented by the formula:
[0202]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula:
[0203]
Embedded image
The t-butyl 1-adamantanecarboxylate represented by the following formula was added in the same wt% as the polymer to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0204]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 8.5 mJ / cm.²In this way, an L & S pattern having a width of 0.275 μm was resolved. Even when PEB was performed after being left for 30 minutes after exposure, an L & S pattern having a width of 0.275 μm was resolved at the same irradiation dose.
[0205]
The threshold energy Eth of the irradiation dose when PEB is performed immediately after exposure is 5.5 mJ / cm.²When PEB was performed after 30 minutes from the exposure, there was almost no change.
[Example 32]
Structural formula
[0206]
Embedded image
A copolymer of vinylphenol having a composition ratio of 60:40 and tert-butyl methacrylate (manufactured by Maruzen Petroleum) represented by the formula:
[0207]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula:
[0208]
Embedded image
The di-t-butyl fumarate represented by the following formula was added to the polymer at 30 wt% to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0209]
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 12 mJ / cm²In this way, an L & S pattern having a width of 0.275 μm was resolved. Even when PEB was performed after being left for 30 minutes after exposure, an L & S pattern having a width of 0.275 μm was resolved at the same irradiation dose.
[0210]
The threshold energy Eth of the irradiation dose when PEB is performed immediately after exposure is 8 mJ / cm.²When PEB was carried out after leaving for 30 minutes after exposure, there was almost no change.
[Example 33]
Structural formula
[0211]
Embedded image
A copolymer of vinyl phenol and tert-butyl methacrylate having a composition ratio of 50:50 (manufactured by Maruzen Petroleum) represented by the following formula:
[0212]
Embedded image
5% by weight of diphenyliodonium triflate represented by the formula:
[0213]
Embedded image
The di-t-butyl fumarate represented by the following formula was added to the polymer at 30 wt% to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0214]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 18 mJ / cm.²In this way, an L & S pattern having a width of 0.275 μm was resolved. Even when PEB was performed after being left for 30 minutes after exposure, an L & S pattern having a width of 0.275 μm was resolved at the same irradiation dose.
[0215]
The threshold energy Eth of the irradiation dose when PEB is performed immediately after exposure is 8 mJ / cm.²When PEB was performed after 30 minutes from the exposure, there was almost no change.
[Example 34]
Structural formula
[0216]
Embedded image
A copolymer of vinyl phenol and tert-butoxycarbonyloxystyrene having a composition ratio of 70:30 (manufactured by Maruzen Petroleum) represented by the following formula:
[0217]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula:
[0218]
Embedded image
20 wt% of 1-adamantane carboxylate was added to the polymer to give an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0219]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 35 mJ / cm²In this way, an L & S pattern having a width of 0.275 μm was resolved. Even when PEB was performed after being left for 30 minutes after exposure, an L & S pattern having a width of 0.275 μm was resolved at the same irradiation dose.
[Comparative Example 16]
Structural formula
[0220]
Embedded image
A copolymer of vinyl phenol and tert-butyl methacrylate having a composition ratio of 50:50 (manufactured by Maruzen Petroleum) represented by the following formula:
[0221]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula was added to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0222]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 13 mJ / cm²In this way, an L & S pattern having a width of 0.275 μm was resolved. However, when the substrate was left for 5 minutes after the exposure and then subjected to PEB at a temperature of 90 ° C. for 60 seconds, the surface became insoluble and the L & S pattern having a width of 0.275 μm could not be resolved at the same irradiation dose.
[Comparative Example 17]
Structural formula
[0223]
Embedded image
A copolymer of vinylphenol having a composition ratio of 60:40 and tert-butyl methacrylate (manufactured by Maruzen Petroleum) represented by the formula:
[0224]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula was added to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0225]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 8 mJ / cm²The L & S pattern having a width of 0.3 μm was resolved. However, when the substrate was left for 10 minutes after the exposure and then subjected to PEB at a temperature of 90 ° C. for 60 seconds, the surface became insoluble, and an L & S pattern having a width of 0.3 μm could not be resolved at the same irradiation dose.
[0226]
The threshold energy Eth of the irradiation dose when PEB is performed immediately after exposure is 5.5 mJ / cm.²However, when PEB was performed after being left for 30 minutes after exposure, Eth was 10 mJ / cm.²Met.
[Comparative Example 18]
Structural formula
[0227]
Embedded image
A copolymer of vinyl phenol and tert-butoxycarbonyloxystyrene having a composition ratio of 70:30 (manufactured by Maruzen Petroleum) represented by the following formula:
[0228]
Embedded image
5 wt% of triphenylsulfonium triflate represented by the formula was added to obtain an 18 wt% ethyl lactate solution. This solution was applied on a Si wafer by spin coating, and baked on a hot plate at a temperature of 110 ° C. for 90 seconds to form a 0.7 μm thick resist film.
[0229]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 90 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 1 minute.
At this time, the irradiation dose was 30 mJ / cm²In this way, an L & S pattern having a width of 0.275 μm was resolved. However, when the substrate was left for 10 minutes after the exposure and then subjected to PEB at a temperature of 90 ° C. for 60 seconds, the surface became insoluble and the L & S pattern having a width of 0.275 μm could not be resolved at the same irradiation dose.
[Example 35]
After t-butyl methacrylate monomer and itaconic anhydride monomer were charged at a ratio of 1: 1 to prepare a 2 mol / l 1,4-dioxane solution, 5 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 10 hours. After the completion of the polymerization, the precipitate was purified with n-hexane. As a result, the structural formula
[0230]
Embedded image
A copolymer having a composition ratio of 63:37, a weight average molecular weight of 6,500, and a dispersity of 2.23 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0231]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0232]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed for 60 seconds using a solution (volume ratio, NMD-3: water = 1: 5) of NMD-3, which is an alkaline aqueous solution, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. Resolution is 30mJ / cm²Indicates an L & S pattern having a width of 0.275 μm. Also, no peeling or falling of the pattern was observed.
[0233]
As a developer, instead of a solution having a volume ratio of NMD-3 and water of 1: 5, a solution having a volume ratio of NMD-3 and water of 1:10 or a volume ratio of NMD-3 and water of 1:20 is used. Similar results were obtained when using the solution of
[Comparative Example 19]
After making t-butyl methacrylate monomer a 2 mol / l 1,4-dioxane solution, 5 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 10 hours. After the polymerization, precipitation and purification were carried out with a solution of methanol and water (methanol: water = 3: 1). As a result, the structural formula
[0234]
Embedded image
And a polymer having a weight average molecular weight of 10097 and a dispersity of 1.88 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0235]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0236]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. The resolution is 56 mJ / cm²Indicates an L & S pattern having a width of 0.35 μm. However, the L & S pattern below it was peeled off and disappeared.
[0237]
When a solution having a volume ratio of NMD-3 to water of 1: 5 is used instead of NMD-3 as the developer, the threshold energy Eth of the irradiation dose is 16.1 mJ / cm.²Met. The resolution is 56 mJ / cm²Indicates an L & S pattern having a width of 0.3 μm. However, the L & S pattern below it was peeled off and disappeared.
[Example 36]
After adamantyl methacrylate monomer, t-butyl acrylate monomer, and itaconic anhydride monomer were charged in a ratio of 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. . Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0238]
Embedded image
A copolymer having a composition ratio of 58:14:28, a weight average molecular weight of 13,000 and a dispersity of 1.81 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0239]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0240]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. Resolution is 50mJ / cm²Indicates an L & S pattern having a width of 0.25 μm. Also, no peeling or falling of the pattern was observed.
[0241]
When PEB is set at 100 ° C. for 60 seconds and a solution having a volume ratio of NMD-3 to isopropyl alcohol of 5: 1 is used instead of NMD-3 as a developing solution, the threshold energy Eth of the irradiation dose becomes 25.5mJ / cm²Met. Resolution is 44mJ / cm²Indicates an L & S pattern having a width of 0.275 μm. Also, no peeling or falling of the pattern was observed.
[Comparative Example 20]
After adamantyl methacrylate monomer and t-butyl acrylate monomer were charged at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0242]
Embedded image
A polymer having a composition ratio of 58:42, a weight average molecular weight of 5100, and a dispersity of 1.43 was obtained. The glass transition temperature of this polymer was 126 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0243]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0244]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 50 mJ / cm.²Met. The resolution is 130 mJ / cm²Indicates an L & S pattern having a width of 0.45 μm. However, the remainder between the patterns was conspicuous, and the patterns were peeled and fell.
[Example 37]
Dimethyl adamantyl methacrylate, t-butyl acrylate monomer, and itaconic anhydride monomer were charged at 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, and then 10 mol% of AIBN was added as a polymerization initiator. . Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0245]
Embedded image
A copolymer having a composition ratio of 58:14:28, a weight average molecular weight of 13,000 and a dispersity of 1.81 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0246]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0247]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. Resolution is 50mJ / cm²Indicates an L & S pattern having a width of 0.25 μm. Also, no peeling or falling of the pattern was observed.
[Example 38]
After adamantyl methacrylate monomer, t-butyl α-chloroacrylate monomer, and itaconic anhydride monomer were charged in a ratio of 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was used as a polymerization initiator. Was added. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0248]
Embedded image
A copolymer having a composition ratio of 58:14:28, a weight average molecular weight of 13,000 and a dispersity of 1.81 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0249]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0250]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. Resolution is 50mJ / cm²Indicates an L & S pattern having a width of 0.25 μm. Also, no peeling or falling of the pattern was observed.
[Comparative Example 21]
After adding adamantyl methacrylate monomer and t-butyl α-chloroacrylate monomer at a ratio of 1: 1 to prepare a 5 mol / l toluene solution, 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0251]
Embedded image
A polymer having a composition ratio of 58:42, a weight average molecular weight of 5100, and a dispersity of 1.43 was obtained. The glass transition temperature of this polymer was 126 ° C. according to thermal analysis.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0252]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0253]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds.
In this case, the pattern was severely peeled off, and the minimum resolution pattern was an L & S pattern having a width of 0.5 μm.
[Example 39]
After adamantyl methacrylate monomer, dimethylbenzyl methacrylate monomer, and itaconic anhydride monomer were charged in a ratio of 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. . Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0254]
Embedded image
A copolymer having a composition ratio of 56:11:33, a weight average molecular weight of 16,000, and a dispersity of 1.91 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0255]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0256]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 8 mJ / cm.²Met. Resolution is 23mJ / cm²Indicates an L & S pattern having a width of 0.275 μm. Also, no peeling or falling of the pattern was observed.
[Example 40]
After adamantyl methacrylate monomer, 3-oxocyclohexyl methacrylate monomer, and itaconic anhydride monomer were charged in a ratio of 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was used as a polymerization initiator. Was added. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0257]
Embedded image
And a terpolymer having a composition ratio of 65:15:20, a weight average molecular weight of 13,200, and a dispersity of 1.92 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0258]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0259]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 19.2 mJ / cm.²Met. Resolution is 54mJ / cm²Indicates an L & S pattern having a width of 0.25 μm. Also, no peeling or falling of the pattern was observed.
[Comparative Example 22]
After adamantyl methacrylate monomer and 3-oxohexyl methacrylate monomer were charged at a ratio of 1: 1 to obtain a 5 mol / l toluene solution, 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0260]
Embedded image
A polymer having a composition ratio of 65:35, a weight average molecular weight of 14,400, and a degree of dispersion of 1.53 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0261]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0262]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 60.2 mJ / cm.²Met. The resolution is 208 mJ / cm.²Indicates an L & S pattern having a width of 0.4 μm. However, peeling of the pattern was severe.
[Example 41]
After adding adamantyl methacrylate monomer, tetrahydropyranyl methacrylate monomer, and itaconic anhydride monomer in a ratio of 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. did. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0263]
Embedded image
A terpolymer having a composition ratio of 57:14:29, a weight average molecular weight of 36,200, and a degree of dispersion of 2.14 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0264]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0265]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 42.2 mJ / cm.²Met. Resolution is 114 mJ / cm²Indicates an L & S pattern having a width of 0.30 μm. Also, no peeling or falling of the pattern was observed.
[Comparative Example 23]
After adamantyl methacrylate monomer and tetrahydropyranyl methacrylate monomer were charged at a ratio of 1: 1 to obtain a 5 mol / l toluene solution, 20 mol% of AIBN was added as a polymerization initiator. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0266]
Embedded image
A copolymer having a composition ratio of 58:42, a weight average molecular weight of 23,000, and a dispersity of 1.90 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0267]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0268]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. However, a pattern could not be formed.
[Example 42]
After adamantyl methacrylate monomer, t-butoxystyrene monomer, and itaconic anhydride monomer were charged at 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. . Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0269]
Embedded image
A copolymer having a composition ratio of 21:36:43, a weight average molecular weight of 8,200, and a dispersity of 1.95 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0270]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0271]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, no peeling or falling of the pattern was observed.
[Example 43]
After adamantyl methacrylate monomer, t-BOC styrene monomer, and itaconic anhydride monomer were charged at 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. . Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0272]
Embedded image
A copolymer having a composition ratio of 21:36:43, a weight average molecular weight of 8,200, and a dispersity of 1.95 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0273]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0274]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, no peeling or falling of the pattern was observed.
[Example 44]
Itaconic anhydride monomer and di-t-butyl itaconate monomer were charged at a ratio of 2: 3, and 20 mol% of dimethyl 2,2-azoisobisbutyrate was added as a polymerization initiator. Thereafter, bulk polymerization was carried out at a temperature of 80 ° C. for about 3 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0275]
Embedded image
And a copolymer having a composition ratio of 23:77, a weight average molecular weight of 6357, and a degree of dispersion of 2.34 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0276]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0277]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 12.6 mJ / cm.²Met. Resolution is 38mJ / cm²Indicates an L & S pattern having a width of 0.3 μm. Also, no peeling or falling of the pattern was observed.
[Example 45]
Itaconic anhydride monomer and di-t-butyl fumarate monomer were charged at a ratio of 2: 3, and 20 mol% of dimethyl 2,2-azoisobisbutyrate was added as a polymerization initiator. Thereafter, bulk polymerization was carried out at a temperature of 80 ° C. for about 3 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0278]
Embedded image
And a copolymer having a composition ratio of 23:77, a weight average molecular weight of 6357, and a degree of dispersion of 2.34 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0279]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and prebaked on a hot plate at a temperature of 60 ° C. for 100 seconds.
[0280]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 12.6 mJ / cm.²Met. Resolution is 38mJ / cm²Indicates an L & S pattern having a width of 0.3 μm. Also, no peeling or falling of the pattern was observed.
[Example 46]
Methacrylonitrile monomer, t-butyl methacrylate monomer, and itaconic anhydride monomer were charged at 4: 2: 4, 5 mol / l of a 1,4-dioxane solution and 1 mol% of a polymerization initiator AIBN were added, and the temperature was 80 ° C. For about 8 hours. After the completion of the polymerization, the precipitate was purified with n-hexane. As a result, the structural formula
[0281]
Embedded image
A terpolymer having a composition ratio of 41:21:38, a weight average molecular weight of 26,400, and a dispersity of 1.87 was obtained.
Next, this polymer was made into a 13 wt% cyclohexanone solution, and this solution was used as an acid generator in the structural formula
[0282]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by the following formula was added to the polymer in an amount of 15% by weight to obtain a resist solution. This solution was applied on a silicon wafer by spin coating, and then prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a thin film having a thickness of 0.7 μm.
[0283]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 60 seconds. As a result, the irradiation dose was 41 mJ / cm²The L & S pattern having a width of 0.3 μm was resolved.
[Comparative Example 24]
A methacrylonitrile monomer and a t-butyl methacrylate monomer were charged at a ratio of 1: 1, a 5 mol / l 1,4-dioxane solution and 1 mol% of a polymerization initiator AIBN were added, and the mixture was polymerized at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation and purification were performed using a mixed solution of methanol and water (methanol: water = 2: 1). As a result, the structural formula
[0284]
Embedded image
A copolymer having a composition ratio of 41:59, a weight average molecular weight of 16,400, and a dispersity of 1.77 was obtained.
Next, this polymer was made into a 13 wt% cyclohexanone solution, and this solution was used as an acid generator, and the structural formula
[0285]
Embedded image
The triphenylsulfonium hexafluoroantimony represented by the following formula was added to the polymer in an amount of 15% by weight to obtain a resist solution. This solution was applied on a silicon wafer by spin coating, and then prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds to form a thin film having a thickness of 0.7 μm.
[0286]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Subsequently, development was performed with a 2.38% TMAH aqueous solution for 60 seconds. As a result, the irradiation dose was 70 mJ / cm²As a result, an L & S pattern having a width of 0.3 μm could be resolved, but the sensitivity was lower than when no methacrylonitrile was used (Comparative Example 19).
[Example 47]
After charging α-methyl cyanoacrylate monomer, t-butyl acrylate monomer, and itaconic anhydride monomer in a ratio of 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. did. Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0287]
Embedded image
A copolymer having a composition ratio of 58:14:28, a weight average molecular weight of 13,000 and a dispersity of 1.81 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0288]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0289]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. Resolution is 50mJ / cm²Indicates an L & S pattern having a width of 0.25 μm. Also, no peeling or falling of the pattern was observed.
[Example 48]
After adamantyl methacrylate monomer, t-amyl methacrylate monomer, and itaconic anhydride monomer were charged at 4: 2: 4 to obtain a 1 mol / l 1,4-dioxane solution, 10 mol% of AIBN was added as a polymerization initiator. . Thereafter, polymerization was carried out at a temperature of 80 ° C. for about 8 hours. After completion of the polymerization, precipitation purification was performed with methanol. As a result, the structural formula
[0290]
Embedded image
A copolymer having a composition ratio of 58:14:28, a weight average molecular weight of 13,000 and a dispersity of 1.81 was obtained.
Next, the polymer synthesized in this way is used as an acid generator with a structural formula
[0291]
Embedded image
15 wt% of triphenylsulfonium hexafluoroantimony represented by the formula (1) was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0292]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 130 ° C. for 60 seconds. Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 17 mJ / cm.²Met. Resolution is 50mJ / cm²Indicates an L & S pattern having a width of 0.25 μm. Also, no peeling or falling of the pattern was observed.
[Example 49]
Structural formula
[0293]
Embedded image
A copolymer of 3-oxocyclohexyl methacrylate and adamantyl methacrylate having a composition ratio of 50:50 and having a composition ratio of 50:50 was used as a 15 wt% cyclohexanone solution. Antimony was added at 2 wt% to the polymer to form a resist solution.
[0294]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
A solution prepared by dissolving a polyolefin resin in t-butylcyclohexane at a concentration of 5 wt% was spin-coated on the wafer, and baked on a hot plate at 100 ° C. for 100 seconds to form a 0.2 μm-thick protective film.
[0295]
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
Subsequently, development was performed by immersion in a 2.38% TMAH aqueous solution for 60 seconds.
As a result, the irradiation dose was 210 mJ / cm²Resolved an L & S pattern having a width of 0.45 μm.
[Comparative Example 25]
Structural formula
[0296]
Embedded image
A copolymer of 3-oxocyclohexyl methacrylate and adamantyl methacrylate having a composition ratio of 50:50 and having a composition ratio of 50:50 was used as a 15 wt% cyclohexanone solution. Antimony was added at 2 wt% to the polymer to form a resist solution.
[0297]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
When a solution obtained by dissolving a polyolefin resin in heptane at a concentration of 5 wt% was spin-coated on the wafer, the solution did not spread uniformly on the wafer surface, and the protective film could not be applied.
[Comparative Example 26]
Structural formula
[0298]
Embedded image
A adamantyl methacrylate represented by the following formula was used as a 15 wt% cyclohexanone solution.
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
[0299]
When a solution in which a polyolefin resin was dissolved at a concentration of 5 wt% in t-butylcyclohexane was spin-coated on this wafer, the thin film of adamantyl methacrylate was dissolved.
[Comparative Example 27]
Structural formula
[0300]
Embedded image
A copolymer of 3-oxocyclohexyl methacrylate and adamantyl methacrylate having a composition ratio of 50:50 and having a composition ratio of 50:50 was used as a 15 wt% cyclohexanone solution. Antimony was added at 2 wt% to the polymer to form a resist solution.
[0301]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
After exposing the wafer with a KrF excimer stepper without applying a protective film on the wafer, PEB was performed at a temperature of 150 ° C. for 60 seconds.
[0302]
Subsequently, development was performed with a 2.38% aqueous solution of TMAH (tetramethylammonium hydroxide).
As a result, an insolubilized layer was formed on the resist surface, and the irradiation dose was 300 mJ / cm.²However, the pattern could not be resolved.
[Example 50]
Structural formula
[0303]
Embedded image
A copolymer of 3-oxocyclohexyl methacrylate and adamantyl acrylate having a composition ratio of 45:55, represented by the following formula, was used as a 15 wt% cyclohexanone solution, and triphenylsulfonium hexafluoro was used as an acid generator in this solution. Antimony was added to the polymer at 2 wt% to form a resist solution.
[0304]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
On this wafer, the structural formula
[0305]
Embedded image
A solution obtained by dissolving a polyolefin resin at a concentration of 5 wt% in 1,5-cyclooctagen represented by (1) was spin-coated and baked on a hot plate at 100 ° C. for 100 seconds to form a 0.2 μm thick protective film. .
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 150 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
[0306]
Subsequently, development was performed by immersing in a solution obtained by mixing a 2.38% TMAH aqueous solution and isopropyl alcohol at a weight ratio of 8: 1 for 60 seconds.
As a result, the irradiation dose was 70 mJ / cm²Resolved an L & S pattern having a width of 0.275 μm.
[Comparative Example 28]
Structural formula
[0307]
Embedded image
A copolymer of 3-oxocyclohexyl methacrylate and adamantyl acrylate having a composition ratio of 45:55, represented by the following formula, was used as a 15 wt% cyclohexanone solution, and triphenylsulfonium hexafluoro was used as an acid generator in this solution. Antimony was added to the polymer at 2 wt% to form a resist solution.
[0308]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
After exposing the wafer with a KrF excimer stepper without applying a protective film, PEB was performed at a temperature of 150 ° C. for 60 seconds.
[0309]
Subsequently, development was performed by immersing in a solution obtained by mixing a 2.38% TMAH aqueous solution and isopropyl alcohol at a weight ratio of 8: 1 for 60 seconds.
As a result, the irradiation dose was 100 mJ / cm²Even if it was raised, only the L & S pattern having a width of 0.35 μm could be resolved.
[Example 51]
Structural formula
[0310]
Embedded image
The copolymer of 3-oxocyclohexyl methacrylate and dimethyl adamantyl methacrylate having a composition ratio of 45:55 and having a composition ratio of 45:55 was used as a 15 wt% cyclohexanone solution. In this solution, triphenylsulfonium hexane was used as an acid generator. 5% by weight of fluoroantimony was added to the polymer to prepare a resist solution.
[0311]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
On this wafer, the structural formula
[0312]
Embedded image
A solution obtained by dissolving a polydiene resin at a concentration of 5 wt% in limonene indicated by was spin-coated, and baked on a hot plate at 100 ° C. for 100 seconds to form a protective film having a thickness of 0.2 μm.
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 150 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
[0313]
Subsequently, development was performed by immersing in a solution obtained by mixing a 2.38% TMAH aqueous solution and isopropyl alcohol at a weight ratio of 3: 1 for 60 seconds.
As a result, the irradiation dose was 18 mJ / cm²Resolved an L & S pattern having a width of 0.25 μm.
[Comparative Example 29]
Structural formula
[0314]
Embedded image
The copolymer of 3-oxocyclohexyl methacrylate and dimethyl adamantyl methacrylate having a composition ratio of 45:55 and having a composition ratio of 45:55 was used as a 15 wt% cyclohexanone solution. In this solution, triphenylsulfonium hexane was used as an acid generator. 5% by weight of fluoroantimony was added to the polymer to prepare a resist solution.
[0315]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
After exposing the wafer with a KrF excimer stepper without applying a protective film, PEB was performed at a temperature of 150 ° C. for 60 seconds.
[0316]
Subsequently, development was performed by immersing in a solution obtained by mixing a 2.38% aqueous solution of TMAH and isopropyl alcohol at a weight ratio of 3: 1 for 60 seconds.
As a result, the irradiation dose was 18 mJ / cm²Could resolve the L & S pattern having a width of 0.25 μm, but a line pattern much thinner than the desired pattern was formed.
[Example 52]
Structural formula
[0317]
Embedded image
The ternary copolymer of t-butyl methacrylate, adamantyl acrylate, and methacrylic acid having a composition ratio of 40:40:20 represented by the formula: is a 15 wt% cyclohexanone solution, and the acid generator Then, 2% by weight of triphenylsulfonium hexafluoroantimony was added to the polymer to form a resist solution.
[0318]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
A solution obtained by dissolving a polyolefin resin at a concentration of 5 wt% in p-cymene was spin-coated on this wafer, and baked on a hot plate at 100 ° C. for 100 seconds to form a 0.2 μm thick protective film.
[0319]
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 150 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
Subsequently, development was performed by immersion in a 2.38% TMAH aqueous solution for 60 seconds.
As a result, the irradiation dose was 35 mJ / cm²Resolved an L & S pattern having a width of 0.3 μm.
[Comparative Example 30]
Structural formula
[0320]
Embedded image
A copolymer of t-butyl methacrylate and adamantyl acrylate having a composition ratio of 50:50 represented by the following formula is used as a 15 wt% cyclohexanone solution. Was added to the polymer at 2 wt% to form a resist solution.
[0321]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
When a solution in which a polyolefin resin was dissolved in p-cymene at a concentration of 5 wt% was spin-coated on this wafer, the resist thin film was dissolved.
[Comparative Example 31]
Structural formula
[0322]
Embedded image
The ternary copolymer of t-butyl methacrylate, adamantyl acrylate, and methacrylic acid having a composition ratio of 40:40:20 represented by the formula: is a 15 wt% cyclohexanone solution, and the acid generator Then, 2% by weight of triphenylsulfonium hexafluoroantimony was added to the polymer to form a resist solution.
[0323]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
When a solution in which a polyolefin resin was dissolved in xylene at a concentration of 5 wt% was spin-coated on this wafer, the resist thin film was dissolved.
[Example 53]
Structural formula
[0324]
Embedded image
The terpolymer of t-butyl methacrylate, norbornyl methacrylate, and hydroxyethyl methacrylate having a composition ratio of 30:40:30, represented by the following formula, was used as a 15 wt% cyclohexanone solution. 5% by weight of triphenylsulfonium hexafluoroantimony was added to the polymer as a generator to form a resist solution.
[0325]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
On this wafer, the structural formula
[0326]
Embedded image
Was spin-coated with a solution of a polydiene resin at a concentration of 5 wt% in 1-decene, and baked on a hot plate at 100 ° C. for 100 seconds to form a 0.2 μm thick protective film.
After the resist film on the wafer thus obtained was exposed with a KrF excimer stepper, PEB was performed at a temperature of 150 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
[0327]
Subsequently, development was performed by immersion in a 2.38% TMAH aqueous solution for 60 seconds.
As a result, the irradiation dose was 40 mJ / cm²Resolved an L & S pattern having a width of 0.3 μm.
[Comparative Example 32]
Structural formula
[0328]
Embedded image
A copolymer of t-butyl methacrylate and norbornyl methacrylate having a composition ratio of 45:55 and having a composition ratio of 45:55 was used as a 15 wt% cyclohexanone solution. Was added to the polymer at 2 wt% to form a resist solution.
[0329]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
On this wafer, the structural formula
[0330]
Embedded image
When a solution obtained by dissolving a polydiene resin at a concentration of 5 wt% in 1-decene represented by (1) was spin-coated, the resist thin film was dissolved.
[Comparative Example 33]
Structural formula
[0331]
Embedded image
The terpolymer of t-butyl methacrylate, norbornyl methacrylate, and hydroxyethyl methacrylate having a composition ratio of 30:40:30, represented by the following formula, was used as a 15 wt% cyclohexanone solution. 5% by weight of triphenylsulfonium hexafluoroantimony was added to the polymer as a generator to form a resist solution.
[0332]
Next, the solution was applied on a HMDS-treated Si wafer by spin coating, and prebaked at 100 ° C. for 100 seconds on a hot plate to form a 0.7 μm thick resist thin film.
After exposing the wafer with a KrF excimer stepper without applying a protective film, PEB was performed at a temperature of 150 ° C. for 60 seconds.
[0333]
Subsequently, development was performed by immersion in a 2.38% TMAH aqueous solution for 60 seconds.
As a result, an insolubilized layer was formed on the resist surface, and the pattern could not be resolved.
[Example 54]
Structural formula
[0334]
Embedded image
In a terpolymer of adamantyl methacrylate having a composition ratio of 58:14:28, t-butyl acrylate, and itaconic anhydride, triphenylsulfonium hexafluoroantimony as an acid generator was 15 wt%. This was added to form a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0335]
Structural formula on this wafer
[0336]
Embedded image
A solution obtained by dissolving a polyolefin resin at a concentration of 5 wt% in t-butylcyclohexane represented by the following formula was spin-coated and baked on a hot plate at 100 ° C. for 100 seconds to form a protective film having a thickness of 0.2 μm.
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
[0337]
Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 13 mJ / cm.²Met. In addition, 41mJ / cm²In this manner, a resolution capable of forming an L & S pattern having a width of 0.25 μm was obtained.
[Comparative Example 34]
Structural formula
[0338]
Embedded image
To a copolymer of adamantyl methacrylate having a composition ratio of 58:42 and t-butyl acrylate, 15% by weight of triphenylsulfonium hexafluoroantimony as an acid generator was added to obtain a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0339]
Structural formula on this wafer
[0340]
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Was spin-coated with a solution of a polyolefin resin dissolved in t-butylcyclohexane at a concentration of 5 wt%, and the resist thin film became cloudy.
[Comparative Example 35]
Structural formula
[0341]
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In a terpolymer of adamantyl methacrylate having a composition ratio of 58:14:28, t-butyl acrylate, and itaconic anhydride, triphenylsulfonium hexafluoroantimony as an acid generator was 15 wt%. This was added to form a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0342]
When a solution in which a polyolefin resin was dissolved in xylene at a concentration of 5 wt% was spin-coated on this wafer, the resist thin film was dissolved.
Note that the resist thin film was similarly dissolved when toluene or ethylbenzene was used instead of xylene as a coating solvent.
[Example 55]
Structural formula
[0343]
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In a terpolymer of adamantyl methacrylate having a composition ratio of 58:14:28, t-butyl acrylate, and itaconic anhydride, triphenylsulfonium hexafluoroantimony as an acid generator was 15 wt%. This was added to form a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0344]
Structural formula on this wafer
[0345]
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Was spin-coated with a solution in which a polyolefin resin was dissolved at a concentration of 5 wt% in limonene, and baked on a hot plate at 100 ° C. for 100 seconds to form a protective film having a thickness of 0.2 μm.
After exposing the resist film on the wafer thus obtained with a KrF excimer stepper, PEB was performed at a temperature of 100 ° C. for 60 seconds. Thereafter, cyclohexane was spin-coated on the wafer, and the protective film was peeled off.
[0346]
Subsequently, development was performed using NMD-3, which is an aqueous alkaline solution, for 60 seconds, and rinsed with pure water for 30 seconds. At this time, the threshold energy Eth of the irradiation dose is 13 mJ / cm.²Met. In addition, 41mJ / cm²In this manner, a resolution capable of forming an L & S pattern having a width of 0.25 μm was obtained.
In addition, instead of limonene as a coating solvent, the structural formula
[0347]
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1,5-cyclooctadiene or a structural formula
[0348]
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The same resolving power was obtained by using 1-decene represented by the formula (1) as a protective film.
[Comparative Example 36]
Structural formula
[0349]
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In a terpolymer of adamantyl methacrylate having a composition ratio of 58:14:28, t-butyl acrylate, and itaconic anhydride, triphenylsulfonium hexafluoroantimony as an acid generator was 15 wt%. This was added to form a cyclohexanone solution. This solution was applied on a silicon wafer to a thickness of 0.7 μm by spin coating, and was prebaked on a hot plate at a temperature of 100 ° C. for 100 seconds.
[0350]
When a solution obtained by dissolving a polyolefin resin in methylcyclohexane at a concentration of 5 wt% was spin-coated on the wafer, the solution was not uniformly spread on the wafer surface, and a protective film could not be applied.
[0351]
【The invention's effect】
As described above, according to the present invention, the radiation-sensitive material has the general formula
[0352]
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And a substance that generates an acid upon irradiation, the α-position of R 1 or R 2 is a small and weakly hydrophobic proton. As the hydrophobicity decreases and its hardness decreases, familiarity with the developer increases, and it easily penetrates, and diffusion of the protonic acid as a catalyst becomes easy, and a large amount of alkali-soluble carboxylic acid is generated. I do. Accordingly, development is facilitated, sensitivity is improved, and stable patterning characteristics can be obtained.
[0356]
The radiation-sensitive material is a general formula
[0357]
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Hydroxyethyl methacrylate represented by, Unit structure containing alicyclic groupAnd a polymer having a unit structure that generates an alkali-soluble group by an acid, and a substance that generates an acid by irradiation, so that hydroxyethyl methacrylate is introduced into the polymer as a hydrophilic group. This increases the solubility, facilitates compatibility with the developer, facilitates penetration, and increases solubility.
[0358]
The radiation-sensitive material is a general formula
[0359]
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Since the copolymer contains a tertiary copolymer and a substance that generates an acid upon irradiation, the copolymer contains a strongly hydrophobic adamantyl group, so that hydroxyethyl methacrylate is introduced as a hydrophilic group into the polymer. The effect of this is great, and high sensitivity and stable patterning characteristics can be realized.
[0369]
In addition, the radiation sensitive material has a general formula
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A polymer comprising a unit structure represented by the formula and a unit structure capable of forming an alkali-soluble group by an acid and a substance generating an acid upon irradiationThe polymer has an alicyclic groupThereby, since a highly polar nitrile group is introduced, the adhesion is improved, and stable patterning characteristics can be obtained.
[0376]
Also, the general formula
[0377]
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Itaconic anhydride represented by, Unit structure containing alicyclic groupA resist having excellent adhesion is formed by using a radiation-sensitive material comprising a copolymer having, as a unit structure, a polymer containing a unit structure that generates an alkali-soluble group by an acid, and a substance that generates an acid upon irradiation. be able to. That is, due to the strong polarity of itaconic anhydride, the adhesion to the substrate is significantly improved.
[0378]
The introduction of such an alkali-soluble group has a remarkable effect of improving the pattern removability, particularly in an alicyclic-based resist, and can improve the patterning characteristics.
The specific structure of the copolymer containing itaconic anhydride has a general formula
[0379]
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Etc.
In addition, a resist is formed using the above radiation-sensitive material, and a fine pattern can be formed stably by applying the resist on a substrate to be processed, pre-baking, exposing, post-baking, and developing. it can.
[0383]
Further, by using a mixed solution of an organic alkali aqueous solution and isopropyl alcohol as a developer, the solubility is remarkably increased, and the difference in solubility between the surface layer portion and the inside is reduced, so that stable patterning can be performed.
Thus, in lithography using an excimer laser as an exposure source, not only excellent transparency and etching resistance, but also a high-sensitivity, low-peeling radiation-sensitive material and a pattern forming method using the radiation-sensitive material are provided. And can greatly contribute to the stable formation of high-precision patterns.
[0384]
In addition, a material having an alicyclic acrylate structure or a methacrylate structure, and an acrylate structure having a highly polar unit in the ester portion or a methacrylate structure having a highly polar unit in the ester portion Since the polymer containing the material increases the polarity of the base polymer, the very strong hydrophobicity due to the alicyclic group can be reduced. As a result, a difference in polarity occurs between the protective film and the hydrocarbon-based protective film, so that the protective film can be applied without dissolving the resist film. Accordingly, a pattern having a desired size can be formed.
[0385]
In addition, in the resist containing itaconic anhydride, a hydrocarbon-based polymer which has not been able to be used as a protective film is conventionally formed on the resist because of the strong polarity of itaconic anhydride. It is possible to apply.
By forming such a protective film on the resist, PED (Post Exposure Delay) which is a problem peculiar to the chemically amplified resist can be prevented.
[0386]
Further, by using a hydrocarbon-based solvent having a large molecular weight as a coating solvent for the protective film, the protective film can be more reliably applied.

Claims (20)

General formula
A radiation-sensitive material comprising a copolymer represented by the formula (I) and a substance which generates an acid upon irradiation with radiation. The radiation-sensitive material according to claim 1,
A radiation-sensitive material, wherein the unit structure having an alicyclic group in the copolymer is 40 to 70 mol%. General formula
1. A radiation-sensitive material comprising: a polymer having a hydroxyethyl methacrylate represented by the following formula, a unit structure containing an alicyclic group and a unit structure generating an alkali-soluble group by an acid, and a substance generating an acid by irradiation. General formula
A radiation-sensitive material comprising: a terpolymer represented by the formula: and a substance which generates an acid upon irradiation. The radiation-sensitive material according to claim 3 or 4,
A radiation-sensitive material, wherein the content of the hydroxyethyl methacrylate in the copolymer is 5 mol% or more. General formula
Consists of a polymer having a unit structure represented by and a unit structure that produces an alkali-soluble group by an acid and a substance that produces an acid by irradiation,
A radiation-sensitive material, wherein the polymer has an alicyclic group. The radiation-sensitive material according to claim 6,
A radiation-sensitive material, wherein the copolymer has a t-butyl group. The radiation-sensitive material according to claim 6,
The general formula
A radiation-sensitive material, wherein the structure represented by is acrylonitrile or methacrylonitrile. The radiation-sensitive material according to claim 8,
A radiation-sensitive material, wherein the acrylonitrile or the methacrylonitrile in the copolymer is 10 to 70 mol%. General formula
Itaconic anhydride represented by, a copolymer containing in the unit structure a polymer containing a unit structure containing an alicyclic group and a unit structure that produces an alkali-soluble group by an acid,
A radiation-sensitive material comprising: a substance which generates an acid upon irradiation. The radiation-sensitive material according to claim 10,
The copolymer has a general formula
A radiation-sensitive material, characterized by being represented by: The radiation-sensitive material according to claim 10 or 11,
The radiation-sensitive material according to claim 1, wherein the copolymer contains a unit structure composed of the itaconic anhydride at a ratio of 5 to 50 mol%. A resist is formed using the radiation-sensitive material according to any one of claims 1 to 12,
Applying the resist on a substrate to be processed,
After performing the pre-bake of the substrate to be processed, the resist on the substrate to be processed is selectively exposed to radiation,
A pattern forming method, wherein after performing post-baking of the substrate to be processed, developing the resist on the substrate to be processed to form a predetermined resist pattern. A resist is formed using a radiation-sensitive material containing an alicyclic structure, the resist is applied on a substrate to be processed, a pre-bake of the substrate to be processed is performed, and radiation is selectively applied to the resist on the substrate to be processed. Exposure, performing post-baking of the substrate to be processed, developing the resist on the substrate to be processed, in a pattern forming method of forming a predetermined resist pattern,
A pattern forming method, wherein a mixed solution of an organic alkali aqueous solution and isopropyl alcohol is used as a developer. The pattern forming method according to claim 14,
A pattern forming method, wherein the developer contains 5 vol% to 95 vol% of the isopropyl alcohol. Acrylic ester unit having an alicyclic group in the ester part or methacrylic ester unit having an alicyclic group in the ester part, and acrylate unit having a polar structure in the ester part or methacrylic acid having a polar structure in the ester part After forming a resist using a polymer containing an ester unit and applying the resist on a substrate to be processed, a pre-baking of the substrate to be processed is performed, and a hydrocarbon-based hydrocarbon transparent to far ultraviolet light is formed on the resist. After applying a protective film made of a polymer, performing a heat treatment, selectively exposing the resist on the processed substrate to radiation, performing post-baking of the processed substrate, and removing the protective film. In a pattern forming method for forming a predetermined resist pattern by developing the resist on the substrate to be processed,
The coating solvent for the hydrocarbon polymer in the protective film is a non-aromatic hydrocarbon or a general formula.
A pattern forming method, characterized by being an aromatic hydrocarbon represented by the formula: A resist is formed using the radiation-sensitive material according to any one of claims 10 to 12,
After applying the resist on the substrate to be processed, pre-baking the substrate to be processed,
After applying a protective film made of a hydrocarbon-based polymer that is transparent to far ultraviolet light on the resist, a heat treatment is performed,
After selectively exposing the resist on the processed substrate to radiation, post-baking the processed substrate is performed.
A pattern forming method, comprising: after removing the protective film, developing the resist on the substrate to be processed to form a predetermined resist pattern. The pattern forming method according to claim 16 or 17,
The pattern forming method, wherein the coating solvent of the hydrocarbon polymer in the protective film is limonene, 1,5-cyclooctadiene, 1-decene, t-butylcyclohexane, p-cymene, or dodecylbenzene. . In the pattern forming method according to any one of claims 16 to 18,
The pattern forming method according to claim 1, wherein the hydrocarbon polymer is an olefin polymer or a diene polymer. The pattern forming method according to claim 16,
The substance having a polar structure has a structure in which a ketone, an alcohol, an ether, an ester, a carboxylic acid, an acid anhydride structure, or a structure in which some atoms of these structures are substituted with sulfur, nitrogen, or halogen. A pattern forming method characterized by the above-mentioned.