JP3515326B2 - Resist composition - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to a fine pattern forming resist composition.

[0002]

2. Description of the Related Art Pattern formation of a semiconductor integrated device typified by a VLSI is a thin film of a resist composition (hereinafter often abbreviated as resist) sensitive to high energy rays such as light, X-rays and electron rays on a semiconductor substrate. Is formed, and is irradiated with the high energy ray, and then developed. FIG. 3 is a diagram illustrating a pattern forming process using a conventional resist composition. In FIG. 3, reference numeral 1 is a substrate, 2 is a resist film, 3 is a high energy ray (light,
(X-ray, electron beam, etc.), 4 means an etching reaction species. Therefore, for the resist, in addition to being sensitive to high energy rays with high sensitivity from the viewpoint of rapid pattern formation processing, it is also sensitive to high energy rays and has high pattern resolution. It is required to have high etching resistance when processing. Generally, the thinner the resist film, the smaller the spread of high-energy rays in the resist film, and thus the higher the pattern resolution, and the smaller the processing dimension difference from the resist pattern, the more accurate the pattern processing is during substrate processing. In order to improve, the pattern formation is performed by making the resist film thickness as thin as possible. In particular, in the research and development of cutting-edge devices such as next-generation VLSI and quantum effect devices, the pattern dimension will be in the nanometer range from 150 nm to 10 nm, and it is increasingly required to make the resist film thinner from the viewpoint of miniaturization and high accuracy. ing.

The resist materials used for such ultra-fine processing are roughly classified into the following five types. (1) a resist having an alkali-soluble resin and a diazizonaphthoquinone compound photosensitizer (2) an acrylic main chain cleavage type resist (3) a resist having an alkali-soluble resin and an azide compound photosensitizer (4) a chloromethyl group or Crosslinking type resist having epoxy group (5) Chemical amplification type resist having alkali-soluble resin, acid generator and solubility control agent having acid labile group

(1) is a resist material for ultraviolet exposure which is generally used for LSI processing, and the diazonaphthoquinone compound as a photosensitive material is chemically changed by ultraviolet rays to improve the solubility of the alkali-soluble resin, A pattern is formed. Alkali-soluble resins include novolac resins, phenolic resins, polyhydroxystyrene (Poly
hydroxy styrene), but novolac resin is usually used. It is used for forming patterns up to about 200 nm with a relatively thick film thickness.

(2) is a resist which is mainly used for ultrafine processing of 200 nm or less, and the acrylic linear polymer is cleaved by irradiation of electron beam / X-ray / ultraviolet ray of wavelength of 300 nm or less, A pattern is formed due to the improved solubility. Typical materials for this type of resist are polymethylmethacrylate (PMMA) or a copolymer of α-chloromethacrylate and α-methylstyrene Z
EP (manufactured by Zeon Corporation), poly-2,2,2-trifluoroethyl α-chloroacrylate (EBR-9, manufactured by Toray),
The English name is poly 2,2,2-trifluoroethyl α-chloro acryla
te). Since the resist of this type has a large difference in solubility between the irradiated portion and the non-irradiated portion, a very high resolution can be obtained. Therefore, it is often used as a thin film for the purpose of forming an ultrafine pattern of 100 nm or less.

As an example of forming a nanometer pattern in the region of 50 to 10 nm by forming a thin resist film, for example, Applied Physics Letters (Appl. Phys. Le) is used.
tt. ), Vol. 62, No. 13, 1499-1501
As described on page (1993), polymethylmethacrylate (PMM), which is a typical high resolution resist, is used.
A) is used to dry-etch a mixed gas of silicon tetrachloride (SiCl ₄ ) and carbon tetrafluoride (CF ₄ ) into a Si substrate>
It is reported that the film thickness of PMMA is set to 65 nm when etching is performed. Also the Journal of
Vacuum Science and Technology (JV
ac. Sci. Technol. ), Vol. B13, No. 6
No. 2170-2174 (1995).
As an example using a ZEP resist (manufactured by Zeon Corporation), which has almost the same resolution as A and is said to have relatively high etching resistance, the ZEP film thickness is 50 nm when the substrate is subjected to oxygen plasma treatment. It has been reported that

On the other hand, in the formation of a nanometer pattern in a relatively large region of 50 to 150 nm, the use of the high energy beam such as the electron beam described above does not make the resist thin so much even under the present circumstances by using the PMMA or ZEP resist described above. Both have achieved resolution. Therefore, in this area, rather focusing on the realization of good substrate processing without the occurrence of defects due to etching,
In order to secure the dry etching resistance, the resist film thickness is made as thick as possible within the range where the resolution is not deteriorated. In the above-mentioned relatively large nanometer pattern region, the resist film thickness is usually about 0.1 to 0.5 μm.

(3) is a resist for exposure to ultraviolet rays or electron beams, which is also partially used for LSI processing, in which an azide compound as a photosensitive material is chemically changed by irradiation and is combined with an alkali-soluble resin to form a novolak. The resin becomes insoluble and a pattern is formed. The resist of (4) is
It has a polymer having a highly reactive chloromethyl group or an epoxy group, and a pattern is formed by cross-linking the polymers by irradiation of ultraviolet rays, electron beams or X-rays to make them insoluble. It is mainly used for forming a negative pattern where the irradiated part remains by electron beam exposure.

(5) is an alkali-soluble resin, an acid generator,
Also, in a resist having a solubility control agent having an acid labile group, an acid is generated from the acid generator by irradiation with ultraviolet rays, electron beams or X-rays, and this reacts with the acid labile group in a chain reaction, The pattern is formed by changing the solubility of the alkali-soluble resin. Since the generated acid causes a chain reaction, a very high sensitivity is achieved, and thus it has been used recently. As the alkaline soluble resin, novolac resin, phenol resin, poly (hydroxy styrene), etc. are used.
In the chemically amplified type, the alkali-soluble resin may also serve as a solubility control agent having an acid labile group, or the resin having an acid labile group may react with an acid to become alkali-soluble. However, in this resist, acid is inactivated by water, ammonia, etc. contained in the outside air, and the resist sensitivity changes significantly with time. Conventionally, an organic thin film called an overcoat is applied on the resist film to prevent the intrusion of inactive substances. To stabilize the sensitivity.

[0010]

The problems common to the resists of the above types (1) to (5) are as follows. First, in the conventional fine pattern forming method as described above, even if a resist having relatively high resistance is used,
Practically, the use limit of the resist film thickness is about 50 nm, and if the resist film is thinned based on the above-mentioned reason in order to guarantee highly accurate substrate processing, as shown in FIG. However, there was a problem that the etching resistance of the resist film was insufficient and a defect due to etching occurred on the processed substrate.

In particular, in the main chain cutting type resist of (2), the main chain is also cut by the etching reaction species, so that the etching resistance is weak and the resist is used as a direct etching mask in the process involving dry etching processing. Has become difficult. FIG. 7 shows an electron micrograph taken by forming a 0.05 μm line-and-space pattern with a thin resist film. As is clear from the photograph, the resist in the low-irradiation area near the irradiation area during development is shown. There is a problem that the film is dissolved and a high contrast fine pattern having a vertical sectional shape cannot be formed.

In forming a nanometer pattern (50 to 150 nm) in a relatively large area in the conventional process, when the resist film thickness is set to about 0.2 to 0.5 μm in order to secure sufficient etching resistance, Aspect ratio of pattern (ratio of pattern height to pattern width)
Is 4 or 5 or more. The inventor of the present invention paid attention to the problem that such a pattern having a high aspect ratio collapses under the influence of the surface tension of the rinse liquid during drying by the rinse liquid in the developing process. The collapse of the pattern due to the higher aspect ratio is caused by the mechanical strength of the resist film. When the resist film thickness is set to about 50 nm, which is the practical practical use limit at present, 10 n
In the ultra-fine pattern near m, the aspect ratio was larger than 4, and the pattern had collapsed. Therefore, in forming the nanometer pattern, the insufficient mechanical strength of the resist film has been a serious problem in forming the pattern. Further, the present inventor has taken a measure (5) as a problem peculiar to a chemically amplified resist that uses an acid generated by irradiation of high energy rays as a catalyst, as described above, for stabilizing the sensitivity. We paid attention to the problem that not only the process becomes necessary and the process becomes complicated, but also the sensitivity stabilization is insufficient even if the measures are taken. In particular, when the resist film is made thin, a substance that inactivates the acid catalyst is likely to enter, and unless the resist is immediately developed after irradiation with high energy rays, the sensitivity of the resist is lowered, and highly accurate pattern formation becomes extremely difficult.

An object of the present invention is to provide a resist composition which realizes highly accurate processing which solves the above problems in forming a fine pattern on a semiconductor substrate or the like.

[0014]

In order to solve the above-mentioned problems, in the invention according to claim 1, a resist sensitive to any one of an electron beam, an X-ray and an ultraviolet ray, and a resist mixed in the resist. A resist composition having one or both of fullerene and a fullerene derivative, wherein the weight of one or both of the fullerene and the fullerene derivative is less than the weight of the resin component of the resist. A resist composition is provided. According to the invention of claim 2, in the invention of claim 1, one or both of the fullerene and the fullerene derivative are mixed in an amount of 1 to 50 parts by weight with respect to 100 parts by weight of the resist. Is characterized in that.

The type of the resist may be any one of claims 3 to
As described in 7, (1) a resist containing an alkali-soluble resin and a diazozonaphthoquinone compound photosensitizer (2) an acrylic main chain scission resist (3) a resist containing an alkali-soluble resin and an azide compound photosensitizer (4) Cross-linking type resist having chloromethyl group or epoxy group (5) Alkali-soluble resin, acid generator, and chemically amplified resist having solubility control agent having acid labile group can be used . Further, as described in claim 8, a novolac resin may be used as the alkali-soluble resin.

[0016]

According to the resist composition of the present invention, the density of the resist film is increased by filling the voids in the resist with fine particles, and the fine particles are the main constituent elements of the aggregate of carbon atoms having high etching resistance. Due to the two effects of being fine particles, the penetration of etching reactive species into the film is inhibited and the etching resistance of the resist film is amplified.

Regarding the high etching resistance effect of the aggregate of carbon atoms, see, for example, Applied Physics Letters (Appl. Phys. Lett.), No. 4
8 (13), pp. 835-837 (1986), as compared with a resist based on novolac resin, which is said to have higher etching resistance than PMMA against oxygen plasma dry etching. Even so, it has been shown that the film consisting only of aggregates of carbon atoms is about twice as durable as it is.

In addition to the amplification of etching resistance,
Penetration of the developing solution into the film is also inhibited, and the contrast of the resist pattern is also amplified. This is because, for example, as described in Kagaku Daiji (Kyoritsu Shuppansha, 1981), Vol. 5, p. 749, aggregates composed of pure carbon atoms are generally insoluble in organic and inorganic solvents. Therefore, it is insoluble in a resist developing solution using ordinary organic and inorganic chemicals. When such fine particles of carbon are filled, the solubility of the resist composition decreases, but in the resists of types (1), (2), and (5) above, volatile components are generated in the irradiated portion by a chemical reaction. Is generated, the existing liquid is likely to penetrate into the resist film, and the difference in solubility between the irradiated portion and the non-irradiated portion becomes large, so that high resolution can be obtained. Further, in the chemically amplified resist, penetration of substances such as water and ammonia which inactivate the acid catalyst into the film is also inhibited, and the resist sensitivity is stabilized. In addition,
Since fine particles having an aggregate of carbon atoms as a main constituent element generally have a high melting point (for example, fullerene C ₆₀ described later is 700 ° C. or higher) as compared with an organic substance such as a resist, thermal movement of resist molecules And the heat resistance of the resist composition is also improved.

As the fine particles having an aggregate of carbon atoms as a main constituent, fullerene can be used as described above. Fullerenes in which carbon atoms have a spherical shell-like molecular structure include various forms called C ₆₀ and other fullerenes. The fullerenes include high-order fullerenes having 60 or more carbon atoms, nanotubes elongated in a cylindrical shape with one kind of high-order fullerenes, metal-encapsulated fullerenes in which a metal is incorporated in a spherical shell-like molecular structure, and the like. Among these fullerenes, those having a molecular volume as small as possible are preferable from the viewpoint of improving resistance and improving resolution by increasing the density.

Further, a fullerene derivative in which an atom such as hydrogen or a group such as a methyl group is bonded to a carbon atom of fullerene,
It is effective in filling the voids of the resist composition and enhancing the etching resistance. In addition, any fullerene derivative can be used in principle, but from the viewpoint of improving the resistance and resolution by increasing the density, the molecular volume is as small as possible and it can be dissolved in the solvent for coating conventional resists. Those having a functional group such that are most suitable. In the present invention, a mixture of the above-mentioned fullerenes or a mixture of a fullerene and a fullerene derivative may be used.

As an example of using fullerene as a resist material, JP-A-6-167812 has been filed. This consists of fullerenes and photosensitizers,
A resist system comprising a combination of a resin such as a conventional novolac resin and a photosensitizer, and is characterized by using fullerene or a derivative thereof instead of the novolac resin. In the present invention, since the resin component of the resist is fullerene or its derivative, problems such as an increase in the price of the resist and a change in the conventional resist process remain. This is because the solvent used for development is a solvent that sufficiently dissolves fullerenes and fullerene derivatives, and is limited to those commonly used in conventional processes. Further, in the present invention,
As its effect, it is mentioned that the resistance to dry etching is made higher and the resistance to dry etching is made higher by improving the sensitivity.

On the other hand, in the present invention, carbon-based fine particles are simply added to the conventional resist material having a resin and a photosensitizer.
Various properties of conventional resists such as etching resistance, resolution, heat resistance, mechanical strength, and stability of sensitivity after exposure can be significantly improved. In addition, the amount added is smaller than that of the resin component, and since the resist can be developed using a conventional developer, it is not necessary to change the conventional resist process, and a currently expensive substance such as fullerene is used. Even if it is used, the cost of the resist is not greatly raised, and the practicability and the economical efficiency are high.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a pattern forming process using the resist composition of the present invention. In FIG. 1, reference numerals 1 to 4 are synonymous with the reference numerals in FIG. 3, and reference numeral 5 means fine particles whose main constituent is an aggregate of carbon atoms. As is clear from FIG. 1, in the resist composition according to the present invention, the voids in the resist film as shown in FIG. 3 contain fine particles having an aggregate of carbon atoms as a main constituent element.

Next, a method for manufacturing the resist composition will be described with reference to FIG. That is, FIG. 2 is a diagram for explaining a method for producing a resist composition containing fine particles having an aggregate of carbon atoms as a main constituent in one embodiment of the present invention. In FIG. 2, reference numerals 1, 2, and 5 have the same meanings as those in FIG. 2A to 2C correspond to the following three steps (a) to (c). (A) First, a resist is applied on the substrate and heat-treated. (B) Next, fine particles having an aggregate of carbon atoms as a main constituent element are attached to the resist. (C) Repeat (a) and (b). In this way, a resist film to which the resist composition of the present invention having a desired thickness is attached can be obtained. Also, the resist composition according to the present invention can be obtained by a method of spin coating a conventional resist and a solution containing fine particles having an aggregate of carbon atoms as a main constituent instead of this method.

[0026]

EXAMPLES Hereinafter, the details of the resist composition and the method for producing the same according to the present invention will be described more specifically based on examples, but the present invention is not limited to these examples. In the following description, Examples 1 to 5 and 7 to 15 are resists of the type (2) above, Examples 6 and 16 are resists of the above type (5), and Example 17 is a resist of the above (4). Example 18 is a resist of the type (3) above.
Example 19 uses the resist of the type (1) above.

Example 1 The resist composition of the present Example 1 is a typical PMMA (molecular weight: resist for positive electron beam (a resist in which a portion sensitive to an electron beam is removed during development to form a pattern)). 600,000), and 1 to 50 parts by weight of fine particles having an aggregate of carbon atoms as a main constituent was mixed with 100 parts by weight of PMMA to obtain a resist composition.

Next, a method for producing the resist composition of this embodiment will be described with reference to FIG. Step 1 (see FIG. 2A): A PMMA resist is spin-coated on a Si substrate by 10 nm and heat-treated at 170 ° C. for 30 minutes. Step 2 (see FIG. 2B): Next, the Si substrate on which the PMMA resist film is formed is placed in a vacuum discharge device, the carbon electrode is discharged, and carbon fine particles are attached to the PMMA resist film. In this case, the size and amount of the carbon fine particles formed can be controlled by the degree of vacuum, the discharge time, and the like. In Example 1, by setting the degree of vacuum to about 10 ⁻³ Torr and the discharge time to 0.2 seconds, carbon fine particles of 1 nm or less could be formed. The amount of adhesion was set so that the coverage of the substrate area was about 30%.
The size and amount of the fine particles were measured by an atomic force microscope.

Step 3 (see FIG. 2 (c)): Further, after taking out the substrate from the vacuum discharge device, the processes of (a) and (b) are repeated to obtain a resist composition containing carbon fine particles. . In this case, during the heat treatment after the application of the uppermost PMMA, the fine carbon particles attached to the lower PMMA film move due to the thermal motion of the PMMA molecules, and the uniform distribution of the fine carbon particles in the film is promoted. In Example 1, the process of steps 1 and 2 was repeated 5 times to obtain a resist film of about 50 nm. After forming the resist film, a pattern forming experiment was continuously performed using an electron beam drawing apparatus with an accelerating voltage of 50 kV, and a standard developing solution of PMMA (a 2/1 mixture solution of methyl isobutyl ketone and isopropyl alcohol) was used. It was possible to form a pattern of 15 nm, and it was confirmed that the resolution was comparable to that of conventional PMMA.

Further, the pattern contrast was evaluated by a 0.05 μm line and space pattern under the same process condition as the above-mentioned evaluation of resolution. 6 and 7 show the resist of this embodiment (FIG. 6) and the resist of the conventional method (FIG. 7), respectively.
3 is an electron micrograph of a pattern formed by. As is clear from the photograph, it is understood that the pattern contrast is amplified in the resist of this example.

FIG. 4 shows the result of evaluation of dry etching resistance compared with the conventional PMMA resist. In FIG. 4, the etching rate of the resist of the first embodiment is 1 as the etching rate. The black circles in FIG. 4 are PMMs.
A, white circles show the results of Example 1 and white diamonds show the results of Si.

First, for reactive dry etching of oxygen (O ₂ ) gas for etching an organic polymer film, gas flow rate: 20 SCCM, gas pressure: 2 Pa, power: 5
Under the etching condition of 0 W, the resist of the first embodiment is PM.
The etching rate is reduced by about 20% with respect to MA, and the resistance is increased accordingly. Further, for electron cyclotron resonance (ECR) dry etching using chlorine gas (Cl ₂ ) for etching a Si substrate, gas flow rate: 40 SCCM, gas pressure: 0.05 P
a, microwave power: 200 W under etching conditions,
It has been proved that the resist of Example 1 has about 3 times higher resistance to PMMA, and that the substrate can be processed to the same depth as the conventional one with a film thickness of about 1/3 of PMMA. As a result, as shown in FIGS. 1C and 3C, even if the conventional resist has a film thickness that causes a defect due to etching, the resist of the first embodiment does not cause a defect. Good substrate processing can be realized.

In this embodiment, the vacuum discharge method was used in the carbon fine particle deposition process. However, a vacuum vapor deposition method of fine particles having an aggregate of carbon atoms as a main constituent element, a sputtering method using a carbon target, acetylene, Chemical vapor deposition using a hydrocarbon gas such as ethylene (Chemical
Vapor Deposition, CVD) may be used. With these methods, it is usually difficult to form pure carbon fine particles because impurities such as hydrogen and oxygen are contained in the formed carbon fine particles. However, even in that case, etching is performed depending on the purity of the carbon fine particles. Improved resistance is feasible.

Further, in this embodiment, after the processes of steps 1 and 2 were repeated 5 times, pattern formation was subsequently carried out. However, for convenience of the pattern forming process, the two processes of the resist composition production and the resist film formation may be separated. In this case, after the resist composition is formed on a substrate, the composition is dissolved in a resist coating solvent to adjust the coating film thickness, and the dissolved composition is spin-coated on another substrate.

Example 2 The resist composition of Example 2 also uses PMMA (molecular weight: 600,000, manufactured by Tokyo Ohka Co., Ltd.), which is a typical positive electron beam resist, and 100 parts by weight of this PMMA is used for fullerene C. 35 parts by weight of ₆₀ (manufactured by Tokyo Chemical Industry Co., Ltd.) were mixed to prepare a resist composition. PMMA was dissolved in methyl cellosolve acetate at a concentration of 10% by weight, and fullerene C ₆₀ was dissolved in monochlorobenzene at a concentration of 1% by weight, and then both solutions were mixed to prepare a fullerene C _60- containing PMMA resist solution.
In order to evaluate the resolution of this resist, 5
After spin coating at 0 nm and heat treatment at 170 ° C. for 30 minutes, a drawing experiment was conducted with an electron beam drawing apparatus (50 kV).
A 15 nm pattern can be formed by developing with a standard PMMA developer (2/1 mixture of methyl isobutyl ketone and isopropyl alcohol) for 3 minutes.
A resolution comparable to that of MMA was confirmed.

Further, the pattern contrast was evaluated by a 0.05 μm line and space pattern under the same process conditions as the above-mentioned resolution evaluation. As a result, it was confirmed that the pattern had a high contrast as in Example 1. Further, FIG. 5 shows the evaluation result of dry etching resistance compared with the conventional PMMA resist. In Figure 5, the etching rate is PMM
The etching rate of the A resist is 1. In addition,
In FIG. 5, black circles indicate the results of PMMA, white triangles indicate the results of Example 2 and white squares indicate the results of Example 3 below.

First, for reactive dry etching of oxygen (O ₂ ) gas for etching an organic polymer film, gas flow rate: 20 SCCM, gas pressure: 2 Pa, power: 5
Under the etching condition of 0 W, the resist of the second embodiment is PM.
The etching rate is about 20% smaller than that of MA, and the resistance is amplified accordingly. Further, for electron cyclotron resonance (ECR) dry etching using chlorine gas (Cl ₂ ) for etching a Si substrate, gas flow rate: 40 SCCM, gas pressure: 0.05 P
a, microwave power: 200 W under etching conditions,
It has been proved that the resist of the present Example 2 has about twice as high resistance to PMMA, and that the substrate can be processed to the same depth as the conventional one with a film thickness of about 1/2 of PMMA. As a result, as shown in FIGS. 1C and 3C, even if the conventional resist has a film thickness that causes a defect due to etching, the resist of the second embodiment does not cause a defect. Good substrate processing can be realized.

Example 3 The resist composition of Example 3 had PMMA (molecular weight: 6).
A resist composition was prepared by adding 35 parts by weight of hydrogenated fullerene C ₆₀ H ₃₆ (made by MER) to 100 parts by weight of 100,000 (made by Tokyo Ohka Co., Ltd.). In order to evaluate the resolution of this resist composition, a spin coating of 50 nm was performed on a Si substrate, a heat treatment was carried out at 170 ° C. for 30 minutes, and then a drawing experiment was conducted with an electron beam drawing apparatus (50 kV).
By developing with a standard PMMA developer (2/1 mixture of methyl isobutyl ketone and isopropyl alcohol) for 3 minutes, a pattern of 15 nm can be formed as in Example 2, and a solution having the same degree as that of the conventional PMMA can be formed. The image quality was confirmed.
Also, under the same process conditions as the above resolution evaluation, 0.05μ
The pattern contrast was evaluated by the m-line and space pattern. As a result, it was confirmed that the pattern had a high contrast as in Example 1.

FIG. 5 shows the results of evaluation of dry etching resistance in comparison with the conventional PMMA resist. In FIG. 5, the etching rate of the PMMA resist is set to 1. First, for the reactive dry etching of oxygen (O ₂ ) gas for etching the organic polymer film, the resist of Example 3 was prepared under the etching conditions of gas flow rate: 20 SCCM, gas pressure: 2 Pa and power: 50 W. The etching rate is about 20% smaller than that of PMMA, and the resistance is amplified accordingly. Further, for electron cyclotron resonance (ECR) dry etching using chlorine gas (Cl ₂ ) for etching a Si substrate, gas flow rate: 40 SCCM, gas pressure: 0.0
Under the etching conditions of 5 Pa and microwave power: 200 W, the resist of Example 3 has about twice as high resistance to PMMA, and in this case also, as in Example 2, the film thickness is about 1/2 of PMMA. It was proved that the substrate can be processed to the same depth as the conventional one.

Example 4 In place of the hydrogenated fullerene in Example 3, a methyl group-introduced methylated fullerene (manufactured by Tokyo Chemical Industry Co., Ltd.) was used, and almost the same results as in Example 3 were obtained.

[0041] Instead of the fullerene C ₆₀ in Example 5 Example 2, using a lanthanum fullerene C ₆₀ containing therein the (La) (MER Corp.) to obtain substantially the same results as in Example 2.

Example 6 The resist composition of this Example 6 is one of the conventional chemically amplified negative resists, and has a solid content of a SAL601 resist (manufactured by Shipley Co.) in which a high energy ray sensitive portion remains as a pattern. 3 parts by weight of fullerene C ₆₀ (manufactured by Tokyo Chemical Industry Co., Ltd.) was mixed with 100 parts by weight to obtain a resist composition. Fullerene C ₆₀ was dissolved in monochlorobenzene to a concentration of 1% by weight, and then mixed with the above SAL601 resist to obtain a fullerene C _60- containing SAL601 resist solution. 100nm of this resist solution on Si substrate
After spin coating, heat treatment at 105 ° C. for 2 minutes and drawing with an electron beam drawing apparatus (50 kV), the drawn substrate was left in the atmosphere to perform a resist sensitivity evaluation experiment. For sensitivity evaluation, a substrate left in the atmosphere for a predetermined time at 105 ° C. for 2 mi
After heat treatment for n times and development with a 0.27N tetramethylammonium hydride aqueous solution for 6 minutes, the residual film with respect to the drawing dose was measured and determined with a film thickness meter.

FIG. 8 shows SAL60 containing no fullerene.
The sensitivity evaluation results in comparison with 1 resist (conventional chemically amplified resist) are shown. That is, FIG. 8 is a diagram for comparing and explaining the sensitivity stability of the resist composition of the present invention and the conventional resist composition. In FIG. 8, the vertical axis represents the resist sensitivity (%) based on the value immediately after writing, and the horizontal axis represents the leaving time (hour) after writing. In FIG. 8, white circles represent the results of the resist composition of Example 6, and black circles represent the results of the conventional chemically amplified resist. As shown in FIG. 8, the resist of this embodiment has 100
Sensitivity decrease (immediately after drawing) is several% even after a lapse of time, while the conventional chemically amplified resist decreases sensitivity by 80% or more. As is clear from this result, the sensitivity of the chemically amplified resist can be stabilized by the resist of this embodiment.

Example 7 In the resist composition of Example 7, 10 parts by weight of fullerene C ₆₀ (manufactured by Kanto Chemical Co., Inc.) was added to 100 parts by weight of solid content of the positive electron beam resist ZEP520 (manufactured by Zeon Corporation). A resist composition was formulated. Fullerene C ₆₀ was dissolved in ortho-dichlorobenzene to a concentration of about 1% by weight and then mixed with the ZEP520 resist to prepare a fullerene C _60- containing ZEP520 resist solution. This resist solution was spin-coated on a Si substrate in a thickness of 50 nm, heat-treated at 165 ° C. for 30 minutes, and drawn by an electron beam drawing apparatus (25 kV), and then the standard developing solution for ZEP520 resist, n.
By developing with amyl acetate for 3 minutes, a high-contrast pattern could be formed almost in the same manner as in Example 1.

Further, the resist solution of this embodiment was spin-coated on a Si substrate in a thickness of 50 nm, heat-treated at 165 ° C. for 30 minutes, drawn by an electron beam drawing device (25 kV), and then ZEP52.
3 minutes with diethyl ketone, which is a strong developer of 0 resist
After development, the residual film with respect to the drawing dose was measured with a film thickness meter to determine the resist sensitivity. Fig. 9 shows Z containing no fullerene
Sensitivity curves are shown as compared to EP520 resist (conventional resist). That is, FIG. 9 is a diagram for comparing and explaining sensitivity curves of the resist composition of the present invention and a conventional resist composition. In FIG. 9, the vertical axis represents the residual film rate (%), and the horizontal axis represents the drawing dose (μC / cm ² ). In FIG. 9, white circles indicate the results of the resist composition of Example 7, and black circles indicate the results of the conventional resist.

As shown in FIG. 9, in both cases, the exposure amount (resist sensitivity) at which the residual film ratio (percentage of the film thickness after development to the initial film thickness before development) becomes 0% is about 5 μC / cm ² . Higher sensitivity has been achieved (about 50 μC / cm ² when using the above standard developing solution). However, in the conventional ZEP520 resist, as shown in FIG. 9, by using a strong developing solution, the initial film thickness in the low-exposed and unexposed regions is reduced by about 30%, and a so-called film-reduction phenomenon occurs to cause a pattern contrast. Is clearly degraded. On the other hand, in the resist of this Example 7, no film reduction phenomenon was observed, and therefore,
Higher sensitivity can be realized without degrading the pattern contrast. Further, even with reactive dry etching of oxygen gas and ECR dry etching using chlorine gas, the etching resistance was improved as shown in Example 2, and the resist composition of Example 7 was also made highly resistant. Was confirmed.

Further, the heat resistance of the resist of Example 7 was evaluated. For evaluation, the resist solution of this example was spin-coated on a Si substrate in a thickness of 150 nm, heat-treated at 165 ° C. for 30 minutes, and drawn by an electron beam drawing apparatus (25 kV). Then, a pattern of 150 nm pitch was formed by the standard developing solution and heated. In the furnace 3
After heat treatment in the range of 100 to 200 ° C. for 0 min,
The pattern cross section was observed by an electron microscope. Figure 1
0 and FIG. 11 are electron micrographs of the cross sections of the patterns of the resist of Example 7 and the resist of the conventional method after the heat treatment, respectively. That is, FIG. 10 is an electron micrograph showing the heat resistance of a fine pattern using the resist composition of the present invention, and FIG. 11 is an electron micrograph showing the heat resistance of a fine pattern using the conventional resist composition. is there. As is clear from FIG. 10 and FIG. 11, it can be seen that the resist of Example 7 has increased heat resistance.

Further, the mechanical strength of the resist of Example 7 was evaluated. For evaluation, the resist solution of this example was spin-coated on a Si substrate to a thickness of 150 nm, heat-treated at 165 ° C. for 30 minutes, and drawn with an electron beam drawing apparatus (25 kV), and then ZEP.
It was carried out by developing for 3 min with n-amyl acetate, which is a standard developing solution for 520 resist, and obtaining the minimum pinch that can be resolved normally without the occurrence of pattern peeling, collapse, meandering or adhesion. 12 and 13 show the seventh embodiment, respectively.
3 is an electron micrograph of a cross section of a pattern showing the mechanical strength of the resist of FIG. That is, FIG. 12 is an electron micrograph showing the mechanical strength of a fine pattern using the resist composition of the present invention, and FIG. 13 shows the mechanical strength of a fine pattern using the conventional resist composition. It is an electron micrograph. As is clear from FIGS. 12 and 13, in the resist of Example 7, the pattern of 60 nm pitch was well resolved, but in the resist of the conventional method, even when the pattern of 90 nm pitch was used, pattern peeling and meandering occurred. Occurs, and adjacent patterns adhere to each other, making it impossible to resolve. This pattern collapse occurs during drying by the rinse liquid in the developing process, that is, the pattern with a high aspect ratio cannot avoid the influence of the surface tension of the rinse liquid. The fullerene mixed acts as a reinforcing material for the resist resin, and as a result, the mechanical strength of the resist of Example 7 is also amplified (eg, the conventional pattern aspect ratio is 3 whereas the pattern aspect ratio of the present invention is 4 to 5).
Improved).

Example 8 In the resist composition of Example 8, 100 parts by weight of the solid content of the positive type electron beam resist ZEP520 (manufactured by Zeon Corporation) was used and 4 of fullerenes C ₆₀ and C ₇₀ manufactured by Kanto Chemical Co., Inc. were used. / 1
10 parts by weight of the mixture (C _60/70 ) was mixed to _prepare a resist composition. Fullerene C _60/70 ortho - After dissolving so as to be about 1 weight% concentration in dichlorobenzene and fullerene C _60/70 containing ZEP520 resist solution was mixed with the ZEP520 resist. This resist solution was spin-coated on a Si substrate, and the same evaluation test as in Example 7 was performed. As a result, also in the resist composition of Example 8, high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength could be realized as in Example 7. It should be _noted that, in addition to C _60/70 , a mixture containing a trace amount of a higher fullerene may be used, and in this case, it is more advantageous in terms of cost.

Example 9 The resist composition of Example 9 was hydrogenated fullerene C, which is a derivative of fullerene, based on 100 parts by weight of the solid content of the positive electron beam resist ZEP520 (manufactured by Zeon Corporation).
_A resist composition was prepared by mixing 10 parts by weight of ₆₀ H ₃₆ (manufactured by MER). This resist composition was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. as a result,
As with Example 7, the resist composition of Example 9 was also able to achieve high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength.

Example 10 The resist composition of Example 10 was hydrogenated fullerene C ₆₀ H ₁₈ (a fullerene derivative) based on 100 parts by weight of the solid content of the positive electron beam resist ZEP520 (manufactured by Zeon Corporation). 10 parts by weight (manufactured by MER) was blended to obtain a resist composition. This resist composition was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, also in the resist composition of Example 10, as in Example 7, high etching resistance, high contrast,
Higher sensitivity, higher heat resistance, and higher strength were achieved.

Example 11 The resist composition of this Example 11 was prepared by using fullerene C ₆₀ (manufactured by Kanto Chemical Co., Inc.) and hydrogenated fullerene based on 100 parts by weight of solid content of the positive electron beam resist ZEP520 (manufactured by Zeon Corporation). Approximately 1: 1 mixture of C ₆₀ H ₃₆ (manufactured by MER) 1
0 part by weight was blended to obtain a resist composition. This resist composition was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, also in the resist composition of Example 11, high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength could be realized as in Example 7.

Example 12 The resist composition of Example 12 was prepared by using 100 parts by weight of the solid content of the positive electron beam resist ZEP520 (manufactured by Zeon Corporation) and fullerene C ₆₀ (manufactured by Kanto Chemical Co., Inc.) and hydrogenated fullerene. Approximately 1 to 1 mixture of C ₆₀ H ₁₈ (manufactured by MER) 1
0 part by weight was blended to obtain a resist composition. This resist composition was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, also in the resist composition of Example 12, high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength could be realized as in Example 7.

Example 13 The resist composition of this Example 13 was prepared based on 100 parts by weight of solid content of the positive electron beam resist ZEP520 (manufactured by Zeon Corporation) and fullerene C ₆₀ (manufactured by Kanto Chemical Co., Inc.) and C ₇₀ (manufactured by Kanto Chemical Co., Ltd.). A resist composition was prepared by mixing 10 parts by weight of a 1: 1: 1 mixture of hydrogenated fullerene C ₆₀ H ₃₆ (manufactured by MER) with Kanto Chemical Co., Inc. Mixing various types of substances in this way has the advantage of improving solubility.
This resist composition was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, Example 13
Similarly to Example 7, the resist composition of Example 1 could achieve high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength.

Example 14 The resist composition of this Example 14 was compared with 100 parts by weight of the solid content of the positive type electron beam resist ZEP520 (manufactured by Zeon Corporation) and fullerene C ₆₀ (manufactured by Kanto Kagaku Co.) and C ₇₀ (manufactured by Kanto Chemical Co., Ltd.). 10 parts by weight of a mixture of hydrogenated fullerene C ₆₀ H ₁₈ (manufactured by MER) and hydrogenated fullerene C ₆₀ H ₃₆ (manufactured by MER) at a ratio of about 1: 1: 1: 1. It was a resist composition. This resist composition was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, also in the resist composition of Example 14, as in Example 7, high etching resistance, high contrast,
Higher sensitivity, higher heat resistance, and higher strength were achieved.

Example 15 The resist composition of this Example 15 was prepared based on 100 parts by weight of solid content of a fluorine-containing acrylic main chain cutting type positive electron beam resist EBR-9 (manufactured by Toray). 4/1 mixture of fullerene C ₆₀ and C ₇₀ (C _60/70 ) 10
Part by weight was blended to obtain a resist composition. Fullerene C
_60/70 was dissolved in orthodichlorobenzene to a concentration of about 1% by weight and then mixed with the above EBR-9 resist to _obtain a fullerene C _{60 / 70-} containing EBR-9 resist solution. This resist solution was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, also in the resist composition of this example, high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength could be realized as in Example 7.

Example 16 The resist composition of Example 16 was prepared by using fullerene C ₆₀ (manufactured by Kanto Chemical Co., Inc.) based on 100 parts by weight of solid content of a chemically amplified positive electron beam resist ZEP-AC134 (manufactured by Zeon Corporation). ) 10 parts by weight were blended to obtain a resist composition. About 1% by weight of fullerene C ₆₀ in ortho-dichlorobenzene
ZEP-AC134
Fullerene C _60- containing ZEP-AC13 mixed with resist
4 resist solution. This resist solution was spin-coated on a Si substrate, and the same evaluation experiment as in Example 7 was conducted. As a result, also in the resist composition of Example 15, high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength could be realized as in Example 7. In Example 6, the realization of stabilization of sensitivity was shown by the present invention by taking a standard chemically amplified negative resist as an example. In Example 16, the chemically amplified positive resist is the same as in Example 6. As described above, according to the present invention, stabilization of sensitivity can be realized.

[0058] resist sets composition as Example 17 This Example 17, crosslinked negative electron beam resist having a chloromethyl group, with respect to 100 parts by weight of a solid content of chloromethylated polystyrene (CMS), fullerene _{C 60} 5 parts by weight (manufactured by Kanto Chemical Co., Inc.) was blended to obtain a resist composition. Fullerene C ₆₀ was dissolved in orthodichlorobenzene to a concentration of about 1% by weight and then mixed with the above CMS resist to obtain a CMS resist solution containing fullerene C ₆₀ . This resist solution was spin-coated on a Si substrate, and the evaluation experiment as shown in Example 7 was conducted. As a result, also in the resist composition of this example, high etching resistance, high heat resistance, and high strength similar to those in Example 7 could be realized.

Example 18 In the resist composition of Example 18, 5 parts of fullerene C ₆₀ (manufactured by Kanto Chemical Co., Inc.) was added to 100 parts by weight of solid content of the negative electron beam resist RI-1210N (manufactured by Hitachi Chemical Co., Ltd.). Part by weight was blended to obtain a resist composition. Fullerene C ₆₀ was dissolved in ortho-dichlorobenzene to a concentration of about 1% by weight, and then mixed with the RI-1210N resist to obtain a fullerene C _60- containing RI-1210N resist solution. This resist solution was spin-coated on a Si substrate, and the evaluation experiment as shown in Example 7 was conducted. As a result, also in the resist composition of Example 18, high etching resistance, high contrast, high sensitivity, high heat resistance, and high strength could be realized as in Example 7.

Example 19 The resist composition of this Example 19 is the photoresist TH
MR-iP3300 (Tokyo Ohka Co., Ltd.) solid content 100 weight
Fullerene C for the quantity part₆₀(Made by Tokyo Kasei) 7 parts by weight
Was blended to obtain a resist composition. Fullerene C₆₀The
To a concentration of about 1% by weight in ruto-dichlorobenzene
After dissolving, mix it with the THMR-iP3300 resist.
Combined fullerene C₆₀Containing THMR-iP3300 Regis
Solution. Spin coating this resist solution on Si substrate
The same evaluation as in Example 7 was performed using a reduction projection exposure apparatus.
A price experiment was conducted. As a result, the resist of Example 19 was
Also, as in Example 7, high etching resistance and high
Contrast, high sensitivity, high heat resistance, high strength
I was able to appear. In the nineteenth embodiment, the circuit pattern for VLSI is exposed.
THMR-iP currently widely used in optical processes
Although the 3300 resist was used, as described above, the present invention
In principle, it includes other resists for excimer lasers.
Applicable to all photoresists, and C
₆₀Not limited to C ₇₀, C₆₀H₃₆Etc., other fullerenes, fullers
It is possible to use len derivatives.

[0061]

[Effects of the Invention] That is, according to the resist composition of the present invention, a dense resist film containing carbon-based fine particles can be obtained, the etching resistance is improved, the resist pattern has a high contrast, and the resist sensitivity is high. In addition, high heat resistance of the resist film, improvement of the mechanical strength of the resist pattern, and stabilization of the resist sensitivity can be achieved, so that highly precise fine processing can be realized. Moreover, the conventional developing solution and developing method can be used at the time of pattern formation, and there is an effect on process compatibility.

[0062] In the case of using a fullerene, improves the mechanical strength of the resist by mixing fullerene, in the pattern of a high aspect ratio (the ratio of the pattern height to the pattern width), by the rinse liquid in the developing process The problem that the pattern collapses during drying is solved. Further, by mixing fullerene, the resist film is densified and the invasion of the acid inactive substance into the film is prevented, so that the temporal change in sensitivity after exposure, which is a problem of the chemically amplified resist, is suppressed. In addition, this eliminates the need for sensitivity stabilization measures such as overcoating and simplifies the process.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a pattern forming process using the resist composition of the present invention.

FIG. 2 is a diagram illustrating a method for producing a resist composition containing fine particles having an aggregate of carbon atoms as a main constituent in one example of the present invention.

FIG. 3 is a diagram illustrating a pattern forming process using a conventional resist composition.

FIG. 4 is a diagram comparatively explaining the etching resistance of the resist composition of the present invention and the conventional resist composition.

FIG. 5 is a diagram comparatively explaining the etching resistance of the resist composition of the present invention and the conventional resist composition.

FIG. 6 is an electron micrograph of a fine pattern in a pattern forming example using the resist composition of the present invention.

FIG. 7 is an electron micrograph of a fine pattern in a pattern forming example using a conventional resist composition.

FIG. 8 is a diagram comparatively explaining the sensitivity stability of the resist composition of the present invention and the conventional resist composition.

FIG. 9 is a diagram for comparing and explaining sensitivity curves of the resist composition of the present invention and a conventional resist composition.

FIG. 10 is an electron micrograph showing heat resistance of a fine pattern using the resist composition of the present invention.

FIG. 11 is an electron micrograph showing the heat resistance of a fine pattern using a conventional resist composition.

FIG. 12 is an electron micrograph showing the mechanical strength of a fine pattern using the resist composition of the present invention.

FIG. 13 is an electron micrograph showing the mechanical strength of a fine pattern using a conventional resist composition.

[Explanation of symbols]

1 ... Substrate, 2 ... Resist film, 3 ... High energy ray, 4 ...
Fine particles mainly composed of etching reaction species, 5 ... Carbon atom aggregates

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01L 21/027 H01L 21/30 502R (72) Inventor Kenji Kurihara 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone (56) References JP 10-228117 (JP, A) JP 10-90893 (JP, A) JP 10-1306 (JP, A) JP 9-211862 (JP, A) JP-A-7-134413 (JP, A) JP-A-7-33751 (JP, A) JP-A-6-167812 (JP, A) JP-A-6-19136 (JP, A) (58) Survey Fields (Int.Cl. ⁷ , DB name) G03F 7/004 501 G03F 7/022 G03F 7/038 505 G03F 7/039 501 G03F 7/039 601 H01L 21/027

Claims (8)

(57) [Claims] 1. A resist composition comprising a resist sensitive to any one of an electron beam, an X-ray and an ultraviolet ray, and one or both of fullerene and a fullerene derivative mixed in the resist, A resist composition, wherein the weight of either or both of the fullerene and the fullerene derivative is smaller than the weight of the resin component of the resist. 2. A mixing amount of either or both of the fullerene and fullerene derivative, the resist 1
The resist composition according to claim 1, which is 1 to 50 parts by weight with respect to 00 parts by weight . 3. The resist composition according to claim 1, wherein the resist contains an alkali-soluble resin and a diazozonaphthoquinone compound photosensitizer. 4. The resist composition according to claim 1, wherein the resist is an acrylic main chain cleavage type resist. 5. The resist composition according to claim 1, wherein the resist contains an alkali-soluble resin and an azide compound photosensitizer. 6. The resist composition according to claim 1, wherein the resist is a cross-linked resist having a chloromethyl group or an epoxy group. 7. The resist is an alkali-soluble resin,
3. The resist composition according to claim 1 or 2, which is a chemically amplified resist having an acid generator and a solubility control agent having an acid labile group. 8. The resist composition according to claim 3, wherein the alkali-soluble resin is a novolac resin.