JP3215562B2 - Dissolution inhibitor, method for synthesizing the same, and resist material containing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist material, and more particularly to a fine resist material having high sensitivity to high energy rays such as far ultraviolet rays, electron beams and X-rays and which can be developed with an aqueous alkali solution. It relates to a positive resist material suitable for processing.

[0002]

2. Description of the Related Art A pattern rule has been required to be finer in accordance with high integration and high speed of an LSI (high-density integrated circuit). However, light emitted from a light source used in a normal light exposure technique has been required. Has a long wavelength and is not a single wavelength, so there is a limit to the miniaturization of pattern rules. Therefore, g-rays (wavelength: 436 nm) or i-rays (wavelength: 365 nm) emitted from an ultra-high pressure mercury lamp have been used as a light source.

However, even in this case, about 0.5 μm
The pattern rule with the resolution of m is the limit, and the LSI that can be manufactured has only the integration degree of about 16 Mbit DRAM. Therefore, in recent years, far-ultraviolet lithography using far-ultraviolet light as a light source, which has a shorter wavelength than g-line and i-line, is regarded as promising.

According to deep ultraviolet lithography, 0.1
It is also possible to form a pattern rule of about 0.3 μm, and when a resist material having a small light absorption is used,
Since it is possible to form a pattern having a side wall nearly perpendicular to the substrate, and to transfer the pattern at a time, the pattern formation processing efficiency (throughput) is lower than that of lithography using an electron beam. Excellent in high points. In recent years, as a light source for far ultraviolet rays,
Along with the fact that an rF excimer laser can be used, it is necessary to use a highly sensitive resist material from the viewpoint of mass-producing an LSI using the light source.

Therefore, in recent years, a chemically amplified resist material which has a sensitivity equal to or higher than that of the conventional high-sensitivity resist material, has high resolution and high dry etching resistance, and is produced using an acid as a catalyst has been developed (for example, Lew resist). (Liu)
Et al., Journal of Vacuum Science and Technology (J. Vac. Techno.), B6, 379, 1988);
The chemical amplification type negative resist material (SAL601ER7: trade name of Shipley Co.), which is composed of a novolak resin, a melamine compound and an acid generator, has been commercialized by the company (Hipley).

However, when a negative resist material is used in an LSI manufacturing process, it is easy to form a wiring and a gate portion, but it is difficult to form a contact hole that requires fine processing. There was a disadvantage that it was. Further, when a pattern is formed using far-ultraviolet rays, an electron beam, or X-rays using a chemically-amplified positive resist material that has been conventionally proposed as it is,
Since the solubility of the resist surface decreases and the pattern after development tends to be overhanging, it becomes difficult to control the dimensions of the pattern, and the dimensional controllability during substrate processing using dry etching is reduced. There was a drawback that not only spoiled but also caused the pattern to collapse [KG Chiong et al., Journal of Vacuum Science and Technology, B7
Vol., (6), p. 1771, 1989].

Therefore, there has been a strong demand for the development of a high-performance, chemically amplified positive resist material free of such disadvantages. In response to such a demand, Ito et al. Have developed a chemically amplified type obtained by adding an onium salt to a poly (butoxycarbonyloxystyrene) (PBOCST) resin in which the OH group of polyhydroxystyrene is protected with t @ butoxycarbonyl group. (Polymers in Electronics, A.C.
S Symposium Series [Polymers in
Electronics, ACS symposi
um Series 242 (American Chemical Society, Washington, DC, 1984), page 11]).

However, the above-mentioned onium salt has a drawback that it contaminates the substrate because it contains antimony as a metal component. In addition, Ueno et al.
Styreneoxytetrahydropyranyl) as the main component,
A positive resist material for far-ultraviolet light obtained by adding an acid generator to this has been proposed (36th Japan Society of Applied Physics Related Lectures, 1989, 1p @ k @ 7). However,
The above-mentioned positive resist material has a disadvantage that it is easily inverted from a positive type to a negative type with respect to far ultraviolet rays, electron beams or X-rays.

In addition to the above-mentioned drawbacks, the above-mentioned two-component positive resist material comprising a resin in which an OH group is protected with a protecting group and an acid generator is required to be further dissolved in a developing solution. Since many protecting groups need to be decomposed, LSI
In the manufacturing process, there is a disadvantage that the film thickness of the resist changes and stress and bubbles are easily generated in the film. Therefore, a three-component positive resist material comprising an alkali-soluble resin, a dissolution inhibitor and an acid generator has been developed as a chemically amplified positive resist material which has improved the disadvantages of the two-component positive resist material. ing.

As such a three-component positive resist material, a novolak resin, a resist material containing an acetal compound as a dissolution inhibitor and an acid generator (RA
Y / PF resist material: Hoechst) has been developed for X-ray lithography. However, since this resist material undergoes chemical amplification at room temperature, the resist sensitivity greatly depends on the time from X-ray exposure to development. Therefore, it is necessary to strictly control the time at all times. However, since the control is difficult, there is a drawback that the dimensions of the pattern cannot be stabilized, and the absorption of the KrF excimer laser light (wavelength: 248 nm) is reduced. Due to its large size, it has a drawback that it is not suitable for use in lithography using the laser.

By the way, in general, heat treatment is often required after exposure for chemical amplification. In this case, although the number of steps is increased as compared with the case of a resist material that performs chemical amplification at room temperature, the resist characteristics are stable because it is not necessary to strictly control the time from exposure to development. . Further, in the case of a system in which hydrolysis is performed in the process of performing chemical amplification, water is required for hydrolysis, so that it is necessary to include moisture in the resist material.

However, as a solvent used when applying a resist material to a substrate, an organic solvent that is not soluble in water, such as ethoxyethyl acetate, is generally used in many cases.
Further, since many of the resins themselves used as resist materials are not compatible with water, it is difficult to contain water in the resist material, and even if it is contained, control of the water becomes complicated.

On the other hand, in the decomposition reaction of the t-butoxycarbonyloxy group, the reaction proceeds with two components of the t-butoxycarbonyloxy group and an acid serving as a catalyst, and no water is required. This is suitable for
Further, since many compounds having a t-butoxycarbonyloxy group have an effect of inhibiting the solubility of a novolak resin, it is known that the t-butoxycarbonyloxy group has a dissolution inhibiting effect on the novolak resin. Have been.

From such a viewpoint, Schlegel (Sch
Nobelak resin, bisphenol A
Has proposed a ternary Posi-type resist material consisting of a dissolution inhibitor with a t-butoxycarbonyl group introduced into it and pyrogallol methanesulfonate (Spring Li, 1990, The 37th Annual Meeting of the Japan Society of Applied Physics) , 28p─
ZE $ 4). However, in this case, it is difficult to put it into practical use because the light absorption of the novolak resin is large.

Also, Schwarm et al. Have developed bis (pt @ butoxycarbonyloxyphenyl) iodonium hexafluoroantimonate as a material which also serves as a dissolution inhibitor and an acid generator [Polymer for Microelectronics (polyme
r for Microelectronics), Tokyo, 1989, Session A38], and proposes a positive resist material for far ultraviolet rays obtained by mixing the same with a novolak resin. However, the above-mentioned positive resist material has a drawback that it is difficult to put to practical use because the novolak resin contains a metal having a large light absorption.

In the case of a ternary chemically amplified positive resist material comprising a resin, a dissolution inhibitor and an acid generator, the dissolution rate of the resist film in an alkali developing solution is controlled by the dissolution inhibitor. Dissolution rate of energy beam irradiated part) / (Dissolution rate of non-irradiated part)
(Hereinafter referred to as “dissolution rate ratio”) is known to greatly affect the performance as a resist material. In other words, when a substance (dissolution inhibitor) that rapidly dissolves a portion of the resist film when irradiated with high-energy rays such as ultraviolet rays in an alkali developing solution is added to the resist material, the resist pattern becomes The formation efficiency becomes extremely good.

Examples of such a dissolution inhibitor conventionally known include di (t-butoxycarbonyl) bisphenol A represented by the following formula (3) and di (t-butoxycarbonyl) represented by the following formula (4). ) Bisphenol F,
Examples thereof include 4-t-butoxycarbonylbiphenyl represented by the following formula 5, t-butylcholate represented by the following formula 6, and t-butyldeoxycholate represented by the following formula 7.

[0018]

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Embedded image (However, in Chemical Formula 3, Chemical Formula 4 and Chemical Formula 5, t-Bu-t represents a t-butyl group.) However, since all of these dissolution inhibitors have the following disadvantages, the resist material It was difficult to put it to practical use.

The disadvantages described above are that di (t-butoxycarbonyl) bisphenol A and di (t-butoxycarbonyl) bisphenol F have a large dissolution inhibiting effect on the resin and have a low ultraviolet absorptivity. Although it has the feature of being inexpensive, the dissolution rate ratio is small and the compatibility with the resin is low, so that the amount added is limited.In the case of 4-t-butoxycarbonylbiphenyl, Although the dissolution rate ratio is relatively large, the light transmittance to the resist film cannot be controlled due to the large ultraviolet absorptivity.

In the case of t-butyl deoxycholate, the UV absorption is small, and when used for novolak resin, the compatibility is good and the poly () is excellent as a dissolution inhibitor. When used for (hydroxystyrene), the dissolution inhibiting effect is insufficient, so that the resist film in the non-irradiated portion dissolves in an alkali developing solution, causing a film reduction phenomenon. Supply is unstable because of natural products. Furthermore, when polyhydroxystyrene is used as the resin for forming a film and the dissolution inhibitors mentioned above are combined, the solubility of these dissolution inhibitors in polyhydroxystyrene is insufficient, and Due to the insufficient inhibitory effect, it was difficult to control the initial film thickness reduction of the resist.

[0021]

Accordingly, in a chemically amplified positive resist composition comprising a combination of a resin, a dissolution inhibitor and an acid generator, the present inventors have conducted intensive studies to solve the drawbacks of the conventional dissolution inhibitors. Have proposed a new compound, bis-t, for poly (hydroxystyrene) resin.
-It has been found that by combining butoxycarbonylmethylthymolphthalein as a dissolution inhibitor, it is possible to obtain a positive resist material for high energy rays having unprecedented high sensitivity, high resolution and excellent process suitability. The invention has been reached.

Accordingly, a first object of the present invention is to provide a novel compound, bis-t-butoxycarbonylmethylthymolphthalein. A second object of the present invention is to provide a method for producing bis-t-butoxycarbonylmethylthymolphthalein. A third object of the present invention is to provide a positive resist material for high energy rays having high sensitivity, high resolution, and excellent process suitability, which has not been achieved in the past.

[0023]

The above objects of the present invention are attained by a resin, a dissolution inhibitor and an acid generator represented by the following formula (8).
A chemical dissolution inhibitor for a positive resist material comprising a dispersing agent and a method for producing the same, and a poly (hydroxystyrene) resin a, a dissolution inhibitor b and an onium salt c each having a weight fraction of 0.1%. 55 ≦ a, 0.07 ≦ b ≦ 0.40, 0.
A positive resist material that contains 005 ≦ c ≦ 0.15 and a + b + c = 1 and that can be developed with an alkaline aqueous solution and that is sensitive to high energy rays. This has been achieved by a positive resist material characterized by being bis-t-butoxycarbonylmethylthymolphthalein represented by Chemical formula 8.

[0024]

Embedded image In addition, bis-t-butoxycarbonylmethylthymolphthalein represented by the above formula 8 is t-butoxycarbonyl α
-A novel compound produced by reacting haloacetic acid with thymolphthalein represented by the following formula:

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This compound can be synthesized using thymolphthalein as a raw material, which is easily available as a commercial product. That is, it can be produced by reacting thymolphthalein with α-halogenated acetic acid tert-butyl ester in a solvent in the presence of a suitable acid trapping agent. As α-halogenated acetic acid, α-chloroacetic acid tertiary butyl ester or α-bromoacetic acid tertiary butyl ester is used. The acid trapping agent is not particularly limited as long as it is a weak base. Carbonates such as potassium carbonate, sodium hydrocarbon, and potassium potassium, and tertiary amines such as triethylamine and dimethylaniline are preferably used.

The reaction solvent is not particularly limited, but it is preferable to use an aprotic polar solvent such as dimethylformamide, dimethylacetamide and dimethylsulfoxide. The reaction temperature may range from room temperature to the boiling point of the reaction solvent,
The reaction time is not particularly limited, but the reaction is completed in a range of about 1 hour to 10 hours. The compound of the present invention thus synthesized contains some impurities, which can be easily removed by washing the residue with a solvent or by performing chromatography. The compound thus produced is isolated as a pure substance by performing a recrystallization operation.

The content of the dissolution inhibitor b in the resist material is used in a ratio sufficient to control the alkali solubility of the resist film, but is generally preferably in the range of 7 to 40% by weight. When the content is less than 7% by weight, the dissolution inhibiting effect is small, and when the content is 40% by weight or more, the mechanical strength and heat resistance of the resist film decrease. By the way, when bis-t-butoxycarbonylmethylthymolphthalein of the present invention is added as a dissolution inhibitor, even when polyhydroxystyrene is used as a base resin for film formation, the alkali-developed portion of the non-irradiated portion is not removed. It is possible to sufficiently control the reduction in film thickness, and since the portion irradiated with light becomes alkali-soluble, it exhibits extremely excellent performance as a resist.

That is, while this dissolution inhibitor has a sufficient dissolution inhibiting effect on polyhydroxystyrene, the protective group is easily released under acidic conditions formed by irradiation of the acid generator with light, and the phenolic hydroxyl group And a compound having a carboxylic acid group. In this case, since a carboxylate ion is particularly generated, a large alkali dissolution rate can be obtained.

In the case where polyhydroxystyrene having a wide molecular weight distribution, such as that obtained by radical polymerization, is used, the resist material contains a large molecular weight that is difficult to dissolve in an aqueous alkali solution. It causes hem after forming. Therefore, it is preferable to use monodisperse polyhydroxystyrene as obtained by living polymerization.

Incidentally, in the present invention, a resist material using polyhydroxystyrene (for example, one having an average molecular weight of 10,000 and a molecular weight distribution of 1.1) obtained by living polymerization is used. When a pattern of lines and spaces is formed, a pattern with good accuracy can be formed without skirting. Further, even if the thus obtained pattern is baked at 150 ° C. for 10 minutes, no deformation is observed in the pattern, and the heat resistance is sufficient.

On the other hand, using a resist material using polyhydroxystyrene (for example, one having an average molecular weight of 12,000 and a molecular weight distribution of 3.0) obtained by radical polymerization, a line of 0.5 μm is formed. When the pattern of the space is formed, the heat resistance of the pattern is substantially the same, but since the bottom is seen, a resolution of 0.2 μm cannot be obtained very much.

The monodispersity means that the molecular weight distribution is Mw / Mn.
= 1.05 to 1.50. Where M
w is the weight average molecular weight of the polymer, and Mn is the number average molecular weight. In the case of living polymerization, the weight average molecular weight can be easily obtained by calculating from the weight of the monomer and the number of moles of the initiator, or by using a light scattering method. The number average molecular weight is easily measured using a membrane osmometer.

The molecular weight distribution can be evaluated by gel permeation chromatography (GPC), and the molecular structure is determined by infrared absorption (IR) spectrum or ¹ H
で き る It can be easily confirmed by NMR spectrum. As a method of obtaining a monodisperse polymer, first, a method of fractionating a polymer having a wide molecular weight distribution obtained by polymerization by a radical polymerization method or the like, and second, a method of monodispersing a polymer from the beginning by a living polymerization method Although a method for obtaining the same can be mentioned, a living polymerization method is preferably adopted because the step of monodispersion is simple.

By the way, even if the p-hydroxystyrene monomer is subjected to living polymerization as it is, the polymerization does not start because the hydroxyl group of the monomer reacts with the polymerization initiator. Therefore, a method is used in which a monomer having a protective group for protecting the hydroxyl group introduced therein is subjected to living polymerization, and then the protective group is eliminated to obtain a desired parahydroxystyrene. Examples of the protecting group used include a tertiary butyl group, a dimethylphenylcarbylmethylsilyl group, a tertiary butoxycarbonyl group, a tetrahydropyranyl group, a tertiary butyldimethylsilyl group, and the like.

For example, the compound can be easily obtained by subjecting a monomer represented by the following formula (10) or (11) to living anionic polymerization and then removing a dimethylphenylcarbylsilyl group or a t-butyl group.

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In the living anionic polymerization, it is preferable to use an organometallic compound as a polymerization initiator. Preferred organic metal compounds include, for example, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, sodium naphthalene, sodium anthracene, sodium α-methylstyrene tetramer,
Organic alkali metal compounds such as cumyl potassium and cumyl cesium are exemplified.

The living anionic polymerization is preferably carried out in an organic solvent. The organic solvent used in this case is a solvent such as an aromatic hydrocarbon, a cyclic ether, or an aliphatic hydrocarbon, and specific examples thereof include, for example, benzene,
Examples include toluene, tetrahydrofuran, dioxane, tetrahydropyran, dimethoxyethane, n-hexane, cyclohexane and the like.

These organic solvents may be used alone or as a mixture, but it is particularly preferable to use tetrahydrofuran. The concentration of the monomer in the polymerization is 1
The amount is suitably from 50 to 50% by weight, particularly from 1 to 30% by weight, and the reaction is preferably carried out under high vacuum or with stirring under an inert gas atmosphere such as argon or nitrogen.

The reaction temperature can be arbitrarily selected within a range from -100 ° C. to the boiling point of the organic solvent used. Especially when a tetrahydrofuran solvent is used,
The reaction is preferably carried out at 78 ° C to 0 ° C and at room temperature when a benzene solvent is used. By conducting the reaction under the above conditions for about 10 minutes to 7 hours, only the vinyl group is selectively reacted and polymerized, and for example, a polymer represented by the following formula (12) or (13) can be obtained.

[0040]

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Embedded image When the desired degree of polymerization is reached, for example, methanol, water,
By adding a polymerization reaction terminator such as methyl bromide to the reaction system to terminate the polymerization reaction, a living polymer having a desired molecular weight can be obtained.

Further, the living polymer can be purified and isolated by precipitating the obtained reaction mixture using an appropriate solvent (for example, methanol), washing and drying. In the polymerization reaction, since 100% of the monomer reacts, the yield of the living polymer produced is approximately 100%.
%. Therefore, by adjusting the amount of the monomer used and the number of moles of the reaction initiator, the molecular weight of the obtained living polymer can be appropriately adjusted.

The molecular weight distribution of the living polymer thus obtained is monodisperse (Mw / Mn = 1.05-1.
50). Further, by cleaving the ether bond of the dimethylphenylcarbinylvinyldimethylsilyl group or the t-butyl group of the polymer represented by the formula (12) or (13), poly (p-hydroxystyrene) represented by the following formula (14) is obtained. Can be obtained.

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The reaction for cleaving the ether bond is carried out by dissolving the polymer represented by the formula (12) or (13) in a solvent such as dioxane, acetone, acetonitrile, benzene or a mixture thereof, and then adding hydrochloric acid, hydrobromic acid or the like. Alternatively, it can be easily carried out by dropping an acid such as pyridinium paratoluenesulfonate. In the above reaction, the resulting poly (p-hydroxystyrene) is monodisperse because the main chain of the polymer is not cut or a cross-linking reaction does not occur between the molecules.

The onium salt c used in the present invention includes:
Although it is not particularly limited as long as it is for a conventional chemically amplified photoresist, an onium salt such as a sulfonium salt or an iodonium salt, a diazo compound such as di (phenylsulfonyl) diazomethane or a substituted product thereof, Benzyl tosylate such as 6-dinitrobenzyl tosylate, benzoin tosylate and triazine derivative are usually used.

As such an onium salt, for example,
Compounds represented by the following formulas 15 to 19 are exemplified.

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X in the above formula is p-toluenesulfonic acid anion, trifluoromethanesulfonic acid anion, hexafluoroantimonate anion, hexafluorophosphate anion, or tetrafluoroborate anion. Represents The content of the onium salt in the resist material is 0.5 to 15% by weight.
Is preferably within the range. If the content is less than 0.5% by weight, the sensitivity of the resist material cannot be improved,
If it is 15% by weight or more, the cost of the resist material increases and the mechanical strength of the resist film decreases.

The resist material of the present invention is obtained by dissolving these components in an organic solvent. The organic solvent at this time is preferably one in which each component is sufficiently dissolved and the resist film spreads uniformly. Specifically, butyl acetate, xylene, acetone, cellosolve acetate, ethylene glycol monomethyl ether, diethylene glycol Examples thereof include butyl ether, diethylene glycol dimethyl ether, ethyl lactate, methyl lactate, propyl lactate, butyl lactate, and propylene glycol methyl ether acetate.

The formation of a pattern on a substrate using the resist material of the present invention can be easily performed by the following method. That is, after a resist material solution is spin-coated on a substrate, prebaking is performed to obtain a coated substrate. When a high energy ray is irradiated to the obtained coated substrate, the acid generator in the coated film is decomposed to generate an acid.

Then, when the substrate is exposed to heat and then heat-treated, the dissolution inhibitor and the t-butoxycarbonyloxy group of the poly (hydroxystyrene) resin are decomposed by using the generated acid as a catalyst, and the dissolution inhibiting effect of the resist is lost. Thus, a substrate having a latent image formed is obtained. next,
A positive pattern can be formed by developing the substrate having the latent image with an alkaline aqueous solution and washing the substrate with water.

[0050]

The bis-t-butoxycarbonylmethylthymolphthalein of the present invention exhibits high solubility, especially in poly (hydroxystyrene) resin, and a large inhibitory effect on dissolution in an alkali developing solution. When used as a dissolution inhibitor for a chemically amplified positive resist material using a resin, it is possible to sufficiently prevent the initial film loss of the resist film.

The positive resist composition using the above-mentioned dissolution inhibitor of the present invention has high sensitivity to high energy rays, especially high sensitivity to far ultraviolet rays (KrF excimer laser, etc.) having a short wavelength. Since it has low absorption, it is a resist material suitable for fine processing of a substrate used for an LSI or the like. Further, the positive resist material of the present invention does not contain a metal element, so that it does not contaminate the substrate, has little dependence on aging after exposure, and does not require moisture in the chemical amplification process. Therefore, it is a suitable positive resist material.

[0052]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Embodiment 1 Thymolphthalein 25g
(0.058 mol), t-butyl bromoacetate 25.
7 g (0.13 mol), 1.25 g of tetra-n-butylammonium hydrogen sulfate, and 50 g of potassium carbonate (0.
(36 mol) was suspended in 150 ml of dimethyl sulfoxide, and reacted by stirring at 60 ° C. for 6 hours. After allowing the reaction solution to cool, pour it into 300 ml of cold water, and add 200 ml
Extracted twice with chloroform. The organic layer was washed with 300 ml of saturated saline, dried over anhydrous sodium sulfate, and then the solvent was distilled off. The obtained residue was purified using silica gel chromatography, and recrystallized from hexane to obtain 29.4 g (yield 77%) of colorless prism crystals.

The melting point of the obtained prism crystals was 93 to 94.
° C. Also, the measured value δ of ¹ HNMR (CDCl ₃ )
Are 1.03 (6H, d), 1.68 (6H, d),
1.46 (18H, s), 3.25 (2H, m), 4.
51 (4H, s), 6.46 (2H, s), 6.84
(2H, s), 7.33 (1H, d), 7.55 (1
H, t), 7.69 (1H, t), 7.94 (1H,
d), which was confirmed to be bis-t-butoxycarbonylmethylthymolphthalein.

Embodiment 2 FIG. Except that t-butyl chloroacetate was used instead of t-butyl bromoacetate used in Example 1, and the reaction was carried out by stirring at 60 ° C. for 12 hours.
When the synthesis was carried out in exactly the same manner as in Example 1, bis-
t-butoxycarbonylmethylthymolphthalein is 2
7.3 g (yield 72%) was obtained.

Embodiment 3 FIG. 81 parts by weight of poly-p-hydroxystyrene (number average molecular weight 1.4 × 10 ⁻⁴ g / mol, molecular weight distribution 1.10), 14 parts by weight of bis-t-butoxycarbonylmethylthymolphthalein, diphenyl (p
-Methoxyphenyl) sulfonium trifluoromethanesulfonate (5 parts by weight) and diglyme (400 parts by weight) were mixed in a resist solution of 2,000 on a Silicone substrate.
Spin coating at 0 revolutions / minute, 85 ° C on hot plate
Pre-paque for 1 minute at a resist film thickness of 0.7μ
m of the resist-coated substrate was obtained.

An acceleration voltage of 3 was applied to the coating side of the obtained coating substrate.
After drawing with an electron beam of 0 kV, heat treatment was performed at 85 ° C. for 2 minutes. Subsequently, development was performed for 1 minute using an aqueous solution of 2.4% by weight of tetramethylammonium hydroxide (TMAH), followed by washing with water for 30 seconds to obtain a silicone substrate (pattern substrate) on which a pattern was formed. The pattern of the obtained substrate shows a positive characteristic, and the D ₀ sensitivity of the resist film is 3.
It was 6 μC / cm ² .

In place of the electron beam, K
D ₀ sensitivity, assessed using rF excimer laser beam (wavelength 248 nm) was 30 mJ / cm ^2. Further, when the heat treatment after drawing was performed at 85 ° C. for 5 minutes, the electron beam sensitivity was 2.5 μC / cm ² . The resolution of the obtained pattern was 0.25 μm when an electron beam was used.

Embodiments 4 to 9 Instead of the onium salt diphenyl (p-methoxyphenyl) sulfonium fluoromethanesulfonate used in Example 3, the following Table 1 was used.
A resist solution was prepared in exactly the same manner as in Example 3 except that the onium salt was used to obtain a resist-coated substrate.

[0060]

[Table 1]

The coated substrate obtained in each case was used in Example 3
Each pattern substrate was obtained by drawing with an electron beam in exactly the same manner as described above. Each of the obtained patterns showed positive characteristics, and the D ₀ sensitivity of the resist film was as shown in Table 1 above. Further, it was confirmed that the resolution of each pattern was 0.25 μm as in the case of Example 3.

Embodiments 10-16. Each of the resist coated substrates obtained in Examples 3 to 9 was used, and instead of the electron beam, a soft X-ray (SR light) generated from a small superconducting ring was used as an exposure light source. A pattern substrate was obtained in exactly the same manner as in No. 3. Each of the obtained patterns showed positive characteristics, and the D ₀ sensitivity of the resist film was as shown in Table 2 below.
As shown in FIG.

[0063]

[Table 2]

The sensitivity of each resist film was 50 mJ / c.
m ² or less, and the resolution was 0.15 μm. These results show that, at an exposure dose of 50 mJ / cm ² , 20 6-inch wafers can be produced per hour. By using the resist of the present invention, X-ray lithography can be performed with photolithography. It demonstrates that the same productivity can be secured.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jun Watanabe 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center (72) Inventor Minoru Takamizawa Takatsu-ku, Kawasaki-shi, Kanagawa 3-2-1 Sakado Shin-Etsu Chemical Co., Ltd. Corporate Research Center (72) Inventor Keijun Tanaka 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References 4-296754 (JP, A) JP-A-5-181279 (JP, A)

Claims (3)

(57) [Claims] 1. A resin and a dissolution inhibitor represented by the following formula 1.
Amplified Positive Resist Material Consisting of Chemical and Acid Generator
Dissolution inhibitors. Embedded image 2. The method for producing a dissolution inhibitor according to claim 1, wherein t-butoxycarbonyl α-haloacetic acid is reacted with thymolphthalein represented by the following formula (2). Embedded image 3. A poly (hydroxystyrene) resin a, a dissolution inhibitor b and an onium salt c are each added in a weight fraction of 0.5.
5 ≦ a, 0.07 ≦ b ≦ 0.40, 0.005 ≦ c ≦
2. A positive resist material which contains 0.15 and a + b + c = 1 and can be developed with an alkaline aqueous solution and which is sensitive to high energy rays, wherein the dissolution inhibitor b is in claim 1. A positive resist material, which is bis-t-butoxycarbonylmethylthymolphthalein.