JP2002258480A - Method for manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a negative pattern which is transparent in the far UV region including 193 nm wavelength of ArF excimer laser light, which has a chemical structure with high durability against dry etching and shows excellent resolution without swelling in a 2.38% tetramethylammonium hydroxide aqueous solution as a standard developer. SOLUTION: The alkali solubility of a δ-hydroxy acid is controlled by adding an alkyl group or a dialkyl group to the α-position of the δ-hydroxyl acid. Such a reaction that a part or whole of the α-alkyl-δ-hydroxy acid structure or α,α'-dialkyl-δ-hydroxy acid structure changes into a lactone structure by an acid catalyst reaction is used to form a negative pattern with high resolution and no swelling by water-based alkali development.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microlithography process used in microfabrication technology in a manufacturing process of a semiconductor device and the like, a method of manufacturing a semiconductor device and the like including the microlithography process, and a radiation-sensitive method used therein. Composition. More specifically, an optical lithography process using far ultraviolet light having a wavelength of 220 nm or less, such as a high-pressure mercury lamp or a KrF excimer laser, which is a current ultraviolet light source, and a shorter wavelength light source such as an ArF excimer laser beam, especially a phase shift method. The present invention relates to a method for manufacturing a semiconductor device including formation of a negative pattern suitable for a lithography process using such a super-resolution technique, and a radiation-sensitive composition used therefor.

[0002]

2. Description of the Related Art A photolithography technique for forming a fine pattern on the order of microns or submicrons in an electronic device such as a semiconductor has played a central role in mass production fine processing technology. The recent demand for higher integration and higher density of semiconductor devices is
Many advances have been made in microfabrication technology. In particular, as the minimum processing size approaches the exposure wavelength, photolithography technology using a KrF excimer laser (248 nm) from g-line (436 nm) and i-line (365 nm) of a high-pressure mercury lamp and a shorter wavelength light source is developed. It has been. In response to these changes in the exposure wavelength, materials corresponding to the respective wavelengths of the photoresist have been developed. Conventionally, photoresists suitable for these wavelengths have different photosensitizers or photosensitive mechanisms, but aqueous alkali development utilizing the aqueous alkali solubility of a resin or a polymer material having a phenol structure has been industrially used. Was. These resins or polymer materials inevitably contain a large amount of aromatic rings, which was also a chemical structural element for improving the etching resistance in a dry etching step after the formation of a resist pattern.

A negative resist using such a resin having a phenol structure is disclosed in JP-A-62-1640.
No. 45, cross-linking type and JP-A-4-1653
No. 59, there is a dissolution inhibiting type. In any case, a submicron fine pattern can be formed without swelling.

[0004] In recent years, expectations have been growing for photolithography using an ArF excimer laser (193 nm) as a light source as a photolithography in a region where the minimum processing dimension is smaller than 0.25 μm. However, this wavelength is the absorption maximum due to the aromatic ring, and in the conventional industrially used photoresist material having a phenol structure as a main component, an exposure latent image can be formed only on the very surface of the photoresist film, It was difficult to form a fine resist pattern by aqueous alkali development.

On the other hand, various resist materials having high transmittance in this wavelength region and high dry etching resistance have been proposed. ArF excimer laser wavelength 1
The use of an adamantane skeleton as a chemical structure that is transparent in the deep ultraviolet region including 93 nm and can impart dry etching resistance to a resist material instead of an aromatic ring is disclosed in Japanese Patent Application Laid-Open No. 4-39.
665 and JP-A-5-265212, and similarly, the use of a norbornane skeleton is disclosed in JP-A-5-80515 and JP-A-5-257284.
In addition to these structures, a tricyclodecanyl group, etc.
The fact that an alicyclic structure is generally effective is disclosed in JP-A-7-2823.
No. 7, JP-A-8-259626.

The wavelength of the ArF excimer laser is 193 nm.
With respect to a resist material which has a chemical structure transparent in the deep ultraviolet region and which is capable of developing with aqueous alkali, JP-A-4-39665 and JP-A-4-184
As disclosed in JP-A-345-345, JP-A-4-226461 and JP-A-5-80515, attempts have been made to utilize the carboxylic acid structure of acrylic acid or methacrylic acid. In these, the aqueous alkali solubility of the portion dissolved in the developer in aqueous alkali development depends on the carboxylic acid structure of acrylic acid or methacrylic acid. JP-A-8-259626 discloses a polymer compound in which a carboxylic acid group is added to an alicyclic structure introduced into a methacrylic acid ester side chain.

In a phenol structure conventionally used as an alkali-soluble group, pKa = 10.0 (phenol), whereas in these carboxylic acid structures, pKa is
The value is low at Ka = 4.8 (acetic acid) and the acidity is high. Therefore, when they are used as the alkali-soluble groups of the base resin, the resin having a carboxylic acid structure generally has a higher dissolution rate in an aqueous alkali at the same mole fraction, and has a lower dissolution rate than the resin having a phenol structure. The resin having a carboxylic acid structure dissolves even in an alkaline developer having a high concentration. When a resin having a carboxylic acid as described above is used, if a crosslinking agent as disclosed in JP-A-62-164045 is used, a carboxylic acid having a high acidity remains in a cross-linked portion. However, there is a disadvantage that the alkaline developer infiltrates and swells to form a fine pattern. Further, when a compound having a dissolution inhibiting action is formed by the acid generated upon exposure, as disclosed in JP-A-4-165359, a resin having a carboxylic acid does not provide a dissolution contrast and a negative resist. There was a drawback that it did not become. On the other hand, as a method for forming a non-swelling negative pattern using a resin having a carboxylic acid structure, a γ- or δ-hydroxy acid structure disclosed in Japanese Patent Application Laid-Open No. There is known one utilizing the change into a γ-lactone or δ-lactone structure by a reaction.

[0008]

SUMMARY OF THE INVENTION Japanese Patent Application Laid-Open No. H11-1096
In the pattern formation method using a resin having a γ- or δ-hydroxy acid structure found in JP-A-27-27, the resin used therein is 5-methylenebicyclo [2.2.
1] It is synthesized by subjecting a non-conjugated cyclic diene such as hept-2-ene to maleic anhydride to a radical copolymer, reducing the maleic anhydride portion to lactone, and hydrolyzing and modifying it. You. However, since this resin has high hydrophilicity, the conventional g-line, i-line and K
2.38% by weight aqueous solution of tetramethylammonium hydroxide, which is a standard developer used in a microlithography process using a resist for rF excimer laser, has too high a developer concentration to obtain high resolution. However, there is a drawback that a diluted developer must be used.

It is a first object of the present invention to provide a method of manufacturing a semiconductor device including a pattern having excellent resolution performance capable of developing a fine pattern without swelling. A second object of the present invention is to provide a radiation-sensitive composition used for forming such a pattern.

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the specification of the present application, typical ones are summarized as follows. A coating film comprising a radiation-sensitive composition containing at least an α-alkyl-δ-hydroxy acid structure or an α, α'-dialkyl-δ-hydroxy acid structure is formed on a predetermined substrate, and a predetermined pattern is formed on the coating film. Is irradiated with actinic radiation, and the carboxylic acid structure of the irradiated portion of the actinic radiation is changed to an α-alkyl-δ-lactone structure or α, α′-dialkyl-δ.
-A lactone structure, and then a predetermined pattern is developed in the coating film using an aqueous alkaline developer.

The alkyl group in the α-alkyl-δ-hydroxy acid structure or α, α'-dialkyl-δ-hydroxy acid structure is preferably an alkyl group having 1 to 10 carbon atoms. Examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a cyclohexyl group. These may be used alone or as a mixture. The two alkyl groups having the α, α′-dialkyl-δ-hydroxy acid structure may be the same alkyl group or a combination of different alkyl groups.

The α-alkyl-δ-hydroxy acid structure and the α, α′-dialkyl-δ-hydroxy acid structure can be used alone or in a mixture of both. As for the alkyl group, different alkyl groups can be mixed.

The α-alkyl-δ-hydroxy acid structure or the α, α′-dialkyl-δ-hydroxy acid structure is an alkali-soluble group and has one or two carbon atoms at the α-position, ie, at the carbon atom adjacent to the carboxyl group. Has an alkyl group.
As a result, the hydrophobicity around the carboxyl group is increased, and a necessary dissolution rate is obtained in a 2.38% aqueous solution of tetramethylammonium hydroxide or the like.

An α-alkyl-δ-hydroxy acid structure or an α, α'-dialkyl-δ-hydroxy acid structure undergoes a dehydration reaction by an acid catalyst, and undergoes intramolecular esterification to form a corresponding α-alkyl-δ-lactone structure. Or α, α '
-Dialkyl-δ-lactone structure. As a result, the number of carboxylic acids that are alkali-soluble groups is greatly reduced, and those that were initially soluble in an aqueous alkaline developer become insoluble. As a result, a negative pattern is formed by development with an aqueous alkaline developer. The generated δ
-The lactone structure is not hydrolyzed in the commonly used aqueous solution of tetraalkylammonium hydroxide,
Stable during development. In addition, in the portion where the δ-lactone structure is generated, no swelling occurs because the developer does not penetrate.

Here, the acid for causing the acid-catalyzed reaction is realized by using an acid generator that generates an acid upon irradiation with actinic radiation. Specific acid generators include onium salts such as triphenylsulfonium triflate,
Examples thereof include sulfonyloxyimides such as trifluoromethanesulfonyloxynaphthylimide, and sulfonic acid esters, and may be any as long as they generate an acid by irradiation with actinic radiation, for example, an ArF excimer laser.

The α-alkyl-δ-hydroxy acid structure or α, α′-dialkyl-δ-hydroxy acid structure is preferably a chemical structure represented by the following formula (1) or (2). desirable.

[0017]

Embedded image

Embedded image In the formula, R ¹ and R ² each represent an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a cyclohexyl group. These may be used alone or as a mixture.

Further, α- represented by the formula (1) or (2)
The alkyl-δ-hydroxy acid structure and the α, α′-dialkyl-δ-hydroxy acid structure can be used alone or in a mixture of both. Also, different alkyl groups can be mixed for R ¹ and R ² there. Further, R ¹ , R
² may be connected to each other to form a cyclic alkyl group. The solubility of the carboxylic acid can be controlled to some extent by changing the carbon number, series, and size of these alkyl groups. Furthermore, since the above formula (1) or (2) contains an alicyclic structure, it has a feature that it has high dry etching resistance while maintaining transparency in the wavelength region of an ArF excimer laser having a wavelength of 193 nm. is there. The α-alkyl-δ-hydroxy acid structure or the α, α′-dialkyl-δ-hydroxy acid structure, and among them, the carboxylic acid structure represented by the formula (1) or (2), is used for the radiation-sensitive composition. It is desirable to be included in the constituent film forming components. The film-forming component generally has a weight average molecular weight of 1,000 to 300,0.
A high molecular compound of about 00 may be mentioned, but it is not limited to a high molecular compound as long as it can be coated with a solvent, and may be an oligomer or a low molecular compound capable of forming a film. The number of the carboxylic acid structures contained in the film-forming component may be at least the amount at which the film-forming component becomes soluble in the developer used. The above-mentioned film-forming component or the radiation-sensitive composition containing the same preferably further contains an alicyclic structure. Examples of the alicyclic structure include adamantyl, norbornane, tricyclodecane and androstane structures. These structures have high dry etching resistance,
Since it is transparent in the wavelength region of far ultraviolet light, particularly ArF excimer laser light, by including such a structure, dry etching resistance can be improved without reducing transmittance.

The active radiation to be used includes far ultraviolet light having a wavelength of 250 nm or less, and vacuum ultraviolet light such as ArF excimer laser light. Note that an electron beam, EUV, X-ray, or the like can also be used. When irradiating a predetermined pattern of actinic radiation, vacuum ultraviolet light such as ArF excimer laser light is formed into a predetermined pattern through a normal mask or reticle. In this case, it is more preferable that the mask be a phase shift mask because a high-resolution pattern can be obtained.
Examples of the phase shift mask include a Levenson type, an outrigger type, a halftone type, and a shifter edge type, but any phase shift mask may be used.

As the aqueous alkaline developer to be used, an aqueous solution of a tetraalkylammonium hydroxide having 1 to 5 carbon atoms can be used. Also, general-purpose 2. has been used for developing i-line and g-line resists and KrF excimer laser resists.
Although a 38% aqueous solution of tetramethylammonium hydroxide can be used, an appropriately diluted solution thereof can also be used.

It is preferable that the method further includes a step of heating the coating film after the step of irradiating with the actinic radiation and before the step of developing with an aqueous alkaline developer. By the step of heating the coating film, the intramolecular esterification reaction for generating δ-lactone proceeds more efficiently.

The method may further include a step of forming a resist pattern on a semiconductor substrate by any one of the above-described pattern forming methods and etching the substrate based on the formed resist pattern or implanting ions into the substrate. It was done.

Examples of the etching method used include dry etching methods such as plasma etching, reactive ion etching, and reactive ion beam etching, and wet etching methods.

Examples of the substrate to be processed include an oxide film such as a silicon dioxide film and a coatable glass film formed by a CVD method or a thermal oxidation method, and a nitride film such as a silicon nitride film.
In addition, various metal films such as aluminum and its alloys, tungsten, and polycrystalline silicon can be used. An element, particularly a memory element, manufactured by the method for manufacturing a semiconductor device according to the present invention includes:
Since a fine pattern can be formed, the degree of integration can be increased. Therefore, since the elements can be made small, the number of elements that can be obtained from one wafer increases, and the yield improves. Also, the bit cost can be reduced. Therefore, it is suitable for manufacturing a flash memory or a DRAM (Dynamic Random Access Memory) which is a nonvolatile semiconductor memory device.

Further, the radiation-sensitive composition comprises a compound having an α-alkyl-δ-hydroxy acid structure or an α, α′-dialkyl-δ-hydroxy acid structure as an alkali-soluble group, and an acid generated by irradiation with actinic radiation. At least a compound represented by the formula:

The alkyl group in the α-alkyl-δ-hydroxy acid structure or α, α'-dialkyl-δ-hydroxy acid structure is preferably an alkyl group having 1 to 10 carbon atoms. Examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a cyclohexyl group. These may be used alone or as a mixture. The two alkyl groups having the α, α′-dialkyl-δ-hydroxy acid structure may be the same alkyl group or a combination of different alkyl groups.

The α-alkyl-δ-hydroxy acid structure and the α, α'-dialkyl-δ-hydroxy acid structure can be used alone or in a mixture of both. As for the alkyl group, different alkyl groups can be mixed.

The α-alkyl-δ-hydroxy acid structure or the α, α′-dialkyl-δ-hydroxy acid structure undergoes a dehydration reaction by an acid catalyst to undergo intramolecular esterification to form a corresponding α-alkyl-δ-lactone structure. Or α, α '
-Dialkyl-δ-lactone structure. As a result, the number of carboxylic acids that are alkali-soluble groups is greatly reduced, and those that were initially soluble in an aqueous alkaline developer become insoluble. As a result, a negative pattern is formed by development with an aqueous alkaline developer. The generated δ
-The lactone structure is not hydrolyzed in the commonly used aqueous solution of tetraalkylammonium hydroxide,
Stable during development. In addition, in the portion where the δ-lactone structure is generated, no swelling occurs because the developer does not penetrate.

The above α- used in the radiation-sensitive composition.
The alkyl-δ-hydroxy acid structure or α, α'-dialkyl-δ-hydroxy acid structure is more preferably a chemical structure represented by the following formula (1) or (2).

[0030]

Embedded image

Embedded image In the formula, R ¹ and R ² each represent an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a cyclohexyl group. These may be used alone or as a mixture.

Further, α- represented by the formula (1) or (2)
The alkyl-δ-hydroxy acid structure and the α, α′-dialkyl-δ-hydroxy acid structure can be used alone or in a mixture of both. Also, different alkyl groups can be mixed for R ¹ and R ² there. Further, R ¹ , R
² may be connected to each other to form a cyclic alkyl group. The solubility of the carboxylic acid can be controlled to some extent by changing the carbon number, series, and size of these alkyl groups. Formula (1) or (2)
Some of them contain an alicyclic structure, so that the wavelength 1
There is a feature that the dry etching resistance is high while maintaining transparency in the wavelength region of the 93 nm ArF excimer laser. The α-alkyl-δ-hydroxy acid structure or α, α′-dialkyl-δ-hydroxy acid structure, and among them, the carboxylic acid structure represented by the formula (1) or (2) constitutes a radiation-sensitive composition. It is desirable to be included in the film-forming component. The film-forming component generally includes a high molecular compound having a weight average molecular weight of about 1,000 to 300,000.
An oligomer or a low molecular compound capable of forming a film may be used as long as it can be applied with a solvent. The number of the carboxylic acid structures contained in the film-forming component may be at least the amount at which the film-forming component becomes soluble in the developer used. The above-mentioned film-forming component or the radiation-sensitive composition containing the same preferably further contains an alicyclic structure. Examples of the alicyclic structure include adamantyl, norbornane, tricyclodecane and androstane structures. These structures have high dry etching resistance, far ultraviolet light,
In particular, since it is transparent in the wavelength region of ArF excimer laser light, by including such a structure, dry etching resistance can be improved without reducing transmittance. Examples of the compound capable of generating an acid upon irradiation with actinic radiation include onium salts such as triphenylsulfonium triflate, dimethylphenylsulfonium triflate, dimethyl-4-hydroxynaphthyl triflate, N-trifluoromethanesulfonyloxynaphthylimide, Sulfonyloxyimides such as -methanesulfonyloxynaphthylimide, N-trifluoromethanesulfonyloxysuccinimide, and N-perfluorooctanesulfonyloxysuccinimide; and sulfonic acid esters.
It is only necessary to generate an acid by irradiation with an rF excimer laser or the like, and the invention is not limited thereto. Further, two or more of these acid generators may be used simultaneously.

The acid generator is used in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the film-forming component of the radiation-sensitive composition.
It is desirable to use it by weight, more preferably in the range of 0.5 to 20 parts by weight. Radiation-sensitive compositions also include basic compounds such as 2-benzylpyridine, phenylpyridine, tripentylamine, and triethanolamine, and tetraiodide to improve resolution, process stability, and storage stability. Salts such as methylammonium, tetrapentylammonium chloride and tetraethylphosphonium iodide may be added. It is desirable to add 0.01 to 100 parts by weight of these basic compounds and salts to the acid generator used.

In order to enhance the heat resistance of the formed pattern, the radiation-sensitive composition contains hexamethoxymethylmelamine, 1,3,4,6-tetrakis (methoxymethyl) glucoururil, 1,4-dioxane as a crosslinking agent. −2,
3-diol and the like can be contained. These crosslinking agents are desirably used in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the film-forming component of the radiation-sensitive composition.

The radiation-sensitive composition is used by dissolving it in a solvent and spin-coating it on a substrate as a solution. At this time, any solvent may be used as long as the above components are sufficiently dissolved and a uniform coating film can be formed by spin coating. Moreover, you may use individually or in mixture of 2 or more types.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. First, prior to the examples, synthetic examples of the materials used in the present invention will be described. <Synthesis Example 1> Synthesis of polymer (3f) having α-methyl-δ-hydroxy acid structure Under dry nitrogen, 9.3 g of epiandrosterone (0.0 g
32 mol) was dissolved in 150 ml of benzene, and 3.4 g (0.048 mol) of pyrrolidine was added thereto. The mixture was cooled on ice, and the temperature did not exceed 5 ° C., and over 30 minutes, 80 ml of a 0.2 M titanium (IV) chloride toluene solution was used.
(0.016 mol) was added. After dropping, the mixture was allowed to stand at 0 ° C. for 1 hour, and then left at room temperature for about 20 hours.

After the formed precipitate was separated by filtration, the solvent was distilled off from the filtrate under reduced pressure to obtain a solid. Further, it was recrystallized with acetone to obtain epiandrosterone enamine (3a)
7.7 g (0.022 mol) were obtained. Since this enamine was unstable to air oxidation, it was used immediately for the next reaction.

[0037]

Embedded image Enamine of epiandrosterone under nitrogen flow (3a)
7.5 g (0.022 mol) of dry dioxane 150
in 1 ml of methyl iodide.
32 mol) and heated under reflux for about 14 hours.
Thereafter, 75 ml of water and 5 ml of acetic acid were added, and the mixture was further heated under reflux for 5 hours. After heating under reflux, the solvent was distilled off under reduced pressure, and the mixture was concentrated.
The mixture was extracted twice with 0 ml, washed with water and dried over magnesium sulfate. After the ethyl acetate was distilled off under reduced pressure, recrystallization was performed with acetone, and methylated epiandrosterone (3.
b) 5.4 g (0.018 mol) were obtained.

[0038]

Embedded image 5.2 g of methylated epiandrosterone (3b) (0.
017 mol), pyridine 1.5 g (0.019 mol)
l) was dissolved in 200 ml of tetrahydrofuran, and a solution of 1.6 g (0.018 mol) of acrylic acid chloride in 30 ml of tetrahydrofuran was added dropwise at 0 ° C. After the addition, the mixture was further stirred at room temperature for several hours, and the precipitated hydrochloride of pyridine was filtered off. Ethyl acetate 150 in the filtrate
Then, the mixture was washed four times with 100 ml of water. After washing with water, the organic layer was dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. The residue crystallized. This was recrystallized from an ethanol / tetrahydrofuran mixed solvent to give methylated epiandrosterone acrylate (3c) 3.1.
g was obtained.

[0039]

Embedded image 4.0 g of the synthesized methylated epiandrosterone acrylate (3c) was dissolved in 40 ml of THF, and 2,2′-azobis (isobutyronitrile) was used as a reaction initiator.
0.19 g was added, and the mixture was refluxed by heating at 70 ° C. to carry out polymerization for 6 hours. After the polymerization, the solution was poured into 500 ml of n-hexane, and the polymer was precipitated and dried to obtain 3.6 g of poly (methylated epiandrosterone acrylate) (3d).

[0040]

Embedded image In the formula, n represents an integer.

When the molecular weight of this polymer in tetrahydrofuran was measured by gel permeation chromatography (GPC), the weight average molecular weight was 2,800 and the number average molecular weight was 2,300.

The polymer synthesized as described above (3d)
3.0 g was dissolved in tetrahydrofuran (100 ml), and acetic acid (100 ml) and hydrogen peroxide (50 ml) were added thereto.
Stirred at 0 ° C. for several hours. After the reaction, the solvent was distilled off under reduced pressure, and the mixture was poured into 500 ml of water. The precipitate was separated by filtration and dried to obtain 2.7 g of a polymer (3e) having an α-methyl-δ-lactone structure.

[0043]

Embedded image In the formula, n represents an integer.

The polymer (3e) synthesized as described above
2.5 g is dissolved in 100 ml of tetrahydrofuran,
150 ml of 0.5N aqueous sodium hydroxide solution was added, and 2
Stirred for hours. An aqueous solution of hydrochloric acid was gradually added thereto to make it weakly acidic. About 150 ml of ethyl acetate was added to this solution and extraction was performed twice, and the obtained organic layer was washed twice with 100 ml of water. After washing, the organic layer was dried over anhydrous sodium sulfate, and then the solvent was reduced by distillation under reduced pressure.
The mixture was poured into 00 ml, and the polymer was precipitated and dried to obtain 2.3 g of a white powdery polymer (3f) having an α-methyl-δ-hydroxy acid structure. The structure of the obtained polymer was found to be mainly the following structure from various analytical methods.

[0045]

Embedded image In the formula, l and m represent an integer.

100 parts by weight of the obtained polymer (3f) having an α-methyl-δ-hydroxy acid structure was dissolved in 1000 parts by weight of 1-methoxy-2-propanol and filtered with a filter having a pore size of 0.2 μm. It was spin-coated and baked at 100 ° C. for 2 minutes to obtain a thin film. When the film (300 nm) applied on the silicon substrate was immersed in an aqueous solution of tetramethylammonium hydroxide (concentration: 2.38% by weight), the interference color changed and dissolved in 10 seconds.
The remaining film became zero. The absorption spectrum of the film coated on the lithium fluoride substrate was measured using a vacuum ultraviolet spectrometer (ARC).
As a result, the absorbance at 193 nm showed a film thickness of 1.0
It was 0.27 in μm, indicating that the absorption was small. <Synthesis Example 2> Synthesis of polymer (4f) having α, α'-dimethyl-δ-hydroxy acid structure 7.0 g of methylated epiandrosterone (3b) synthesized as in Synthesis Example 1 was dissolved in 100 ml of acetic acid. Then, 0.1 g of p-toluenesulfonic acid monohydrate was added thereto,
Further, 50 ml of 30% hydrogen peroxide solution was added, and the mixture was stirred at 50 ° C. for several hours. After the reaction, the solvent was removed by distillation under reduced pressure, and the mixture was poured into about 500 ml of water. After standing overnight, the precipitated solid was filtered off, redissolved in about 50 ml of tetrahydrofuran, poured again into about 500 ml of water, left overnight, and the precipitated solid was filtered off and dried to obtain α. 6.0 g of compound (4a) having a -methyl-δ-lactone structure was obtained.

Embedded image Next, 26 ml of dry tetrahydrofuran was added to 24 ml (0.0475 mol) of a 2.0 M solution of lithium diisopropylamide in heptane / tetrahydrofuran / ethylbenzene under a nitrogen stream, and the mixture was cooled to -78 ° C. Thereafter, 5.8 g of the compound (4a) having a δ-lactone structure
(0.019 mol) in dry tetrahydrofuran 20 m
1 was added dropwise over 1 hour, and the mixture was further stirred at -78 ° C for 30 minutes. Next, a solution of 3.4 g (0.019 mol) of hexamethylphosphoric triamide, 8.1 g (0.057 mol) of methyl iodide and 5 ml of dry tetrahydrofuran was quickly added dropwise, and the mixed solution was gradually cooled to 0 ° C. Warmed and stirred for 3 hours. Thereafter, 50 ml of a 10% hydrochloric acid aqueous solution was added to the reaction solution to stop the reaction,
200 ml of diethyl ether was added, and the ether layer was washed with water,
Next, it was washed with saturated saline and dried over magnesium sulfate. Thereafter, 5.5 g of the compound (4b) having an α, α′-dimethyl-δ-lactone structure was obtained by removing the solvent.
I got

[0047]

Embedded image 5.4 g (0.017 mol) of the compound (4b) having an α, α′-dimethyl-δ-lactone structure, pyridine 1.
5 g (0.019 mol) of tetrahydrofuran 200
dissolved in 1.6 ml of acrylic acid chloride
(0.018 mol) in 30 ml of tetrahydrofuran was added dropwise at 0 ° C. After the addition, the mixture was further stirred at room temperature for several hours, and the precipitated hydrochloride of pyridine was filtered off. 150 ml of ethyl acetate was added to the filtrate, and 100 ml of water was added.
For 4 times. After washing with water, the organic layer was dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure. The residue crystallized. This was recrystallized from a mixed solvent of ethanol / tetrahydrofuran to obtain an acrylate monomer (4c) 3.4 having an α, α'-dimethyl-δ-lactone structure.
g was obtained.

[0048]

Embedded image 3.3 g of the synthesized acrylate monomer (4c) having an α, α'-dimethyl-δ-lactone structure was added to THF 30
Then, 0.16 g of 2,2′-azobis (isobutyronitrile) was added as a reaction initiator, and the mixture was heated at 70 ° C. under reflux and polymerized for 6 hours. After the polymerization, the solution was poured into 500 ml of n-hexane, and the polymer was precipitated and dried to obtain 3.1 g of a polymer (4d) having an α, α′-dimethyl-δ-lactone structure.

[0049]

Embedded image In the formula, n represents an integer.

When the molecular weight of this polymer in terms of polystyrene was examined in tetrahydrofuran by gel permeation chromatography (GPC), the weight average molecular weight was 2,900 and the number average molecular weight was 2,300.

Polymer (4d) synthesized as described above
Dissolve 2.9 g in 100 ml of tetrahydrofuran,
150 ml of 0.5N aqueous sodium hydroxide solution was added, and 2
Stirred for hours. An aqueous solution of hydrochloric acid was gradually added thereto to make it weakly acidic. About 150 ml of ethyl acetate was added to this solution and extraction was performed twice, and the obtained organic layer was washed twice with 100 ml of water. After washing, the organic layer was dried over anhydrous sodium sulfate, and then the solvent was reduced by distillation under reduced pressure.
The polymer was precipitated and dried to obtain 2.6 g of a white powdery polymer (4f) having an α, α′-dimethyl-δ-hydroxy acid structure. The structure of the obtained polymer was found to be mainly the following structure from various analytical methods.

[0052]

Embedded image In the formula, l and m represent an integer.

100 parts by weight of the obtained polymer (4f) having an α, α'-dimethyl-δ-hydroxy acid structure was
It was dissolved in 1000 parts by weight of -methoxy-2-propanol and filtered through a filter having a pore size of 0.2 µm. It was spin-coated and baked at 100 ° C. for 2 minutes to obtain a thin film. When the film (300 nm) applied on the silicon substrate was immersed in an aqueous solution of tetramethylammonium hydroxide (concentration: 0.113% by weight), the film was not dissolved in a developing solution of that concentration. Next, when immersed in an aqueous solution of tetramethylammonium hydroxide (concentration: 2.38% by weight), the interference color was changed and dissolved in 20 seconds, and the residual film became zero. The absorption spectrum of the film coated on the lithium fluoride substrate was measured with a vacuum ultraviolet spectrometer (manufactured by ARC).
The absorbance in nm was 0.26 at a film thickness of 1.0 μm, indicating that the absorption was small. <Embodiment 1> Polymer (3f) 10 having an α-methyl-δ-hydroxy acid structure synthesized in Synthesis Example 1
0 parts by weight, 2 parts by weight of an acid generator triphenylsulfonium triflate, and 0.01 parts by weight of 2-benzylpyridine.
-Methoxy-2-propanol dissolved in 900 parts by weight,
The solution was filtered using a Teflon (registered trademark) filter having a pore size of 0.20 μm to obtain a resist solution.

The above resist solution was spin-coated on a silicon substrate treated with hexamethyldisilazane, and heated at 110 ° C. for 2 minutes after coating to form a resist film having a thickness of 350 nm. This resist film was exposed through an Levenson-type phase shift mask using an ArF excimer laser stepper (ISI Microstep, NA = 0.60). After that, baking was performed at 120 ° C. for 2 minutes after exposure. When the resist film was immersed in an aqueous solution of tetramethylammonium hydroxide (2.38% by weight) at 23 ° C., the unexposed portion of the film dissolved in 12 seconds. Therefore, the development was performed for 24 seconds, twice as long, and
Rinse with pure water for 5 seconds. As a result, the exposure amount was 30 mJ /
In cm ² , a negative 0.12 μm line and space pattern was obtained. At this time, no swelling of the pattern was observed. When the obtained substrate with the pattern was immersed in tetrahydrofuran, the pattern was instantaneously dissolved, and it was found that no cross-linking had occurred.

Further, regarding the above resist film, CHF
Etching was performed by a parallel plate type reactive ion etching apparatus using _three gases. The conditions were CHF ₃ flow rate 35 sccm, gas pressure 10 mTorr, and RF bias power 150 W. As a result, the etch rate of this resist was 1.19 when the commercially available novolak resin was 1.0, indicating that the dry etching resistance was high.

The above resist applied on the NaCl plate is
Similarly, an ArF excimer laser beam was irradiated at 30 mJ / cm ² , and infrared absorption spectra before and after baking after exposure were measured by FT-1720X manufactured by PerkinElmer. As a result, it was found that the peak around 3466 cm ⁻¹ due to the carboxylic acid was significantly reduced after the post-exposure bake. 1712cm due to lactone
It was found that the peak of ^-1 increased.

The resist film initially had the structure of the polymer (1f) having an α-methyl-δ-hydroxy acid structure, and was alkali-soluble by its carboxylic acid. ArF excimer laser exposure generated trifluoromethanesulfonic acid from the acid generator triphenylsulfonium triflate. Using the acid as a catalyst during the post-exposure bake, the structure of the δ-hydroxy acid in the polymer undergoes a dehydration reaction in the molecule and is esterified to form a δ-lactone structure. As a result, the exposed part becomes insoluble in the alkaline developer,
A negative pattern was formed. The mechanism of the negative conversion at this time was not a crosslinking reaction but a large decrease in the amount of the carboxylic acid due to the lactonization, so that swelling was avoided and a fine pattern could be formed. <Embodiment 2> α used in Embodiment 1 of the invention
Polymer having a -methyl-δ-hydroxy acid structure (3
Instead of f), 100 parts by weight of the polymer (4f) having an α, α′-dimethyl-δ-hydroxy acid structure synthesized in Synthesis Example 2, 3 parts by weight of an acid generator triphenylsulfonium nonaflate, tetrapentylammonium 0.01 parts by weight of chloride is 1-methoxy-2-propanol 9
The resultant was dissolved in 00 parts by weight and filtered using a Teflon filter having a pore size of 0.20 μm to obtain a resist solution.

The resist solution described above is spin-coated on a silicon substrate treated with hexamethyldisilazane in the same manner as in the first embodiment of the present invention, and then heated at 110 ° C. for 2 minutes to form a resist having a thickness of 340 nm. A film was formed.

In the same manner as in the first embodiment of the present invention, exposure was performed through a chromium mask using an ArF excimer laser stepper, followed by baking after exposure at 120 ° C. for 2 minutes. When the resist film was immersed in an aqueous solution of tetramethylammonium hydroxide (2.38% by weight) at 23 ° C., the unexposed portion of the film dissolved in 25 seconds. So the development
The cleaning was performed for 50 seconds, which is about twice the time, and then rinsed with pure water for 20 seconds. As a result, at an exposure amount of 36 mJ / cm ² ,
A negative 0.16 μm line and space pattern was obtained. At this time, no swelling of the pattern was observed.

Further, with respect to the above resist film, Example 1
Etching was performed under the following conditions. As a result, the etch rate of this resist was 1.17 when the etching rate of the coating film of a commercially available novolak resin was 1.0, indicating that the dry etching resistance was high. <Embodiment 3> In the same manner as in Synthesis Example 1, a polymer (5) having an α-ethyl-δ-hydroxy acid structure in which the methyl group at the α-position of a δ-hydroxy acid was changed to an ethyl group was synthesized.

[0061]

Embedded image In the formula, l and m represent an integer.

100 parts by weight of a polymer (5) having an α-ethyl-δ-hydroxy acid structure, 3 parts by weight of an acid generator triphenylsulfonium nonaflate, and 0.015 parts by weight of phenylpyridine are mixed with 1-methoxy-2-propanol The solution was dissolved in 900 parts by weight and filtered using a Teflon filter having a pore size of 0.20 μm to obtain a resist solution.

The resist solution was spin-coated on a silicon substrate treated with hexamethyldisilazane in the same manner as in the first embodiment of the invention, and then heated at 110 ° C. for 2 minutes to form a film having a thickness of 0.35 μm. Was formed.

As in the first embodiment of the present invention, exposure was performed by an ArF excimer laser stepper through a phase shift mask, followed by baking after exposure at 110 ° C. for 2 minutes. 2
When the resist film was immersed in an aqueous solution of tetramethylammonium hydroxide (2.38%) at 3 ° C., the unexposed portion of the film dissolved in 20 seconds. Therefore, development was performed for 40 seconds, twice as long, and then rinsed with pure water for 15 seconds. As a result, a negative type 0.12 μm line and space pattern was obtained at an exposure amount of 35 mJ / cm ² .
At this time, no swelling of the pattern was observed.

The resist film was exposed through a Levenson-type phase shift mask using a KrF excimer laser stepper (NA = 0.45). After baking at 110 ° C. for 2 minutes after exposure, the resist film was immersed in an aqueous solution of tetramethylammonium hydroxide (2.38% by weight) at 23 ° C., and the unexposed portion of the film dissolved in 20 seconds. Therefore, development takes twice as long as 4 times.
This was performed for 0 seconds, and then rinsed with pure water for 15 seconds. As a result, at an exposure dose of 50 mJ / cm ² , a negative 0.18 μm
A line and space pattern was obtained. At this time, no swelling of the pattern was observed. Further, the resist film was etched under the conditions of Example 1. As a result, the etching rate of this resist was 1.0 when the etching rate of a commercially available novolak resin coating film was 1.0.
1.18, which indicates that the dry etching resistance is high. <Embodiment 4> In the same manner as in Synthesis Example 2, α-methyl-α′-ethyl-δ-hydroxy obtained by replacing one of the two methyl groups at the α-position of a δ-hydroxy acid with an ethyl group. Polymer (6) having an acid structure was synthesized.

[0066]

Embedded image In the formula, l and m represent an integer.

100 parts by weight of the polymer (6) having an α-methyl-α′-ethyl-δ-hydroxy acid structure, 3 parts by weight of an acid generator trifluoromethanesulfonyloxysuccinimide, 1,3,4,6- 10 parts by weight of tetrakis (methoxymethyl) glucoururil was dissolved in 600 parts by weight of diacetone alcohol, and filtered using a Teflon filter having a pore size of 0.20 μm to obtain a resist solution.

The resist solution was spin-coated on a silicon substrate treated with hexamethyldisilazane in the same manner as in the first embodiment of the present invention, and then heated at 120 ° C. for 2 minutes to form a film having a thickness of 0.33 μm. Was formed.

Exposure was performed by an ArF excimer laser stepper through a phase shift mask in the same manner as in the first embodiment of the present invention, followed by baking after exposure at 120 ° C. for 2 minutes. 2
When the resist film was immersed in an aqueous solution of tetramethylammonium hydroxide (2.38% by weight) at 3 ° C., the unexposed portion of the film dissolved in 35 seconds. So the development is 2
The cleaning was performed for 70 seconds, which was twice as long, followed by rinsing with pure water for 20 seconds. As a result, a negative 0.13 μm line and space pattern was obtained at an exposure amount of 35 mJ / cm ² .
At this time, no swelling of the pattern was observed.

Further, this resist film is subjected to an acceleration voltage of 50 k
A line and space pattern was exposed using a V electron beam lithography system. Baking and development were performed under the same conditions as in the ArF excimer laser exposure.
At μC / cm ² , a negative 0.13 μm line and space pattern was obtained. At this time, no swelling of the pattern was observed.

Further, with respect to the above resist film, Example 1
Etching was performed under the following conditions. As a result, the etching rate of this resist was 1.15 when the etching rate of the coating film of a commercially available novolak resin was 1.0, indicating that the dry etching resistance was high. <Embodiment 5> FIG. 1 is a sectional view of a known MOS (metal-oxide-semiconductor) transistor. The transistor has a structure in which a drain current flowing between the source electrode 16 and the drain electrode 17 is controlled by a voltage applied to the gate electrode 18.

Here, the steps of fabricating such a structure consist of dozens of steps. These steps can be roughly divided into three steps: a step up to formation of a field oxide film, a step up to gate formation, and a final step. You can do it. Here, the process up to the first field oxide film formation (FIG. 2) includes a process of forming a resist pattern on the silicon nitride film. This field oxide film was formed as in the following examples.

As shown in FIG. 2A, a 50 nm oxide film 22 is formed on a p-type silicon wafer 21 by a known method, and a 200 nm silicon nitride film is formed thereon by plasma CVD to form a substrate. . Example 1
A resist pattern 24 having a 0.30 μm line is formed by the materials and methods shown in FIG. 2 (FIG. 2B). After the silicon nitride film is etched by a known method using the resist pattern as a mask (FIG. 2C), boron ions for channel stopper are implanted using the resist as a mask again. After removing the resist (Fig. 2
(D)) A 1.2 μm field oxide film is formed in the element isolation region by selective oxidation using the silicon nitride film as a mask (FIG. 2E).

Thereafter, a gate forming step and a final step were performed according to a known method. After etching the silicon nitride film, the gate is oxidized to grow polycrystalline silicon (FIG. 2 (f)). A resist pattern of 0.12 μm line is formed on this substrate by using the pattern forming method described in the third embodiment (FIG. 2G). Using this resist pattern as a mask, the polysilicon is etched by a known method to form a gate (FIG. 2 (h)). Source,
The thin oxide film of the drain is etched, and then arsenic is diffused in the polysilicon gate, source and drain, and an oxide film is formed in the polysilicon gate, source and drain regions. The contacts for aluminum wiring to the gate, source, and drain are viewed from the opening, aluminum coating and patterning are performed, a protective film is formed, and pads for bonding are opened. Thus, a MOS transistor as shown in FIG. 1 is formed.

Here, regarding the MOS transistor,
In particular, a method for forming a field oxide film has been described. However, it is needless to say that the present invention is not limited to this, but can be applied to other semiconductor device manufacturing methods and processes. <Embodiment 6> A semiconductor memory device was manufactured by using the pattern forming method described in any one of Embodiments 1 to 4 of the present invention. FIG. 3 is a cross-sectional view showing main steps of manufacturing the device. As shown in FIG. 3A, a P-type Si semiconductor 3
1 is used as a substrate, and an element isolation region 32 is formed on the surface thereof by using a known element isolation technique.

Next, for example, polycrystalline Si having a thickness of 150 nm
And a 200 nm-thick SiO ₂ layered word line 33 are formed.
50 nm of SiO ₂ is deposited and processed anisotropically to form SiO ₂ side spacers 34 on the side walls of the word lines.
Next, the n diffusion layer 35 is formed by a usual method. Next, FIG.
As shown in FIG. 2B, a data line 36 made of polycrystalline Si, a refractory metal silicide, or a laminated film of these is formed through a normal process. Next, as shown in FIG. 3C, a storage electrode 38 made of polycrystalline Si is formed through a normal process.

Thereafter, Ta ₂ O ₅ , Si ₃ N ₄ , S
A capacitor insulating film 39 is formed by depositing iO ₂ , BST, PZT, ferroelectric, or a composite film thereof. Subsequently, a low-resistance conductor such as polycrystalline Si, high-melting-point metal, high-melting-point metal silicide, or Al or Cu is applied to form the plate electrode 40. Next, FIG.
As shown in FIG. 7, the wiring 41 is formed through a normal process.
Next, a memory element was manufactured through a normal wiring forming step and a passivation step.

Although only typical production steps have been described here, other ordinary production steps were used. Further, the present invention can be applied even if the order of each step is changed. In most of the lithography processes in the device manufacturing process, the pattern forming method described in any one of the first to third embodiments of the present invention is applied. However, the process or the pattern size that is not suitable for forming a pattern with a negative resist is not suitable. The present invention does not necessarily need to be applied to a process having a large value. For example, the present invention was not applied to a conductive hole forming step in a passivation step or a pattern formation in an ion implantation mask forming step.

Next, a pattern formed by lithography will be described. FIG. 4 shows a pattern arrangement of a memory portion of a typical pattern constituting a manufactured memory element. 42 is a word line, 43 is a data line, 44 is an active area, 45
Is a storage electrode, and 46 is a pattern of an electrode extraction hole. Also in this example, the pattern formation of Examples 1 to 3 of the present invention was used for all except the 46 electrode extraction holes shown here. The present invention is used in processes using the minimum design rule other than the pattern formation shown here.

In the device manufactured by using the present invention, the dimension between patterns can be reduced as compared with the device manufactured by using the conventional method. Therefore, the device having the same structure can be reduced. The number of wafers that can be manufactured from one wafer has increased, and the yield has improved.

[0081]

According to the present invention, a fine pattern can be formed with high precision by using a photosensitive composition having a small swelling and excellent resolution.

Particularly, in a polymer having a structure in which an alkyl group or a dialkyl group is added to the α-position of a δ-hydroxy acid, alkali solubility is controlled by the alkyl group. By using a reaction in which a part or all of the α-alkyl-δ-hydroxy acid structure or α, α′-dialkyl-δ-hydroxy acid structure is changed to a lactone structure by an acid-catalyzed reaction, an ArF excimer is obtained. Transparent in the deep ultraviolet region including the laser wavelength of 193 nm,
In addition, while having a chemical structure with high dry etching resistance, a 2.38% tetramethylammonium hydroxide aqueous solution as a standard developer can form a negative pattern with excellent swelling and excellent resolution performance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a MOS (metal-oxide-semiconductor) transistor.

FIG. 2 is a diagram showing a method for forming a field oxide film and a silicon gate using the pattern forming method of the present invention.

FIG. 3 is a cross-sectional view illustrating a process of a method of manufacturing a semiconductor memory device using the pattern forming method of the present invention.

FIG. 4 is a pattern layout diagram of a memory portion of a typical pattern constituting a memory element.

[Explanation of symbols]

12, 25 field oxide film, 13 source contact, 14 drain contact, 15 polycrystalline silicon, 16 source electrode, 17 drain electrode, 18 gate electrode, 19 protective film, 22 oxide film, 24 ... resist pattern, 26 ... polycrystalline silicon film, 27 ... resist pattern, 28 ... polycrystalline silicon gate, 31 ... P-type Si semiconductor substrate, 32 ... element isolation region, 33, 42 ... word line, 34 ... side spacer, 35 ... n diffusion layer, 36,
43 data line, 38, 45 storage electrode, 39 insulating film for capacitor, 40 plate electrode, 41 wiring, 44
... active area, 46 ... electrode extraction hole.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroshi Shiraishi 1-280 Higashi Koigakubo, Kokubunji-shi, Tokyo F-term in Central Research Laboratory, Hitachi, Ltd. (Reference) 2H025 AA02 AA04 AB16 AC04 AC08 AD01 BE00 CB14 CB41 CB42 FA17 4J002 BG071 EJ016 EV176 EV236 EV296 FD206 GP03 4J100 AL08P BA03H BA11P BA16H BC53P CA01 CA04 HA08 HB25 HB39 JA38

Claims (13)

[Claims] 1. A method according to claim 1, wherein at least α-alkyl-
δ-hydroxy acid structure or α, α′-dialkyl-δ
-Forming a coating film comprising a radiation-sensitive composition containing a hydroxy acid structure, and irradiating the coating film with a predetermined pattern of actinic radiation to change the carboxylic acid structure of the irradiated portion of the actinic radiation to an α-alkyl -Δ-lactone structure or α,
converting the film to an α'-dialkyl-δ-lactone structure, developing the film using an aqueous alkaline developer to form a film having a predetermined pattern. Production method. 2. The method for manufacturing a semiconductor device according to claim 1, wherein the α-alkyl-δ-hydroxy acid structure or the α, α′-dialkyl-δ-hydroxy acid structure is represented by the following formula (1) or (1). A method for manufacturing a semiconductor device, characterized by having the chemical structure represented by 2). Embedded image Embedded image In the formula, R ¹ and R ² each represent an alkyl group having 1 to 10 carbon atoms. 3. The method for manufacturing a semiconductor device according to claim 1, wherein the radiation-sensitive composition contains a polymer compound, and at least the polymer compound has the α-alkyl-δ-hydroxy acid structure or α, α'-dialkyl-
A method for manufacturing a semiconductor device, comprising a δ-hydroxy acid structure. 4. The method of manufacturing a semiconductor device according to claim 1, wherein said active radiation has a wavelength of 250 nm.
A method for manufacturing a semiconductor device, comprising far ultraviolet light of nm or less. 5. The method of manufacturing a semiconductor device according to claim 1, wherein said active radiation is ArF excimer laser light. 6. The method of manufacturing a semiconductor device according to claim 1, wherein the active radiation of the predetermined pattern is an ArF excimer laser beam through a phase shift mask. Manufacturing method. 7. The method for manufacturing a semiconductor device according to claim 1, wherein said aqueous alkaline developer is an aqueous solution of tetraalkylammonium hydroxide. 8. A method for manufacturing a semiconductor device according to claim 1, wherein after the step of irradiating the active radiation, a step of developing a pattern on the coating film using the aqueous alkaline developer. A method of manufacturing the semiconductor device, comprising a step of heating the coating before the step (c). 9. The method for manufacturing a semiconductor device according to claim 1, further comprising a step of etching the substrate or implanting ions with the coating having the predetermined pattern as a mask. A method for manufacturing a semiconductor device, comprising: 10. An alkali-soluble group comprising α-alkyl-
δ-hydroxy acid structure or α, α′-dialkyl-δ
A radiation-sensitive composition comprising at least a compound having a hydroxy acid structure and a compound that generates an acid upon irradiation with actinic radiation. 11. The radiation-sensitive composition according to claim 10, wherein the compound having the α-alkyl-δ-hydroxy acid structure or the α, α′-dialkyl-δ-hydroxy acid structure further comprises an alicyclic structure. A radiation-sensitive composition comprising: 12. The radiation-sensitive composition according to claim 10, wherein the α-alkyl-δ-hydroxy acid structure or the α, α′-dialkyl-δ-hydroxy acid structure has the following formula (1) or A radiation-sensitive composition having the chemical structure represented by (2). Embedded image Embedded image In the formula, R ¹ and R ² each represent an alkyl group having 1 to 10 carbon atoms. 13. The radiation-sensitive composition according to claim 11, wherein the alkali-soluble group is an α-alkyl-δ-hydroxy acid structure or α, α′-.
A compound having a dialkyl-δ-hydroxy acid structure,
A radiation-sensitive composition, which is a polymer compound.