JPH11297597A - Material and method for pattern forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material and a method capable of forming a resist pattern having high sensitivity with respect to both light and charged particle beams, as well as maintain a good shape during alignment using either light or charged particle beams. SOLUTION: This pattern forming material contains a solubility-changeable compound that changes the solubility with an alkaline solution by using acid, a first acid generating agent that generates acid through the irradiation of exposure light used in the photolithography process, and a second acid generating agent that generates acid by irradiation of a charged particle beam. As a result, the cross-section shape of the resist pattern formed by light irradiation can be kept in a rectangular shape and a high sensitivity to the charged particle beam can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming material and a pattern forming method, and more particularly, to a pattern forming material and a pattern forming method used when performing fine processing of a semiconductor device or the like by forming a resist pattern.

[0002]

2. Description of the Related Art A resist is used for fine processing of a semiconductor device or the like. In particular, the chemically amplified resist disclosed in JP-A-63-27829 has excellent sensitivity and is suitable for use in the above-mentioned fine processing.

[0003] Chemically amplified resists are broadly classified into positive and negative resists. A positive chemically amplified resist is a three-component composition containing an alkali-soluble resin, a dissolution inhibitor and an acid generator, or an alkali-soluble resist having a dissolution-inhibiting substituent (dissolution-inhibiting group) introduced therein. It is a two-component composition containing a resin and an acid generator.

According to the positive type chemically amplified resist,
At the time of non-exposure, the dissolution of the alkali-soluble resin is suppressed by the dissolution inhibitor or the dissolution inhibiting group. The resist is irradiated with actinic radiation such as light, X-rays or high-energy electron beams to generate an acid from the acid generator, and then baked, the dissolution inhibitor or the dissolution inhibiting group is decomposed by the generated acid. Its dissolution inhibiting ability is lost. Therefore, in the positive chemically amplified resist, the exposed portion becomes soluble in alkali, and is selectively removed by a developing process using an alkali developing solution.

On the other hand, a negative type chemically amplified resist is a composition containing an acid generator, a compound having a substituent capable of crosslinking in the presence of an acid, and, if necessary, an alkali-soluble resin. When a negative chemically amplified resist is irradiated with actinic radiation to generate an acid from an acid generator and further baked, the generated acid promotes the above-mentioned crosslinking. Therefore, in the negative type chemically amplified resist, the alkali solubility of the exposed portion is reduced, and the non-exposed portion is selectively removed by a developing process using an alkali developing solution.

An acid generated by irradiating the above-mentioned acid generator with actinic radiation functions as a catalyst in both positive and negative chemically amplified resists.
Therefore, according to the chemically amplified resist, a plurality of molecules can be reacted with one photon, and higher sensitivity can be obtained as compared with a conventional resist.

Conventionally, the pattern formation using the above-described chemically amplified resist has been performed by exposing a resist layer formed using the resist to KrF excimer laser light. However, in recent years, LSI patterns have been increasingly miniaturized, and electron beam exposure has been frequently used.

[0008] The chemically amplified resist used for exposure with an electron beam is composed of substantially the same components as the chemically amplified resist used for exposure with KrF light. Therefore, when forming a fine pattern and an ultra-fine pattern on a resist layer composed of a chemically amplified resist, the fine pattern is formed by irradiating KrF light,
It is considered that a very fine pattern can be formed by irradiating an electron beam. However, in practice, the following problems occur when performing the above-described pattern formation.

When a resist layer composed of a chemically amplified resist is exposed to KrF light, the acid generator contained in the resist absorbs KrF light when generating an acid. This means that the intensity of the incident light is attenuated from the KrF light irradiation surface of the resist layer toward the deep part. In such a case, since the amount of absorbed energy per unit volume is different between the vicinity of the surface of the resist layer and the deep portion, the cross-sectional shape of the resist pattern formed after development cannot be made an ideal rectangular shape. That is, when the chemically amplified resist is positive, it has a forward tapered shape, and when it is negative, it has an inverse tapered shape. Therefore, in a chemically amplified resist used for exposure with KrF light, the concentration of the acid generator is controlled to a low concentration.

On the other hand, when the chemically amplified resist is exposed to an electron beam, the above-described attenuation does not occur. However, the decomposition reaction of the acid generator contained in the chemically amplified resist by the electron beam is much lower in efficiency than that by the KrF light. For this reason, in the chemically amplified resist for electron beam exposure, the concentration of the acid generator is higher than that in the chemically amplified resist for KrF light exposure in order to obtain sufficient sensitivity.

As described above, when a conventional resist layer composed of a chemically amplified resist for KrF light exposure is exposed to an electron beam, there arises a problem that sensitivity is insufficient. Further, when a resist layer made of a conventional chemically amplified resist for electron beam exposure is exposed to KrF light, a problem arises in that the cross-sectional shape of the developed resist pattern cannot be made rectangular.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, has high sensitivity to both light and charged particle beams, and has a high sensitivity to light and charged particle beams. An object of the present invention is to provide a pattern forming material and a pattern forming method capable of forming a resist pattern having a good shape even when exposure is performed using any of them.

[0013]

In order to solve the above-mentioned problems, the present invention relates to a solubility-variable compound which changes the solubility in an alkaline solution by applying an acid, and an exposure light used in a photolithography process. And a second acid generator that transmits an exposure light and generates an acid when irradiated with a charged particle beam. Provide a pattern forming material.

Preferred embodiments of the pattern forming material are described below.

(1) The exposure light is selected from the group consisting of KrF light, ArF light and i-line.

(2) The exposure light is KrF light.

(3) The molar extinction coefficient of the second acid generator with respect to the exposure light is 1/10 or less of the molar extinction coefficient of the first acid generator with respect to the exposure light.

(4) The molar extinction coefficient of the first acid generator to the exposure light is 5,000 to 200,000, and the molar extinction coefficient of the second acid generator to the exposure light is 1 to 200. 2,000.

(5) The product of the molar extinction coefficient of the second acid generator with respect to the exposure light and the molar concentration of the second acid generator is the mole of the first acid generator with respect to the exposure light. 1/1/3 of the product of the extinction coefficient and the molar concentration of the first acid generator
10 or less.

(6) The second acid generator contains at least one compound represented by the following chemical formulas (1) to (4).

[0021]

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(7) The variable solubility compound has an alkali-soluble resin exhibiting solubility in an alkaline solution, and has a dissolution inhibiting ability for inhibiting the dissolution of the alkali-soluble resin in an alkaline solution, and is capable of inhibiting dissolution in the presence of an acid. And a dissolution inhibitor which loses its dissolution inhibiting ability by being decomposed in the step.

(8) The variable solubility compound is an alkali-insoluble resin that is insoluble in an alkali solution and decomposes in the presence of an acid to produce an alkali-soluble resin that is soluble in an alkali solution. thing.

(9) The variable solubility compound is a resin-forming compound which exhibits solubility in an alkaline solution and crosslinks in the presence of an acid to form a resin insoluble in an alkaline solution.

(10) An alkali-soluble resin having solubility in an alkali solution is further contained, and the solubility variable compound is soluble in an alkali solution, and is crosslinked in the presence of an acid to form an alkali solution. A resin-forming compound that generates an unnecessary resin for

The present invention also relates to a solubility variable compound which changes the solubility in an alkaline solution by applying an acid, and a first compound which generates an acid by irradiating exposure light used in a photolithography process. An acid generator, and a step of forming a resist layer by applying a pattern forming material containing a second acid generator that transmits the exposure light and generates an acid by irradiating a charged particle beam onto a substrate, A pattern forming method, comprising: irradiating the resist layer with the exposure light; and irradiating the resist layer with the charged particle beam.

Preferred embodiments of the above-described pattern forming method are described below.

(1) A step of developing the resist layer irradiated with the exposure light and the electron beam with the alkaline solution is provided.

(2) The charged particle beam is selected from the group consisting of an electron beam and an ion beam.

(3) The charged particle beam is an electron beam.

(4) The exposure light is selected from the group consisting of KrF light, ArF light and i-line.

(5) The exposure light is KrF light.

(6) The molar extinction coefficient of the second acid generator with respect to the exposure light is 1/10 or less of the molar extinction coefficient of the first acid generator with respect to the exposure light.

(7) The molar extinction coefficient of the first acid generator with respect to the exposure light is 5,000 to 200,000, and the molar extinction coefficient of the second acid generator with respect to the exposure light is 1 to 200. 2,000.

(8) The product of the molar extinction coefficient of the second acid generator with respect to the exposure light and the molar concentration of the second acid generator is the mole of the first acid generator with respect to the exposure light. 1/1/3 of the product of the extinction coefficient and the molar concentration of the first acid generator
10 or less.

(9) The second acid generator contains at least one of the compounds represented by the following chemical formulas (1) to (4).

[0037]

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(10) The variable solubility compound has an alkali-soluble resin exhibiting solubility in an alkaline solution, and has a dissolution inhibiting ability for inhibiting the dissolution of the alkali-soluble resin in an alkaline solution, and is capable of inhibiting dissolution in the presence of an acid. And a dissolution inhibitor which loses its dissolution inhibiting ability by being decomposed in the step.

(11) The variable solubility compound is an alkali-insoluble resin which is insoluble in an alkali solution and decomposes in the presence of an acid to produce an alkali-soluble resin which is soluble in an alkali solution. thing.

(12) The variable solubility compound is a resin-forming compound which exhibits solubility in an alkaline solution and crosslinks in the presence of an acid to produce an unnecessary resin in the alkaline solution.

(13) The pattern forming material further contains an alkali-soluble resin that is soluble in the alkaline solution, and the variable solubility compound is soluble in the alkaline solution and the presence of an acid. A resin-forming compound that crosslinks below to produce an unnecessary resin in an alkaline solution.

[0042]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The pattern forming material of the present invention is a chemically amplified resist containing a variable solubility compound, a first acid generator, and a second acid generator.

The variable solubility compound is a compound that changes the solubility in an alkaline solution by applying an acid. As the solubility variable compound, different compounds are used depending on whether the pattern forming material of the present invention is a positive type or a negative type.

That is, when the pattern forming material is a positive type, as a solubility variable compound, an alkali which is insoluble in an alkali solution and which is soluble in an alkali solution by decomposing in the presence of an acid. Insoluble resins can be used. On the other hand, when the pattern forming material is a negative type, as a solubility variable compound, it shows solubility in an alkaline solution, and forms a resin insoluble in an alkaline solution by crosslinking in the presence of an acid. Compounds can be used.

The first and second acid generators contained in the pattern forming material of the present invention are compounds that generate an acid upon irradiation with actinic radiation. The actinic radiation referred to here is KrF light from an excimer laser, which is generally used for exposure in a photolithography process.
rF light and F ₂ light, mercury lamp g- line, h- lines and i
-Including light such as a line, and charged particle beams such as an electron beam and an ion beam.

The first and second acid generators will be described in more detail. The first acid generator includes KrF light and ArF light used in a photolithography process.
It absorbs at least one of light and exposure light, such as i-ray, to generate an acid. Further, the first acid generator generates an acid even when irradiated with a charged particle beam such as an electron beam or an ion beam.

On the other hand, like the first acid generator, the second acid generator generates an acid when irradiated with a charged particle beam such as an electron beam or an ion beam. However, the second acid generator transmits the exposure light absorbed by the first acid generator. That is, the second acid generator has a low absorptivity to the above-mentioned exposure light, and even when irradiated with this exposure light, generation of an acid hardly occurs.

When the first and second acid generators having different molar extinction coefficients with respect to the predetermined exposure light are contained in the pattern forming material, high sensitivity to both light and charged particle beams is obtained. And a resist pattern having a good shape can be formed even when exposure is performed using either light or charged particle beam. The reason will be described below.

When a predetermined exposure light is applied to the resist layer made of the pattern forming material, the first acid generator absorbs the exposure light to generate an acid. At this time, since the decomposition reaction of the first acid generator by light irradiation occurs with high efficiency, a low concentration of the first acid generator in the pattern forming material is sufficient. Since the second acid generator transmits the exposure light, when the first acid generator is controlled at a low concentration, the exposure light reaches a deep portion of the resist layer while maintaining a relatively high intensity. I do. Therefore, by performing a predetermined developing process or the like on the resist layer after light irradiation, a resist pattern having a good shape can be formed.

On the other hand, when the resist layer is irradiated with a charged particle beam, both the first and second acid generators generate an acid. Generally, the decomposition reaction of an acid generator by a charged particle beam is less efficient than that by light. However, according to the pattern forming material, a relatively good sensitivity can be obtained because both the first and second acid generators generate an acid. In addition, since the second acid generator transmits the exposure light, even when the second acid generator is contained at a high concentration in the pattern forming material, the exposure light is hardly attenuated at the time of exposure by light irradiation. Therefore, according to the pattern forming material, the second
Can be contained at a high concentration, and a high sensitivity can be obtained even during the charged particle beam exposure.

In the above pattern forming material, the molar extinction coefficient of the first acid generator with respect to the exposure light is 5,000.
0 to 200,000, preferably 5,000
~ 50,000, more preferably 10,000
More preferably, it is 0 to 30,000. When the molar extinction coefficient is not less than the lower limit, the concentration of the first acid generator in the pattern forming material can be reduced. Therefore, undesired attenuation of the exposure light at the resist layer can be prevented. If the molar extinction coefficient is less than the upper limit, the sensitivity to exposure light is significantly reduced. If the concentration is increased to further increase the sensitivity, the resolution of the resist is impaired. If the molar extinction coefficient exceeds the upper limit, the exposure light may be undesirably attenuated, thereby damaging the pattern shape.

The molar extinction coefficient of the second acid generator with respect to the exposure light is preferably 1 to 2,000, more preferably 1,000 or less, and more preferably 300 or less.
It is more preferred that: When the molar extinction coefficient of the second acid generator is equal to or less than the upper limit, the concentration of the second acid generator in the pattern forming material can be reduced without causing undesired attenuation of the exposure light in the resist layer. Can be enhanced. Therefore, the sensitivity of the pattern forming material to the charged particle beam can be increased.

The molar extinction coefficient of the second acid generator with respect to the exposure light with respect to the first acid generator is preferably 1/10 or less, more preferably 1/50, and more preferably 1/100. It is more preferred that there be. When the molar extinction coefficient ratio is equal to or less than the above value, undesired attenuation of the exposure light during exposure by light irradiation can be prevented. Therefore, in this case, the second in the pattern forming material
Can be increased to increase the sensitivity to charged particle beams.

The product of the molar extinction coefficient of the second acid generator with respect to the exposure light and the molar concentration of the second acid generator is
It is preferably at most 1/10, more preferably at most 1/50 of the product of the molar extinction coefficient of the first acid generator to the exposure light and the molar concentration of the first acid generator. / 100 or less is more preferable. Here, the ratio of the product of the molar extinction coefficient and the molar concentration corresponds to the ratio of the absorbance. Therefore, when the ratio is equal to or less than the predetermined numerical value, it is possible to prevent the exposure light from being undesirably attenuated during the exposure by light irradiation.

In the pattern forming material of the present invention, the first
The total amount of the acid generator and the second acid generator is preferably 0.1 to 30% by weight based on the total solid components,
More preferably, the content is 0.5 to 20% by weight. When the content of the first and second acid generators is less than the lower limit, it becomes difficult to obtain sufficient photosensitivity to exposure light and charged particle beams. When the content exceeds the upper limit, the exposure light in the resist layer is excessively attenuated, so that it is difficult to form a resist pattern having a good shape.
Further, in this case, a residue (scum) may be generated when the resist layer is developed or when the formed resist pattern is removed.

The molar ratio of the second acid generator to the first acid generator is preferably 0.5 to 20,
It is more preferably 0.5 to 10, and further preferably 1 to 5. If the above molar ratio is less than the lower limit, sufficient sensitivity to charged particle beams cannot be obtained while maintaining appropriate sensitivity to exposure light. If the molar ratio exceeds the upper limit, the sensitivity to exposure light may be insufficient even if sufficient sensitivity to charged particle beams can be obtained.

As described above, the pattern forming material of the present invention comprises a first acid generator which generates an acid by irradiating a predetermined exposure light, and irradiates a charged particle beam through the exposure light. And a second acid generator that generates an acid. Therefore, the cross-sectional shape of the resist pattern formed by light irradiation can be made rectangular, and high sensitivity to charged particle beams can be obtained.

Next, the material used for the pattern forming material will be described.

(Soluble Solubility Compound) As described above, the solubilities variable compound is a compound that changes the solubility in an alkaline solution by applying an acid. First, an alkali-insoluble resin, which is a compound whose solubility in an alkaline solution is increased by applying an acid, will be described.

The alkali-insoluble resin is not particularly limited as long as it has the above properties, but is preferably an ester or ether of a phenol compound. Examples of the phenol compound include phenol, cresol, xylenol, bisphenol A, bisphenol S, hydroxybenzophenone, 3,3,3 ', 3'-
Tetramethyl 1,1′-spirobiindane 5,6,7,
5 ', 6', 7'-hexanol, phenolphthalein, cresolphthalein, polyvinylphenol, novolak resin and the like can be mentioned.

The above-mentioned alkali-insoluble resin can be obtained, for example, by esterifying or etherifying the hydroxy group of the above-mentioned phenol compound using a suitable esterifying agent or etherifying agent. Examples of the ester and ether obtained using the phenol compound include, for example, methyl ester, ethyl ester, n-propyl ester, iso-propyl ester, tert-butyl ester, n-butyl ester, iso-butyl ester, benzyl ester, Tetrahydropyranyl ether, benzyl ether, methyl ether, ethyl ether, n-propyl ether, iso-propyl ether, tert-butyl ether, allyl ether, methoxymethyl ether, p-bromophenacif ether,
Trimethylsilyl ether, benzyloxycarbonyl ether, tert-butoxycarbonyl ether, t
tert-butyl acetate, 4-tert-butyl benzyl ether, and the like.

Specific examples of the alkali-insoluble resin are shown in the following chemical formulas (5) to (19).

[0064]

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[0065]

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[0066]

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As the alkali-insoluble resin, those having a structure represented by the following general formula (20) are preferable.

[0068]

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However, in the general formula (20), R
¹ is a monovalent organic group, m is 0 or a positive number of 1 or more, and n is a positive number.

In the general formula (20), the substituent R ¹
Is not particularly limited as long as it is a monovalent organic group. For example, methyl, ethyl, n-propyl, iso-propyl, n-
Butyl, tert-butyl, iso-butyl, sec-
Examples thereof include butyl and benzyl groups. Among them, a tert-butyl group is particularly preferable.

In the general formula (20), m and n preferably satisfy the following relationship. That is, n
/ (M + n) is preferably in the range of 0.03 to 1, more preferably 0.05 to 0.70. This is because if n / (m + n) is less than 0.03, the difference in dissolution rate between the exposed and non-exposed portions becomes small, and the resolution may be reduced.

The compound having the structure represented by the above general formula (20) preferably has a molecular weight of 1,000 or more. In this case, heat resistance can be improved.

Next, a compound whose solubility in an alkali solution is reduced by applying an acid, that is, a resin-forming compound will be described. In the pattern forming material of the present invention, the resin forming compound is not particularly limited as long as it is a substance that crosslinks in the presence of an acid and causes a decrease in solubility in an alkali developer. However, among them, C-O-
It is preferable to use a compound having an R group (R is an alkyl group) or a compound having an epoxy group.

Specific examples of the compound having a C—O—R group include an alkyl etherified melamine resin, an alkyl etherified benzoguanamine resin, an alkyl etherified urea resin, and a phenolic compound containing an alkyl ether group. it can.

The alkyl etherified melamine resin can be synthesized according to a conventional method. The synthesis method is described in detail in "Urea Melamine Resin" (1979, published by Nikkan Kogyo Shimbun), edited by Ichiro Miwa and Hideo Matsunaga. The alkyl etherified melamine resin is synthesized by subjecting methylol melamine obtained by condensing melamine and formaldehyde under basic conditions to alkyl etherification with an alcohol. In the pattern forming material of the present invention, as the alkyl etherified melamine resin,
From the viewpoint of good storage stability, it is preferable to use a melamine resin containing a hexaalkyletherified melamine as a main component, and particularly preferable to use a hexamethyletherified melamine resin.

The alkyl etherified benzoguanamine resin can be easily synthesized by using benzoguanamine instead of melamine of the alkyl etherified melamine resin. In the pattern forming material of the present invention,
As the alkyl etherified benzoguanamine resin, a tetraalkyl etherified benzoguanamine resin is preferably used because of good storage stability, and among them, a tetramethyl etherified benzoguanamine resin is particularly preferable.

The alkyl etherified urea resin can be synthesized according to a conventional method. The synthesis method is also described in detail in the above “Urea-Melamine Resin”. The alkyl etherified urea resin is synthesized by alkyl etherifying methylol urea obtained by condensing urea and formaldehyde with an alcohol.
In the pattern forming material of the present invention, as the alkyl etherified urea resin, it is preferable to use an alkyl etherified product of monomethylol urea, dimethylol urea, trimethylol urea, and a urone compound, and to use an alkyl etherified product of trimethylol urea. Is more preferred.

Specific examples of the alkyl ether group-containing phenolic compound include compounds having a structure represented by the following general formula (21).

[0079]

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In the general formula (21), R ¹
Represents an alkyl group, an alkoxy group, an alkenyl group, or an alkenyloxy group; R ² represents an alkyl group;
Represents an integer of 1 to 5, more preferably an integer of 1 to 3.

Specific examples of the compound having an epoxy group include glycidyl ether epoxy resins such as bisphenol A epoxy, bisphenol F epoxy, bisphenol S epoxy, bisphenol E epoxy, novolak epoxy, and brominated epoxy; Alicyclic aliphatic epoxy resin containing cyclohexene oxide group, tricyclodecene oxide group, cyclopentin oxide group, etc .; glycidyl ester epoxy resin; glycidylamine epoxy resin; heterocyclic epoxy resin; multifunctional epoxy resin And the like.

These epoxy resins can be synthesized according to a conventional method. The synthesis method is described in detail in "Epoxy Resin" (1935, published by Shokodo) edited by Hiro Horiuchi.

The resin-forming compounds described above can be used alone or in combination of two or more.

(First Acid Generator) Next, a first acid generator which generates an acid by irradiating exposure light having a predetermined wavelength will be described. Various known compounds can be used as the first acid generator. For example, CF ₃ SO
^{_{3 -, p-CH 3 PhSO}} 3 -, p-NO 2 PhSO 3
^- diazonium salts containing ions such as, phosphonium salts,
Sulfonium salts or iodonium salts (Ph is a phenyl group); organic halogen compounds; orthoquinone-diazidosulfonyl chloride; sulfonic acid esters;

The organic halogen compound is a compound that forms hydrohalic acid. Such compounds include U.S. Pat. No. 3,515,552 and U.S. Pat.
No. 36489, US Pat. No. 3,779,778,
And West German Patent Publication No. 2243621.

Further, in addition to the above-mentioned compounds, as a first acid generator, JP-A-54-74728,
JP-A-5-24113, JP-A-55-77742, JP-A-60-3626, and JP-A-60-138
Compounds disclosed in JP-A-539, JP-A-56-17345 and JP-A-50-36209 can be used.

Specific examples of the first acid generator include di (p-tert-butylphenyl) iodonium trifluoromethanesulfonate, diphenyliodonium trifluoromethanesulfonate, benzoin tosylate, orthonitrobenzyl paratoluenesulfonate, triphenyl Sulfonium trifluoromethanesulfonate, tri (tert-butylphenyl) sulfonium trifluoromethanesulfonate, benzenediazonium paratoluenesulfonate, 4- (di-n-propylamino) -benzonium tetrafluoroborate,
4-p-tolyl-mercapto-2,5-diethoxy-benzenediazonium hexafluorophosphate, tetrafluoroborate, diphenylamine-4-diazonium sulfate, 4-methyl-6-trichloromethyl-2-pyrone, 4- (3,4 , 5-Trimethoxy-styryl) -6- (3,3,3-trichloro-propenyl)
-2-pyrone, 4- (4-methoxystyryl) -6-
(3,3,3-trichloropropenyl) -2-pyrone,
2-trichloromethyl-benzimidazole, 2-tribromomethyl-quinoline, 2,3-dimethyl-1-tribromoacetyl-benzene, 4-dibromoacetyl-benzoic acid, 1,4-bis-dibromomethyl-benzene, tris -Dibromomethyl-S-triazine, 2- (6-methoxy-naphthyl-2-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (naphthyl-1-yl) -4,6-bis -Trichloromethyl-S-triazine, 2- (naphthyl-2-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-ethoxyethyl-naphthyl-1-yl) -4,6- Bis-trichloromethyl-S-triazine, 2- (benzopyran-3-
Yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-methoxy-anthrac-1-yl)-
4,6-bis-trichloromethyl-S-triazine, 2
-(Phenanth-9-yl) -4,6-bis-trichloromethyl-S-triazine and o-naphthoquinonediazide-4-sulfonic acid chloride.

The sulfonic acid ester used as the first acid generator includes naphthoquinonediazide-4-sulfonic acid ester, naphthoquinonediazide-5-sulfonic acid ester, p-toluenesulfonic acid-o-nitrobenzyl ester, And p-toluenesulfonic acid-2,6
-Dinitrobenzyl ester and the like.

As the first acid generator, particularly, o
-Quinonediazide compounds can be used. The o-quinonediazide compound used as the first acid generator is not particularly limited, but is preferably an ester of o-quinonediazidesulfonic acid and a phenol compound. Such an ester can be obtained by reacting o-quinonediazidesulfonic acid chloride or the like with a phenol compound according to a conventional method.

The o-quinonediazidesulfonic acid chloride used in the synthesis of the above ester includes, for example, 1-
Benzophenone-2-diazo-4-sulfonic acid chloride, 1-naphthoquinone-2-diazo-5-sulfonic acid chloride, 1-naphthoquinone-1-diazo-4-sulfonic acid chloride, and the like can be used. Examples of the phenol compound include phenol, cresol, xylenol, bisphenol A, bisphenol S, hydroxybenzophenone, 3,3,3 ′,
3'-Tetramethyl-1,1'-spirobiind-5,
6,7,5 ′, 6 ′, 7′-hexanol, phenolphthalein, dimethyl p-hydroxybenzylidenemalonate, dinitrile p-hydroxybenzylidenemalonate, cyanophenol, nitrophenol, nitrosophenol, hydroxyacetophenone, trihydroxybenzoate Methyl acid, polyvinyl phenol, novolak resin and the like can be used.

Specific examples of the o-quinonediazide compound are shown in the following chemical formulas (22) to (47).

[0092]

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[0093]

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[0094]

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In the chemical formulas (22) to (47), X, Y and Z represent the following substituents.

[0096]

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As the first acid generator, among the above-mentioned o-quinonediazide compounds, it is particularly preferable to use 1-naphthoquinone-2-diazo-4-sulfonic acid ester. This ester is described in J. J. Grunwald e
t. al. , SPIE Vol, 1262, Advan
ces in Resist Technology
and Processing VII, p444 (1
990), a carboxylic acid and sulfonic acid, which is a stronger acid than the carboxylic acid, are produced by light irradiation. That is, the ester has a large catalytic action and is particularly effective as the first acid generator.

The first acid generator includes compounds represented by the following formulas (48) to (50).

[0099]

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In the general formula (48), R ¹¹ represents a monovalent organic group or a monovalent organic group into which at least one selected from the group consisting of a halogen atom, a nitro group and a cyano group has been introduced. , R ¹² , R ¹³ and R ¹⁴ each represent a hydrogen atom, a halogen atom, a nitro group, a cyano group,
A monovalent organic group or a monovalent organic group into which at least one selected from the group consisting of a halogen atom, a nitro group, and a cyano group is introduced.

[0101]

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In the above general formula (49), R ²¹ and R
²³ is a monovalent organic group, or a halogen atom, a nitro group,
And a monovalent organic group into which at least one selected from the group consisting of and a cyano group has been introduced, and R ²² represents a sulfonyl group or a carbonyl group.

[0103]

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In the above formula (50), R ³¹ and R ³²
And R ³³ represents a monovalent organic group, or a halogen atom, a monovalent organic group in which at least one member selected from the group consisting of a nitro group and a cyano group, is introduced, R ³⁵ is a hydrogen atom, 1 R ³⁴ represents a monovalent organic group into which at least one selected from the group consisting of a halogen atom, a nitro group, and a cyano group has been introduced, and R ³⁴ represents a sulfonyl group, a sulfyl group, a sulfur atom, or a carbonyl group; Represents a group.

Specific examples of the monovalent organic group introduced as substituents R ¹¹ , R ¹² , R ¹³ and R ¹⁴ into the compound represented by the general formula (48) include allyl, anisyl, anthraquinolyl, acetonaphthyl, anthryl, Azulenyl, benzofuranyl, benzoquinolyl, benzoxazinyl, benzoxazolyl, benzyl, biphenylenyl, bornyl, butenyl, butyl, cinnamyl, crezotoyl, cumenyl, cyclobutanedienyl, cyclobutenyl, cyclobutyl, cyclopentadienyl, cyclopentatrienyl, cycloheptyl, cyclohexenyl, Cyclopentyl, cyclopropyl, cyclopropenyl, decyl, dimethoxyphenethyl, diphenylmethyl, docosyl, dodecyl, eicosyl, ethyl, fluorenyl, furfuryl, geranyl, heptyl, Kisadeshiru, hexyl, hydroxymethyl, indanyl, isobutyl, isopropyl, isopropyl benzyl, Isokiazoriru, menthyl, mesityl, methoxybenzyl, methoxyphenyl,
Methyl, methylbenzyl, naphthyl, naphthylmethyl,
Nonyl, norbonyl, octakodyl, octyl, oxazinyl, oxazolidinyl, oxazolinyl, oxazolyl, pentyl, phenacyl, phenanthryl, phenethyl, phenyl, phthalidyl, propynyl, propyl,
Pyranyl, pyridyl, quinazonyl, quinolyl, salicyl, terephthal, tetrazolyl, thiazolyl, thiabenyl, thienyl, tolyl, trityl, trimethylsilylmethyl, trimethylsilyloxymethyl, undecyl,
Valeryl, veratyl, xylyl and the like can be mentioned.

In the compound represented by the general formula (48), at least one selected from the group consisting of a halogen atom, a nitro group and a cyano group used for the substituents R ¹¹ , R ¹² , R ¹³ and R ^14. Examples of the monovalent organic group into which is introduced are those in which at least one of the hydrogen atoms of the above organic group is substituted with any of a halogen atom, a nitro group, and a cyano group.

Specific examples of the compound represented by the above general formula (48) include phenylmethylsulfone, ethylphenylsulfone, phenylpropylsulfone, methylbenzylsulfone, benzylsulfone (dibenzylsulfone), phenylsulfonylacetonitrile, toluenesulfonylacetonitrile, benzyl Phenylsulfone, nitrophenylsulfonylacetonitrile, chlorophenylsulfonylacetonitrile, fluorophenylsulfonylacetonitrile, methoxyphenylsulfonylacetonitrile, α-methylphenylsulfonylacetonitrile, methylthiomethyl p-toluylsulfone, phenylsulfonylacetophenone, phenylsulfonylpropionitrile, phenylsulfonylpropionic acid and Its ester compound, bromomethy 2- (phenylsulfonyl) benzene, naphthylmethyl sulfone, 1-methyl -
2-((phenylsulfonyl) methyl) benzene, trimethyl-3-phenylsulfonyl) orthopropionate and the like can be mentioned.

In the compound represented by the general formula (48), at least one of the substituents R ¹² , R ¹³ and R ¹⁴ is preferably an electron-withdrawing group. In particular, when at least one of the substituents R ¹² , R ¹³ and R ¹⁴ is a cyano group, the efficiency of acid generation during exposure is high, and the sensitivity of the pattern forming material can be further improved. Further, in the compound represented by the general formula (48), when at least one of the substituents R ¹² , R ¹³ and R ¹⁴ is a hydrogen atom, the compound has high solubility in an alkali developing solution, so that scum during development is reduced. Can be reduced.

The compound represented by the general formula (48) has a structure in which the substituent R ¹¹ is bonded to the substituent R ¹² , R ¹³ or R ¹⁴ , or the substituents R ¹² , R ¹³ and R ¹⁴ are bonded to each other. To form a ring. Such cyclic compounds include phenylsulfonyltetrahydropyran; phenylsulfonylcyclohexane; 3-phenyl-2H-thiopyran 1,1-dioxide and 6-methyl-3-phenyl-2H-thiopyran 1,1-dioxide. Thiopyrandioxide compounds; and compounds represented by the following chemical formulas (51) and (52).

[0110]

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The compound represented by the general formula (49) is an organic compound in which two sulfonyl groups are bonded to a specific carbon atom, or one sulfonyl group and one carbonyl group are bonded to a specific carbon atom. is there. Specific examples of the monovalent organic group to be introduced as the substituents R ²¹ and R ²³ into the compound represented by the general formula (49) include the same as those described with respect to the general formula (48). . Further, the hydrogen atom of these organic groups may be substituted by at least one selected from the group consisting of a halogen atom, a nitro group, and a cyano group.

Specific examples of the compound represented by the general formula (49) include bis (phenylsulfonyl) methane, (methylsulfonyl) (phenylsulfonyl) methane, phenylsulfonylacetophenone, and methylsulfonylacetophenone.

The compound represented by the general formula (49) also has R ²¹ and R
^{And 23} may combine with each other to form a ring. As such a cyclic compound, for example, the following chemical formula (5)
The compounds shown in 3) and (54) can be mentioned.

[0114]

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The compound represented by the formula (49) has high alkali solubility and high acid generation efficiency upon exposure. Therefore, when the compound represented by the general formula (49) is used as the first acid generator, the sensitivity of the pattern forming material to light irradiation can be further improved.

The compound represented by the above general formula (50) is an organic compound in which at least two sulfonyl groups and one sulfur-containing substituent or one carbonyl group are bonded to a specific carbon atom. . Specific examples of the monovalent organic group introduced as the substituents R ³¹ , R ³² , R ³³ , and R ³⁵ into the compound represented by the general formula (50) are the same as those described with respect to the general formula (48). Can be mentioned.
Further, the hydrogen atom of these organic groups may be substituted with at least one selected from the group consisting of a halogen atom, a nitro group and a cyano group, or a hydroxyl group, a carboxyl group or an esterified carboxyl group. Further, in the compound shown by the general formula (50), a sulfonyl group as a substituent R ^34, it is preferable to use any of the sulfinyl group, and a sulfur atom.

Specific examples of the compound represented by the general formula (50) include tris (phenylsulfonyl) methane, phenylthio-bis (phenylsulfonyl) -methane, phenylmercapto-bis (methylsulfonyl) -methane, and bis (phenylsulfonyl) -Methylsulfonyl-methane,
Bis (methylsulfonyl) -phenylsulfonyl-methane, phenylsulfonyl-ethylsulfonyl-methylsulfonyl-methane, tris (4-nitrophenylsulfonyl) methane, tris (2,4-nitrophenylsulfonyl) methane, bis (phenylsulfonyl)- (4-nitrophenylsulfonyl) -methane, bis (phenylsulfonyl)-(3-nitrophenylsulfonyl) -methane, bis (phenylsulfonyl)-(2-nitrophenylsulfonyl) -methane, bis (phenylsulfonyl)
-(P-tolylsulfonyl) -methane, bis (methylsulfonyl)-(4-nitrophenylsulfonyl) -methane, bis (methylsulfonyl)-(4-chlorophenylsulfonyl) -methane, bis (phenylsulfonyl)-
(4-fluorophenylsulfonyl) -methane, 1,1,
1-tris (phenylsulfonyl) ethane and the like can be mentioned.

In the compound represented by the general formula (48), R
¹¹ is at least one of R ²¹ and R ^{23 in} the compound represented by the general formula (49), and at least one of R ³¹ , R ³² and R ³⁵ is an aromatic group in the compound represented by the general formula (50) Is preferred. According to the pattern forming material using such a compound as the first acid generator, Kr
In the case of performing exposure using F excimer laser light, the dry etching resistance and heat resistance of the resist layer can be improved. In addition, as the first acid generator, among the compounds represented by the above general formulas (48) to (50), those having a melting point of 50 ° C. or more and high solubility in an organic solvent are preferably used.

When the compounds represented by the general formulas (48) to (50) are sulfonyl compounds having a basic substituent such as sulfamide, the acid generated by exposure may be deactivated. In the case of a sulfonyl compound having a highly alkali-soluble acidic group such as sulfonic acid, the alkali solubility in the unexposed portion of the pattern forming material may be excessively increased. Therefore, the use of these sulfonyl compounds as the first acid generator may be limited.

(Second Acid Generator) Next, a second acid generator which transmits exposure light having a predetermined wavelength and generates an acid by irradiating a charged particle beam will be described. The compound used as the second acid generator is not particularly limited as long as it has the above-mentioned properties. As the second acid generator,
For example, compounds represented by the following chemical formulas (1) to (4) can be used.

[0121]

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(Alkali-Soluble Resin) The pattern forming material of the present invention may contain an alkali-soluble resin having solubility in an alkali solution in order to control the dissolution rate of the resist layer in an alkali developer.

When an alkali-soluble resin is contained in the pattern forming material, the content of the alkali-soluble resin is preferably at most 90 parts by weight, more preferably at most 80 parts by weight, based on 100 parts by weight of the variable solubility compound. Is more preferable. When the content of the alkali-soluble resin exceeds the upper limit, the difference in the dissolution rate between the exposed part and the non-exposed part of the resist layer becomes small, and the resolution may be reduced.

As the alkali-soluble resin, a resin containing an aryl group or a carboxy group into which a hydroxy group has been introduced is desirable. Specifically, phenol novolak resin; cresol novolak resin; xylesol novolak resin; vinylphenol resin; isopropenylphenol resin; copolymer of vinylphenol with acrylic acid, methacrylic acid derivative, acrylonitrile, styrene derivative, and the like; Copolymer of propenylphenol with acrylic acid, methacrylic acid derivative, acrylonitrile, styrene derivative, etc .; copolymer of styrene derivative with acrylic resin, methacrylic resin, acrylic acid, methacrylic acid, maleic acid, maleic anhydride, acrylonitrile, etc. Polymer; or a compound containing silicon in these polymers. Further, quinone in phenol resin generated by oxidation may be reduced to improve transparency.

Among these alkali-soluble resins, a resin containing an aromatic ring or a resin containing an aliphatic ring, such as a phenol novolak resin or a cresol novolak resin, is preferable. When such a compound is contained in the pattern forming material, the resistance of the resist layer to dry etching can be improved. Further, quinone in phenol resin generated by oxidation may be reduced to improve transparency.

Specific examples of the alkali-soluble resin include poly-p-vinylphenol, poly-o-vinylphenol, poly-m-isopropenylphenol, m, p-cresol novolak resin, xylesol novolak resin, p-vinyl A copolymer of phenol and methyl methacrylate, a copolymer of p-isopropenylphenol and maleic anhydride, a copolymer of polymethacrylic acid, a rubornene derivative and maleic anhydride, and a compound represented by the following chemical formula (5)
5) to (62).

[0127]

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[0128]

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Next, a pattern forming method using the pattern forming material will be described.

FIGS. 1A to 1E schematically show process diagrams of a pattern forming method according to an embodiment of the present invention. 1A to 1E are cross-sectional views.

First, as shown in FIG. 1A, the positive pattern forming material according to the embodiment of the present invention is applied onto the substrate 1 by a method such as spin coating. 150 ℃
Thereafter, the resist layer 2 is formed on the substrate 1 by preferably drying at a temperature of 70 to 140 ° C. here,
As the substrate 1, for example, a silicon wafer; a silicon wafer on which an insulating film, an electrode, a wiring layer, and the like are formed and a step is formed on the surface; mask blanks; GaAs or AlG
III-V compound semiconductor wafers such as aAs.

Next, as shown in FIG.
The region 5 of the resist layer 2 is exposed by irradiating the resist layer 2 with exposure light 4 using the method described above. Exposure light used for this pattern exposure is K light from an excimer laser.
rF light, ArF light and F ₂ light, mercury lamp g- line, h
Light such as-line and i-line can be used.

Subsequently, as shown in FIG. 1C, the area 7 of the resist layer 2 is exposed using a charged particle beam 6 such as an electron beam or an ion beam.

After the exposure with light and a charged particle beam is completed as described above, the exposure is performed at 60 to 160 ° C., preferably 80 to 160 ° C.
Post-exposure baking is performed at a temperature of 50 ° C. This allows
As shown in FIG. 1D, a latent image is formed in the regions 5 and 7 of the resist layer 2.

Further, by developing the resist layer 2 with an aqueous alkali solution, washing with pure water and drying the substrate, the resist pattern shown in FIG. 1E can be formed.

As described above, the first acid generator contained in the resist layer 2 generates an acid by irradiating the exposure light 4, and the second acid generator transmits the exposure light 4. . Further, the concentration of the first acid generator in the resist layer 2 is kept low. That is, since the attenuation of the exposure light at the time of exposure by light irradiation is suppressed to a negligible level, the sectional shape of the latent image formed in the area 5 is rectangular.

When the charged particle beam 6 is irradiated, the first
And the second acid generator is exposed to light to generate an acid. Originally, the photosensitive efficiency of the acid generator by the charged particle beam is low, but the resist layer 2 has high sensitivity because it contains the first and second acid generators.

Therefore, according to the above-described method, the pattern shape does not deteriorate even when exposed by light irradiation, and a pattern can be formed with high sensitivity even when a charged particle beam is used.

As described above, the resist pattern is formed by irradiating the electron beam after the light irradiation. However, the light irradiation may be performed after the electron beam irradiation. The above-described method has been described for the case where the pattern forming material is a positive type, but the same applies to the case where the pattern forming material is a negative type. Hereinafter, a pattern forming method using a negative pattern forming material will be described.

FIGS. 2A to 2E schematically show process charts of a pattern forming method according to the embodiment of the present invention. 2A to 2E are cross-sectional views.

First, as shown in FIG. 2A, the negative pattern forming material according to the embodiment of the present invention is applied onto the substrate 1 by a method such as spin coating. Note that a polysilicon layer 11, an antireflection film 12, and the like may be formed on the substrate 1. The resist layer 13 is formed on the substrate 1 by drying the pattern forming material applied on the substrate 1.

Next, as shown in FIG.
The region 5 of the resist layer 13 is exposed by irradiating the resist layer 13 with exposure light 4 using the method described above. Subsequently, FIG.
As shown in (c), the region 7 of the resist layer 13 is exposed using a charged particle beam 6 such as an electron beam or an ion beam.

After the exposure with the light and the charged particle beam is completed as described above, post-exposure baking is performed. As a result, as shown in FIG. 2D, a latent image is formed in the regions 5 and 7 of the resist layer 13.

Further, by developing the resist layer 13 with an aqueous alkali solution, washing with pure water and drying the substrate, the resist pattern shown in FIG. 2E can be formed.

As described above, the pattern forming method using the negative type pattern forming material is performed by the resist layer 1 of the exposed portions 5 and 7.
Except that 3 remains, it is almost the same as the case of using the positive pattern forming material. Therefore, the cross-sectional shape of the resist pattern can be made rectangular, and high sensitivity can be obtained even for charged particle beams. In addition,
Various conditions for a pattern forming method using a negative pattern forming material are the same as those in the case of using a positive pattern. Therefore, the description is omitted.

[0146]

Embodiments of the present invention will be described below.

(Example 1) In this example, a resist pattern was formed using a positive pattern forming material. Hereinafter, description will be made with reference to FIG.

First, as an alkali-insoluble resin, as shown in the following chemical formula (64), polyvinyl phenol resin 90 having a substituent having a dissolution inhibiting effect introduced into a part of the side chain is used.
% By weight, 2% by weight of triphenylsulfonium triflate as a first acid generator, and 5% by weight of succinimidyl trifluoromethanesulfonate represented by the above chemical formula (1) as a second acid generator. A pattern forming material was prepared.

[0149]

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Next, this pattern forming material is spin-coated on the silicon wafer 1 and dried at 100 ° C. for 2 minutes to form a film having a thickness of 0.1 to 1 μm on the wafer 1 as shown in FIG. Of the resist layer 2 was formed.

Subsequently, as shown in FIG. 1B, KrF
The resist layer 2 was exposed by a reduction projection exposure apparatus using excimer laser light (wavelength: 248 nm). Further, as shown in FIG. 1C, the resist layer 2 was subjected to electron beam exposure using an electron beam exposure apparatus (acceleration voltage: 50 kV).

After the above exposure, the resist layer 2 is baked after exposure (PEB: post exposure ba).
ke). That is, the latent images 5 and 7 shown in FIG. 1D were formed on the resist layer 2 by placing the substrate 1 on a hot plate and heating the resist layer 2 at a temperature of 100 ° C. for 1 minute. Further, the resist pattern shown in FIG. 1E was formed by performing development processing using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH).

The sensitivity and the resolution of the pattern forming material are as follows.
/ Cm ² was 0.25 μm, and exposure with an electron beam was 0.1 μm at 5 μC / cm ² . When the cross-sectional shape of the formed resist pattern was observed, it was found that both of the patterns formed using KrF light and the electron beam had favorable rectangular shapes.

Comparative Example 1 A resist pattern was formed in the same manner as in Example 1 except that only the first acid generator was used as the acid generator. That is, the above chemical formula (64)
95% by weight of a polyvinyl phenol resin shown in (1) and 2% by weight of triphenylsulfonium triflate as an acid generator were mixed to prepare a pattern forming material, and a resist pattern was formed in the same manner as in Example 1. Formed.

Observation of the cross-sectional shape of the formed resist pattern revealed that each of the patterns formed by using KrF light and an electron beam had a good rectangular shape. Also,
The sensitivity and resolution of the pattern forming material were 0.25 at an exposure dose of 20 mJ / cm ² for exposure with KrF light.
μm, but 20 μm for electron beam exposure.
It was 0.1 μm in μC / cm ² . That is, the sensitivity to the electron beam was reduced to about 1/4 times as compared with the first embodiment.

Comparative Example 2 A resist pattern was formed in the same manner as in Example 1 except that the composition of the pattern forming material was different. Hereinafter, description will be made with reference to FIGS.

FIGS. 4A to 4E schematically show process diagrams of a pattern forming method according to a conventional example. FIG.
(A)-(e) is sectional drawing, respectively.

First, a pattern forming material was prepared by mixing 90% by weight of a polyvinylphenol resin represented by the above formula (64) and 10% by weight of triphenylsulfonium triflate as an acid generator.

Next, this pattern forming material is spin-coated on the silicon wafer 1 and dried at 90 ° C. for 2 minutes to form a film having a thickness of 0.1 to 1 μm on the wafer 1 as shown in FIG. Of the resist layer 22 was formed.

Subsequently, as shown in FIG.
The resist layer 22 was exposed by a reduction projection exposure apparatus using excimer laser light (wavelength: 248 nm). further,
As shown in FIG. 4C, the resist layer 22 was subjected to electron beam exposure using an electron beam exposure apparatus (acceleration voltage: 50 kV).

After the above exposure, the substrate 1 was placed on a hot plate, and the resist layer 22 was heated at a temperature of 100 ° C. for 1 hour.
By heating for 25 minutes, the region 25 shown in FIG.
27, a latent image was formed. Further, a resist pattern shown in FIG. 4E was formed by performing development processing using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH).

The sensitivity and the resolution of the pattern forming material are as follows.
² was 0.3 μm, and exposure with an electron beam was 0.2 μm at 5 μC / cm ² . The sensitivity to KrF light was improved to about four times as compared with Example 1, and the sensitivity to electron beams was similar to that of Example 1. However, the resolution was lower than in Example 1 when using either KrF light or an electron beam.

When the cross-sectional shape of the formed resist pattern was observed, it was found that the pattern formed using KrF light had a severe degree of failure, and had a forward tapered shape as shown in FIG. .

(Example 2) A resist pattern was formed in the same manner as in Example 1 except that the composition of the pattern forming material was different.

That is, first, 5% by weight of triphenylsulfonium triflate as a first acid generator was added to 85% by weight of a polyvinylphenol resin represented by the above chemical formula (64) as an alkali-insoluble resin, and further a second acid generator was added. A succinimidyl camphorsulfonate represented by the above formula (2) was added as an agent in an amount of 10% by weight to prepare a pattern forming material.

Next, a resist pattern was formed using this pattern forming material in the same manner as in Example 1.

The sensitivity and the resolution of the pattern forming material are as follows.
a 0.25μm m ^2, and the respect exposure by the electron beam was 0.1μm in 2~5μC / cm ^2. When the cross-sectional shape of the formed resist pattern was observed, the pattern formed using KrF light and the electron beam had a good rectangular shape.

Example 3 A pattern forming material was prepared in the same manner as in Example 3 except that a different compound was used as the second acid generator.

That is, first, 5% by weight of triphenylsulfonium triflate as a first acid generator was added to 85% by weight of a polyvinylphenol resin represented by the chemical formula (64) as an alkali-insoluble resin, and further a second acid generator was added. A pattern forming material was prepared by adding 10% by weight of bis (cyclohexylsulfonyl) diazomethane represented by the above chemical formula (3) as an agent.

Next, a resist pattern was formed using this pattern forming material in the same manner as in Example 1.

The sensitivity and the resolution of the pattern forming material are as follows: the exposure amount is 20 mJ / c for the exposure with KrF light.
a 0.25μm m ^2, and the respect exposure by the electron beam was 0.1μm at 15 .mu.C / cm ^2. Also,
Observation of the cross-sectional shape of the formed resist pattern revealed that the pattern formed using KrF light and an electron beam had a good rectangular shape.

Example 4 A pattern forming material was prepared in the same manner as in Example 3 except that a different compound was used as the second acid generator.

That is, first, 5% by weight of triphenylsulfonium triflate as a first acid generator was added to 85% by weight of a polyvinylphenol resin represented by the above chemical formula (64) as an alkali-insoluble resin, and further a second acid generator was added. A pattern forming material was prepared by adding 10% by weight of 1,2,3-tris (methanesulfonioxy) benzene represented by the above chemical formula (4) as an agent.

Next, a resist pattern was formed using this pattern forming material in the same manner as in Example 1.

The sensitivity and resolution of the pattern forming material are as follows: when the exposure is performed by KrF light, the exposure amount is 20 mJ / c.
a 0.25μm m ^2, and the respect exposure by the electron beam was 0.1μm at 15 .mu.C / cm ^2. Also,
Observation of the cross-sectional shape of the formed resist pattern revealed that the pattern formed using KrF light and an electron beam had a good rectangular shape.

Example 5 In this example, a gate pattern of a transistor was formed using a negative pattern forming material. Hereinafter, FIGS. 2A to 2E and FIG.
This will be described with reference to (a) to (c).

FIGS. 3A to 3C schematically show process charts of a pattern forming method according to the embodiment of the present invention. 3A to 3C are perspective views.

First, 90% by weight of a xylenol novolak resin as an alkali-soluble resin, 10% by weight of methylolmelamine as a resin-forming compound, and 5% by weight of 2-methoxyphenyl-4,6-bistrichloromethyltriazine as a first acid generator. % And 5% by weight of succinimidyl trifluoromethanesulfonate as a second acid generator
Was mixed to prepare a pattern forming material.

Next, the pattern forming material was spin-coated on the substrate 1 on which the polysilicon layer 11 and the antireflection film 12 were formed. In addition, on the board | substrate 1, FIG.
A source 15 and a drain 16 are formed as shown in FIG. By drying the pattern forming material applied on the substrate 1 at 110 ° C. for 2 minutes, a resist layer 1 having a thickness of 0.15 μm was formed on the wafer 1 as shown in FIG.
3 was formed.

Subsequently, as shown in FIG. 2B, KrF
The resist layer 13 was exposed by a reduction projection exposure apparatus using excimer laser light (wavelength: 248 nm). The exposure with the KrF light was performed on the region 5 shown in FIG.

Next, as shown in FIG. 2C, the resist layer 1 was exposed using an electron beam exposure apparatus (acceleration voltage: 50 kV).
3 was subjected to electron beam exposure. The exposure with the electron beam was performed on the region 7 shown in FIG. Note that the width of the region 7 is 0.1 μm. FIG.
1A and 1B, the resist layer 13 is omitted.

After the above exposure, the substrate 1 was placed on a hot plate and the resist layer 13 was heated at 110 ° C. for 9 hours.
By heating for 0 second, the resist layer 13 is
The latent images 5 and 7 shown in (d) were formed. Furthermore, 2.38
% By weight of tetramethylammonium hydroxide (T
MAH) By performing development processing using an aqueous solution, the resist patterns 5, 7 shown in FIGS.
Was formed.

The sensitivity and the resolution of the pattern forming material are as follows: the exposure amount is 20 mJ / c for the exposure with KrF light.
a 0.25μm m ^2, and the respect exposure by the electron beam was 0.1μm at 5 [mu] C / cm ^2. Also, when observing the cross-sectional shape of the formed resist pattern,
Each of the patterns formed using the KrF light and the electron beam had a good rectangular shape.

In the above embodiment, the PEB is performed after the KrF light exposure and the electron beam exposure are completed. However, the PEB may be performed after each exposure.

The molar extinction coefficients and the melting temperatures of the acid generators used in the above Examples and Comparative Examples are shown in Table 1 below. Further, the acid generator used in the pattern forming materials of the above Examples and Comparative Examples, its molar extinction coefficient, molar concentration, the ratio of the molar extinction coefficients of the first and second acid generators, and the first and second The absorbance ratio is shown in Table 2 below.

[0186]

[Table 1]

[0187]

[Table 2]

[0188]

As described above, the pattern forming material of the present invention comprises a first acid generator which generates an acid upon irradiation with a predetermined exposure light, and a charged particle beam which transmits the exposure light and emits a charged particle beam. A second acid generator that generates an acid upon irradiation. Since the second acid generator transmits the exposure light, the use of the second acid generator hardly attenuates the exposure light. Therefore, the cross-sectional shape of the resist pattern formed by light irradiation can be rectangular.

Further, the first acid generator generates an acid even when irradiated with a charged particle beam, so that high sensitivity to the charged particle beam can be obtained.

As described above, according to the present invention, it is possible to form a pattern with high sensitivity without deteriorating the pattern shape even when exposed by light irradiation, and even when using a charged particle beam. .

[Brief description of the drawings]

FIGS. 1A to 1E are cross-sectional views schematically showing a process chart of a pattern forming method according to an embodiment of the present invention.

FIGS. 2A to 2E are cross-sectional views schematically showing a process chart of a pattern forming method according to an embodiment of the present invention.

FIGS. 3A to 3C are perspective views schematically showing process diagrams of a pattern forming method according to an embodiment of the present invention.

4A to 4E are cross-sectional views each schematically showing a process chart of a pattern forming method according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2, 13, 22 ... Resist layer 3 ... Mask 4 ... Exposure light 5, 7, 25, 27 ... Region 6 ... Charged particle beam 11 ... Polysilicon layer 12 ... Antireflection film 15 ... Source 16 ... Drain

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Waka Sugihara 8 Shinsugita-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Toshiba Yokohama Office

Claims (14)

[Claims] 1. A solubility variable compound that changes the solubility in an alkaline solution by applying an acid, a first acid generator that generates an acid by irradiating exposure light used in a photolithography process, And a second acid generator that transmits the exposure light and generates an acid when irradiated with a charged particle beam. 2. The pattern forming material according to claim 1, wherein the exposure light is KrF light. 3. The method according to claim 1, wherein a molar extinction coefficient of the second acid generator with respect to the exposure light is 1/10 or less of a molar extinction coefficient of the first acid generator with respect to the exposure light. Item 3. The pattern forming material according to Item 1 or 2. 4. A molar extinction coefficient of the first acid generator with respect to the exposure light is 5,000 to 200,000,
The molar extinction coefficient of the second acid generator with respect to the exposure light is 1 to 2,000.
The pattern forming material according to any one of the above. 5. The product of the molar extinction coefficient of the second acid generator with respect to the exposure light and the molar concentration of the second acid generator is the molar absorption of the first acid generator with respect to the exposure light. 1/10 of the product of the coefficient and the molar concentration of the first acid generator
5. The method according to claim 1, wherein:
Item. 6. The method according to claim 1, wherein the second acid generator contains at least one of the compounds represented by the following chemical formulas (1) to (4). Pattern forming material. Embedded image 7. A variable solubility compound that changes the solubility in an alkaline solution by applying an acid, a first acid generator that generates an acid by irradiating exposure light used in a photolithography process, And a step of forming a resist layer by applying a pattern forming material containing a second acid generator, which transmits the exposure light and generates an acid by irradiating a charged particle beam, on a substrate, Irradiating the exposure light and irradiating the resist layer with the charged particle beam. 8. The pattern forming method according to claim 7, further comprising a step of developing the resist layer irradiated with the exposure light and the electron beam with the alkaline solution. 9. The pattern forming method according to claim 7, wherein the charged particle beam is an electron beam. 10. The pattern forming method according to claim 7, wherein the exposure light is KrF light. 11. The method according to claim 1, wherein a molar extinction coefficient of the second acid generator with respect to the exposure light is 1/10 or less of a molar extinction coefficient of the first acid generator with respect to the exposure light. Item 11. The pattern forming method according to any one of Items 7 to 10. 12. The molar extinction coefficient of the first acid generator with respect to the exposure light is 5,000 to 200,000, and the molar extinction coefficient of the second acid generator is 1 to 2 with respect to the exposure light. 10. The method according to claim 7, wherein
12. The pattern forming method according to any one of items 11 to 11. 13. The product of the molar extinction coefficient of the second acid generator with respect to the exposure light and the molar concentration of the second acid generator is the molar absorption of the first acid generator with respect to the exposure light. 1/1 of the product of the coefficient and the molar concentration of the first acid generator
The pattern forming method according to any one of claims 7 to 12, wherein the value is 0 or less. 14. The method according to claim 7, wherein the second acid generator contains at least one compound represented by the following chemical formulas (1) to (4). Pattern formation method. Embedded image