TWI588609B - Negative resist composition and pattern forming process - Google Patents

Description

Negative photoresist composition and pattern forming method

The present invention relates to a negative-type photoresist composition, in particular, a chemically amplified negative-type photoresist composition using a polymer compound having a polarity-changing function used in processing a semiconductor substrate or a photomask substrate, and using the composition Pattern forming method.

With the increase in density and speed of LSI, it has been known to require the miniaturization of pattern rules. Along with this, the exposure method and the photoresist composition are also largely changed, and in particular, when lithography of a pattern of 0.2 μm or less is performed, KrF, ArF excimer laser light, or an electron beam is used as the exposure light source, and the photoresist composition is used. The isothermal energy ray shows a good sensitivity and gives a high resolution chemically amplified photoresist composition.

The photoresist composition has a positive type in which the exposed portion is dissolved and a negative type in which the exposed portion remains as a pattern, and a photoresist composition which is easier to use is selected in accordance with the necessary photoresist pattern. The chemically amplified negative-type photoresist composition generally comprises: a polymer dissolved in an aqueous alkali developing solution, an acid generator which generates an acid by decomposition of an exposure light, and a cross-linking between the polymers by using an acid as a catalyst to polymerize The crosslinking agent insoluble in the developer (as the case may be, the polymer compound and the crosslinking agent are integrated); and a basic compound for controlling the diffusion of the acid generated by the exposure is usually added.

The use of a phenol unit as a negative-type photoresist composition constituting an alkali-soluble unit type of a polymer compound dissolved in the above aqueous alkali developing solution has been developed in particular by the use of KrF excimer laser light exposure. When the exposure light is at a wavelength of 150 to 220 nm, the phenol unit does not have translucency, so it cannot be used as an ArF excimer laser light, but in recent years, it is used as an exposure method for obtaining a finer pattern, that is, a negative resist for EB and EUV exposure. In addition, the composition is highly regarded as a photoresist composition which can give a very high resolution even when it is used as a film. For example, Patent Document 1 (JP-A-2010-276910) and Patent Document 2 (Japanese Patent) Japanese Laid-Open Patent Publication No. 2010-164933, and Japanese Patent Laid-Open No. Publication No. 2008-249762.

Further, in addition to this, many materials for chemically increasing negative photoresist have been developed. For example, the alkali-soluble polymer used for the negative-resistance photoresist composition is not dissolved by the action of the acid generated when the high-energy ray is irradiated, and the cross-linking agent used in the above-mentioned Patent Documents 1 to 3 has been used, and has been developed. Many crosslinkers. On the other hand, there have been many attempts to introduce a polymer with a crosslinking agent, and a method of introducing an alkoxymethoxy-substituted styrene unit has been proposed (Patent Document 4: Japanese Patent Laid-Open No. Hei 5-232702) And a method of introducing a repeating unit having an alkoxymethylamine group (Patent Document 5: JP-A-H8-202037) and a method of introducing a repeating unit having an epoxy group (Patent Document 6: JP-A-2001- Japanese Patent No. 226430), a method of introducing a styrene-based repeating unit having an acid-releasing group (Patent Document 7: JP-A-2003-337414), and an adamantyl-based repeating unit having an acid-desorbable hydroxyl group introduced therein (Patent Document 8: JP-A-2001-154357), a method of introducing an aliphatic hydrocarbon group having an acid-desorbable hydroxyl group and an alicyclic hydrocarbon-based repeating unit (Patent Document 9: US Patent No. 7, 300, 739) No. Patent Document 10: U.S. Patent No. 7,393,624; Patent Document 11: U.S. Patent No. 7,563,558, etc., and other materials for acid-desorbable hydroxyl groups, non-patent literature 1 (H. Ito, and R. Sooriyakumaran, IBM T Echnical Disclosure Bulletin Vol. 35, No. 1B, 397 (1992)), Non-Patent Document 2 (H. Ito, Y. Maekawa, R. Sooriyakumaran, and EA Mash, ACS Symposium Series 537, Chaper 5, pp64-87 ( 1994)), Non-Patent Document 3 (M. Yoshida, and JMJ Frechet, Polymer, 35 (1), 5 (1994)) and the like have been proposed. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2010-164933 (Patent Document 3) JP-A-2008-249762 (Patent Document 4) Japanese Patent Laid-Open No. 5-232702 [Patent Document 5] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. 2001-226430 (Patent Document 7) Japanese Laid-Open Patent Publication No. 2003-337414 (Patent Document 8) US Pat. No. 7,300,739 [Patent Document 10] US Patent No. 7,393,624 [Patent Document 11] US Patent No. 7,563,558 [Patent Document 12] Japanese Patent Laid-Open Publication No. 2008-102383 [Patent Document 13] JP-A-2008-304590 [Patent Document 14] JP-A-2013-018391 [Non-Patent Document]

[Non-Patent Document 1] H. Ito, and R. Sooriyakumaran, IBM Technical Disclosure Bulletin Vol. 35, No. 1B, 397 (1992) [Non-Patent Document 2] H. Ito, Y. Maekawa, R. Sooriyakumaran, and EA Mash, ACS Symposium Series 537, Chaper 5, pp64-87 (1994) [Non-Patent Document 3] M. Yoshida, and JMJ Frechet, Polymer, 35 (1), 5 (1994)

[Problem to be Solved by the Invention] In order to pursue the drawing of a finer pattern, it is not necessary to solve the image property, and the LER is required to be small and the temperature dependency is small. The photoresist composition described in the patent document 14 (JP-A-2013-018391) has improved resolution and overcomes pattern density dependence, but further improvement in performance is required. If the sensitivity of the photoresist is high, the resolution is lowered, which is a trade-off of the chemically amplified photoresist composition. Therefore, it is considered that reducing the sensitivity of the photoresist composition is one way to improve the resolution. However, the decrease in sensitivity means that the amount of current at the time of drawing increases, and at this time, there is a problem that the baking temperature dependency of the pattern size is newly increased. Therefore, it is necessary to have a photoresist composition having a small temperature dependency at 50 A or more, especially at a high current amount of 200 A or more. Further, heat generated locally due to high current amount drawing may be caused by volatilization of components present in the exposed portion (for example, an acid or a basic compound generated from a photoacid generator) and adhesion to an unexposed portion. It has caused problems in pattern resolution and dimensional control, and has become a problem to be solved.

An object of the present invention is to provide a negative-type photoresist composition which can achieve high resolution of 50 nm or less, small LER, and is not affected by heat generated by irradiation of high-energy rays of an electron beam, and has low temperature dependency. For chemical flash stabilization, and providing a pattern forming method using this composition. [How to solve the problem]

In order to solve the above-described problems, the inventors of the present invention have repeatedly attempted to improve the polymer containing the aromatic ring-containing cyclic olefin unit and the side chain acid-releasing group unit disclosed in Patent Document 14 in order to improve the high resolution. The photoresist composition.

The reason for the above temperature dependency is presumably because the drawing portion is locally generated by the drawing of a large current amount, and the quenching agent is volatilized. However, if an amine compound having a relatively high boiling point is used, the above temperature dependency is lowered, but it is not satisfactory, and the LER is also increased. However, when a carboxy ruthenium chloride compound is used as a quencher, and a unit which generates an acid by exposure to a polymer chain is introduced, a pattern having a small temperature dependency and a satisfactory resolution and roughness can be obtained. The present invention has been completed.

That is, the present invention provides the following photoresist composition and pattern forming method. [1] A negative-type photoresist composition comprising: (A) a polymer compound containing a repeating unit represented by the following formula (1), and further comprising the following formulas (a1), (a2), (a3) At least one of the repeating units; (B) a salt represented by the following formula (3a); In the formula, A represents a single bond or an alkylene group having 1 to 10 carbon atoms which may have an etheric oxygen atom in the middle of the chain; R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; and R ² represents a hydrogen atom, a halogen atom, a linear, branched or cyclic methoxy group which may be substituted by halogen, or a linear or branched carbon number of 1 to 6 which may be substituted by halogen. Or a cyclic alkyl group, or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by a halogen; L is a hydrogen atom or may contain an etheric oxygen atom in the middle of the chain; a linear monovalent, branched or cyclic aliphatic monovalent hydrocarbon group having 1 to 10 carbon atoms or a carbonyloxy group; or a monovalent aromatic ring group having a substituent; Rx and Ry each being a hydrogen atom; Or an alkyl group having 1 to 15 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group or a monovalent aromatic ring group which may have a substituent, and Rx and Ry may be bonded to each other and together with the carbon atom to which they are bonded. Forming a ring; further, Rx and Ry are not hydrogen atoms at the same time; f is an integer of 1-3, s represents an integer of 0-2, a is an integer of (5+2s-f); m represents 0 or 1; Wherein R ^{12 is} each independently a hydrogen atom or a methyl group, R ¹³ is a single bond, a phenyl group, a -OR ²² -, or -C(=O)-Z ² -R ²² -; Z ² is an oxygen atom. Or NH, R ²² is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group (-CO-) or an ester group (-COO-). ), an ether group (-O-) or a hydroxyl group; L' represents a single bond, or -Z ³ -C(=O)-O-, and Z ³ represents a linear chain having a carbon number of 1 to 20 which may also be substituted by a hetero atom a divalent hydrocarbon group in the form of a branch, a branch or a ring; Z ¹ is a single bond, a methylene group, an ethyl group, a phenyl group, a phenyl group, a -OR ²³ -, or -C(=O)- Z ⁴ -R ²³ -; Z ⁴ is an oxygen atom or NH, and R ²³ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group. , an ester group, an ether group or a hydroxyl group; M ^- represents a non-nucleophilic relative ion; R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ are each independently represented or heterocyclic Atom-substituted, or a monovalent hydrocarbon group having a carbon number of 1 to 20 or a branched or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms; or a part of hydrogen atoms of the group may be substituted a hetero atom selected from an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom may be inserted with a hetero atom selected from an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, a hydroxyl group, a cyano group or a carbonyl group may be formed or inserted. An ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group; further, R ¹⁴ and R ¹⁵ may be bonded to each other and The sulfur atom forms a ring together, or two or more of R ¹⁶ , R ¹⁷ and R ¹⁸ , or two or more of R ¹⁹ , R ²⁰ and R ²¹ may be bonded to each other and together with the sulfur atom in the formula Form a ring; [chemical 3] In the formula, R ¹¹ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and each may have a fluorine atom. Any one of a nitrogen atom, an ether group, an ester group, a lactone ring, an indole ring, a carbonyl group, and a hydroxyl group; M represents a relative cation having a substituent, and represents any one of a phosphonium cation, a phosphonium cation, and an ammonium cation. By. [2] The negative-type photoresist composition according to [1], wherein the polymer compound of (A) further contains a repeating unit selected from one or more of the following general formulae (2) and (3); 4] In the formula, B and C represent a single bond or an alkylene group having 1 to 10 carbon atoms which may have an etheric oxygen atom in the middle of the chain; D represents a single bond or may be substituted by fluorine, or may contain an ether in the middle of the chain. a linear, branched or cyclic (v+1)-valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, a carbonyl group or a carbonyloxy group; and R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoro group. methyl; R ^3, R ⁴ each independently represent a hydrogen atom, a halogen atom, having 2 to 8 carbon atoms may be substituted by halogen of the linear, branched or cyclic acyl group having the carbon number of 1 to 6 a linear, branched or cyclic alkyl group substituted by halogen, or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by halogen; Rf ₁ , Rf ₂ represents an alkyl group having at least one fluorine atom having 1 to 6 carbon atoms, and Rf ₁ may be bonded to D and form a ring together with the carbon atom to which they are bonded; g is an integer of 0 to 3, and h is 1 Or 2, r is 0 or 1, v is 1 or 2, t, u are integers of 0~2, b is an integer of (5+2t-g), c is an integer of (5+2u-h), and n and p are independent The ground represents 0 or 1; when r is 0, p is 1. [3] The negative-type photoresist composition of [1] or [2], wherein the polymer compound of (A) further contains a repeating one or more selected from the group consisting of the following general formulae (4) and (5) Unit; In the formula, R ⁵ and R ⁶ each independently represent a hydrogen atom, a halogen atom, a linear, branched or cyclic decyloxy group having a carbon number of 2 to 8 which may be substituted by halogen, and a carbon number of 1 to 6; a linear, branched or cyclic alkyl group substituted by halogen, or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by halogen; i, j is An integer from 0 to 3, d is an integer from 0 to 5, and e is an integer from 0 to 3. [4] The negative-type photoresist composition according to any one of [1] to [3], further comprising (C) a polymer compound containing the repeating unit of the above formula (1), and having no high energy due to A repeating unit that produces a portion of the acid by irradiation of radiation. [5] The negative-type photoresist composition according to any one of [1] to [4], further comprising a compound which generates an acid due to irradiation with high-energy rays. [6] A blank mask which has been coated with the negative-type photoresist composition of any one of [1] to [5]. [7] A pattern forming method comprising the steps of: forming a photoresist film using a chemically amplified negative-type photoresist composition according to any one of [1] to [5] on a substrate to be processed; patterning high-energy rays Development was carried out using an alkali developer to obtain a photoresist pattern. [8] The pattern forming method according to [7], wherein the high-energy ray is an EUV or an electron beam. [9] The pattern forming method of [7] or [8], wherein the substrate to be processed is a blank mask. [10] The pattern forming method of [9], wherein the outermost surface of the blank mask is formed of a chromium-based material. [Effects of the Invention]

The negative-type photoresist composition of the present invention has extremely high resolution in the microfabrication technique, particularly in the electron beam lithography technique, and gives a small pattern of LER. Further, since the negative-type photoresist composition of the present invention has a small temperature dependency of the pattern size, it is possible to suppress the deviation of the design from the actual pattern size due to the heat generated locally due to the use of a large current amount for electron beam drawing.

The invention is described in detail below. The present invention provides a negative-type photoresist composition comprising: (A) a polymer compound containing a repeating unit represented by the following formula (1), and further comprising the following formulas (a1), (a2), (a3) At least one of the repeating units; (B) a salt represented by the following formula (3a). Further, it is preferred that the photoresist composition is free of a crosslinking agent. 【化6】 In the above formula (1), A represents a single bond or an alkylene group having 1 to 10 carbon atoms which may have an etheric oxygen atom in the middle of the chain. R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ² represents a hydrogen atom, a halogen atom, a linear, branched or cyclic decyloxy group having a carbon number of 2 to 8 which may be substituted by halogen, or a linear chain having a carbon number of 1 to 6 which may be substituted by halogen. A branched or cyclic alkyl group or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by a halogen. L may be a linear, branched or cyclic aliphatic monovalent hydrocarbon group having an etheric oxygen atom, a carbonyl group or a carbonyloxy group and having a carbon number of 1 to 10 in the middle of a hydrogen atom or a chain, or may be substituted. a monovalent aromatic ring group, Rx and Ry each being a hydrogen atom, or an alkyl group having 1 to 15 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group, or a monovalent aromatic ring group which may have a substituent, Rx, Ry may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded. Further, Rx and Ry are not hydrogen atoms at the same time. f represents an integer from 1 to 3, s represents an integer from 0 to 2, and a represents an integer of (5+2s-f). m represents 0 or 1. 【化7】 In the above formulas (a1), (a2), (a3), R ^{12 is} each independently a hydrogen atom or a methyl group, and R ¹³ is a single bond, a phenyl group, -OR ²² -, or -C(=O)- Z ² -R ²² -. Z ² is an oxygen atom or NH, and R ²² is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group (-CO-) or an ester. A group (-COO-), an ether group (-O-) or a hydroxyl group. L' represents a single bond or -Z ³ -C(=O)-O-, and Z ³ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted by a hetero atom. Z ¹ is a single bond, a methylene group, an ethyl group, a phenyl group, a fluorinated phenyl group, -OR ²³ -, or -C(=O)-Z ⁴ -R ²³ -. Z ⁴ is an oxygen atom or NH, and R ²³ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an extended alkenyl group or a phenyl group, and may also contain a carbonyl group, an ester group, an ether group or Hydroxyl. M ^- represents a non-nucleophilic relative ion. R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ each independently represent a straight chain having a carbon number of 1 to 20 which may be substituted by a hetero atom or may be inserted into a hetero atom. Or a branched or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms. Further, a part of the hydrogen atoms of the groups may be replaced by a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, or a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom may be inserted, and as a result, a hydrogen atom may be formed or A hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group or the like is inserted. Further, R ¹⁴ and R ¹⁵ may be bonded to each other and form a ring together with a sulfur atom in the formula, or two or more of R ¹⁶ , R ¹⁷ and R ¹⁸ or in R ¹⁹ , R ²⁰ and R ²¹ Any two or more of them may be bonded to each other and form a ring together with the sulfur atom in the formula. 【化8】 In the above formula (3a), R ¹¹ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, respectively. There is a fluorine atom, a nitrogen atom, an ether group, an ester group, a lactone ring, an indole ring, a carbonyl group, or a hydroxyl group. M represents a relative cation having a substituent, and represents any of a phosphonium cation, a phosphonium cation, and an ammonium cation.

When the unit represented by the above formula (1) is irradiated with high-energy rays, the acid-decomposable group (-CRxRy-OL group) undergoes a desorption reaction due to the action of an acid generated by the acid generator, and the self-base insolubilization and polymerization are induced. a repeating unit of the cross-linking reaction between substances.

In the case where the side chain of the acid-containing group is substituted with an aromatic ring, the substitution number f is an integer of 1 to 3. L may be a linear, branched or cyclic aliphatic monovalent hydrocarbon group having an etheric oxygen atom, a carbonyl group or a carbonyloxy group and having a carbon number of 1 to 10 in the middle of a hydrogen atom or a chain, or may be substituted. The monovalent aromatic ring group is preferably a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a methylcarbonyl group or a phenyl group.

Each of Rx and Ry is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group, or a monovalent aromatic ring group which may have a substituent, but Rx and Ry are not hydrogen atoms at the same time. The preferred structure of Rx and Ry may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group or a structural isomer thereof, and further a hydroxyl group or an alkoxy group.

The aromatic ring represented by the above formula (1) may be bonded to the main chain by a single bond, or may be bonded to the carbonyloxy group, and may further bond via the linking group A. s represents an integer from 0 to 2, and 0 represents a benzene ring, 1 represents a naphthalene ring, and 2 represents an anthracene ring.

A represents a single bond, or an alkyl group having an etheric oxygen atom (ether bond) having a carbon number of 1 to 10, and an alkyl group such as a methylene group, an ethyl group, a propyl group, and a butyl group. a structural isomer of a carbaryl group, a hexanyl group, and a carbon skeleton having a branched or cyclic structure. When ether oxygen is contained, when m in the formula (1) is 1, it can be inserted at any position other than the carbon at the α position and the carbon at the β position with respect to the ester oxygen. Further, when m is 0, the atom bonded to the main chain is ether oxygen, and the second ether oxygen can be inserted at any position other than the carbon at the α position and the carbon at the β position with respect to the ether oxygen.

The ideal of the repeating unit represented by the above formula (1) is as follows. Further, in the following examples, Me represents a methyl group and Ac represents an ethyl group. 【化9】

【化10】

【化11】

【化12】

The polymer compound used in the present invention contains, in addition to the repeating unit represented by the above formula (1), any repeating unit represented by the following formulas (a1), (a2), and (a3). 【化13】 In the above formulas (a1), (a2), (a3), R ^{12 is} each independently a hydrogen atom or a methyl group, and R ¹³ is a single bond, a phenyl group, -OR ²² -, or -C(=O)- Z ² -R ²² -. Z ² is an oxygen atom or NH, and R ²² is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group (-CO-) or an ester. A group (-COO-), an ether group (-O-) or a hydroxyl group. L' represents a single bond or -Z ³ -C(=O)-O-, and Z ³ represents a linear, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may be substituted by a hetero atom. Z ¹ represents a single bond, a methylene group, an ethyl group, a phenyl group, a fluorinated phenyl group, -OR ²³ -, or -C(=O)-Z ⁴ -R ²³ -. Z ⁴ is an oxygen atom or NH, and R ²³ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an extended alkenyl group or a phenyl group, and may also contain a carbonyl group, an ester group, an ether group or Hydroxyl. M ^- represents a non-nucleophilic relative ion. R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ each independently represent a straight chain having a carbon number of 1 to 20 which may be substituted by a hetero atom or may be inserted into a hetero atom. Or a branched or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms. Further, a part of the hydrogen atoms of the groups may be replaced by a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, or a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom may be inserted, and as a result, a hydrogen atom may be formed or A hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group or the like is inserted. Further, R ¹⁴ and R ¹⁵ may be bonded to each other and form a ring together with a sulfur atom in the formula, or two or more of R ¹⁶ , R ¹⁷ and R ¹⁸ or in R ¹⁹ , R ²⁰ and R ²¹ Any two or more of them may be bonded to each other and form a ring together with the sulfur atom in the formula.

In the above formula, when L' is -Z ³ -C(=O)-O-, Z ³ represents a linear one, a branched or a cyclic one having a carbon number of 1 to 20 which may be substituted by a hetero atom. Specific examples of the hydrocarbon group include the following, but are not limited thereto. 【化14】 (In the formula, the dashed line represents the keying hand.)

In the above formula, R ¹⁴ and R ¹⁵ may be bonded to each other and form a ring together with a sulfur atom in the formula, or two or more of R ¹⁶ , R ¹⁷ and R ¹⁸ , or R ¹⁹ , R ²⁰ and R ^{21 .} Any two or more of them may be bonded to each other and form a ring together with a sulfur atom in the formula, and in this case, a group represented by the following formula may be mentioned. 【化15】 (wherein R ⁵ represents the same as the above-exemplified groups of R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ .)

Specific structures of the phosphonium cations represented by the above formulas (a2) and (a3) are as follows. However, the invention is not limited thereto. 【化16】

The above formulas (a1), (a2), and (a3) are units for producing acid due to high-energy radiation. These units are capable of moderately inhibiting acid diffusion by bonding in the polymer, and it is considered that a pattern of reduced LER can be obtained. Further, when the acid generating unit is bonded to the polymer and baked in a vacuum, the chemical flash phenomenon in which the acid volatilizes from the exposed portion and reattaches to the unexposed portion can be suppressed, and it is considered that the LER can be effectively reduced and reduced. The exposure portion does not want to negatively suppress the defects caused by the reaction.

The negative resist composition of the present invention contains a salt represented by the following formula (3a). 【化17】

In the above formula (3a), R ¹¹ is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. There is a fluorine atom, a nitrogen atom, an ether group, an ester group, a lactone ring, an indole ring, a carbonyl group, or a hydroxyl group. M represents a relative cation having a substituent, and represents any one of a phosphonium cation, a phosphonium cation, and an ammonium cation.

The amount of the salt represented by the above formula (3a) is preferably 0.01 to 20 parts by mass, particularly preferably 0.05 to 15 parts by mass, per 100 parts by mass of the polymer compound of the formula (1) contained in the photoresist composition. The salt represented by the above formula (3a) undergoes an exchange reaction with an acid generated by exposure, and thus functions as an acid diffusion controlling agent. This salt is an ionic compound and does not volatilize due to heat. On the other hand, an amine compound which is often used as an acid diffusion controlling agent volatilizes due to heat generated during baking and drawing. Since the negative-type photoresist composition of the present invention uses an ionic compound as an acid diffusion controlling agent, it is not affected by heat generated during baking and drawing, and has a small temperature dependency of a pattern size.

Specific examples of the anion structure of the salt represented by the above formula (3a) are as follows, but the present invention is not limited thereto. 【化18】

【化19】

In addition, the cation of the formula (3a) is exemplified by the above-described formula (Chemical Formula 15), and specific examples thereof include the phosphonium cation described in the above [Chemical Formula 16].

In order to obtain high resolution, the polymer compound contained in the negative-type photoresist composition of the present invention may advantageously be insoluble in order to remove the acid-desorbable group contained in the repeating unit of the above formula (1). It is preferred to carry out a unit which allows a thermal vibration of a moderate polymer, that is, a repeating unit represented by the following general formula (2) and/or (3). Further, it may contain a repeating unit represented by the following formula (4) or (5).

【化20】

In the above formula (2), R ¹ has the same definition as the above formula (1), and R ³ and b have the same definitions as R ² and a of the above formula (1), and the same specific examples may be mentioned. Further, the definition of the linking group B and the A of the above formula (1) is the same, and the same specific examples may be mentioned.

In the above formula (2), the number g of the hydroxyl group substituted by the aromatic ring is an integer of 0 to 3. However, in order to obtain the solubility of the photoresist to the aqueous alkali developer and the substrate adhesion as will be described later, it is necessary to contain The repeating unit having a phenolic hydroxyl group or the repeating unit of the above formula (3) is preferred. In addition, in order to obtain high resolution by ensuring high activity against the insolubilization reaction accompanying the detachment of the acid-removing group contained in the repeating unit of the above formula (1), it is preferable to include g in the formula (2). 1 or more is preferable, and it is more preferable that the g in the formula (2) containing 50 mol% or more is 1 or more. Further, the fact that g is 0 can be used to adjust the dissolution rate and adjust the thermal vibration tolerance of the polymer, but it may not be included in the design.

Further, similarly to the above formula (1), the aromatic ring contained in the repeating unit may be bonded to the main chain by a single bond, or may be bonded via a carbonyloxy group or may be further bonded via the linking group B. t represents an integer of 0 to 2, when it is 0, it is a benzene ring, a 1 time is a naphthalene ring, and a 2 hour is an anthracene ring.

In the repeating unit represented by the above formula (2), g is 1 or more, n is 0, and B is a single bond, that is, when the aromatic ring is directly bonded to the main chain of the polymer compound, that is, when there is no linking group, the repeating unit A unit derived from a monomer having a hydroxy-substituted aromatic ring and a mono-substituted or unsubstituted vinyl group represented by a hydroxystyrene unit, and preferred examples thereof include 3-hydroxystyrene and 4-hydroxystyrene. 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc., more preferably 3-hydroxystyrene or 4-hydroxystyrene represented by the following formula (6). 【化21】 (wherein R ^{1 is the} same as defined in the above formula (1), and k is 1 to 3.)

Further, when n is 1, that is, a repeating unit having an ester skeleton as the linking group B, and a carbonyl-substituted vinyl monomer unit represented by a (meth) acrylate.

Among the repeating units represented by the formula (2) derived from the (meth) acrylate-based linking group (-CO-OB-), g is preferably 1 or more. 【化22】

In the repeating unit represented by the above formula (2), g is 0, and examples thereof include styrene, vinyl naphthalene, vinyl anthracene, and halogen atoms, decyloxy groups, alkyl groups, alkoxy groups as described above. Replace the repeating unit. Further, when g is 0 and the linking group (-CO-OB-) derived from (meth) acrylate is used, the hydrogen atom having a hydroxyl group is preferably substituted with an acid having an ideal structure when the g is 1 or more. It is a thiol or alkyl group.

In the above formula (3), R ¹ has the same definition as the above formula (1), and R ⁴ and c have the same definitions as R ² and a of the above formula (1), and the same specific examples may be mentioned. Further, the definition of the linking group C and the A of the above formula (1) are the same, and the same specific examples may be mentioned.

In the above formula (3), D represents a single bond or a linear, branched or cyclic group having a carbon number of 1 to 10 which may be substituted by fluorine or an etheric oxygen atom, a carbonyl group or a carbonyloxy group in the middle of the chain. An aliphatic hydrocarbon group having a (v+1) valence. Further, Rf ₁ and Rf _{2 each} represent an alkyl group having 1 to 6 carbon atoms and having at least one fluorine atom, and Rf ₁ may be bonded to D and form a ring together with the carbon atoms bonded thereto. When r is 1, the aromatic ring is inserted between the polymer backbone and the hydroxyl group bonded to the adjacent carbon via the fluorine-substituted carbon, and the substitution number of D is 1 or 2, where D is not a single bond. D has one or two hydroxyl groups in which the adjacent carbon is replaced by fluorine. Further, when r is 0, p is 1, C is a single bond, and D is bonded to the polymer main chain via a carbonyloxy group. At this time, D also has a hydroxyl group in which one or two adjacent carbons are bonded via a fluorine-substituted carbon.

A preferred example of the repeating unit represented by the above formula (3) is as follows, but is not limited thereto. 【化23】

【化24】

The repeating unit represented by the following general formula (4) or (5) is derived from a cyclic olefin containing an aromatic ring. 【化25】

A repeating unit comprising at least one of the above formulas (2) and The photoresist film obtained by the photoresist composition of the polymer of the repeating unit can strongly suppress the irradiated pattern and the formed pattern even when pattern exposure including both the pattern and the equidistant pattern is performed by electron beam or EUV. The pattern of the size depends on the high resolution.

The definitions of R ⁵ and d and R ⁶ and e in the above formulas (4) and (5) are the same as the definitions of R ² and a in the above formula (1), and the same specific examples may be mentioned.

In order to improve the alkali solubility of the polymer from the relationship with other repeating units constituting the polymer, when i and j are 1 or more, the following derivatives are easily obtained, and the desired effect can be achieved ideally. 【化26】

In this case, in all the repeating units constituting the polymer of the present invention, at least one of the repeating units other than the above formula (1) has a phenolic hydroxy unit and/or a fluoroalcohol group unit, and is repeating other than the formula (1) The total of the units (formulas (a1), (a2), (a3), (2), (3), (4), (5)) is 25 to 95% by mole, preferably 40 to 90% by mole. .

The above polymer contained in the negative resist composition of the present invention is soluble in an aqueous alkali developing solution, and is a repeating unit of g≧1 in the above formula (2), a repeating unit of the above formula (3), and a above formula ( 4) A group consisting of a repeating unit of i i 1 and a repeating unit of j ≧ 1 in the above formula (5) is a group of repeating units which impart alkali solubility and substrate adhesion. Therefore, the total of the repeating units belonging to the group is preferably from 25 to 95 mol%, more preferably from 40 to 80 mol%, based on all the repeating units constituting the polymer. Further, when the total of the repeating unit of i≧1 in the above formula (4) and the repeating unit of j≧1 in the above formula (5) account for more than half of the repeating units of the group, the total lower limit of the group is preferably 40. Molar% is preferred. Further, when the total of the repeating unit of g≧1 and the repeating unit of the above formula (3) in the above formula (2) is 20 mol% or more with respect to all the repeating units constituting the entire polymer, the upper limit of the entire group is preferably 80% or less is preferred. When the amount of the repeating unit of the group is less than the above lower limit, dross is likely to occur during development, and bridging is likely to occur between the resist patterns. Further, in particular, when the content of the repeating unit of g≧1 in the above formula (2) is 50 to 70 mol%, high resolution is easily obtained.

Further, the negative-type photoresist composition of the present invention is negatively decomposed by the hydroxyl group contained in the repeating unit of the formula (1) by the action of an acid, and the above formula (1) is repeated in order to obtain this effect. The content of the unit relative to all of the repeating units constituting the polymer is preferably from 5 to 75 mol%, more preferably from 10 to 60 mol%. When the repeating unit of the above formula (1) is less than 5 mol%, the change in alkali solubility due to the acid reaction of the repeating unit of the above formula (1) is insufficient, and the effect of the present invention may not easily be obtained.

Further, in order to obtain the moderate thermal vibration tolerance of the polymer, the total content of the above formula (4) and the above formula (5) is preferably 3 to 30 mol%, more preferably the total repeating unit constituting the polymer. 5~20 mol%.

Further, the content of the repeating unit for the acid-producing by the above formulas (a1), (a2), and (a3) is preferably 0.5 to 20 mol%, and more preferably 1 to 10 mol%. When the repeating unit of the above formulas (a1), (a2), and (a3) is more than 20 mol%, the solubility of the polymer with respect to the photoresist solvent is low, and defects occur.

Other repeating units which may be contained, for example, units represented by the following general formulae (13) to (15). (wherein R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, Y represents an oxygen atom or a methylene group, Z represents a hydrogen atom or a hydroxyl group, and R' represents an alkyl group having 1 to 4 carbon atoms, w An integer of 0 to 3 is shown.) These units are not acidic, and can be used as a unit for imparting adhesion to a substrate and adjusting solubility.

That is, the polymer compound of the component (A) preferably contains a repeating unit represented by the formula (1) in an amount of from 5 to 75 mol%, preferably from 10 to 60 mol%, and a repeating unit represented by the formula (a1) to (a3). 0.5 to 20 mol%, preferably 1 to 10 mol%, and repeating units represented by formulas (2) and (3) are 5 to 94.5 mol%, preferably 15 to 86 mol%, and formula (4) And (5) represents a repeating unit of 0 to 20% by mole, preferably 3 to 15% by mole, and other repeating units of 0 to 20% by mole, preferably 0 to 10% by mole.

The negative resist composition of the present invention may further contain (C) a polymer compound containing a repeating unit of the above formula (1) and containing no repeating unit having a site where acid is generated by high-energy irradiation. Such a polymer compound is, for example, a repeating unit containing the repeating unit of the above formula (1) and one or more selected from the above formulas (2) and (3), and is selected from the above formulas (4) and (5). A polymer compound composed of a polymer of one or more repeating units.

That is, the polymer compound of the component (C) preferably contains the repeating unit represented by the formula (1) in an amount of 5 to 70 mol%, preferably 10 to 60 mol%, and the repeating unit 25 represented by the formulas (2) and (3). ~95% by mole, preferably 40 to 80% by mole, and repeating units represented by formulas (4) and (5) are 0 to 30% by mole, preferably 3 to 20% by mole, and other repeating units are 0~ 20% by mole, preferably 0 to 10% by mole.

By using such a polymer compound in combination with the polymer compound of the above (A), the solubility in the resist solvent and the solubility in the developer can be adjusted. Also, an improvement in resolution can be achieved. In addition, the blending amount of the polymer compound of the component (C) is 0 to 5,000 parts by mass, preferably 0 to 2,000 parts by mass, more preferably 0 to 1,000 parts by mass based on 100 parts by mass of the polymer compound of the component (A). Parts by mass.

As the above-mentioned base polymer, as described above, different polymer compounds may be used in combination, but when they are not mixed, the repeating units having the above functions are determined, and the composition ratio of each repeating unit is designed to give a photoresist film. The ideal resolution.

The polymer compound containing the repeating unit of the above (A) and (C) used in the negative resist composition of the present invention can be subjected to a combination of protection, deprotection reaction and copolymerization as needed according to a known method. . The copolymerization reaction is not particularly limited, and is preferably a radical polymerization. These methods can be referred to Patent Document 3 and the like.

The ideal molecular weight of the polymer compound of the above (A) component and (C) component is measured by gel permeation chromatography (GPC) using polystyrene as a standard sample by a general method, and the weight average molecular weight is 1,000 Å. 50,000, preferably 1,000 to 20,000. When the weight average molecular weight is less than 1,000, as is conventionally known, the head of the pattern is rounded, the resolution is lowered, and the line edge roughness is deteriorated. On the other hand, when the molecular weight is more than necessary, it depends on the pattern of the image to be resolved, but the wire edge roughness tends to increase, and in particular, when the pattern line width is 100 nm or less, it is preferable to control the molecular weight to be 20,000 or less. Preferably.

Further, the polymer compound of the components (A) and (C) used in the present invention has a molecular weight distribution (Mw/Mn) of 1.0 to 3.0, and particularly preferably a narrow dispersion of 1.0 to 2.5. When the molecular weight distribution is wide, foreign matter may appear on the pattern after development or the shape of the pattern may deteriorate.

The negative-type photoresist composition of the present invention shields the mixture of the acid from the antistatic film in the treatment of the chemical flash of the acid irradiated with high-energy rays and the antistatic film material coated on the photoresist, and suppresses the unexpected The undesired negative addition may further contain a polymer compound (D) having a repeating unit represented by the following formula (8) and the following formula (9) having at least one fluorine atom; And repeating units of any one of (10), (11), and (12). Further, by containing the material, the photoresist film in the unexposed portion has a characteristic that the dissolution rate of the alkali developer is increased, and the development defect can also be exerted. 【化27】 (wherein R ⁵⁰ represents a hydrogen atom or a methyl group. R ⁵¹ represents a hydrogen atom or a linear or branched monovalent hydrocarbon group having 1 to 5 carbon atoms which may be inserted into a hetero atom. R ⁵² indicates that a hetero atom may also be inserted. a linear or branched monovalent hydrocarbon group having 1 to 5 carbon atoms, and each of R ⁵³ independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^53a and R ^53b each independently represent a hydrogen atom. Or a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. R ⁵⁴ each independently represents a hydrogen atom, a linear, branched or cyclic monovalent hydrocarbon group having 1 to 15 carbon atoms or A fluorinated monovalent hydrocarbon group or an acid labile group, and when R ⁵⁴ is a monovalent hydrocarbon group or a fluorinated monovalent hydrocarbon group, an ether bond (-O-) or a carbonyl group (-C(=O) may be inserted between the carbon-carbon bonds. --). α is an integer from 1 to 3. β is an integer corresponding to 0≦β≦5+2γ-α. γ is 0 or 1. δ is an integer from 1 to 3. X ¹ represents a single bond, -C(=O O- or -C(=O)NH-, E is a linear, branched or cyclic (δ+1) valence hydrocarbon group or a fluorinated hydrocarbon group having 1 to 20 carbon atoms.

The monovalent hydrocarbon group may, for example, be an alkyl group, an alkenyl group or an alkynyl group, and an alkyl group is preferred. Specific examples of the alkyl group include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a second butyl group, and a n-pentyl group. Further, a carbon-carbon bond to the group may be inserted into a hetero atom selected from an oxygen atom, a sulfur atom or a nitrogen atom.

Formula (8), -OR ⁵¹ should preferably be hydrophilic group. In this case, R ^{52 is} preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms in which an oxygen atom is interposed between carbon-carbon bonds.

Specific examples of the repeating unit represented by the above formula (8) are as follows, but are not limited thereto. 【化28】 (wherein R ^{50 is the} same as above.)

(wherein R ^{50 is the} same as above.)

In the repeating unit represented by the above formula (8), X ¹ is preferably a single bond, more preferably -C(=O)O- or -C(=O)NH-. R ⁵⁰ is preferably a hydrogen atom or a methyl group. X ¹ has an ability to capture acid from an antistatic film by the presence of a carbonyl group. Further, when R ¹ is a methyl group, it becomes a rigid polymer having a higher glass transition temperature (Tg), so acid diffusion is suppressed. Thereby, the stability of the photoresist film with time is good, and the resolution and pattern shape are not deteriorated.

The repeating unit having at least one fluorine atom is preferably at least one selected from the group consisting of repeating units represented by the following formulas (9) to (12). 【化29】 (wherein R ⁵³ each independently represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^53a and R ^53b each independently represent a hydrogen atom or a linear or branched carbon number of 1 to 10 or a cyclic alkyl group. R ⁵⁴ each independently represents a hydrogen atom, a linear, branched or cyclic monovalent hydrocarbon group having 1 to 15 carbon atoms or a fluorinated monovalent hydrocarbon group or an acid labile group, and R ⁵⁴ is In the case of a monovalent hydrocarbon group or a fluorinated monovalent hydrocarbon group, an ether bond (-O-) or a carbonyl group (-C(=O)-) may be inserted between the carbon-carbon bonds. δ is an integer of 1 to 3. E is carbon a straight-chain, branched or cyclic (δ+1)-valent hydrocarbon group or a fluorinated hydrocarbon group of 1 to 20%.

The linear, branched or cyclic alkyl group having 1 to 10 carbon atoms may, for example, be a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a cyclopropyl group, a n-butyl group, an isobutyl group or a second butyl group. , tert-butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-decyl, n-decyl, adamantyl, norbornyl and the like. Among these, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms is preferred.

The linear monovalent, branched or cyclic monovalent hydrocarbon group having 1 to 15 carbon atoms may, for example, be an alkyl group, an alkenyl group or an alkynyl group, and an alkyl group is preferred. The above-mentioned alkyl group may be, in addition to the above, a n-undecyl group, a n-dodecyl group, a thirteen-group, a tetradecyl group, a fifteen-group or the like. The linear, branched or cyclic fluorinated monovalent hydrocarbon group having 1 to 15 carbon atoms may be a group obtained by partially or completely replacing one or all of the hydrogen atoms bonded to the carbon atom of the monovalent hydrocarbon group with a fluorine atom.

The linear or branched or cyclic (δ+1)-valent hydrocarbon group or fluorinated hydrocarbon group having 1 to 20 carbon atoms may be a group obtained by further removing δ hydrogen atoms from the above-mentioned monovalent hydrocarbon group or fluorinated monovalent hydrocarbon group. .

Specific examples of the repeating unit represented by the above formulas (9) to (12) are as follows, but are not limited thereto. 【化30】 (wherein R ^{53 is the} same as above.)

【化31】 (wherein R ^{53 is the} same as above.)

Further, the repeating unit of the above (8) contains 5 to 80 mol%, preferably 15 to 70 mol%, of all the repeating units. The repeating units represented by the above formulas (9) to (12) may be used singly or in combination of two or more kinds, and it is preferred to use 20 to 95 mol% of all the repeating units of the (D) polymer compound. It is preferred to introduce a range of 30 to 85 mol%.

The polymer compound (D) may contain other units than the above repeating unit. Examples of such a repeating unit include those described in paragraphs [0046] to [0078] of JP-A-2014-177407. When the polymer compound (D) contains other repeating units, the content thereof is preferably 50 mol% or less of all the repeating units.

The polymer compound (D) can be obtained by a combination of protection, deprotection reaction, and copolymerization of a monomer as needed according to a known method. The copolymerization reaction is not particularly limited, and is preferably a radical polymerization or an anionic polymerization. For such methods, reference is made to Japanese Laid-Open Patent Publication No. 2004-115630.

The weight average molecular weight (Mw) of the polymer compound (D) is preferably 2,000 to 50,000, more preferably 3,000 to 20,000. If the Mw is less than 2,000, it will promote the diffusion of acid, and sometimes the resolution will deteriorate and the stability over time will be impaired. If the Mw is too large, the solubility to the solvent is reduced, and coating defects sometimes occur. Further, in the present invention, Mw is subjected to a polystyrene conversion measurement obtained by gel permeation chromatography (GPC) using a tetrahydrofuran (THF) solvent.

The molecular weight distribution (Mw/Mn) of the polymer compound (D) is preferably 1.0 to 2.2, more preferably 1.0 to 1.7.

The blending amount of the polymer compound (D) is 0 to 30 parts by mass, preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, per 100 parts by mass of the polymer compound (base resin) of the component (A). .

In the chemically amplified negative-type photoresist composition of the present invention, substantially no crosslinking agent is added, but when fine-tuning the performance is desired, about 0.5 to 5 parts by mass may be added with respect to 100 parts by mass of the polymer. Many cross-linking agents for chemically amplified negative-type photoresist compositions have been known, and there are also examples in Patent Documents 1 to 3.

Examples of the preferable crosslinking agent which may be additionally added include alkoxymethyl glycoluril and alkoxymethyl melamine, and specific examples thereof include tetramethoxymethyl glycoluril and 1,3-bismethoxymethyl. Base-4,5-dimethoxyethylene urea, bismethoxymethylurea, hexamethoxymethylmelamine, hexaethoxymethylmelamine, and the like. The crosslinking agent may be used singly or in combination of plural kinds.

In the polymer compound used in the negative-type photoresist composition of the present invention, since an acid generating portion is formed by exposure, an acid generator is not necessarily added to the photoresist composition, but in order to adjust sensitivity and resolution, An acid generator can be added. In the case of blending, the amount to be added is preferably from 1 to 20 parts by mass, more preferably from 2 to 15 parts by mass, per 100 parts by mass of the polymer. The acid generator can be selected from appropriately known acid generators in accordance with the physical properties to be adjusted. Desirable photoacid generators are an onium salt, a phosphonium salt, a sulfonyldiazomethane, an N-sulfodeoxyquinone imine, an oxime-O-sulfonate type acid generator, and the like. These may be used alone or in combination of two or more.

Specific examples of the acid generator are described in paragraphs [0122] to [0142] of JP-A-2008-111103. Among the specific examples of the above acid generator, an aryl sulfonate type photoacid generator can generate a desorption reaction by inducing an acid detachment group and alkali insolubilization and a polymer due to itself. The acidity of the moderate strength of the cross-linking reaction is preferred. Further, in order to utilize the combination of the acid generating agent and the phosphonium salt contained in the photoresist composition of the present invention to cause an exchange reaction to achieve an LER improving effect, the pKa of the acid generated from the photoacid generator is preferably in the range of -3.0 to 1.5. Good, the range of -1.0~1.5 is better.

As such an acid generator, a compound having an anthracene anion having the structure shown below can be preferably used, and a compound having the phosphonium cation described in the above [Chemical Formula 16] can be preferably used as the paired cation. 【化32】

【化33】

【化34】

【化35】

【化36】

【化37】

The acid diffusion controlling agent is a component which is in fact necessary in order to obtain sensitivity adjustment and high resolution. The negative resist composition of the present invention contains a carboxylate represented by the above formula (3a) as an acid diffusion controlling agent, but other basic compounds may be added. In the case of blending, the amount thereof is preferably 0.01 to 20 parts by mass, particularly preferably 0.05 to 10 parts by mass, per 100 parts by mass of the above polymer. Further, many of the basic compounds which can be used are known (both disclosed in Patent Documents 1 to 5), and primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, and impurities are known. Cyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, guanamines, quinones , urethanes, ammonium salts, and the like. The specific examples are described in the patent documents 2, JP-A-2008-111103, paragraphs [0146] to [0164], and Japanese Patent No. 3790649, and are basically applicable, and two or more types may be selected. Basic compounds are used in combination. Particularly preferred basic compounds which can be blended include gin(2-(methoxymethoxy)ethyl)amine and gin(2-(methoxymethoxy)ethyl)amine-N-oxide. , A morphine derivative, an imidazole derivative, or the like.

In the negative resist composition of the present invention, a surfactant which is conventionally used for improving coatability may be added. When a surfactant is used, many examples have been described as in Patent Documents 1 to 5, and many of them are known, and can be selected with reference to these. Further, a fluorine-containing polymer disclosed in JP-A-2008-304590 (Patent Document 13) may be added.

In addition, the amount of the surfactant to be added is preferably 2 parts by mass or less, preferably 1 part by mass or less, and preferably 0.01 parts by mass or more, based on 100 parts by mass of all the polymer compounds in the resist composition.

The organic solvent used in the preparation of the negative-type photoresist composition of the present invention may be any organic solvent which can dissolve a polymer compound, an acid generator, or other additives. Such organic solvents, for example, ketones such as cyclohexanone and methyl-n-pentanone, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2- Alcohols such as propanol and 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol diethylene glycol Ethers such as ethers, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, 3-ethoxypropionic acid Ethyl ester, tert-butyl acetate, tert-butyl propionate, esters such as propylene glycol-tert-butyl ether acetate, lactones such as γ-butyrolactone, and the like may be used alone or in combination 2 More than one, but not limited to this. In the present invention, it is preferred to use ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and the like, which are most excellent in solubility of the acid generator in the photoresist component among the organic solvents. .

The amount of the organic solvent used is 1,000 to 10,000 parts by mass, particularly 2,000 to 9,700 parts by mass, based on 100 parts by mass of the total of the polymer compound. By adjusting to such a concentration, a spin coating method can be used to stably obtain a photoresist film having a film thickness of 10 to 300 nm with good flatness.

Further, a known dissolution inhibitor or the like may be appropriately added to the negative resist composition of the present invention.

When forming a pattern using the negative photoresist composition of the present invention, a well-known lithography technique can be employed. Generally, it is applied to a substrate for manufacturing an integrated circuit by spin coating or the like (the surface layer material is a silicon wafer such as Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, or an organic anti-reflection film). It is 0.05 to 2.0 μm, and is prebaked on a hot plate at 60 to 150 ° C for 1 to 10 minutes, preferably at 80 to 140 ° C for 1 to 5 minutes. Then, using a mask for forming a target pattern, high-energy rays such as far ultraviolet rays, excimer lasers, and X-rays are irradiated so that the exposure amount is 1 to 200 mJ/cm ² , preferably 10 to 100 mJ/cm ² . In addition to the usual exposure method, the Immersion method of infiltrating the mask and the photoresist film may be used as the case may be. A water-insoluble protective film can also be used at this time. Then, it is carried out on a hot plate at 60 to 150 ° C for 1 to 10 minutes, preferably at 80 to 140 ° C for 1 to 5 minutes after exposure and baking (PEB). Further, a developing solution of an alkali aqueous solution such as tetramethylammonium hydroxide (TMAH) in an amount of 0.1 to 5% by mass, preferably 2 to 3% by mass, is used, by dip method, puddle method, spray ( The usual method such as the spray method is carried out for 0.1 to 3 minutes, preferably for 0.5 to 2 minutes, to form a desired pattern on the substrate.

When the substrate to be processed is a blank mask, a negative photoresist composition is applied to a substrate for manufacturing a mask circuit (a surface material is a quartz substrate such as Cr, CrO, CrON, or MoSi) to have a film thickness of 0.05 to 2.0 μm. It is carried out on a hot plate at 80 to 130 ° C for 4 to 20 minutes, preferably at 90 to 110 ° C for 8 to 12 minutes. Then, in order to form a target pattern for the photoresist film obtained above, pattern exposure is performed. When the processing of the blank mask is performed, a plurality of sheets are not formed by processing, and thus pattern exposure is usually performed by electron beam exposure. The exposure amount is 1 to 100 μC/cm ² , preferably 10 to 100 μC/cm ² . Then, it is subjected to exposure and post-baking (PEB) at 60 to 150 ° C for 0.1 to 5 minutes, preferably 80 to 140 ° C for 0.5 to 3 minutes on a hot plate. Further, a developing solution of an alkali aqueous solution such as tetramethylammonium hydroxide (TMAH) in an amount of 0.1 to 5% by mass, preferably 2 to 3% by mass, is used as a dip method, a puddle method, or a spray. The normal method is carried out for 0.1 to 3 minutes, preferably 0.5 to 2 minutes, to form a target pattern on the substrate.

Further, since the negative-type photoresist composition of the present invention has particularly high etching resistance, it can withstand even under strict etching conditions, and is useful when it is required to use a small LER condition. Further, the substrate to be processed is particularly difficult to use when the adhesion of the photoresist pattern is not easily obtained, and the substrate is provided with a substrate which is susceptible to pattern peeling or pattern collapse, and the metal chromium and oxygen are sputtered. It is useful to form a pattern on a blank reticle on a substrate of a chromium compound of one or more light elements of nitrogen or carbon. [Examples]

The present invention will be specifically described below by way of Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples. Further, in the following examples, Me represents a methyl group. Further, the copolymerization composition ratio is a molar ratio, and the weight average molecular weight (Mw) represents a polystyrene-equivalent weight average molecular weight obtained by gel permeation chromatography (GPC).

[Synthesis Example 1] Synthesis of Polymer 1 In a 3,000 mL dropping cylinder, 890 g of a 50.0 mass% PGMEA solution of 4-hydroxystyrene, 47.7 g of vinyl naphthalene, and 4-(2-hydroxy-) were prepared in a 3,000 mL dropping cylinder. 2-propyl)styrene 169.6 g, 1,1,3,3,3-pentafluoro-2-methylpropenylpropane-1-sulfonate triphenylsulfonium 87.0 g, 2,2'-azo A solution of 96.1 g of bis-(2-methylpropionic acid) dimethyl ester (manufactured by Wako Pure Chemical Industries, Ltd., trade name: V601), 360 g of γ-butyrolactone as a solvent, and 220 g of PGMEA. Further, 580 g of γ-butyrolactone was added to another 5,000 mL of the polymerization flask under a nitrogen atmosphere, and the solution prepared above was added dropwise thereto over a period of 4 hours while heating to 80 °C. After the completion of the dropwise addition, the polymerization temperature was maintained at 80 ° C, stirring was continued for 18 hours, and then cooled to room temperature. The obtained polymerized droplets were added to 22.5 kg of diisopropyl ether, and the copolymer was agglomerated. Diisopropyl ether was removed by decantation, and the copolymer was dissolved in acetone 2,250 g. This acetone solution was added dropwise to 22.5 kg of diisopropyl ether, and the precipitated copolymer was separated by filtration. The filtered copolymer was again dissolved in 2,250 g of acetone, and the acetone solution was added dropwise to 22.5 kg of water, and the precipitated copolymer was separated by filtration. Thereafter, it was dried at 40 ° C for 40 hours to obtain 700 g of a white polymer. The obtained polymer was analyzed by ¹³ C-NMR, ¹ H-NMR, and GPC to obtain the following analysis results. 【化38】 Weight average molecular weight (Mw) = 13,000. Molecular weight distribution (Mw / Mn) = 1.62.

[Synthesis Example 2] The synthesis of the polymers 2 to 14 and the comparative polymers 1, 2 was carried out in the same manner as in the polymer synthesis example 1 except that the types and blending ratios of the respective monomers were changed. Polymers 2 to 14 and comparative polymers 1, 2. Also, in the following Table 1, the introduction ratio represents the molar ratio. Further, the structure of the repeating unit introduced into the polymer is shown in Tables 2 to 5 below.

[Table 1] Table 1

【Table 2】

【table 3】

【Table 4】

【table 5】

[Synthesis Example 3] Synthesis of Polymer 15 In a 200 mL dropping cylinder, 39.26 g of 4-acetoxystyrene, 6.14 g of ethylene naphthalene, and 4-(2-hydroxy-2-propene) were prepared under a nitrogen atmosphere. 19.3 g of styrene, 7.4 g of 2,2'-azobis-(2-methylpropionic acid) dimethyl ester (manufactured by Wako Pure Chemical Industries, Ltd., trade name V601), 7.43 g of methyl ethyl ketone as a solvent, and 90 g of methyl ethyl ketone as a solvent The resulting solution. Further, in another 500 mL polymerization flask under a nitrogen atmosphere, 60 g of methyl ethyl ketone was added and the mixture was heated to 80 ° C, and the solution prepared above was added dropwise over 4 hours. After the completion of the dropwise addition, the polymerization temperature was maintained at 80 ° C, stirring was continued for 18 hours, and then cooled to room temperature. The obtained polymerized droplets were added to 1,000 g of hexane, and the precipitated copolymer was separated by filtration. The filtered copolymer was washed twice with 200 g of hexane. The obtained copolymer was dissolved in a mixed solvent of 126 g of tetrahydrofuran and 42 g of methanol in a 1 L flask under a nitrogen atmosphere, and 16.3 g of ethanolamine was added thereto, and the mixture was stirred at 60 ° C for 3 hours. The reaction solution was concentrated under reduced pressure, and the obtained concentrate was dissolved in 300 g of a mixture solvent of ethyl acetate and water (80 g), and the obtained solution was transferred to a separatory funnel, and 8.2 g of acetic acid was added thereto to carry out a liquid separation operation. The lower layer was distilled off, and 80 g of water and 10.9 g of pyridine were added to the obtained organic layer, and the liquid separation operation was carried out. The lower layer was distilled off, and 80 g of water was added to the obtained organic layer, and the mixture was washed with water (water washing liquid for 5 times). The organic layer after liquid separation is concentrated and dissolved in 140 g of acetone, and the obtained acetone solution is added dropwise to 2,500 g of water, and the obtained precipitate is filtered, washed with water, and subjected to suction filtration for 2 hours, and then obtained again. The filtrate was dissolved in acetone 150 g, and the obtained acetone solution was added dropwise to 2,800 g of water, and the precipitate obtained was filtered, washed with water, and dried to obtain 45.0 g of a white polymer. The obtained polymer was measured by ¹³ C-NMR, ¹ H-NMR, and GPC to obtain the following analysis results. 【化39】 Weight average molecular weight (Mw) = 3,500 Molecular weight distribution (Mw / Mn) = 1.58.

[Synthesis Example 4] Synthesis of Polymer 16 In a 200 mL dropping cylinder, 67.5 g of hydroquinone monomethacrylate, 8.87 g of ethylene naphthalene, and 4-(2-hydroxy-2-propene) were prepared under a nitrogen atmosphere. 23.6 g of styrene, 10.2 g of 2,2'-azobis-(2-methylpropionic acid) dimethyl ester (manufactured by Wako Pure Chemical Industries, Ltd., trade name V601), 10.7 g of methyl ethyl ketone as a solvent, and 120 g of methyl ethyl ketone as a solvent The solution obtained. Further, 60 g of methyl ethyl ketone was added to another 500 mL polymerization flask under a nitrogen atmosphere, and the mixture was heated to 80 ° C, and the solution prepared above was added dropwise over 4 hours. After the completion of the dropwise addition, the polymerization temperature was maintained at 80 ° C, stirring was continued for 18 hours, and then cooled to room temperature. The obtained polymerized droplets were added to 2,000 g of hexane, and the copolymer was separated by filtration. The fractionated copolymer was washed twice with 400 g of hexane. The obtained copolymer was filtered and dried to obtain 45.0 g of a white polymer. The obtained polymer was measured by ¹³ C-NMR, ¹ H-NMR, and GPC to obtain the following analysis results. 【化40】 Weight average molecular weight (Mw) = 4,500 Molecular weight distribution (Mw / Mn) = 1.68 was designated as polymer 16.

[Synthesis Example 5] The synthesis of the polymers 17 to 24 and the comparative polymers 3, 4 changed the kind and blend ratio of each monomer, and in addition, when the polymer containing the A-1 unit was subjected to polymerization In the same manner as in the synthesis of Example 15, in the case of a polymer containing the A-2 unit, the polymers 17 to 24 and the comparative polymers 3 and 4 shown in Table 6 were synthesized in the same manner as in the polymer synthesis example 16. Also, in the following Table 6, the introduction ratio represents the molar ratio. Further, the structure of the repeating unit into which the polymer has been introduced is shown in Tables 2 to 5 above.

[Table 6]

[Examples and Comparative Examples] (Preparation of Negative Photoresist Composition) The above synthesized polymers (polymers 1 to 24, comparative polymers 1 to 4), acid generators (PAG-1 to 3), A basic compound (Q-1~4, comparative Q-1, 2), a part of the composition is added with a crosslinking agent TMGU (tetramethoxymethyl glycoluril) as an additive, or a fluoropolymer FP-1 The composition shown in Tables 7 to 9 was dissolved in an organic solvent to prepare a photoresist composition, and each composition was filtered with a 0.2 μm Teflon (registered trademark) filter to prepare a negative photoresist composition, respectively. Solution. Further, PF-636 (manufactured by OMNOVA SOLUTIONS) as a surfactant was added to the composition in an amount of 0.075 parts by mass based on the solid content.

The structure of the fluoropolymer FP-1 is as follows. 【化41】

The PGMEA of the solvent in Tables 7 to 9 represents propylene glycol monomethyl ether acetate, EL represents ethyl lactate, and PGME represents propylene glycol monomethyl ether. Further, the structures of the acid generator and the basic compound used are shown in Tables 10 and 11, respectively.

[Table 7]

[Table 8]

[Table 9]

[Table 10]

[Table 11]

(E-beam drawing evaluation) (1) Resolution evaluation The negative resist composition (Examples 1 to 41 and Comparative Examples 1 to 14) prepared above was used for ACT-M (Tokyo Power Co., Ltd.) It was spin-coated on a blank mask of 152 mm square on the surface of a chromium oxide nitride film, and prebaked on a hot plate at 110 ° C for 600 seconds to prepare an 80 nm photoresist film. The film thickness measurement of the obtained photoresist film was performed using an optical measuring instrument Nanospec (manufactured by Nanometrics Co., Ltd.). The measurement was performed by excluding the outer edge portion of the outer periphery of the blank substrate to the inner side of 10 mm, and the inner surface of the blank substrate was 81, and the film thickness average 値 and the film thickness range were calculated.

Further, exposure was carried out using an electron beam exposure apparatus (EBM-5000plus manufactured by Nuflare Technology Co., Ltd., acceleration voltage: 50 keV), baking at 130 ° C for 600 seconds (PEB: post exposure bake), and 2.38 mass% of tetramethyl hydroxide. The ammonium aqueous solution was developed to obtain a negative pattern. The obtained photoresist pattern was evaluated in the following manner.

The above blank SEM (scanning electron microscope) observes the blank mask of the attached pattern, and defines the exposure amount of 1:1 line and pitch (LS) of 1:1 resolution to 400 nm as the optimum exposure amount (μC/cm). ² ). Further, the minimum dimension of the exposure amount of the line and the pitch of 1:1 resolution 400 nm was defined as the resolution (the ultimate resolution), and the edge roughness of 200 nm LS was measured by SEM. The evaluation results of the negative-type photoresist composition of the present invention and the comparative photoresist composition depicted by EB are shown in Tables 12 and 13. In addition, in the following results, the resolution of the pattern of the LS (line and pitch) line and the pitch are arranged at intervals of 1:1, the resolution of the isolated line pattern of IL (isolated line), IS (isolated pitch) is isolated The resolution of one of the spacing patterns.

[Table 12]

[Table 13]

(2) Evaluation of pre-baking temperature dependence The above-mentioned (1) resolution evaluation of the spin-coating baking temperature (pre-baking temperature) was changed from 110 ° C to 100 ° C, and the exposure and development were carried out in the same procedure. An exposure amount (μC/cm ² ) obtained by deciphering a line of 1:1 of 400 nm from the pitch (LS). Let the exposure at this time be E ₁₀₀ . Then, the baking temperature after spin coating of the above (1) resolution evaluation was changed from 110 ° C to 120 ° C, and the exposure amount was set to E ₁₀₀ described above, and exposure and development were carried out in the same procedure, and measurement design was performed. The actual size of the pattern with a line width of 400 nm. Let it be W ₁₂₀ and determine the pre-baking temperature dependence according to the following formula. This lanthanum represents the enthalpy of how much the line width of the pattern changes with the change of the pre-baking temperature, and the smaller the 代表 indicates that the pre-baking temperature dependence is smaller. Pre-baking temperature dependence = (W ₁₂₀ -400) / 20 The results are shown in Table 14.

[Table 14]

(3) PEB temperature dependence evaluation The optimum exposure amount of the above (1) resolution evaluation was E ₁₃₀ . The PEB temperature of the above (1) resolution evaluation was changed from 130 ° C to 150 ° C, and the exposure amount was set to E ₁₃₀ described above. Except for this, exposure and development were carried out in the same procedure, and the actual size of the pattern having a design line width of 400 nm was measured. . Let it be W ₁₅₀ and determine the PEB temperature dependence according to the following formula. This 代表 represents the 値 of the pattern line width with the change of the PEB temperature, and the smaller the 代表 indicates the lower the temperature dependence of the PEB. PEB temperature dependence = (W ₁₅₀ -400) / 20 The results are shown in Table 15.

[Table 15]

(4) Chemical flash resistance evaluation A photoresist film was produced under the same conditions as in the above (1) resolution evaluation, and exposed and developed by forming a pattern of a square pitch of 1 μm in the center of a negative pattern of 1 cm square. When the pattern of 1 μm square is formed, it is rated as ○, and when it is not formed, it is evaluated as ×. The results are shown in Table 16.

[Table 16]

(5) PCD: Post Coating Delay (Evaluation after coating) The exposure amount of the 400 nm line and the pitch pattern was the same as that when the film was formed immediately after the photoresist film was formed, and the photoresist film was measured for 2 weeks after film formation. The difference in line width at the time of exposure is defined and expressed as the PCD of the line width variation per month. The smaller the shrinkage, the better the preservation stability after the film formation of the photoresist film. The results are shown in Table 17.

[Table 17]

Explain the results of Tables 12~17 above. The resolution of the photoresist composition of the present invention and the flaw of the line edge roughness are all good results. On the other hand, the photoresist compositions containing the crosslinking agents of Comparative Examples 1 to 6 and the photoresist compositions of the polymers of Comparative Examples 13 and 14 which did not contain the acid generating unit were the result of poor resolution. Further, in the case of using the amine compound as the photoresist composition of the basic compound in Comparative Examples 7, 9, and 11, the resolution and the roughness were slightly inferior, and it was found that the temperature dependency was high and the chemical flash resistance was low. The stability of the photoresist film after film formation is not good. As a result of the increase in temperature dependency, it is considered that if the baking temperature is increased, the basic compound volatilizes, and even if the exposure amount is the same, the line width becomes thick. The stability after film formation is considered to be due to the fact that the basic compound slowly volatilizes during storage. As a result of the low chemical flash resistance, it is considered that the acid generated in the drawing portion is not trapped by the amine compound present in the drawing portion but is volatilized, and then reattached to the unexposed portion, causing an undesired negative reaction to form a pitch pattern. . When the negative-type photoresist composition of the present invention using a carboxylate as a basic compound, since the basic compound is not volatilized from the drawing portion, the temperature dependency of the pattern is small, and the evaluation of chemical flash resistance also shows good results. In order to improve the above-described temperature dependence, storage stability, and chemical flash resistance, it has been considered to solve the problem by using a basic compound having a high boiling point as in Comparative Examples 8, 10, and 12, but at this time, a pattern having a large roughness is formed. The result.

(6) EB exposure evaluation of the photoresist film on which the antistatic film is formed in the upper layer (Reference Examples 1 to 6) If the photoresist film is drawn at 50 A, especially at a large current of 200 A or more, it is caused by the electrification of the photoresist film. Electrostatic repulsion causes the orbit of the electron beam to bend, causing a problem that the pattern cannot be drawn with good positional accuracy. In order to solve this problem, an antistatic film is formed on the upper layer of the photoresist film and patterned.

After the resist film was formed under the conditions of the above (1) resolution evaluation, the conductive polymer composition was dropped, and rot-coated on the entire resist film by ACT-M (manufactured by Tokyo Technica Co., Ltd.). . The film was baked at 90 ° C for 600 seconds on a hot plate to obtain an antistatic film having a film thickness of 60 nm. Further, as the conductive polymer composition, an aqueous dispersion of polystyrene doped with polystyrene described in Proc. SPIE Vol. 8522 85220O-1 is used. A blank mask having an antistatic film formed on the photoresist layer was used, and exposed to an electron beam exposure apparatus (manufactured by Nuflare Technology Co., Ltd., EBM-5000plus, acceleration voltage: 50 keV), and baked at 130 ° C for 600 seconds ( PEB: post exposure bake), and developed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide to obtain a negative pattern. Further, the obtained photoresist pattern was evaluated in the following manner.

<Optimum exposure amount, limit resolution> (1) The same method was used to evaluate the same method as the resolution evaluation. <Surface Resistivity> The surface resistance 値 of the obtained antistatic film and photoresist film was measured using a Hiresta-UP MCP-HT450 (manufactured by Mitsubishi Chemical Corporation). <Sensitivity Change Rate> The sensitivity of Reference Examples 1 to 6 was compared with the sensitivity of Examples 1, 21, 22, 39, 40, and 41, respectively, and the deviation (%) was calculated. <Pattern Shape> The pattern portion was cut to visually determine the SEM image. <PCD: Post Coating Delay> When the film is formed with an antistatic film, the exposure amount of the line of 400 nm and the pitch pattern is the same exposure amount, and the film is formed after the antistatic film is formed for 2 weeks. The difference in line width at exposure is defined and expressed as the daily linewidth variation PCD. The smaller the shrinkage, the better the preservation stability after the film formation of the photoresist film. The above results are shown in Table 18.

[Table 18]

In Reference Examples 1 to 3 in which a photoresist composition containing a fluorine atom-free resin was used, the acid component contained in the antistatic film composition penetrated into the photoresist film, and the sensitivity greatly changed, and the pattern shape was reversely pushed. And the PCD is also big. On the other hand, in Reference Examples 4 to 6 using a photoresist composition containing a fluorine atom-containing resin, the sensitivity change was small, and the pattern shape was also kept rectangular. The PCD is also good. The difference in surface resistivity between Reference Examples 1 and 6 is not large, and the positional accuracy drawing pattern can be well drawn. From the above results, when an antistatic film is formed on the photoresist film and drawn, it is preferred to use a photoresist composition containing a fluorine atom-containing resin.

As apparent from the above description, when the negative-type photoresist composition of the present invention is used, a pattern having high resolution and a small line edge roughness can be formed. Further, since the temperature dependence of the pattern size is small, the pattern forming method using the composition is useful for the manufacture of a semiconductor element, and it is particularly useful for photolithography which is performed at a high current amount of processing of a blank mask.

Further, the present invention is not limited to the above embodiment. The above-described embodiments are exemplified and have substantially the same configuration and the same effects as those of the technical scope of the present invention, and are included in the technical scope of the present invention.

no.

no.

Claims (9)

A negative resist composition comprising: (A) a polymer compound comprising a repeating unit represented by the following formula (1), and further comprising a repeating unit represented by the following formulas (a1), (a2), (a3) At least one of the following; (B) a salt represented by the following formula (3a); (C) a polymer compound containing a repeating unit of the following formula (1), and containing no acid generating portion due to irradiation with high energy rays Repeating unit In the formula, A represents a single bond or an alkylene group having 1 to 10 carbon atoms which may have an etheric oxygen atom in the middle of the chain; R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; and R ² represents a hydrogen atom, a halogen atom, a linear, branched or cyclic methoxy group which may be substituted by halogen, or a linear or branched carbon number of 1 to 6 which may be substituted by halogen. Or a cyclic alkyl group, or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by a halogen; L is a hydrogen atom or may contain an etheric oxygen atom in the middle of the chain; a linear monovalent, branched or cyclic aliphatic monovalent hydrocarbon group having 1 to 10 carbon atoms or a carbonyloxy group; or a monovalent aromatic ring group having a substituent; Rx and Ry each being a hydrogen atom; Or an alkyl group having 1 to 15 carbon atoms which may be substituted by a hydroxyl group or an alkoxy group or a monovalent aromatic ring group which may have a substituent, and Rx and Ry may be bonded to each other and together with the carbon atom to which they are bonded. Forming a ring; further, Rx, Ry are not hydrogen atoms at the same time; f is an integer of 1-3, s represents an integer of 0~2, a is an integer of (5+2s-f); m represents 0 or 1; Wherein R ^{12 is} each independently a hydrogen atom or a methyl group, R ¹³ is a single bond, a phenyl group, a -OR ²² -, or -C(=O)-Z ² -R ²² -; Z ² is an oxygen atom. Or NH, R ²² is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group (-CO-) or an ester group (-COO-). ), an ether group (-O-) or a hydroxyl group; L' represents a single bond, or -Z ³ -C(=O)-O-, and Z ³ represents a linear chain having a carbon number of 1 to 20 which may also be substituted by a hetero atom a divalent hydrocarbon group in the form of a branch, a branch or a ring; Z ¹ is a single bond, a methylene group, an ethyl group, a phenyl group, a phenyl group, a -OR ²³ -, or -C(=O)- Z ⁴ -R ²³ -; Z ⁴ is an oxygen atom or NH, and R ²³ is a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, an alkenyl group or a phenyl group, and may also contain a carbonyl group. , an ester group, an ether group or a hydroxyl group; M ^- represents a non-nucleophilic relative ion; R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ are each independently represented or heterocyclic Atom-substituted, or a monovalent hydrocarbon group having a carbon number of 1 to 20 or a branched or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms; or a part of hydrogen atoms of the group may be substituted From a hetero atom of an atom, a sulfur atom, a nitrogen atom or a halogen atom may be inserted with a hetero atom selected from an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, a hydroxyl group, a cyano group, a carbonyl group or an ether bond may be formed or inserted. , ester bond, sulfonate bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride, haloalkyl group; further, R ¹⁴ and R ¹⁵ may also be bonded to each other and the sulfur atom in the formula Forming a ring together, or two or more of R ¹⁶ , R ¹⁷ and R ¹⁸ , or two or more of R ¹⁹ , R ²⁰ and R ²¹ may be bonded to each other and form a ring together with a sulfur atom in the formula R ¹¹ -CO ₂ ^- M ⁺ (3a) wherein R ¹¹ is a linear, branched or cyclic alkyl group having from 1 to 20 carbon atoms, and an alkenyl group having from 2 to 20 carbon atoms. Or an aryl group having 6 to 20 carbon atoms, which may each have a fluorine atom, a nitrogen atom, an ether group, an ester group, a lactone ring, an indole ring, a carbonyl group, or a hydroxyl group; and M represents a substituent. The relative cation means any one of a phosphonium cation, a phosphonium cation, and an ammonium cation. The negative-type photoresist composition of the first aspect of the invention, wherein the polymer compound of (A) further comprises a repeating unit selected from the group consisting of one or more of the following general formulae (2) and (3); In the formula, B and C represent a single bond or an alkylene group having 1 to 10 carbon atoms which may have an etheric oxygen atom in the middle of the chain; D represents a single bond or may be substituted by fluorine, or may contain an ether in the middle of the chain. a linear, branched or cyclic (v+1)-valent aliphatic hydrocarbon group having 1 to 10 carbon atoms, a carbonyl group or a carbonyloxy group; and R ¹ represents a hydrogen atom, a fluorine atom, a methyl group or Trifluoromethyl; R ³ and R ⁴ each independently represent a hydrogen atom, a halogen atom, a linear, branched or cyclic decyloxy group having a carbon number of 2 to 8 which may be substituted by halogen, and a carbon number of 1 to 4; a linear, branched or cyclic alkyl group which may be substituted by halogen, or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by halogen; Rf ₁ And Rf ₂ represents an alkyl group having at least one fluorine atom having 1 to 6 carbon atoms, and Rf ₁ may be bonded to D and form a ring together with the carbon atom to which they are bonded; g is an integer of 0 to 3, h Is 1 or 2, r is 0 or 1, v is 1 or 2, t, u are integers from 0 to 2, b is an integer of (5+2t-g), and c is an integer of (5+2u-h) , n, p each independently represent 0 or 1; when r is 0, p is 1. The negative-type photoresist composition according to the first or second aspect of the invention, wherein the polymer compound of (A) further contains one or more repeating units selected from the group consisting of the following general formulas (4) and (5); In the formula, R ⁵ and R ⁶ each independently represent a hydrogen atom, a halogen atom, a linear, branched or cyclic decyloxy group having a carbon number of 2 to 8 which may be substituted by halogen, and a carbon number of 1 to 6; a linear, branched or cyclic alkyl group substituted by halogen, or a linear, branched or cyclic alkoxy group having a carbon number of 1 to 6 which may be substituted by halogen; i, j is An integer from 0 to 3, d is an integer from 0 to 5, and e is an integer from 0 to 3. The negative-type photoresist composition of claim 1 or 2 further contains a compound which generates an acid due to irradiation with high-energy rays. A blank reticle having been coated with a negative-type photoresist composition according to any one of claims 1 to 4. A pattern forming method comprising the steps of: forming a photoresist film on a substrate to be processed using a chemically amplified negative-type photoresist composition according to any one of claims 1 to 4; patterning high-energy rays; The alkali developer was developed to obtain a photoresist pattern. The pattern forming method of claim 6, wherein the high energy ray is an EUV or an electron beam. The pattern forming method of claim 6 or 7, wherein the substrate to be processed is a blank mask. The pattern forming method of claim 8, wherein the outermost surface of the blank mask is formed of a chromium-based material.