JP2018017780A - Radiation-sensitive composition and pattern formation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive composition excellent in sensitivity, resolution, etching resistance and substrate contamination suppression property, and to provide a pattern formation method.SOLUTION: A radiation-sensitive composition contains a metal-containing component containing a metal oxide and an organic solvent, where the metal-containing component has at least two kinds of a first metal-containing component and a second metal-containing component, the first metal-containing component contains a first metal atom being tin, indium, antinomy, bismuth, gallium, germanium, aluminum or a combination thereof, and the second metal-containing component contains no first metal atom, and contains a second metal atom being Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11 or a combination thereof. The second metal atom is preferably titanium, zirconium, hafnium, tantalum, tungsten or a combination thereof.SELECTED DRAWING: None

Description

  The present invention relates to a radiation-sensitive composition and a pattern forming method.

  Radiation sensitive compositions used for microfabrication by lithography are exposed to irradiated parts such as deep ultraviolet rays such as ArF excimer laser light and KrF excimer laser light, electromagnetic waves such as extreme ultraviolet rays (EUV), and charged particle beams such as electron beams. An acid is generated in the substrate, and a chemical reaction using the acid as a catalyst causes a difference in the dissolution rate of the exposed portion and the unexposed portion with respect to the developer, thereby forming a pattern on the substrate.

  Such a radiation-sensitive composition is required to improve the resist performance as the processing technique becomes finer. In response to this requirement, the types and molecular structures of polymers, acid generators and other components used in the composition have been studied, and further their combinations have been studied in detail (Japanese Patent Application Laid-Open No. 11-125907, special features). (See Kaihei 8-146610 and JP-A 2000-298347).

  Currently, pattern miniaturization has progressed to a level of 40 nm or less, but radiation-sensitive compositions are required to have higher resist performance, and are particularly sensitive to exposure light such as electron beams and EUV. , Higher resolution, and higher etching resistance of the formed film are required. Furthermore, when a radiation-sensitive composition is applied to the surface of a substrate such as a silicon wafer, contamination by metal or the like can be reduced by easily washing the composition adhering to the side and back surfaces of the substrate by rinsing. It is required to have excellent substrate contamination suppression properties. However, the above-mentioned conventional radiation-sensitive composition cannot satisfy all of these requirements.

Japanese Patent Laid-Open No. 11-125907 JP-A-8-146610 JP 2000-298347 A

  This invention is made | formed based on the above situations, The objective is to provide the radiation sensitive composition and pattern formation method which are excellent in a sensitivity, resolution, an etching tolerance, and board | substrate pollution suppression property. is there.

  The invention made in order to solve the above problems is also referred to as a metal-containing component containing a metal oxide (hereinafter also referred to as “[A] metal-containing component”) and an organic solvent (hereinafter also referred to as “[B] organic solvent”). And the [A] metal-containing component is a first metal-containing component (hereinafter also referred to as “[A1] metal-containing component”) and a second metal-containing component (hereinafter referred to as “[A2] metal-containing component”). And the above-mentioned [A1] metal-containing component is tin, indium, antimony, bismuth, gallium, germanium, aluminum, or a combination thereof, also referred to as “metal atom (x)”. And the [A2] metal-containing component does not contain the metal atom (x), and includes Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9 Group, Group 10, Group 11 atoms or combinations thereof There second metal atom (hereinafter, also referred to as "metal atom (y)") is a radiation-sensitive composition comprising a.

  Another invention made to solve the above problems is a process of applying the radiation-sensitive composition on one surface side of the substrate, a process of exposing a film formed by the coating process, And a step of developing the exposed film.

  According to the radiation-sensitive composition and the pattern forming method of the present invention, a pattern with high sensitivity, high resolution, high etching resistance, and reduced substrate contamination can be formed. Therefore, these can be suitably used for manufacturing semiconductor devices that are expected to be further miniaturized in the future.

<Radiation sensitive composition>
The radiation-sensitive composition contains [A] a metal-containing component and [B] an organic solvent. The radiation-sensitive composition may contain an optional component as long as the radiation-sensitive composition does not impair the effects of the present invention.

  The radiation-sensitive composition is excellent in sensitivity, resolution, etching selectivity, and substrate contamination suppression. The reason why the radiation-sensitive composition has the above-described configuration provides the above-mentioned effects is not necessarily clear, but can be inferred as follows, for example. That is, in the radiation-sensitive composition, [A] metal-containing component includes [A1] metal-containing component containing a specific metal atom (x) and [A2] metal-containing component containing a specific metal atom (y). Containing. [A1] Containing a metal-containing component, which is considered to have a remarkable change in the structure of the metal oxide by exposure light, improves the sensitivity of the radiation-sensitive composition. In addition, the [A] metal-containing component has a relatively small molecular size for both the [A1] metal-containing component and the [A2] metal-containing component, and is less likely to increase in size due to aggregation or the like. Will improve. Furthermore, since the film to be formed contains [A2] metal-containing component containing metal atom (y) in addition to [A1] metal-containing component, etching resistance is improved. In addition, when the [A1] metal-containing component and the [A2] metal-containing component are both contained, the interaction between the substrate and the substrate tends to become strong. [A1] The interaction between the metal-containing component and the substrate is reduced. It is considered that the contamination of the substrate by the metal is suppressed. Hereinafter, each component will be described.

<[A] metal-containing component>
[A] The metal-containing component is a component containing a metal oxide. “Metal oxide” refers to a compound containing a metal atom and an oxygen atom. [A] The metal-containing component has a [A1] metal-containing component containing a metal atom (x) and a [A2] metal-containing component containing a metal atom (y). The component containing both the metal atom (x) and the metal atom (y) does not correspond to the [A] metal-containing component. [A] The metal-containing component may contain [A3] metal-containing component other than [A1] metal-containing component and [A2] metal-containing component.

(Metal oxide)
A metal oxide is a compound containing a metal atom and an oxygen atom. [A] Since the metal-containing component contains a metal oxide, the solubility in the developer can be changed by changing the structure of the metal oxide or the substance bonded to the metal atom by exposure. Thereby, a pattern can be formed.

  The metal oxide may contain atoms other than metal atoms and oxygen atoms. As said other atom, a boron, a carbon atom, a hydrogen atom, a nitrogen atom, a phosphorus atom, a sulfur atom, a halogen atom etc. are mentioned, for example.

  As a minimum of the total content rate of the metal atom and oxygen atom in the said metal oxide, 30 mass% is preferable, 50 mass% is more preferable, 70 mass% is further more preferable, 90 mass% is especially preferable. On the other hand, the upper limit of the total content is preferably 99.9% by mass. By setting the total content of the metal atoms and oxygen atoms in the above range, the structural change of the [A] metal-containing component by exposure light can be more effectively promoted. As a result, the sensitivity of the radiation-sensitive composition and The resolution can be further improved. The total content of the metal atoms and oxygen atoms may be 100% by mass.

Examples of the metal oxide include a compound having a metal-oxo-hydroxo crosslinked structure, an organic ligand, and a metal-carbon bond and / or a metal-carboxylate bond. In this compound, the metal ion has a metal-ligand M—C bond and / or a M—O ₂ C bond (the ligand that forms these bonds is referred to as an “organic stabilizing ligand”). In addition to the organic stabilizing ligand, it is usually bonded to one or more oxo ligands (MO) and / or hydroxo ligands (M-OH). This organic stabilizing ligand and oxo / hydroxo ligand can more appropriately control the condensation process of the metal oxide. [B] By using an organic solvent, the stability of the solution is improved. Further, by performing organic solvent development, the development speed contrast from the latent image can be further increased for both the positive pattern and the negative pattern. By using a compound containing this organic stabilizing metal ion as the metal oxide, the sensitivity and etching resistance of the radiation-sensitive composition can be further increased, and a pattern with a finer structure can be formed. The composition of the metal oxide containing the organic stabilizing metal ion can be appropriately selected depending on the type and energy (wavelength) of exposure light.

  The metal oxide containing the organic stabilizing metal ion has a polynuclear metal oxo / hydroxo cation and an organic ligand. The polynuclear metal oxo / hydroxo cation may include a metal suboxide cation, which is a polyatomic cation having an oxygen atom covalently bonded to a metal element. Metal suboxide cations having peroxide ligands and methods of using them are described in US Pat. No. 8,415,000 (Stowers et al.). Aqueous solutions of metal suboxides or metal hydroxides tend to be unstable with respect to gelation and / or precipitation. In particular, the solution is destabilized by solvent removal and forms an oxo-hydroxide bridged structure with the metal cation. Although stability can be enhanced by using a radiation-sensitive ligand such as peroxide, instability regarding the formation of a crosslinked structure still remains. This difficult to control cross-linked structure formation reduces sensitivity and / or film development speed contrast.

  Organic ligands improve the stability of the composition to condensation. In particular, when the concentration of the organic ligand is relatively high, the formation of a metal oxide or metal hydroxide by condensation is very slow even if the condensation occurs spontaneously at room temperature. Due to this stabilizing property, the solution can be excellent in storage stability and maintain the property by increasing the concentration of the radiation-sensitive ligand.

  Radiation sensitive ligands include carboxylates, such as organic moieties that can form metal-carbon bonds such as metal-tin bonds. The absorbed exposure light energy can cleave the metal-organic ligand bond. This cleavage reduces or loses stability to condensation. As a result, the composition changes through the production of M-OH or MOM. This change can be controlled by irradiation with radiation. A composition having a high concentration of the radiation-sensitive ligand can avoid spontaneous hydroxide formation or condensation, and has high stability. The metal-containing composition having such a preferable ligand structure can also be obtained as a commercial product.

  As a component other than the metal atom constituting the metal oxide, an organic acid (hereinafter also referred to as “[a] organic acid”) is preferable. Here, “organic acid” refers to an organic compound that exhibits acidity, and “organic compound” refers to a compound having at least one carbon atom.

  [A] The metal-containing component contains a metal oxide composed of a metal atom and [a] an organic acid, whereby the sensitivity and resolution of the radiation-sensitive composition are further improved. This is presumably because, for example, the presence of the [a] organic acid in the vicinity of the [A] metal-containing component due to the interaction with the metal atom improves the dispersibility of the [A] metal-containing component in the solvent.

  [A] The lower limit of the pKa of the organic acid is preferably 0, more preferably 1, more preferably 1.5, and particularly preferably 3. On the other hand, the upper limit of the pKa is preferably 7, more preferably 6, more preferably 5.5, and particularly preferably 5. [A] By setting the pKa of the organic acid within the above range, the interaction with the metal atom can be adjusted to be moderately weak, and as a result, the sensitivity and resolution of the radiation-sensitive composition can be further improved. It can be improved. Here, when the [a] organic acid is a polyvalent acid, the pKa of the [a] organic acid means the first acid dissociation constant, that is, the logarithmic value of the dissociation constant with respect to the dissociation of the first proton.

  [A] The organic acid may be a low molecular compound or a high molecular compound, but a low molecular compound is preferable from the viewpoint of adjusting the interaction with the metal atom to a moderately weak one. Here, the low molecular compound means a compound having a molecular weight of 1,500 or less, and the high molecular compound means a compound having a molecular weight of more than 1,500. [A] The lower limit of the molecular weight of the organic acid is preferably 50, more preferably 80. On the other hand, the upper limit of the molecular weight is preferably 1,000, more preferably 500, still more preferably 400, and particularly preferably 300. [A] By setting the molecular weight of the organic acid within the above range, [A] the dispersibility of the metal-containing component can be adjusted to a more appropriate level, and as a result, the sensitivity and resolution of the radiation-sensitive composition. Can be improved.

  [A] Examples of the organic acid include carboxylic acid, sulfonic acid, sulfinic acid, organic phosphinic acid, organic phosphonic acid, phenols, enol, thiol, acid imide, oxime, and sulfonamide.

Examples of the carboxylic acid include formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, 2-ethylhexanoic acid, oleic acid, acrylic acid, methacrylic acid, trans-2,3-dimethylacrylic acid, stearic acid, linoleic acid, linolenic acid, arachidonic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, pentafluoropropionic acid Monocarboxylic acids such as gallic acid and shikimic acid;
Dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, methylmalonic acid, fumaric acid, adipic acid, sebacic acid, phthalic acid, tartaric acid;
Examples thereof include carboxylic acids having 3 or more carboxy groups such as citric acid.

  Examples of the sulfonic acid include benzenesulfonic acid and p-toluenesulfonic acid.

  Examples of the sulfinic acid include benzenesulfinic acid and p-toluenesulfinic acid.

  Examples of the organic phosphinic acid include diethylphosphinic acid, methylphenylphosphinic acid, diphenylphosphinic acid and the like.

  Examples of the organic phosphonic acid include methylphosphonic acid, ethylphosphonic acid, t-butylphosphonic acid, cyclohexylphosphonic acid, and phenylphosphonic acid.

Examples of the phenols include monovalent phenols such as phenol, cresol, 2,6-xylenol, and naphthol;
Divalent phenols such as catechol, resorcinol, hydroquinone, 1,2-naphthalenediol;
Examples include trivalent or higher phenols such as pyrogallol and 2,3,6-naphthalenetriol.

  Examples of the enol include 2-hydroxy-3-methyl-2-butene and 3-hydroxy-4-methyl-3-hexene.

  Examples of the thiol include mercaptoethanol and mercaptopropanol.

Examples of the acid imide include carboxylic acid imides such as maleimide and succinimide;
Examples thereof include sulfonic acid imides such as di (trifluoromethanesulfonic acid) imide and di (pentafluoroethanesulfonic acid) imide.

Examples of the oxime include aldoximes such as benzaldoxime and salicylaldoxime;
Examples thereof include ketoximes such as diethyl ketoxime, methyl ethyl ketoxime, and cyclohexanone oxime.

  Examples of the sulfonamide include methylsulfonamide, ethylsulfonamide, benzenesulfonamide, and toluenesulfonamide.

  [A] The organic acid is preferably a carboxylic acid, more preferably a monocarboxylic acid, and even more preferably methacrylic acid and benzoic acid, from the viewpoint of further improving the sensitivity and resolution of the radiation-sensitive composition.

  The metal oxide is preferably a metal oxide composed of a metal atom and [a] an organic acid, more preferably a metal oxide composed of a metal atom and a carboxylic acid, and a metal atom and methacrylic acid or benzoic acid. More preferred are metal oxides.

  [A] As a minimum of the content rate of a metal oxide in a metal content ingredient, 60 mass% is preferred, 80 mass% is more preferred, and 95 mass% is still more preferred. Moreover, 100 mass% may be sufficient as the content rate of the said metal oxide. By making the content rate of the said metal oxide into the said range, the sensitivity and resolution of the said radiation sensitive composition can be improved more. [A] The metal-containing component may contain two or more metal oxides.

  [A] When the metal-containing component is composed mainly of a metal oxide composed of a metal atom and an organic acid, the lower limit of the content of [a] organic acid in the [A] metal-containing component is 1% by mass. Preferably, 5 mass% is more preferable, and 10 mass% is further more preferable. On the other hand, as an upper limit of the said content rate, 90 mass% is preferable, 70 mass% is more preferable, and 50 mass% is further more preferable. [A] By setting the content of the organic acid within the above range, the dispersibility of the [A] metal-containing component can be further adjusted to an appropriate level. As a result, the sensitivity and solution of the radiation-sensitive composition can be adjusted. The image quality can be further improved. [A] The metal-containing component may contain one or more [a] organic acids.

  [A] The lower limit of the content of the metal-containing component is preferably 50% by mass, more preferably 70% by mass, and still more preferably 90% by mass with respect to the total solid content. As an upper limit of the said content, 99 mass% is preferable and 95 mass% is more preferable. [A] By making content of a metal containing component into the said range, the sensitivity and resolution of the said radiation sensitive composition can be improved more. “Total solid content” refers to the sum of components other than the organic solvent [B] of the radiation-sensitive composition. The radiation-sensitive composition may contain one or more [A] metal-containing components.

[[A1] metal-containing component]
[A1] The metal-containing component is a component containing a metal atom (x) of tin, indium, antimony, bismuth, germanium, aluminum, or a combination thereof.

[A1] As the metal-containing component, for example, as a component containing tin, monobutyltin oxide, dibutyldiacetoxytin, etc.
As a component containing indium, indium oxide sol, etc.
As a component containing antimony, antimony trioxide, etc.
As a component containing bismuth, bismuth trioxide, etc.
As a component containing germanium, germanium oxide sol, etc.
Examples of the component containing aluminum include triisopropoxy aluminum.

  Among these, monobutyltin oxide, dibutyldiacetoxytin, indium oxide sol, germanium oxide sol, and triisopropoxyaluminum are preferable.

  [A1] The lower limit of the content of the metal-containing component is preferably 5% by mass, more preferably 10% by mass, still more preferably 20% by mass, and 30% by mass with respect to the total solid content of the radiation-sensitive composition. % Is particularly preferred. As an upper limit of the said content, 95 mass% is preferable, 90 mass% is more preferable, 80 mass% is further more preferable, 70 mass% is especially preferable.

  [A1] The lower limit of the content of the metal-containing component is preferably 5% by mass, more preferably 10% by mass, further preferably 20% by mass, and particularly preferably 30% by mass with respect to the [A] metal-containing component. . As an upper limit of the said content, 95 mass% is preferable, 90 mass% is more preferable, 80 mass% is further more preferable, 70 mass% is especially preferable.

  [A1] By setting the content of the metal-containing component in the above range, the radiation-sensitive composition is further improved in sensitivity, resolution, etching resistance, and substrate contamination suppression.

[[A2] metal-containing component]
[A2] The metal-containing component is a component that does not contain a metal atom (x) and contains a metal atom (y).

  The metal atom (y) is a Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11 atom or a combination thereof. .

Examples of Group 3 metal atoms include scandium, yttrium, lanthanum, cerium, and the like.
Examples of Group 4 metal atoms include titanium, zirconium, hafnium, and the like.
Examples of Group 5 metal atoms include vanadium, niobium, and tantalum.
Examples of Group 6 metal atoms include chromium, molybdenum, and tungsten.
Examples of Group 7 metal atoms include manganese and rhenium.
Group 8 metal atoms include iron, ruthenium, osmium,
Examples of Group 9 metal atoms include cobalt, rhodium, iridium,
Group 10 metal atoms include nickel, palladium, platinum, and the like.
Examples of Group 11 metal atoms include copper, silver, and gold.

  As the metal atom (y), atoms of Group 4, Group 5 and Group 6 are preferable, and titanium, zirconium, hafnium, tantalum and tungsten are more preferable.

[A2] As a metal-containing component, for example, as a component containing titanium, a reaction product of titanium (IV) alkoxide and carboxylic acid, etc.
As a component containing zirconium, a reaction product of zirconium (IV) alkoxide and carboxylic acid, a reaction product of zirconium (IV) β-diketonate and carboxylic acid, etc.
As a component containing hafnium, a reaction product of hafnium (IV) alkoxide, carboxylic acid and water, a reaction product of hafnium (IV) .beta.-diketonate and carboxylic acid, etc.
As a component containing tantalum, a reaction product of tantalum (V) alkoxide and a polyhydric alcohol, etc.
Examples of the component containing tungsten include a reaction product of tungsten (IV) chloride, hydrogen peroxide, and hydroxycarboxylic acid.

  Among these, the reaction product of titanium (IV) .tri-n-butoxide stearate and maleic acid, the reaction product of zirconium (IV) .n-butoxide and methacrylic acid, hafnium (IV) .isopropoxy Reaction product of hydrogen, trans-2,3-dimethylacrylic acid and water, reaction product of tantalum (V) ethoxide and diethylene glycol, and bis (cyclopentadienyl) tungsten (IV) dichloride, hydrogen peroxide and lactic acid The reaction product with

  [A2] The lower limit of the content of the metal-containing component is preferably 5% by mass, more preferably 10% by mass, further preferably 15% by mass, and 20% by mass with respect to the total solid content of the radiation-sensitive composition. % Is particularly preferred. As an upper limit of the said content, 80 mass% is preferable, 70 mass% is more preferable, 60 mass% is further more preferable, 50 mass% is especially preferable.

  [A2] The lower limit of the content of the metal-containing component is preferably 5% by mass, more preferably 10% by mass, further preferably 15% by mass, and particularly preferably 20% by mass with respect to the [A] metal-containing component. . As an upper limit of the said content, 80 mass% is preferable, 70 mass% is more preferable, 60 mass% is further more preferable, 50 mass% is especially preferable.

  [A1] The lower limit of the mass ratio of the [A2] metal-containing component to the metal-containing component is preferably 0.05, more preferably 0.1, still more preferably 0.2, and particularly preferably 0.3. The upper limit of the mass ratio is preferably 3, more preferably 2, more preferably 1.2, and particularly preferably 1.

  [A2] By setting the content of the metal-containing component in the above range, the radiation-sensitive composition is further improved in sensitivity, resolution, etching resistance, and substrate contamination suppression.

  [A] The metal-containing component preferably constitutes a particle (hereinafter, [A] the entire metal-containing component particle is referred to as “particle (A)”, and [A1] the metal-containing component particle is referred to as “particle (A1). ) ”, [A2] The particles of the metal-containing component are also referred to as“ particles (A2) ”).

  Examples of the particles (A1) include particles containing monobutyltin oxide, particles containing dibutyldiacetoxytin, particles containing indium oxide sol, particles containing germanium oxide sol, and particles containing triisopropoxyaluminum. .

  Examples of the particles (A2) include particles containing a reaction product of titanium (IV) alkoxide and carboxylic acid, particles containing a reaction product of zirconium (IV) alkoxide and carboxylic acid, and hafnium (IV) alkoxide. Containing reaction product of carboxylic acid and water, particles containing reaction product of tantalum (V) alkoxide and polyhydric alcohol, reaction product of tungsten (IV) chloride, hydrogen peroxide and lactic acid The particle | grains containing are mentioned.

  As a minimum of the average particle diameter of particles (A), 0.5 nm is preferred and 0.8 nm is more preferred. On the other hand, the upper limit of the average particle diameter is preferably 20 nm, more preferably 10 nm, and even more preferably 5.0 nm. Here, the “average particle diameter” refers to a hydrodynamic radius measured by a DLS (Dynamic Light Scattering) method using a light scattering measurement device.

  As a minimum of the average particle diameter of particles (A1), 0.5 nm is preferred and 0.8 nm is more preferred. On the other hand, the upper limit of the average particle diameter is preferably 20 nm, more preferably 10 nm, and even more preferably 5.0 nm.

  As a minimum of the average particle diameter of particles (A2), 0.5 nm is preferred and 0.8 nm is more preferred. On the other hand, the upper limit of the average particle diameter is preferably 20 nm, more preferably 10 nm, and even more preferably 4.0 nm.

  [A] By setting the average particle size of the particles in the metal-containing component in the above range, the sensitivity, resolution, and substrate contamination suppressing property of the radiation-sensitive composition can be further improved.

[[A] Method for synthesizing metal-containing component]
[A] Although a commercially available metal compound can be used as the metal-containing component, for example, [b] a method of performing a hydrolysis-condensation reaction using the metal-containing compound, [b] metal-containing component It can synthesize | combine by the method etc. which perform a ligand exchange reaction using a compound. Here, the “hydrolysis condensation reaction” means that [b] the hydrolyzable group of the metal-containing compound is hydrolyzed to be converted to —OH, and the obtained two —OH is dehydrated and condensed to —O—. Refers to the reaction in which is formed.

([B] metal-containing compound)
[B] The metal-containing compound includes a metal compound (I) having a hydrolyzable group, a hydrolyzate of the metal compound (I) having a hydrolyzable group, and a hydrolysis of the metal compound (I) having a hydrolyzable group. It is a condensate or a combination thereof. Metal compound (I) can be used individually by 1 type or in combination of 2 or more types.

  Examples of the hydrolyzable group include a halogen atom, an alkoxy group, and an acyloxy group.

  As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, for example.

  As said alkoxy group, a methoxy group, an ethoxy group, n-propoxy group, i-propoxybutoxy group etc. are mentioned, for example.

  Examples of the acyloxy group include an acetoxy group, an ethylyloxy group, a propionyloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, an n-hexanecarbonyloxy group, and an n-octanecarbonyloxy group.

  As the hydrolyzable group, an alkoxy group and an acyloxy group are preferable, and an isopropoxy group and an acetoxy group are more preferable.

  [B] When the metal-containing compound is a hydrolysis condensate of the metal compound (I), the hydrolysis condensate of the metal compound (I) has a hydrolyzable group unless the effects of the present invention are impaired. It may be a hydrolysis-condensation product of the metal (I) having and a compound containing a metalloid atom. That is, the hydrolysis condensate of metal compound (I) may contain a metalloid atom within a range not impairing the effects of the present invention. Examples of the metalloid atom include boron, germanium, antimony, tellurium and the like. The content rate of the metalloid atom in the hydrolysis condensate of metal compound (I) is usually less than 50 atomic% with respect to the total of metal atoms and metalloid atoms in the hydrolysis condensate. As an upper limit of the content rate of the said half-metal atom, 30 atomic% is preferable with respect to the sum total of the metal atom and half-metal atom in the said hydrolysis-condensation product, and 10 atomic% is more preferable.

  Examples of the metal compound (I) include a compound represented by the following formula (A) (hereinafter also referred to as “metal compound (I-1)”). By using such a metal compound (I-1), a stable metal oxide can be formed, and as a result, the sensitivity, resolution, etching resistance and substrate contamination suppression of the radiation-sensitive composition are further improved. it can.

  In the above formula (A), Q is a metal atom. L is a ligand. a is an integer of 0-2. When a is 2, the plurality of L may be the same or different. X is a hydrolyzable group selected from a halogen atom, an alkoxy group and an acyloxy group. b is an integer of 2-6. A plurality of X may be the same or different. L is a ligand not corresponding to X.

  Examples of the metal atom represented by Q include metal atoms similar to those exemplified as the metal atom constituting the metal oxide contained in the [A] metal-containing component.

  Examples of the ligand represented by L include a monodentate ligand and a polydentate ligand.

  Examples of the monodentate ligand include a hydroxo ligand, a carboxy ligand, an amide ligand, and the like.

Examples of the amide ligand include unsubstituted amide ligand (NH ₂ ), methylamide ligand (NHMe), dimethylamide ligand (NMe ₂ ), diethylamide ligand (NEt ₂ ), and dipropylamide. And a ligand (NPr ₂ ).

  Examples of the polydentate ligand include hydroxy acid ester, β-diketone, β-keto ester, β-dicarboxylic acid ester, hydrocarbon having π bond, diphosphine, and ammonia.

  Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylic acid ester.

  Examples of the β-diketone include 2,4-pentanedione, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, and the like.

  Examples of the β-ketoester include acetoacetate ester, α-alkyl-substituted acetoacetate ester, β-ketopentanoic acid ester, benzoyl acetate ester, 1,3-acetone dicarboxylic acid ester, and the like.

  Examples of the β-dicarboxylic acid ester include malonic acid diester, α-alkyl substituted malonic acid diester, α-cycloalkyl substituted malonic acid diester, α-aryl substituted malonic acid diester, and the like.

Examples of the hydrocarbon having a π bond include chain olefins such as ethylene and propylene;
Cyclic olefins such as cyclopentene, cyclohexene, norbornene;
Chain dienes such as butadiene and isoprene;
Cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norbornadiene;
Examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene, and indene.

  Examples of the diphosphine include 1,1-bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane, 1,3-bis (diphenylphosphino) propane, and 2,2′-bis (diphenyl). Phosphino) -1,1′-binaphthyl, 1,1′-bis (diphenylphosphino) ferrocene and the like.

  Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  Examples of the alkoxy group represented by X include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Examples of the acyloxy group represented by X include an acetoxy group, an ethylyloxy group, a butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, an n-hexane carbonyloxy group, and an n-octane carbonyloxy group.

  X is preferably an alkoxy group or an acyloxy group, more preferably an isopropoxy group, a butoxy group or an acetoxy group.

  As b, 3 and 4 are preferable and 4 is more preferable. By making b into the said numerical value, the content rate of the metal oxide in a [A] metal containing component can be raised, and generation | occurrence | production of the secondary electron by a [A] metal containing component can be accelerated | stimulated more effectively. As a result, the sensitivity of the radiation sensitive composition can be further improved.

  [B] The metal-containing compound is preferably a metal alkoxide that is neither hydrolyzed nor hydrolyzed and a metal acyloxide that is neither hydrolyzed nor hydrolyzed.

  [B] Examples of the metal-containing compound include zirconium / tetra n-butoxide, zirconium / tetra n-propoxide, zirconium / tetraisopropoxide, hafnium / tetraethoxide, indium / triisopropoxide, and hafnium / tetraisopropoxide. , Hafnium tetrabutoxide, tantalum tetrabutoxide, tantalum pentaethoxide, tantalum pentabutoxide, tungsten tetrabutoxide, tungsten pentamethoxide, tungsten pentaboxide, tungsten hexaethoxide, tungsten hexabutoxide, chloride Iron, zinc diisopropoxide, zinc acetate dihydrate, tetrabutyl orthotitanate, titanium tetra n-butoxide, titanium tetra n-propoxide, zirconi Di-n-butoxide bis (2,4-pentanedionate), titanium-tri-n-butoxide stearate, bis (cyclopentadienyl) hafnium dichloride, bis (cyclopentadienyl) tungsten dichloride, diacetate [ (S)-(−)-2,2′-bis (diphenylphosphino) -1,1′-binaphthyl] ruthenium, dichloro [ethylenebis (diphenylphosphine)] cobalt, titanium butoxide oligomer, aminopropyltrimethoxytitanium, Aminopropyltriethoxyzirconium, 2- (3,4-epoxycyclohexyl) ethyltrimethoxyzirconium, γ-glycidoxypropyltrimethoxyzirconium, 3-isocyanopropyltrimethoxyzirconium, 3-isocyanopropyltriethoxy Zirconium, triethoxymono (acetylacetonato) titanium, tri-n-propoxymono (acetylacetonato) titanium, tri-i-propoxymono (acetylacetonato) titanium, triethoxymono (acetylacetonato) zirconium, tri- n-propoxymono (acetylacetonato) zirconium, tri-i-propoxymono (acetylacetonato) zirconium, diisopropoxybis (acetylacetonato) titanium, di-n-butoxybis (acetylacetonato) titanium, di-n-butoxybis (Acetylacetonato) zirconium, tri (3-methacryloxypropyl) methoxyzirconium, tri (3-acryloxypropyl) methoxyzirconium, tin tetraisopropoxide, tin tetrabut Sid, lanthanum oxide, yttrium oxide, and the like. Of these, metal alkoxides and metal acyloxides are preferred, metal alkoxides are more preferred, and titanium, zirconium, hafnium, tantalum, tungsten, and tin alkoxides are even more preferred.

  [A] When using an organic acid for the synthesis | combination of a metal containing component, as a minimum of the usage-amount of the said organic acid, 10 mass parts is preferable with respect to 100 mass parts of [b] metal containing compounds, and 30 mass parts is more preferable. . On the other hand, as an upper limit of the usage-amount of the said organic acid, 1,000 mass parts is preferable with respect to 100 mass parts of [b] metal containing compounds, 700 mass parts is more preferable, 200 mass parts is further more preferable, 100 mass parts Is particularly preferred. By making the usage-amount of the said organic acid into the said range, the content rate of [a] organic acid in the [A] metal containing component obtained can be adjusted to an appropriate thing, As a result, the said radiation sensitive composition It is possible to further improve the sensitivity, resolution, etching resistance, and substrate contamination suppression of objects.

  [A] In the synthesis reaction of the metal-containing component, in addition to the metal compound (I) and the organic acid [a], a compound that can be a multidentate ligand represented by L in the compound of the above formula (A) You may add the compound etc. which can become a bridge | crosslinking ligand. Examples of the compound that can be a bridging ligand include compounds having a plurality of hydroxy groups, isocyanate groups, amino groups, ester groups, and amide groups.

  [B] Examples of the method for performing the hydrolysis and condensation reaction using the metal-containing compound include a method of [b] hydrolyzing and condensing the metal-containing compound in a solvent containing water. In this case, you may add the other compound which has a hydrolysable group as needed. The lower limit of the amount of water used for this hydrolysis-condensation reaction is preferably 0.2-fold mol, more preferably 1-fold mol, and 3-fold mol based on the hydrolyzable group of [b] metal-containing compound. Further preferred. The upper limit of the amount of water is preferably 20 times mol, more preferably 15 times mol, and even more preferably 10 times mol. The content of the metal oxide in the [A] metal-containing component obtained by adjusting the amount of water in the hydrolysis-condensation reaction to the above range can be increased. As a result, the sensitivity and resolution of the radiation-sensitive composition can be increased. Performance, etching resistance and substrate contamination suppression can be further improved.

  [B] Examples of a method for performing a ligand exchange reaction using a metal-containing compound include a method of mixing [b] a metal-containing compound and [a] an organic acid. In this case, it may be mixed in a solvent or may be mixed without using a solvent. Moreover, in the said mixing, you may add bases, such as a triethylamine, as needed. The amount of the base added is, for example, from 1 part by mass to 200 parts by mass with respect to 100 parts by mass of the total amount of [b] metal-containing compound and [a] organic acid.

  [A] It does not specifically limit as a solvent used for the synthetic reaction of a metal containing component, For example, the solvent similar to what is illustrated as an organic solvent [B] mentioned later can be used. Among these, alcohol solvents, ether solvents, ester solvents and hydrocarbon solvents are preferable, alcohol solvents, ether solvents and ester solvents are more preferable, polyhydric alcohol partial ether solvents, monocarboxylic acids. Ester solvents and cyclic ether solvents are more preferred, with propylene glycol monoethyl ether, ethyl acetate and tetrahydrofuran being particularly preferred.

  [A] When a solvent is used for the synthesis reaction of the metal-containing component, the solvent used may be removed after the reaction, but it is used as it is as the [B] organic solvent of the radiation-sensitive composition without being removed after the reaction. You can also.

  [A] As a minimum of the temperature of the synthesis reaction of a metal content ingredient, 0 ° C is preferred and 10 ° C is more preferred. As an upper limit of the said temperature, 150 degreeC is preferable and 100 degreeC is more preferable.

  [A] The lower limit of the time for the synthesis reaction of the metal-containing component is preferably 1 minute, more preferably 10 minutes, and even more preferably 1 hour. The upper limit of the time is preferably 100 hours, more preferably 50 hours, and even more preferably 10 hours.

<[B] Organic solvent>
[B] The organic solvent is not particularly limited as long as it is a solvent that can dissolve or disperse at least the [A] metal-containing component and an optional component that is optionally contained. [B] As the organic solvent, the organic solvent used when the [A] metal-containing component is synthesized may be used.

  [B] Examples of the organic solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

Examples of alcohol solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , Sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec -Monoalcohol solvents such as heptadecyl alcohol, furfuryl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 -Polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether.

Examples of ether solvents include dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
And aromatic ring-containing ether solvents such as diphenyl ether and anisole.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, Chain ketone solvents such as di-iso-butyl ketone and trimethylnonanone:
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone:
2,4-pentanedione, acetonylacetone, acetophenone and the like can be mentioned.

Examples of the amide solvent include cyclic amide solvents such as N, N′-dimethylimidazolidinone and N-methylpyrrolidone;
Examples thereof include chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide.

Examples of the ester solvent include methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, i-pentyl acetate, sec -Acetate solvents such as pentyl, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, n-nonyl acetate;
Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl acetate Polyhydric alcohol partial ether carboxylate solvents such as ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether;
lactone solvents such as γ-butyrolactone and δ-valerolactone;
Carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate;
Lactic acid ester solvents such as methyl lactate, ethyl lactate, n-butyl lactate, and n-amyl lactate;
Diethyl acetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl acetoacetate, ethyl acetoacetate, diethyl malonate, phthalate Examples thereof include dimethyl acid and diethyl phthalate.

Examples of the hydrocarbon solvent include n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, and cyclohexane. , Aliphatic hydrocarbon solvents such as methylcyclohexane;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene and n-amylnaphthalene Group hydrocarbon solvents and the like.

  Among these, alcohol solvents and ester solvents are preferred, polyhydric alcohol partial ether solvents, polyhydric alcohol partial ether carboxylate solvents and lactic acid ester solvents are more preferred, propylene glycol monomethyl ether, propylene glycol monoethyl More preferred are ether, propylene glycol monomethyl ether and ethyl lactate. The radiation-sensitive composition may contain one or more [B] organic solvents.

<Optional component>
The radiation-sensitive composition contains, for example, an acid diffusion controller, a radiation-sensitive acid generator, a fluorine atom-containing polymer, a surfactant and the like as optional components in addition to the components [A] and [B]. You may do it. The said radiation sensitive composition may contain 1 type, or 2 or more types of arbitrary components, respectively.

[Acid diffusion controller]
The said radiation sensitive composition may contain an acid diffusion control body as needed. The acid diffusion controller controls the diffusion phenomenon in the film of an acid generated from [X] metal salt or the like by exposure, and has an effect of suppressing an undesirable chemical reaction in a non-exposed region. In addition, the storage stability of the radiation-sensitive composition is further improved, and the resolution as a resist is further improved. Furthermore, a change in the line width of the pattern due to fluctuations in the holding time from exposure to development processing can be suppressed, and a radiation-sensitive composition excellent in process stability can be obtained. The inclusion form of the acid diffusion controller in the radiation-sensitive composition may be in the form of a free compound (hereinafter referred to as “acid diffusion controller” as appropriate) or in a form incorporated as part of a polymer. Both forms may be used.

  Examples of the acid diffusion controller include a compound represented by the following formula (a) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound”). (II) ”, compounds having three nitrogen atoms (hereinafter also referred to as“ nitrogen-containing compound (III) ”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

In the above formula (a), R ^a , R ^b and R ^c are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted monovalent alicyclic saturated hydrocarbon group, substituted Or it is an unsubstituted aryl group or a substituted or unsubstituted aralkyl group.

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tri-n-pentylamine; and fragrances such as aniline Group amines and the like.

  Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, and the like.

  Examples of the nitrogen-containing compound (III) include polyamine compounds such as polyethyleneimine and polyallylamine; polymers such as dimethylaminoethylacrylamide.

  Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. It is done.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea and the like.

  Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N- (undecan-1-ylcarbonyloxyethyl) morpholine; imidazole, 2-phenylimidazole, Examples include imidazoles such as 2,4,5-triphenylimidazole; pyrazine, pyrazole and the like.

  Moreover, the compound which has an acid dissociable group can also be used as said nitrogen-containing organic compound. Examples of the nitrogen-containing organic compound having such an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2. -Phenylbenzimidazole, N- (t-butoxycarbonyl) di-n-octylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine and the like.

  Further, as the acid diffusion controlling agent, a photodegradable base that is sensitized by exposure to generate a weak acid can be used. Examples of the photodegradable base include onium salt compounds that are decomposed by exposure and lose acid diffusion controllability, such as triphenylsulfonium salicylate, triphenylsulfonium 10-camphorsulfonate, and the like.

  When the said radiation sensitive composition contains an acid diffusion control agent, as a minimum of content of an acid diffusion control agent, 0.1 mass part is preferable with respect to 100 mass parts of [A] metal containing components, 0 More preferable is 5 parts by mass, and further more preferable is 1 part by mass. As an upper limit of the said content, 20 mass parts is preferable, 10 mass parts is more preferable, and 5 mass parts is further more preferable. 1 type (s) or 2 or more types can be used for an acid diffusion control body.

[Radiosensitive acid generator]
Since the radiation-sensitive composition generates an acid from the [A] metal-containing component upon exposure, a radiation-sensitive acid generator is not always necessary, but the radiation-sensitive composition generates a radiation-sensitive acid. By containing the body, the sensitivity can be further increased. The radiation sensitive acid generator is contained in the radiation sensitive composition in the form of a low molecular weight compound (hereinafter also referred to as “radiation sensitive acid generator” where appropriate). It may be a form incorporated as a part or both of these forms.

  Examples of the radiation sensitive acid generator include onium salt compounds, N-sulfonyloxyimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  Specific examples of the radiation sensitive acid generator include compounds described in paragraphs [0080] to [0113] of JP2009-134088A.

  When the said radiation sensitive composition contains a radiation sensitive acid generator, as a minimum of content of a radiation sensitive acid generator, it is 0.1 mass part with respect to 100 mass parts of [A] metal containing component. Is preferable, 1 mass part is more preferable, and 5 mass parts is further more preferable. As an upper limit of the said content, 30 mass parts is preferable, 20 mass parts is more preferable, and 10 mass parts is further more preferable. 1 type (s) or 2 or more types can be used for a radiation sensitive acid generator.

[Fluorine atom-containing polymer]
The fluorine atom-containing polymer is a polymer having a fluorine atom. When the radiation-sensitive composition contains a fluorine atom-containing polymer, when the film is formed, the distribution tends to be unevenly distributed near the film surface due to the oil-repellent characteristics of the fluorine atom-containing polymer in the film. Yes, it is possible to prevent the radiation-sensitive acid generator, the acid diffusion controller, and the like from being eluted into the immersion medium during immersion exposure. Further, due to the water-repellent characteristics of the fluorine atom-containing polymer, the advancing contact angle between the film and the immersion medium can be controlled within a desired range, and the occurrence of bubble defects can be suppressed. Furthermore, the receding contact angle between the film and the immersion medium becomes high, and high-speed scanning exposure is possible without leaving water droplets. Thus, the said radiation sensitive composition can form the film | membrane suitable for an immersion exposure method by containing a fluorine atom containing polymer.

  When the said radiation sensitive composition contains a fluorine atom containing polymer, as a minimum of content of a fluorine atom containing polymer, 0.1 mass part is preferable with respect to 100 mass parts of [A] metal containing components. 0.5 parts by mass is more preferable, and 1 part by mass is more preferable. As an upper limit of the said content, 20 mass parts is preferable, 15 mass parts is more preferable, and 10 mass parts is further more preferable.

[Surfactant]
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate are listed. Examples of commercially available surfactants include KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, Tochem Products), MegaFuck F171, F173 (above, DIC), Florard FC430, FC431 (above, Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, Asahi Glass) It is done.

  When the said radiation sensitive composition contains surfactant, as a minimum of content of surfactant, 0.1 mass part is preferable with respect to 100 mass parts of [A] metal containing components, 0.3 Part by mass is more preferable. As an upper limit of the said content, 2 mass parts is preferable and 1 mass part is more preferable.

<Method for preparing radiation-sensitive composition>
In the radiation sensitive composition, for example, [A] a metal-containing component, [B] an organic solvent and an optional component as necessary are mixed at a predetermined ratio. Preferably, the obtained mixture has a pore size of about 0.2 μm. It can be prepared by filtering with a membrane filter. The lower limit of the solid content concentration of the radiation-sensitive composition is preferably 0.1% by mass, more preferably 0.5% by mass, further preferably 1% by mass, and particularly preferably 1.5% by mass. The upper limit of the solid content concentration is preferably 50% by mass, more preferably 30% by mass, further preferably 10% by mass, and particularly preferably 5% by mass.

  The radiation-sensitive composition can be used for both alkali development using an aqueous alkali solution as a developer and organic solvent development using an organic solvent-containing solution as a developer.

<Pattern formation method>
The pattern forming method includes a step of applying the radiation-sensitive composition to a substrate (hereinafter also referred to as “coating step”) and a step of exposing a film formed by the coating step (hereinafter referred to as “exposure”). And a step of developing the exposed film (hereinafter also referred to as “developing step”). According to the pattern forming method, since the radiation-sensitive composition described above is used, it is possible to form a pattern with high sensitivity, high resolution, high etching resistance, and reduced substrate contamination. . Hereinafter, each step will be described.

[Coating process]
In this step, the radiation sensitive composition is applied to one side of the substrate. Thereby, a film is formed. Although it does not specifically limit as a coating method, For example, appropriate | suitable coating means, such as rotation coating, cast coating, and roll coating, are employable. Examples of the substrate include a silicon wafer and a wafer coated with aluminum. Specifically, after the radiation-sensitive composition is applied so that the resulting film has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking (PB) as necessary.

  The lower limit of the average film thickness of the film is preferably 1 nm, more preferably 10 nm, still more preferably 20 nm, and particularly preferably 30 nm. The upper limit of the average thickness is preferably 1,000 nm, more preferably 200 nm, still more preferably 100 nm, and particularly preferably 70 nm.

  As a minimum of the temperature of PB, 60 degreeC is preferable and 80 degreeC is more preferable. As an upper limit of the temperature of PB, 140 degreeC is preferable and 120 degreeC is more preferable. The lower limit of the PB time is preferably 5 seconds, and more preferably 10 seconds. The upper limit of the PB time is preferably 600 seconds, and more preferably 300 seconds.

[Exposure process]
In this step, the film formed by the coating step is exposed. In some cases, this exposure is performed by irradiating radiation through a mask having a predetermined pattern through an immersion medium such as water. Examples of the radiation include visible rays, ultraviolet rays, far ultraviolet rays, vacuum ultraviolet rays (extreme ultraviolet rays (EUV); wavelength 13.5 nm), electromagnetic waves such as X-rays and γ rays, and charged particle beams such as electron rays and α rays. Can be mentioned. Among these, radiation that emits more secondary electrons from metal atoms contained in the [A] metal-containing component and the like by exposure is preferable, and EUV and electron beams are more preferable.

  Moreover, you may perform post-exposure baking (PEB) after exposure. As a minimum of the temperature of PEB, 50 degreeC is preferable and 80 degreeC is more preferable. As an upper limit of the temperature of PEB, 180 degreeC is preferable and 130 degreeC is more preferable. The lower limit of the PEB time is preferably 5 seconds, and more preferably 10 seconds. The upper limit of the PEB time is preferably 600 seconds, and more preferably 300 seconds.

  In the present invention, in order to maximize the potential of the radiation-sensitive composition, for example, an organic or inorganic antireflection film can be formed on the substrate to be used. Moreover, in order to prevent the influence of the basic impurity etc. which are contained in environmental atmosphere, a protective film can also be provided, for example on a coating film. When immersion exposure is performed, an immersion protective film may be provided on the film, for example, in order to avoid direct contact between the immersion medium and the film.

[Development process]
In this step, the film exposed in the exposure step is developed. Examples of the developer used for the development include an alkaline aqueous solution and an organic solvent-containing solution.

  Examples of the alkaline aqueous solution include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4. 3.0] -5-nonene and the like, an alkaline aqueous solution in which at least one kind of alkaline compound is dissolved.

  As a minimum of content of the alkaline compound in alkaline aqueous solution, 0.1 mass% is preferred, 0.5 mass% is more preferred, and 1 mass% is still more preferred. As an upper limit of the said content, 20 mass% is preferable, 10 mass% is more preferable, and 5 mass% is further more preferable.

  As the alkaline aqueous solution, a TMAH aqueous solution is preferable, and a 2.38 mass% TMAH aqueous solution is more preferable.

  Examples of the organic solvent in the organic solvent-containing liquid include the same organic solvents exemplified as the [B] organic solvent of the radiation-sensitive composition. Of these, ester solvents are preferred, and butyl acetate is more preferred.

  The lower limit of the content of the organic solvent in the organic solvent developer is preferably 80% by mass, more preferably 90% by mass, further preferably 95% by mass, and particularly preferably 99% by mass.

  These developers may be used alone or in combination of two or more. In general, after development, the substrate is washed with water or the like and dried.

  When an alkaline aqueous solution is used as the developer, a positive pattern can be obtained. Further, when an organic solvent-containing solution is used as the developer, a negative pattern can be obtained.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. Each physical property value was measured by the following method.

[Particle size analysis]
[A] The hydrodynamic radius of the particles contained in the liquid containing the metal-containing component was determined by DLS measurement using a light scattering measurement device (“ALV-5000” from ALV, Germany).

[[A] Solid Concentration of Liquid Containing Metal-Containing Component]
[A] The solid content concentration of the liquid containing the metal-containing component is M2 × 100 from the mass (M1) of the liquid containing the [A] metal-containing component and the mass (M2) after the liquid is dried. / M1 (mass%).

<[A] Synthesis of metal-containing component>
[[A1] Synthesis of metal-containing component]
[Synthesis Example 1]
10.0 g of monobutyltin oxide (BuSnOOH) was added to 240 g of propylene glycol monomethyl ether, and the mixture was stirred at room temperature for 24 hours. After standing for 1 hour, the supernatant was filtered through a PTFE membrane filter having a pore size of 0.20 μm to obtain a liquid containing a metal-containing component (A1-1). The solid content concentration of this liquid was 3.0% by mass, and the hydrodynamic radius of the particles in this liquid was 1.8 nm.

[Synthesis Example 2]
Dibutyldiacetoxytin 5.0 g was dissolved in 95.0 g of propylene glycol monomethyl ether acetate at room temperature to obtain a liquid containing a metal-containing component (A1-2). The solid content concentration of this liquid was 5.0% by mass, and the hydrodynamic radius of the particles in this liquid was 1.5 nm.

[Synthesis Example 3]
2.9 g of indium (III) acetate and 50 g of 2-propanol were mixed, and 0.36 g of water was added thereto and mixed at 50 ° C. for 3 hours. 200 g of ethyl lactate was added to the obtained mixture, and solvent substitution by vacuum concentration was performed to obtain a liquid containing a metal-containing component (A1-3) that is an indium oxide sol. The solid content concentration of this liquid was 5.0% by mass, and the hydrodynamic radius of the particles in this liquid was 3.1 nm.

[Synthesis Example 4]
Tetraisopropoxy germanium (3.1 g), oxalic acid (0.1 g) and 2-propanol (50 g) were mixed, and water (0.54 g) was added thereto, followed by mixing at 60 ° C. for 1 hour. 200 g of propylene glycol monoethyl ether was added to the obtained mixture, and solvent substitution by vacuum concentration was performed to obtain a liquid containing a metal-containing component (A1-4) which is a germanium oxide sol. The solid content concentration of this liquid was 5.0% by mass, and the hydrodynamic radius of the particles in this liquid was 4.5 nm.

[Synthesis Example 5]
A solution containing a metal-containing component (A1-5) was obtained by dissolving 5.0 g of triisopropoxyaluminum in 95.0 g of ethyl lactate at room temperature. The solid content concentration of this liquid was 5.0% by mass, and the hydrodynamic radius of the particles in this liquid was 0.9 nm.

[[A2] Synthesis of metal-containing component]
[Synthesis Example 6]
10.0 g of titanium (IV) .tri-n-butoxide stearylate (90% strength by weight butanol solution) was dissolved in 40.0 g of propylene glycol monoethyl ether. To this solution, a mixture of 10.0 g of propylene glycol monoethyl ether and 0.46 g of maleic acid was added, followed by stirring for 1 hour, and further adding propylene glycol monoethyl ether, thereby adding a metal-containing component (A2- A liquid containing 1) was obtained. The solid content concentration of this liquid was 10.0% by mass, and the hydrodynamic radius of the particles in this liquid was 0.9 nm.

[Synthesis Example 7]
4.0 g of zirconium (IV) · n-butoxide (80% by weight butanol solution) was dissolved in 10.0 g of tetrahydrofuran (THF), 8.0 g of methacrylic acid was added thereto, and the mixture was stirred at room temperature for 24 hours. The resulting liquid was mixed with 100 g of hexane to recover the generated precipitate, and the resulting precipitate was washed with hexane and then vacuum dried to obtain 2.5 g of zirconium-containing particles. This was dissolved in ethyl lactate and stirred for 1 hour to obtain a liquid containing a metal-containing component (A2-2). The solid content concentration of this liquid was 10.0% by mass, and the hydrodynamic radius of the particles in this liquid was 18 nm.

[Synthesis Example 8]
After adding 8.0 g of trans-2,3-dimethylacrylic acid to 4.2 g of hafnium (IV) .isopropoxide and stirring at 65 ° C. for 30 minutes, 0.3 g of water was added and heated at 65 ° C. for another 18 hours. Continued. When 10 g of water was added thereto, formation of a precipitate was confirmed. The precipitate was recovered by centrifugation, dissolved in 5 g of acetone, and 10 g of water was further added to precipitate again. Centrifugation was performed once again, followed by vacuum drying to obtain 1.3 g of hafnium-containing particles. This was dissolved in propylene glycol monomethyl ether acetate and stirred for 1 hour to obtain a liquid containing a metal-containing component (A2-3). The solid content concentration of this liquid was 10.0% by mass, and the hydrodynamic radius of the particles in this liquid was 1.2 nm.

[Synthesis Example 9]
To 100 mL of tetrahydrofuran, 4.1 g of tantalum (V) ethoxide and 2.1 g of diethylene glycol were added and stirred at 65 ° C. for 30 minutes. To this, 200 g of propylene glycol monomethyl ether acetate was added, and solvent substitution by vacuum concentration was performed to obtain a liquid containing a metal-containing component (A2-4) which is a tantalum oxide sol. The solid content concentration of this liquid was 5.0% by mass, and the hydrodynamic radius of the particles in this liquid was 1.4 nm.

[Synthesis Example 10]
Dissolve 3.8 g of bis (cyclopentadienyl) tungsten (IV) dichloride in 44 g of ethyl lactate, stir well, and then add 0.57 g of 30% hydrogen peroxide solution (0.17 g as hydrogen peroxide) to this solution. Was added dropwise at room temperature over 10 minutes. Subsequently, after reacting at room temperature for 2 hours, 0.90 g (10 mmol) of lactic acid was further added and stirred at room temperature for 1 hour to obtain a liquid containing a metal-containing component (A2-5). The solid content concentration of this liquid was 9.0 mass%, and the hydrodynamic radius of the particles in this liquid was 3.4 nm.

[Synthesis Example 11]
2.5 g of benzoic acid, 0.7 g of zirconium (IV) isopropoxide and 0.7 g of tin (IV) isopropoxide were dissolved in 20 g of THF and heated at 65 ° C. for 6 hours. The obtained reaction solution was washed with ultrapure water and acetone to obtain a liquid containing a metal-containing component (a-1). The solid content concentration of this liquid was 9.5% by mass, and the hydrodynamic radius of the particles in this liquid was 2.5 nm.

  Table 1 below shows the [A] metal-containing component and the solvent in the liquid containing the [A] metal-containing component synthesized in Synthesis Examples 1 to 11.

<Preparation of radiation-sensitive resin composition>
[Example 1]
[A1] 100 parts by mass (3 mass parts in terms of solid content) containing (A1-1) as the metal-containing component and 10 parts by mass (solid) containing (A2-1) as the metal-containing component (A2) The resulting mixture is diluted with propylene glycol monomethyl ether to prepare a liquid having a solid content concentration of 3.0% by mass, and filtered through a membrane filter having a pore size of 0.20 μm. A radiation sensitive composition (R-1) was obtained.

[Examples 2 to 10 and Comparative Examples 1 to 8]
The components of the types and solid content ratios shown in Table 2 below are mixed, and a solvent for dilution is added to prepare a liquid having a solid content concentration of 3.0% by mass. The resulting liquid has a pore size of 0.20 μm. It filtered with the membrane filter and obtained the radiation sensitive compositions (R-2)-(R-18). As a solvent for dilution, the solvent of the liquid containing the [A1] metal-containing component was used, and when the [A1] metal-containing component was not used, the solvent of the liquid containing the [A2] metal-containing component was used. “-” In Table 2 below indicates that the corresponding component was not used.

[Comparative Example 9]
The liquid containing the synthesized metal-containing component (a-1) is diluted with propylene glycol monomethyl ether acetate to prepare a liquid having a solid content concentration of 3.0% by mass, and the obtained liquid has a pore size of 0.20 μm. It filtered with the membrane filter and obtained the radiation sensitive composition (R-19). “(A-1)” and “(* 1)” in Table 2 indicate that the metal-containing component (a-1) does not correspond to either [A1] metal-containing component or [A2] metal-containing component. .

[Comparative Example 10]
The liquid containing the synthesized metal-containing component (A2-2) and the solution containing the metal-containing component (A2-3) are mixed so that the solid content ratio is 50/50, ethyl lactate is added, A liquid having a solid content concentration of 3.0% by mass was prepared, and the obtained liquid was filtered through a membrane filter having a pore size of 0.20 μm to obtain a radiation-sensitive composition (R-20). “(* 2)” in Table 2 indicates that 50/50 is the solid content ratio of the metal-containing component (A2-2) / metal-containing component (A2-3).

<Pattern formation>
Each of the prepared radiation sensitive compositions was spin-coated on a silicon wafer, and then PB was performed at 100 ° C. for 60 seconds to form a film having an average thickness of 50 nm. Next, this film was exposed and patterned using a vacuum ultraviolet light exposure apparatus (NA: 0.3, dipole illumination). Thereafter, PEB was performed under conditions of 150 ° C. for 60 seconds, and then developed using a 2-heptanone at 23 ° C. for 1 minute by the paddle method, followed by drying to form a negative pattern.

<Evaluation>
The following items were evaluated for the prepared radiation sensitive composition and the formed pattern according to the following methods. The evaluation results are shown in Table 3 below.

[sensitivity]
By patterning using vacuum ultraviolet rays, a line-and-space pattern (1L1S) composed of a line portion having a line width of 30 nm and a space portion having an interval of 30 nm formed by adjacent line portions is formed in a one-to-one line width. The exposure amount was the optimum exposure amount, and this optimum exposure amount was the sensitivity (mJ / cm ² ). The sensitivity was evaluated as “A (good)” when it was 40 mJ / cm ² or less, and “B (bad)” when it exceeded 40 mJ / cm ² .

[Resolution]
In the formation of the pattern, a line-and-space pattern (1L1S) including a line portion having a line width of 22 nm and a space portion having an interval of 22 nm formed by adjacent line portions is formed in a one-to-one line width. If it is possible, the resolution is “AA (very good)” and the resolution at 22 nm is difficult, but a 25 nm line and space pattern (1L1S) is formed with a line width of 1: 1. If it is difficult to form a 25 nm line and space pattern (1L1S) with a line width of 1 to 1, the resolution is “A (good)”. The resolution was evaluated as “B (defect)”.

[Etching resistance]
Using the prepared radiation-sensitive composition, PB was performed under the conditions described in the above “Pattern formation” to form a film. Next, using a vacuum ultraviolet light exposure apparatus (NA: 0.3, dipole illumination), an area of 1 cm square is irradiated with the “optimum exposure amount” in the above “sensitivity” measurement, and then 150 ° C., 60 ° C. PEB was performed under the conditions of seconds, and then, development was performed by the paddle method at 23 ° C. for 1 minute using 2-heptanone to form a 1 cm square negative pattern. After measuring the film thickness after development, the resist underlayer film (“NFC HM8005” from JSR) is etched at a rate of 200 nm per minute using a dry etching apparatus (“Telius SCCM” from Tokyo Electron). Etching was performed under conditions, the initial film thickness and the film thickness after etching were measured, and the difference between these film thicknesses was calculated as an index of etching resistance. The etching resistance was evaluated as “A (good)” when the difference in film thickness was less than 5 nm, and “B (defect)” when the difference in film thickness was 5 nm or more. When etching resistance is evaluated as good, the pattern formed from the radiation-sensitive composition can function well as a mask when processing a resist underlayer film, a substrate, or the like.

[Substrate contamination suppression]
After coating a radiation-sensitive composition on a substrate on which a resist underlayer film (“NFC HM8005” from JSR, average thickness of 200 nm) is formed, an excessive amount of propylene glycol monomethyl ether is dispensed without passing through a baking step. Then, the coating film was removed. Next, after etching the resist underlayer film under the conditions shown in the above-mentioned “etching resistance” measurement, the amount of contamination of metal atoms on the substrate was measured by ICP-MS analysis. Substrate pollution control property, if the amount of contamination of the metal atoms is less than 1.0 × ¹⁰ 11 Atom / cm ² The "A (good)", when it exceeds 1.0 × ¹⁰ 11 Atom / cm ² is " B (defect) ".

  As is clear from the results in Table 3, the radiation-sensitive compositions of the examples are excellent in all of sensitivity, resolution, etching selectivity, and substrate contamination suppression properties. The comparative radiation sensitive composition is inferior in one or more of the following characteristics: sensitivity, resolution, etching selectivity and substrate contamination control.

According to the radiation-sensitive composition and the pattern forming method of the present invention, a pattern with high sensitivity, high resolution, high etching resistance, and reduced substrate contamination can be formed. Therefore, these can be suitably used for manufacturing semiconductor devices that are expected to be further miniaturized in the future.

Claims (7)

Metal-containing components including metal oxides;
An organic solvent and
The metal-containing component has a first metal-containing component and a second metal-containing component,
The first metal-containing component includes a first metal atom that is tin, indium, antimony, bismuth, gallium, germanium, aluminum, or a combination thereof;
The second metal-containing component does not contain the first metal atom, and includes Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group A radiation-sensitive composition comprising a second metal atom that is a Group 11 atom or a combination thereof.   The radiation-sensitive composition according to claim 1, wherein the second metal atom is titanium, zirconium, hafnium, tantalum, tungsten, or a combination thereof.   The radiation-sensitive composition according to claim 1 or 2, wherein a mass ratio of the second metal-containing component to the first metal-containing component is 0.05 or more and 1 or less.   The radiation-sensitive composition according to claim 1, wherein the total content of the first metal-containing component and the second metal-containing component is 60% by mass or more in terms of solid content.   The radiation-sensitive composition according to any one of claims 1 to 4, wherein the metal-containing component contains particles, and the average particle size of the particles is 0.05 nm or more and 5.0 nm or less. A step of applying the radiation-sensitive composition according to any one of claims 1 to 5 to one surface side of the substrate;
Exposing the film formed by the coating process;
A pattern forming method comprising: developing the exposed film. The pattern forming method according to claim 6, wherein the radiation used in the exposure step is extreme ultraviolet light or an electron beam.