Semiconductor substrate manufacturing method and reversal pattern forming material

Abstract

Provided are: a semiconductor substrate manufacturing method with which it is possible to improve the etching resistance of a reversal pattern of a metal-containing resist pattern and the rectangularity of the reversal pattern; and a reversal pattern forming material. This semiconductor substrate manufacturing method comprises: a step for forming a metal-containing resist film directly or indirectly on a substrate with use of a metal-containing resist forming material; a step for subjecting the metal-containing resist film to light exposure by means of extreme ultraviolet light; a step for developing the light-exposed metal-containing resist film; a step for forming, on the metal-containing resist pattern that is formed in the development step, a film for reversal pattern formation with use of a reversal pattern forming material; and a step for removing the metal-containing resist pattern so as to form a reversal pattern that is formed of the film for reversal pattern formation. The metal-containing resist forming material contains tin atoms, and the reversal pattern forming material contains silicon atoms.

Description

Semiconductor substrate manufacturing method and reverse pattern forming material

[0001] The present invention relates to a method for manufacturing a semiconductor substrate and a reversal pattern forming material.

[0002] 2. Description of the Related Art A widely used technique for manufacturing semiconductor substrates is to form a resist pattern on a substrate and then process the substrate by etching using this pattern as a mask.

[0003] In recent years, semiconductor devices have become increasingly highly integrated, and the exposure light used has tended to be shorter in wavelength, moving from KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) to extreme ultraviolet (13.5 nm, hereinafter also referred to as "EUV").

[0004] A technique has been proposed in which a metal oxide-containing hard mask is used as a material for forming the resist pattern (see JP 2017-116923 A).

[0005] Japanese Patent Application Laid-Open No. 2017-116923

[0006] As the line width of metal-containing resist patterns formed through exposure to extreme ultraviolet rays and the like continues to become finer, there is a demand for pattern rectangularity to ensure the rectangularity of the resist pattern and for suppression of resist pattern collapse, and there is a need for technologies that can achieve further miniaturization.

[0007] An object of the present invention is to provide a method for producing a semiconductor substrate and a material for forming a reversal pattern, which are capable of improving the etching resistance and rectangularity of a reversal pattern of a metal-containing resist pattern.

[0008] As a result of extensive research into solving the above problems, the present inventors have found that the above object can be achieved by employing the following configuration, and have thus completed the present invention.

[0009] In one embodiment, the present invention relates to a method for manufacturing a semiconductor substrate, comprising: a step of forming a metal-containing resist film directly or indirectly on a substrate using a metal-containing resist forming material; a step of exposing the metal-containing resist film to extreme ultraviolet light; a step of developing the exposed metal-containing resist film; a step of forming a reversal pattern forming film on the metal-containing resist pattern formed by the developing step using a reversal pattern forming material; and a step of removing the metal-containing resist pattern to form a reversal pattern formed by the reversal pattern forming film, wherein the metal-containing resist forming material contains tin atoms, and the reversal pattern forming material contains silicon atoms.

[0010] In another embodiment, the present invention relates to a reversal pattern forming material to be embedded in a metal-containing resist pattern, wherein the metal-containing resist pattern contains tin atoms, and the reversal pattern forming material contains silicon atoms.

[0011] The semiconductor substrate manufacturing method and reversal pattern forming material of the present invention provide a reversal pattern corresponding to a metal-containing resist pattern, which has excellent etching resistance and rectangularity. Therefore, they can be suitably used in the manufacture of semiconductor devices, which are expected to become even more miniaturized in the future.

[0012] FIG. 1 is a schematic diagram illustrating a method for forming a reversal pattern according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a method for forming a reversal pattern according to one embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a method for forming a reversal pattern according to one embodiment of the present invention. FIG. 4 is a schematic diagram illustrating a method for forming a reversal pattern according to one embodiment of the present invention. FIG. 5 is a schematic diagram illustrating a method for forming a reversal pattern according to one embodiment of the present invention.

[0013] Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments. Combinations of preferred embodiments are also preferred.

[0014] <<Method for Manufacturing Semiconductor Substrate>> A method for manufacturing a semiconductor substrate according to this embodiment includes the steps of: forming a metal-containing resist film directly or indirectly on a substrate using a metal-containing resist-forming material (hereinafter also referred to as a “metal-containing resist film-forming step”); exposing the metal-containing resist film to extreme ultraviolet light (hereinafter also referred to as an “exposure step”); developing the exposed metal-containing resist film (hereinafter also referred to as a “developing step”); forming a reversal pattern-forming film on the metal-containing resist pattern formed by the developing step using a reversal pattern-forming material (hereinafter also referred to as a “reversal pattern-forming film-forming step”); and removing the metal-containing resist pattern to form a reversal pattern formed by the reversal pattern-forming film (hereinafter also referred to as a “reversal pattern forming step”).

[0015] The method for manufacturing a semiconductor substrate may further include, as necessary, a step of forming an organic underlayer film directly or indirectly on the substrate (hereinafter also referred to as an "organic underlayer film forming step") prior to the metal-containing resist film forming step.

[0016] A representative example of a method for forming a reverse pattern according to this embodiment will be described below with reference to the drawings. Figures 1A to 1F are schematic diagrams illustrating a method for forming a reverse pattern according to one embodiment of the present invention. Details of each step, including the optional organic underlayer film formation step, will be described later.

[0017] As shown in FIG. 1A , in a metal-containing resist film forming step, a metal-containing resist film 10 is formed on a substrate 1 using a metal-containing resist forming material. In FIG. 1A , the metal-containing resist film 10 is formed directly on the substrate 1. Next, as shown in FIG. 1B , in an exposure step, predetermined regions of the metal-containing resist film 1 are exposed to extreme ultraviolet light (indicated by arrows in the figure). Thereafter, as shown in FIG. 1C , in a development step, the exposed metal-containing resist film 10 (see FIG. 1B ) is developed to form a metal-containing resist pattern 11. The metal-containing resist pattern 11 shown in FIG. 1C is a negative pattern in which unexposed portions of the metal-containing resist film 10 have been removed by development.

[0018] Next, as shown in Fig. 1D, in the reversal pattern formation film formation step, a reversal pattern formation film 20 is formed from a reversal pattern formation material on the metal-containing resist pattern 11 formed in the development step. The average thickness of the reversal pattern formation film 20 is greater than the height of the metal-containing resist pattern 11. As a result, in Fig. 1D, the reversal pattern formation material fills the gaps between the metal-containing resist patterns 11, and the top surface of the metal-containing resist pattern 11 is covered with the reversal pattern formation material.

[0019] Next, as shown in Figure 1E, an exposure step is performed in which the upper surface of the reversal pattern formation film 20 is removed to expose the upper surface of the metal-containing resist pattern 11. If the average thickness of the reversal pattern formation film 20 is the same as or smaller than the height of the metal-containing resist pattern 11, the exposure step is unnecessary. Finally, as shown in Figure 1F, in the reversal pattern formation step, the metal-containing resist pattern 11 is removed by etching or the like to form a reversal pattern 21 formed by the reversal pattern formation film 20. As a result of the above, a reversal pattern 21 having a shape complementary to that of the metal-containing resist pattern 11 can be formed.

[0020] [Organic Underlayer Film Formation Step] In this step, prior to the metal-containing resist film formation step, an organic underlayer film is formed directly or indirectly on the substrate 1 (not shown). This step is an optional step. By this step, an organic underlayer film is formed directly or indirectly on the substrate.

[0021] Examples of the substrate 1 include insulating films such as silicon oxide, silicon nitride, titanium oxide, titanium nitride, silicon oxynitride, and polysiloxane, as well as resin substrates. Commercially available interlayer insulating films include wafers coated with low-dielectric insulating films such as AMAT's "Black Diamond," Dow Chemical's "Silk," and JSR's "LKD5109." This substrate may also be patterned with wiring trenches, plug grooves (vias), and the like.

[0022] The organic underlayer film can be formed by coating an organic underlayer film-forming composition, etc. Examples of methods for forming an organic underlayer film by coating an organic underlayer film-forming composition include a method in which the organic underlayer film-forming composition is directly or indirectly applied to a substrate, and the resulting coating film is heated or exposed to light to cure it. Examples of the organic underlayer film-forming composition that can be used include "HM8006" manufactured by JSR Corporation. The heating and exposure conditions can be appropriately determined depending on the type of organic underlayer film-forming composition used, etc.

[0023] An example of a case where an organic underlayer film is formed indirectly on a substrate is a case where an organic underlayer film is formed on a low dielectric insulating film formed on a substrate.

[0024] [Metal-containing resist film forming process] In this process, a metal-containing resist film 10 is formed on a substrate 1 using a metal-containing resist forming material (see FIG. 1A). The metal-containing resist forming material used in this process contains tin atoms. The metal-containing resist film 10 may be either a coated film or a deposited film. Below, a description is given of a metal-containing resist forming material that forms a coated film (hereinafter also referred to as a "first metal-containing resist forming material") and a metal-containing resist forming material that forms a deposited film (hereinafter also referred to as a "second metal-containing resist forming material").

[0025] <First Metal-Containing Resist Forming Material> The first metal-containing resist forming material preferably contains a metal-containing compound (A) containing a tin atom and a solvent. The first metal-containing resist forming material may further contain other components.

[0026] (Metal-Containing Compound (A)) The metal-containing compound (A) is a compound containing a tin atom. The metal-containing compound (A) can be used alone or in combination of two or more. The metal atom constituting the metal-containing compound (A) can be a tin atom alone or a tin atom and two or more other metal atoms in combination. Here, the term "metal atom" refers to a concept including metalloids, i.e., boron, silicon, germanium, arsenic, antimony, and tellurium.

[0027] The other metal atoms constituting the metal-containing compound (A) are not particularly limited, and examples thereof include metal atoms of Groups 3 to 16. Specific examples of the metal atoms include metal atoms of Group 4 such as titanium, zirconium, and hafnium, metal atoms of Group 5 such as tantalum, metal atoms of Group 6 such as chromium and tungsten, metal atoms of Group 8 such as iron and ruthenium, metal atoms of Group 9 such as cobalt, metal atoms of Group 10 such as nickel, metal atoms of Group 11 such as copper, metal atoms of Group 12 such as zinc, cadmium, and mercury, metal atoms of Group 13 such as boron, aluminum, gallium, indium, and thallium, metal atoms of Group 14 such as germanium and lead, metal atoms of Group 15 such as antimony and bismuth, and metal atoms of Group 16 such as tellurium.

[0028] The metal-containing compound (A) preferably further contains other atoms other than tin atoms.The other atoms include, for example, carbon atoms, hydrogen atoms, oxygen atoms, nitrogen atoms, phosphorus atoms, sulfur atoms, halogen atoms, etc., and among these, carbon atoms, hydrogen atoms, and oxygen atoms are preferred.The other atoms in the metal-containing compound (A) can be used alone or in combination of two or more.

[0029] The lower limit of the content of the metal-containing compound (A) in the components other than the solvent in the first metal-containing resist forming material is preferably 50% by mass, more preferably 70% by mass, even more preferably 90% by mass, and particularly preferably 95% by mass. The content may also be 100% by mass.

[0030] (Method for synthesizing metal-containing compound (A)) The metal-containing compound (A) can be obtained by, for example, subjecting a metal compound having a tin atom and a hydrolyzable group, a hydrolyzate of this metal compound, a hydrolyzed condensate of the metal compound, or a combination thereof to a hydrolysis condensation reaction, a ligand exchange reaction, or the like. The above metal compounds can be used alone or in combination of two or more.

[0031] The metal-containing compound (A) is preferably derived from a metal compound having a tin atom and a hydrolyzable group represented by the following formula (4) (hereinafter also referred to as "metal compound (1)"). By using such metal compound (1), a stable metal-containing compound (A) can be obtained.

[0032] In the above formula (4), M is a tin atom. １ is a ligand or a monovalent organic group having 1 to 20 carbon atoms. a1 is an integer of 0 to 6. When a1 is 2 or more, a plurality of L １ may be the same or different. Y is a monovalent hydrolyzable group. b1 is an integer of 2 to 6. Multiple Ys may be the same or different. １ is a ligand or organic group that does not fall under Y.

[0033] The hydrolyzable group represented by Y can be appropriately changed depending on the metal atom represented by M, and examples thereof include a substituted or unsubstituted ethynyl group, a halogen atom, an alkoxy group, an acyloxy group, and a substituted or unsubstituted amino group.

[0034] The substituent in the substituted or unsubstituted ethynyl group and the substituted or unsubstituted amino group represented by Y is preferably a monovalent hydrocarbon group having 1 to 20 carbon atoms, more preferably a chain hydrocarbon group, and still more preferably an alkyl group.

[0035] Examples of the halogen atom represented by Y include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Among these, a chlorine atom is preferred.

[0036] Examples of the alkoxy group represented by Y include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, etc. Among these, an ethoxy group, an i-propoxy group, and an n-butoxy group are preferred.

[0037] Examples of the acyloxy group represented by Y include a formyl group, an acetoxy group, an ethyryloxy group, a propionyloxy group, an n-butyryloxy group, a t-butyryloxy group, a t-amylyloxy group, an n-hexanecarbonyloxy group, an n-octanecarbonyloxy group, etc. Among these, an acetoxy group is preferred.

[0038] Examples of the substituted or unsubstituted amino group represented by Y include an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dipropylamino group, etc. Among these, a dimethylamino group and a diethylamino group are preferred.

[0039] The hydrolyzable group represented by Y is preferably a substituted or unsubstituted ethynyl group, a halogen atom, an alkoxy group, an acyloxy group, or a substituted or unsubstituted amino group, and more preferably a halogen atom.

[0040] L １ The ligand represented by the formula (I) includes a monodentate ligand and a polydentate ligand.

[0041] Examples of the monodentate ligand include a hydroxo ligand, a nitro ligand, and ammonia.

[0042] Examples of the polydentate ligand include hydroxy acid esters, β-diketones, β-ketoesters, malonic acid diesters in which the carbon atom at the α-position may be substituted, and hydrocarbons having a π bond, or ligands derived from these compounds, and diphosphines.

[0043] Examples of the diphosphines include 1,1-bis(diphenylphosphino)methane, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl, and 1,1'-bis(diphenylphosphino)ferrocene.

[0044] L １Examples of the monovalent organic group represented by the formula (I) include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group containing a divalent heteroatom-containing linking group between carbon atoms of the hydrocarbon group (hereinafter also referred to as "group (α)"), a group in which some or all of the hydrogen atoms in the hydrocarbon group or the group (α) have been substituted with monovalent heteroatom-containing substituents (hereinafter also referred to as "group (β)"), and a group comprising a combination of at least two of the hydrocarbon group, the group (α) and the group (β) (hereinafter also referred to as "group (γ)").

[0045] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0046] Examples of the monovalent chain aliphatic hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms and a monovalent chain aliphatic unsaturated hydrocarbon group having 1 to 20 carbon atoms. Examples of the monovalent chain aliphatic saturated hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, and a tert-butyl group. Examples of the monovalent chain aliphatic unsaturated hydrocarbon group having 1 to 20 carbon atoms include alkenyl groups such as an ethenyl group, a propenyl group, and a butenyl group; and alkynyl groups such as an ethynyl group, a propynyl group, and a butynyl group.

[0047] Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic alicyclic saturated hydrocarbon groups such as a cyclopentyl group and a cyclohexyl group; polycyclic alicyclic saturated hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group and a tetracyclododecyl group; monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group and a cyclohexenyl group; and polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group, a tricyclodecenyl group and a tetracyclododecenyl group.

[0048] Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthryl groups, and aralkyl groups such as benzyl, phenethyl, naphthylmethyl, and anthrylmethyl groups.

[0049] Examples of heteroatoms constituting the divalent heteroatom-containing linking group and the monovalent heteroatom-containing substituent include oxygen, nitrogen, sulfur, phosphorus, silicon, and halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms (in this specification, unless otherwise specified, the term "halogen atom" includes these atoms).

[0050] Examples of the divalent heteroatom-containing linking group include —O—, —C(═O)—, —S—, —C(═S)—, —NR′—, and —SO ２ -, a group formed by combining two or more of these, etc. R' is a hydrogen atom or a monovalent hydrocarbon group.

[0051] Examples of the monovalent hetero atom-containing substituent include a halogen atom, a hydroxy group, a carboxy group, a cyano group, an amino group, and a sulfanyl group.

[0052] L １ The lower limit of the number of carbon atoms of the monovalent organic group represented by the formula (I) is preferably 2, more preferably 3. On the other hand, the upper limit of the number of carbon atoms is preferably 10, more preferably 5. １ The monovalent organic group represented by the formula (I) is preferably a substituted or unsubstituted hydrocarbon group, more preferably a substituted or unsubstituted chain hydrocarbon group or a substituted or unsubstituted aromatic hydrocarbon group, further preferably a substituted or unsubstituted alkyl group or a substituted or unsubstituted aralkyl group, and particularly preferably an isopropyl group or a benzyl group.

[0053] As a1, 1 and 2 are preferred, and 1 is more preferred.

[0054] b1 is preferably an integer of 2 to 4. By setting b1 to the above-mentioned value, the content of metal atoms in the metal-containing compound (A) can be increased, and the generation of secondary electrons by the metal-containing compound (A) can be more effectively promoted. As a result, the pattern rectangularity can be improved.

[0055] As the metal compound (1), a tin halide compound is preferred, and isopropyltin trichloride or benzyltin trichloride is more preferred.

[0056] Examples of methods for carrying out the hydrolysis condensation reaction of metal compound (1) include stirring metal compound (1) in water or a solvent containing water in the presence of a base such as tetramethylammonium hydroxide, which is used as needed. In this case, other compounds having hydrolyzable groups may be added as needed. The lower limit of the amount of water used in this hydrolysis condensation reaction is preferably 0.2 times by mole, more preferably 1 time by mole, and even more preferably 3 times by mole, relative to the hydrolyzable groups of metal compound (1) or the like. By setting the amount of water in the hydrolysis condensation reaction within the above range, metal-containing compound (A) can be obtained efficiently.

[0057] In the synthesis reaction of the metal-containing compound (A), in addition to the metal compound (1), L in the compound of the above formula (4) １ Alternatively, a compound capable of becoming a multidentate ligand represented by the formula (I) or a compound capable of becoming a bridging ligand may be added. Examples of the compound capable of becoming a bridging ligand include compounds having two or more coordinating groups such as a hydroxy group, an isocyanate group, an amino group, an ester group, and an amide group.

[0058] The lower limit of the temperature for the synthesis reaction of the metal-containing compound (A) is preferably 0° C., more preferably 10° C. The upper limit of the temperature is preferably 150° C., more preferably 100° C., and even more preferably 50° C.

[0059] The lower limit of the synthesis reaction time of the metal-containing compound (A) is preferably 1 minute, more preferably 10 minutes, and even more preferably 1 hour. The upper limit of the synthesis reaction time is preferably 100 hours, more preferably 50 hours, even more preferably 24 hours, and particularly preferably 4 hours.

[0060] (Solvent) Examples of the solvent include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, nitrogen-containing solvents, water, etc. The solvents may be used alone or in combination of two or more.

[0061] Examples of alcohol solvents include monoalcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol, and polyalcohol solvents such as ethylene glycol, 1,2-propylene glycol, diethylene glycol, and dipropylene glycol.

[0062] Examples of ketone solvents include acetone, 2-butanone, 2-pentanone, 4-methyl-2-pentanone, 2-heptanone, and cyclohexanone.

[0063] Examples of ether solvents include ethyl ether, isopropyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and tetrahydrofuran.

[0064] Examples of ester solvents include ethyl acetate, γ-butyrolactone, n-butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, ethyl propionate, n-butyl propionate, methyl lactate, and ethyl lactate.

[0065] Examples of nitrogen-containing solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0066] The solvent is preferably an ether solvent, more preferably propylene glycol monoethyl ether.

[0067] (Other Optional Components) The metal-containing resist forming material may contain other optional components such as a compound that can act as a ligand, a surfactant, and the like, in addition to the metal-containing compound (A) and the solvent.

[0068] (Compound that can be a ligand) Examples of the compound that can be a ligand include compounds that can be polydentate ligands or bridging ligands, and specific examples include the same compounds that can be polydentate ligands or bridging ligands as exemplified in the synthesis method for the metal-containing compound (A).

[0069] (Surfactant) The surfactant is a component that acts to improve the coatability, striations, etc. Examples of the surfactant include nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate, as well as commercial surfactants such as KP341 (Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, and Polyflow No. 85 (Shin-Etsu Chemical Co., Ltd.). 95 (all manufactured by Kyoeisha Chemical Co., Ltd.), F-Top EF301, EF303, EF352 (all manufactured by Tochem Products Co., Ltd.), Megafac F171, F173 (all manufactured by Dainippon Ink and Chemicals, Inc.), Fluorad FC430, FC431 (all manufactured by Sumitomo 3M Limited), Asahiguard AG710, Surflon S-382, Surflon SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (all manufactured by Asahi Glass Co., Ltd.), and the like.

[0070] (Method for preparing first metal-containing resist-forming material) The first metal-containing resist-forming material can be prepared, for example, by mixing the metal-containing compound (A), a solvent, and, if necessary, other optional components in a predetermined ratio, and preferably filtering the resulting mixture through a membrane filter having a pore size of 0.4 μm or less.

[0071] <Method of Forming a Coating Film Using First Metal-Containing Resist-Forming Material> The method of applying the first metal-containing resist-forming material is not particularly limited, and examples thereof include a rotary coating method.

[0072] To explain this process in more detail, for example, a first metal-containing resist forming material is applied so that the metal-containing resist film to be formed has a predetermined thickness, and then the applied film is pre-baked (hereinafter also referred to as "PB") to volatilize the solvent in the applied film, thereby forming the metal-containing resist film 10.

[0073] The PB temperature and PB time can be appropriately determined depending on the type of the first metal-containing resist-forming material used, etc. The lower limit of the PB temperature is preferably 30°C, more preferably 50°C. The upper limit of the PB temperature is preferably 200°C, more preferably 150°C. The lower limit of the PB time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the PB time is preferably 600 seconds, more preferably 300 seconds.

[0074] <Second Metal-Containing Resist Forming Material and Method for Forming Deposited Film> The second metal-containing resist forming material contains a metal-containing compound (B) containing tin atoms. In this embodiment, the metal-containing resist film 10 is formed by depositing the metal-containing compound (B). The metal-containing resist film 10 is preferably a tin oxide film.

[0075] The deposition is preferably by chemical vapor deposition (CVD) or atomic layer deposition (ALD). Typically, a substrate is provided in a process chamber and sequentially exposed to a tin-containing precursor as the metal-containing compound (B) and an oxygen-containing reactant, which react on the substrate surface to form SnO ２ is formed. To prevent reaction in the bulk of the process chamber, the process chamber is typically purged with an inert gas after the substrate is exposed to the tin-containing precursor and before the oxygen-containing reactant is introduced into the process chamber. Additionally, the process chamber is typically purged with an inert gas after the substrate is treated with the oxygen-containing reactant. Successive exposures are repeated in several cycles, e.g., about 10 to 100 cycles, until a tin oxide layer having a desired thickness is deposited.

[0076] Examples of tin-containing precursors suitable as the metal-containing compound (B) include halide tin-containing precursors (e.g., SnCl ４ , SnBr ４ Non-halogenated tin-containing precursors include organotin compounds, including alkyl-substituted tin amides, and the like. Specific examples of suitable alkyl-substituted tin amides are tetrakis(dimethylamino)tin, tetrakis(ethylmethylamino)tin, and (1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene). Oxygen-containing reactants include, without limitation, oxygen, ozone, water, hydrogen peroxide, and NO. Mixtures of oxygen-containing reactants can also be used.

[0077] Deposition conditions vary depending on the choice of reactants, with more reactive precursors generally reacting at lower temperatures than less reactive precursors. The process is typically carried out at temperatures between about 20 and 500°C and at pressures below atmospheric pressure. To avoid condensation, the temperature and pressure are selected so that the reactants remain gaseous within the process chamber. Each reactant is supplied to the process chamber in a gaseous state, either alone or mixed with a carrier gas such as argon, helium, or nitrogen. The flow rates of these mixtures will depend on the size of the process chamber and are in some embodiments between about 10 and 10,000 sccm.

[0078] As an example, the ALD process involves treating a substrate with SnCl in an ALD vacuum chamber. ４ (tin-containing precursor), and deionized water (oxygen-containing reactant) at temperatures between 200 and 400° C. A specific example of an ALD cycle involves sequential and alternating exposure to SnCl ４ Steam and N ２ The carrier gas mixture is introduced into the ALD process chamber for 0.5 seconds and then exposed to the substrate 1 for 3 seconds. The ALD process chamber is then filled with N ２ for 10 seconds to remove SnCl from the bulk of the process chamber. ４ Remove H ２ O vapor and N ２The carrier gas mixture is flowed into the process chamber for 1 second and exposed to the substrate 1 for 3 seconds. The ALD process chamber is then filled with N ２ The ALD process is carried out at subatmospheric pressure (eg, 0.4 Torr) and at temperatures between 200 and 400°C.

[0079] While tin halide precursors are preferred in many embodiments, in some embodiments, SnCl ４ It is more preferable to use non-halogenated organotin precursors to avoid corrosion problems that can arise from the use of halogenated precursors such as . Examples of suitable non-halogenated organotin precursors include alkylaminotin (alkylated tin amide) precursors such as tetrakis(dimethylamino)tin. In one example of an ALD process, a substrate is heated in an ALD chamber at a temperature of about 50-300°C with tetrakis(dimethylamino)tin and H ２ O ２ Advantageously, the use of this precursor allows for the formation of SnO at low temperatures below 100°C. ２ For example, SnO films can be deposited at 50°C without using plasma to enhance the reaction rate. ２ A film can be deposited.

[0080] In some embodiments, SnO ２The film is deposited by plasma-enhanced ALD (PEALD). The same types of tin-containing precursors and oxygen-containing reactants can be used. In PEALD, the ALD apparatus is equipped with a system for generating a plasma in the process chamber and for treating the substrate with the plasma. In a typical PEALD process sequence, a substrate is provided in the PEALD process chamber and exposed to a tin-containing precursor, which adsorbs to the surface of the substrate. To remove the precursor from the process chamber, the process chamber is purged with an inert gas (e.g., argon or helium), and the substrate is exposed to an oxygen-containing reactant introduced into the process chamber. Simultaneously with the introduction of the oxygen-containing reactant, or after a delay, a plasma is formed in the process chamber. The plasma promotes a reaction between the tin-containing precursor and the oxygen-containing reactant on the surface of the substrate, resulting in the formation of tin oxide. The process chamber is then purged with an inert gas, and a cycle including tin precursor injection, purging, oxygen-containing reactant injection, plasma treatment, and a second purge is repeated as many times as necessary to form a tin oxide film of the desired thickness.

[0081] The average thickness of the metal-containing resist film 10 is not particularly limited. Whether it is a coated film or a deposited film, the lower limit of the average thickness of the metal-containing resist film 10 is preferably 5 nm, more preferably 10 nm, even more preferably 15 nm, and particularly preferably 20 nm. The upper limit of the average thickness is preferably 100 nm, more preferably 80 nm, even more preferably 60 nm, and particularly preferably 40 nm.

[0082] [Exposure Step] In this step, the metal-containing resist film 10 is exposed to extreme ultraviolet light (wavelength 13.5 nm, etc., also referred to as "EUV") (see FIG. 1B). This step causes a difference in the physical properties of the metal-containing resist film 10 between the exposed and unexposed areas of the metal-containing resist film 10. The exposure conditions can be appropriately determined depending on the type of metal-containing resist-forming material used, etc.

[0083] Furthermore, in this process, after the exposure, post-exposure baking (hereinafter also referred to as "PEB") can be performed to improve the performance of the resist film, such as resolution, pattern profile, and developability. The PEB temperature and PEB time can be appropriately determined depending on the type of resist film-forming composition used, etc. The lower limit of the PEB temperature is preferably 50°C, more preferably 70°C. The upper limit of the PEB temperature is preferably 200°C, more preferably 150°C. The lower limit of the PEB time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the PEB time is preferably 600 seconds, more preferably 300 seconds.

[0084] [Development Step] In this step, the exposed metal-containing resist film 10 is developed (see FIG. 1C). Development may involve volatilization of the metal-containing resist film 10 by heating or reducing pressure, or dissolution in a developer. When a developer is used for this development, examples of the developer include an alkaline aqueous solution (alkaline developer) and an organic solvent-containing solution (organic solvent developer). For example, in the case of a positive-tone resist film using an alkaline developer, the solubility of the exposed portions of the metal-containing resist film 10 in an alkaline aqueous solution is increased, and thus the exposed portions are removed by alkaline development to form a positive-tone metal-containing resist pattern. In the case of a negative-tone resist film using an organic solvent developer, the solubility of the exposed portions of the metal-containing resist film 10 in an organic solvent is reduced, and thus the unexposed portions, which are relatively more soluble in organic solvents, are removed by organic solvent development to form a negative-tone metal-containing resist pattern 11 (see FIG. 1C).

[0085] Examples of the shape of the metal-containing resist pattern 11 include a trench pattern, a line-and-space pattern, a hole pattern, and a pillar pattern. Examples of the trench pattern and the line-and-space pattern include a pattern including a recess having a width of 5 nm to 100 nm, and a pattern including a recess having a depth of 1 nm to 100 nm. Examples of the hole pattern include a pattern including a hole having a diameter of 5 nm to 100 nm, and a pattern including a hole having a depth of 1 nm to 100 nm. Examples of the pillar pattern include a pattern including a pillar having a width of 5 nm to 100 nm, and a pattern including a pillar having a height of 1 nm to 100 nm.

[0086] The developer used in alkaline development is not particularly limited, and known developers can be used. Examples of developers for alkaline development include alkaline aqueous solutions in which at least one alkaline compound such as 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, and 1,5-diazabicyclo-[4.3.0]-5-nonene is dissolved. Among these, a TMAH aqueous solution is preferred, and a 2.38 mass % TMAH aqueous solution is more preferred.

[0087] When organic solvent development is performed, examples of the developer include the same solvents as those exemplified for the metal-containing resist-forming material described above. As the organic solvent, ketone-based solvents and ester-based solvents are preferred, and 2-heptanone and propylene glycol monomethyl ether acetate are more preferred.

[0088] The development of the exposed metal-containing resist film is preferably an organic solvent development.

[0089] Examples of development methods include a method of immersing a film-coated substrate in a tank filled with a developer for a certain period of time (dip method), a method of developing by piling up a developer on the surface of the substrate by surface tension and leaving it to stand for a certain period of time (puddle method), a method of spraying a developer onto the surface of the substrate (spray method), and a method of continuously discharging developer while scanning a developer discharge nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispense method).

[0090] In this step, washing and / or drying may be carried out after the development.

[0091] [Reverse Pattern Forming Film Forming Step] In this step, a reverse pattern forming film 20 is formed on the metal-containing resist pattern 11 formed in the developing step using a reversal pattern forming material (see FIG. 1D). The reversal pattern forming film 20 is preferably a coated film. Coating methods include spin coating, casting coating, and roll coating. Coating of the reversal pattern forming material may be performed during the washing step after the developing step.

[0092] <Reverse pattern forming material> The reverse pattern forming material contains silicon atoms. Although the form in which the reverse pattern forming material contains silicon atoms is not particularly limited, it is preferable that the reverse pattern forming material contains a silicon-containing compound containing silicon atoms. Such a silicon-containing compound is a compound that can reduce the etching rate R of the reverse pattern formed by the reverse pattern forming material. Ｒ The etching rate R of the metal-containing resist pattern Ｍ Ratio to Ｒ / R Ｍ ) is preferably 0.5 or less.

[0093] The reverse pattern forming material preferably contains polysiloxane or polycarbosilane as the silicon-containing compound. The reverse pattern forming material preferably contains a solvent. Other optional components may be contained within a range that does not impair the effects of the present invention.

[0094] (Polysiloxane) When the silicon-containing compound is a polysiloxane, the polysiloxane preferably has a structural unit represented by the following formula (2-1) (hereinafter also referred to as "structural unit (2-1)"). The polysiloxane may have one or more types of structural unit (2-1). (In the above formula (2-1), R １２ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrogen atom. e is an integer of 1 to 3. When e is 2 or more, multiple R １２ are the same or different.)

[0095] R １２ Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a combination thereof.

[0096] Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, isobutyl, and tert-butyl; alkenyl groups such as ethenyl, propenyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.

[0097] Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic alicyclic saturated hydrocarbon groups such as a cyclopentyl group and a cyclohexyl group; polycyclic alicyclic saturated hydrocarbon groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group and a tetracyclododecyl group; monocyclic alicyclic unsaturated hydrocarbon groups such as a cyclopentenyl group and a cyclohexenyl group; and polycyclic alicyclic unsaturated hydrocarbon groups such as a norbornenyl group, a tricyclodecenyl group and a tetracyclododecenyl group.

[0098] Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthryl groups, and aralkyl groups such as benzyl, phenethyl, naphthylmethyl, and anthrylmethyl groups.

[0099] R１２ When has a substituent, examples of the substituent include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, an alkoxy group such as a methoxy group, an ethoxy group, or a propoxy group, an alkoxycarbonyl group such as a methoxycarbonyl group or an ethoxycarbonyl group, an alkoxycarbonyloxy group such as a methoxycarbonyloxy group or an ethoxycarbonyloxy group, an acyl group such as a formyl group, an acetyl group, a propionyl group, or a butyryl group, a cyano group, a nitro group, and an amino group.

[0100] R １２ The monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably a monovalent chain hydrocarbon group having 1 to 6 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 10 carbon atoms. Of these, an alkyl or alkenyl group having 1 to 5 carbon atoms is preferred. As the substituent for these groups, a halogen atom is preferred, and a fluorine atom or an iodine atom is more preferred.

[0101] e is preferably 1 or 2, and more preferably 1.

[0102] When the polysiloxane has the structural unit (2-1), the lower limit of the content of the structural unit (2-1) relative to all structural units constituting the polysiloxane is preferably 2 mol %, more preferably 5 mol %, and even more preferably 8 mol %, and the upper limit of the content of the structural unit (2-1) may be 100 mol %, 80 mol %, or 50 mol %.

[0103] The polysiloxane preferably has a structural unit represented by the following formula (2-2) (hereinafter also referred to as "structural unit (2-2)").

[0104] When the polysiloxane has the structural unit (2-2), the lower limit of the content of the structural unit (2-2) relative to all structural units constituting the polysiloxane is preferably 10 mol%, more preferably 20 mol%, and even more preferably 25 mol%, and the upper limit of the content of the structural unit (2-1) may be 100 mol%, preferably 96 mol%, and more preferably 92 mol%.

[0105] (Polycarbosilane) When the silicon-containing compound is polycarbosilane, the polycarbosilane preferably has a structural unit represented by the following formula (3-1) (hereinafter also referred to as "structural unit (3-1)"). The polycarbosilane may have one or more types of structural unit (3-1). (In formula (3-1), R ３１ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrogen atom. h is 1 or 2. When h is 2, two R ３１ are the same or different. ３２ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms bonded to two silicon atoms. q is an integer of 1 to 3. When q is 2 or more, multiple R ３２ are the same or different, provided that h+q is 4 or less.

[0106] R ３１ The monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the formula (2-1) is R １２ A monovalent hydrocarbon group having 1 to 20 carbon atoms and represented by the following formula can be suitably used.

[0107] R ３１ When R has a substituent, the substituent may be any of the above-mentioned R １２ The substituents that may be possessed by the group may be suitably employed.

[0108] R ３１is preferably a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, and more preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms. Monovalent groups in which some or all of the hydrogen atoms of these groups have been substituted with halogen atoms are also preferred. As the halogen atom, a fluorine atom or an iodine atom is preferred.

[0109] R ３２ Examples of the substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms and bonded to two silicon atoms include a substituted or unsubstituted divalent chain hydrocarbon group having 1 to 20 carbon atoms, a substituted or unsubstituted divalent aliphatic cyclic hydrocarbon group having 3 to 20 carbon atoms, and a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0110] Examples of unsubstituted divalent chain hydrocarbon groups having 1 to 20 carbon atoms include chain saturated hydrocarbon groups such as methanediyl group and ethanediyl group, and chain unsaturated hydrocarbon groups such as ethenediyl group and propenediyl group.

[0111] Examples of the unsubstituted divalent aliphatic cyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic saturated hydrocarbon groups such as a cyclobutanediyl group, monocyclic unsaturated hydrocarbon groups such as a cyclobutenediyl group, polycyclic saturated hydrocarbon groups such as a bicyclo[2.2.1]heptanediyl group, and polycyclic unsaturated hydrocarbon groups such as a bicyclo[2.2.1]heptenediyl group.

[0112] Examples of the unsubstituted divalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenylene group, a biphenylene group, a phenyleneethylene group, and a naphthylene group.

[0113] R ３２ Examples of the substituent in the substituted divalent hydrocarbon group having 1 to 20 carbon atoms represented by the formula (I) include a halogen atom, a hydroxy group, a cyano group, a nitro group, an alkoxy group, an acyl group, and an acyloxy group.

[0114] R ３２ As the alkyl group, an unsubstituted chain saturated hydrocarbon group is preferred, and a methanediyl group or an ethanediyl group is more preferred.

[0115] h is preferably 1. q is preferably 2 or 3.

[0116] The polycarbosilane has, as the structural unit (3-1), R ３１ is a hydrogen atom (hereinafter also referred to as "structural unit (3-1-a)"), and R ３１ and a structural unit (3-1-b) which is a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, or a monovalent group in which some or all of the hydrogen atoms in a monovalent hydrocarbon group have been substituted with halogen atoms.

[0117] When the polycarbosilane has the structural unit (3-1-a), the lower limit of the content of the structural unit (3-1-a) in all structural units constituting the polycarbosilane is preferably 5 mol %, more preferably 10 mol %, and even more preferably 20 mol %. The upper limit of the content of the structural unit (3-1-a) may be 100 mol %, but is preferably 90 mol %, and more preferably 80 mol %.

[0118] When the polycarbosilane has the structural unit (3-1-b), the lower limit of the content of the structural unit (3-1-b) in all structural units constituting the polycarbosilane is preferably 10 mol %, more preferably 20 mol %, and even more preferably 30 mol %. The upper limit of the content of the structural unit (3-1-b) may be 100 mol %, preferably 95 mol %, and more preferably 90 mol %.

[0119] The lower limit of the content of the silicon-containing compound is preferably 0.1% by mass, more preferably 0.5% by mass, even more preferably 1% by mass, and particularly preferably 1.5% by mass, based on the total components of the reverse pattern forming material. The upper limit of the content is preferably 10% by mass, more preferably 8% by mass, even more preferably 5% by mass, and particularly preferably 3% by mass.

[0120] The silicon-containing compound is preferably in the form of a polymer. "Polymer" refers to a compound having two or more structural units, and when two or more identical structural units are consecutive in a polymer, this structural unit is also referred to as a "structural unit". When the silicon-containing compound is in the form of a polymer, the lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of the silicon-containing compound measured by gel permeation chromatography (GPC) is preferably 800, more preferably 1,000, even more preferably 1,300, and particularly preferably 1,500. The upper limit of Mw is preferably 8,000, more preferably 6,000, even more preferably 4,000, and particularly preferably 3,000. The method for measuring Mw of the silicon-containing compound is as described in the Examples.

[0121] <Synthesis of the Silicon-Containing Compound> When the silicon-containing compound is a polysiloxane, it can be obtained, for example, by hydrolysis and condensation of one or more silane compounds to give the structural unit (2-1) or the structural unit (2-2). When the silicon-containing compound is a polycarbosilane, it can be obtained, for example, by hydrolysis and condensation of a polycarbosilane having one or more structural units (3-1), or by hydrolysis and condensation of a polycarbosilane having one or more structural units (3-1) with one or more silane compounds that give the structural unit (3-1). During either hydrolysis and condensation, other silane compounds may be added as necessary. The hydrolysis and condensation can be carried out in a solvent such as diisopropyl ether in the presence of a catalyst such as oxalic acid and water, and preferably by purifying the solution containing the resulting hydrolysis and condensation product via solvent substitution in the presence of a dehydrating agent such as an orthoester or molecular sieve. It is believed that each hydrolyzable silane monomer, regardless of type, is incorporated into the silicon-containing compound through a hydrolysis condensation reaction or the like, and the proportions of the structural unit (2-1), the structural unit (2-2), the structural unit (3-1), and other structural units contained in the synthesized silicon-containing compound are generally equivalent to the proportions of the amounts of the respective monomer compounds used in the synthesis reaction.

[0122] (Solvent) As the solvent contained in the reversal pattern forming material, the solvent contained in the first metal-containing resist forming material can be suitably used.

[0123] Among these, ether-based solvents, ester-based solvents, and water are preferred, and ether-based solvents and ester-based solvents having a glycol structure, and water are more preferred because of their excellent film-forming properties.

[0124] Examples of ether solvents and ester solvents having a glycol structure include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, etc. Among these, propylene glycol monomethyl ether acetate or propylene glycol monoethyl ether is preferred.

[0125] The content of the ether solvent and ester solvent having a glycol structure in the solvent is preferably 20% by mass or more, more preferably 60% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass.

[0126] The lower limit of the solvent content in the reverse pattern forming material is preferably 80% by mass, more preferably 85% by mass, even more preferably 90% by mass, and particularly preferably 95% by mass, and the upper limit of the solvent content is preferably 99.9% by mass, more preferably 99% by mass.

[0127] <Other Optional Components> Examples of the other optional components include acid generators, basic compounds (including base generators), orthoesters, radical generators, surfactants, colloidal silica, colloidal alumina, organic polymers, etc. The other optional components may be used either individually or in combination of two or more.

[0128] (Acid Generator) The acid generator is a component that generates an acid upon exposure to light or heating. When the reversal pattern forming material contains an acid generator, the condensation reaction of the compound (A) can be promoted even at relatively low temperatures (including room temperature).

[0129] Examples of acid generators that generate acid upon exposure to light (hereinafter also referred to as "photoacid generators") include the acid generators described in paragraphs

[0077] to

[0081] of JP-A No. 2004-168748, triphenylsulfonium trifluoromethanesulfonate, and compounds represented by the following formula:

[0130]

[0131] Examples of acid generators that generate acid upon heating (hereinafter also referred to as "thermal acid generators") include onium salt-based acid generators exemplified as photoacid generators in the above-mentioned patent documents, as well as 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and alkylsulfonates.

[0132] When the reverse pattern forming material contains an acid generator, the lower limit of the content of the acid generator is preferably 0.1 parts by mass, more preferably 1 part by mass, relative to 100 parts by mass of the silicon-containing compound, and the upper limit of the content of the acid generator is preferably 10 parts by mass, more preferably 6 parts by mass, relative to 100 parts by mass of the silicon-containing compound.

[0133] (Basic Compound) The basic compound promotes the curing reaction of the reversal pattern forming material, thereby improving the strength of the formed film. The basic compound also improves the removability of the film with an acidic solution. Examples of basic compounds include compounds having a basic amino group, and base generators that generate compounds having a basic amino group under the action of acid or heat. Examples of compounds having a basic amino group include amine compounds. Examples of base generators include amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds. Specific examples of amine compounds, amide group-containing compounds, urea compounds, and nitrogen-containing heterocyclic compounds include the compounds described in paragraphs

[0079] to

[0082] of JP 2016-27370 A.

[0134] When the reverse pattern forming material contains a basic compound, the lower limit of the content of the basic compound is preferably 0.1 parts by mass, more preferably 1 part by mass, relative to 100 parts by mass of the silicon-containing compound, and the upper limit of the content is preferably 10 parts by mass, more preferably 6 parts by mass.

[0135] (Orthoester) An orthoester is an ester of an orthocarboxylic acid. An orthoester reacts with water to give a carboxylic acid ester or the like. Examples of the orthoester include orthoformic acid esters such as methyl orthoformate, ethyl orthoformate, and propyl orthoformate; orthoacetic acid esters such as methyl orthoacetate, ethyl orthoacetate, and propyl orthoacetate; and orthopropionic acid esters such as methyl orthopropionate, ethyl orthopropionate, and propyl orthopropionate. Of these, orthoformic acid esters are preferred, and trimethyl orthoformate is more preferred.

[0136] When the reverse pattern forming material contains an orthoester, the lower limit of the orthoester content is preferably 5 parts by mass, more preferably 10 parts by mass, and even more preferably 12 parts by mass, relative to 100 parts by mass of the silicon-containing compound, and the upper limit of the content is preferably 30 parts by mass, more preferably 20 parts by mass, and even more preferably 18 parts by mass.

[0137] <Method for preparing reverse pattern forming material> The method for preparing the reverse pattern forming material is not particularly limited. For example, the reverse pattern forming material can be prepared by mixing a solution of the silicon-containing compound and a solvent with other optional components used as needed in a predetermined ratio, and preferably filtering the resulting mixed solution through a filter or the like having a pore size of 0.4 μm or less.

[0138] Although the average thickness of the reverse pattern forming film 20 is not particularly limited, the lower limit is preferably 10 nm or more, and more preferably 20 nm. The upper limit of the average thickness is preferably 1,000 nm, and more preferably 500 nm.

[0139] The average thickness (nm) of the reversal pattern formation film 20 is preferably greater than the height (nm) of the metal-containing resist pattern 11. This allows the upper surface of the metal-containing resist pattern 11 to be covered with the reversal pattern formation material while filling the gaps between the metal-containing resist patterns 11 with the reversal pattern formation material, thereby improving the flatness of the reversal pattern formation film 20.

[0140] Furthermore, this process may include a heating step of heating the formed reverse pattern formation film 20. The heating conditions are adjusted appropriately depending on the composition of the reverse pattern formation material, etc., but the lower limit of the heating temperature is preferably 80°C, more preferably 100°C. The upper limit of the heating temperature is preferably 280°C, more preferably 250°C. By setting the baking temperature within the above range, the removal step described below, particularly the removal processing by the wet etch-back method, can be carried out smoothly. The lower limit of the heating time is preferably 10 seconds, more preferably 20 seconds. The upper limit of the heating time is preferably 300 seconds, more preferably 180 seconds.

[0141] [Removal Step] In this step, the upper surface of the reversal pattern formation film 20 is removed so as to expose the upper surface of the metal-containing resist pattern 11 (see FIG. 1E ). As described above, this step is unnecessary when the average thickness of the reversal pattern formation film 20 is equal to or smaller than the height of the metal-containing resist pattern 11 and the upper surface of the metal-containing resist pattern 11 is exposed.

[0142] The removal method used in this step may be an etching method such as dry etch-back or wet etch-back, or a chemical mechanical polishing (CMP) method. ３ , C.F. ４ , C ２ F ６ , C ３ F ８ , S.F. ６ Dry etch-back or wet etch-back using a fluorine-based gas such as fluorine-containing gas is preferred because it is low cost. The removal treatment conditions in this step are not particularly limited and can be adjusted as appropriate.

[0143] [Reverse Pattern Forming Step] In this step, the metal-containing resist pattern 11 is removed, and a reverse pattern 21 formed by the reversal pattern forming film 20 is formed (see FIG. 1F).

[0144] The method for removing the metal-containing resist pattern 11 is not particularly limited, and examples thereof include etching and dissolution, but etching is preferred. As for the etching conditions, the etching rate R of the reverse pattern 21 is Ｒ The etching rate R of the metal-containing resist pattern 11 Ｍ Ratio to Ｒ / R Ｍ ) is preferably 0.5 or less, more preferably 0.4 or less, and even more preferably 0.3 or less.

[0145] The metal-containing resist pattern 11 is removed by H ２ , HBr, NH ３ , H ２ O, hydrocarbons, Cl ２ and BCl ３ It is preferable to perform etching using at least one plasma activated reactant selected from the group consisting of: (a) and (b) above. This allows the above etching rate ratio to be suitably achieved, and the metal-containing resist pattern 11 to be efficiently removed. The above etching methods are broadly classified into hydrogen-based etching and chlorine-based etching. Each method will be described below in order for the case where the metal-containing resist pattern 11 is a tin oxide film.

[0146] (Hydrogen-Based Etching) Etching of the tin oxide that constitutes the metal-containing resist pattern 11 is carried out by hydrogen-based etching. Hydrogen-based etching involves exposing the tin oxide to a hydrogen-containing reactant (typically involving plasma activation of the reactant), which then converts the tin oxide into a volatile tin hydride. SnH ４ has a boiling point of -52°C and can be easily removed from the process chamber. Examples of hydrogen-containing reactants include H ２ , HBr, NH ３ , H ２ O, and hydrocarbons (CH ４Mixtures of hydrogen-containing reactants can also be used. Hydrogen-based etching involves forming a plasma in a process gas containing a hydrogen-containing reactant and, optionally, an inert gas, and contacting the substrate with the formed plasma. Examples of inert gases include nitrogen (N), helium (He), argon (Ar), neon (Ne), and xenon (Xe).

[0147] In some embodiments, H ２ is a preferred hydrogen-containing reactant, and in some embodiments, at least 50% by volume, e.g., at least 80% by volume H ２ In another embodiment, HBr is used as the hydrogen-containing reactant. For example, a process gas consisting essentially of HBr and an inert gas, e.g., HBr, N ２ and argon mixtures can be used to selectively etch tin oxide. Hydrogen-based etches are typically performed using process gases that are free of oxygen- and fluorine-containing species. In some embodiments, the process gas consists essentially of one or more hydrogen-containing reactants and, optionally, an inert gas.

[0148] The etching is carried out at a substrate temperature of less than 100° C. The etching reaction is preferably SnH ４ The etching process produces only volatile species such as HCl, which can be easily removed from the etching process chamber by evacuation and / or purging.

[0149] The power used to generate the plasma can range from about 50 W to 1,000 W.

[0150] The preferred gas flow rate per showerhead (for processing one 300 mm wafer) is H ２ The gas is 25 to 750 sccm, and the He gas is 0 to 500 sccm (for example, 5 to 100 sccm).

[0151] The etching process may be carried out at a pressure of about 1 to 175 mTorr in some embodiments.

[0152] In some embodiments, HBr is used as the hydrogen-containing reactant in a hydrogen-based etch. In one implementation, the etch method includes flowing HBr at a rate of 100-500 sccm, flowing an inert gas (e.g., helium, argon, etc.) at a rate of 100-500 sccm, and forming a plasma in the process gas using an RF power of 100-500 W (per 300 mm wafer). This process can be performed at a substrate temperature below 100° C. and a pressure of 5-50 mTorr.

[0153] Chlorine-Based Etching Etching of tin oxide is carried out using a chlorine-based etch, which involves exposing the tin oxide to a chlorine-containing reactant (typically involving plasma activation of the reactant), which converts the tin oxide to volatile tin chloride. SnCl ４ has a boiling point of 114°C and can be easily removed from the process chamber. Examples of suitable chlorine-containing reactants include Cl ２ and BCl ３ In one embodiment, Cl ２ and BCl ３ In one implementation, a chlorine-based etch involves forming a plasma in a process gas containing a chlorine-containing reactant and, optionally, an inert gas, and contacting a substrate with the formed plasma.

[0154] In one implementation, the etching method includes using BCl at a flow rate of 5-100 sccm. ３ and Cl at a flow rate of 50 to 500 sccm. ２ and an inert gas (e.g., helium) at a flow rate of 100-500 sccm, and forming a plasma in the process gas using an RF power of 100-500 W (per 300 mm wafer). This process can be performed at temperatures below 100° C. and pressures of 5-50 mTorr.

[0155] By going through the above steps, a reverse pattern 21 having a shape complementary to the metal-containing resist pattern 11 can be formed.

[0156] <<Reverse Pattern Forming Material>> The reversal pattern forming material is a reversal pattern forming material to be embedded in a metal-containing resist pattern, the metal-containing resist pattern containing tin atoms, and the reversal pattern forming material containing silicon atoms. As the reversal pattern forming material, the reversal pattern forming material used in the semiconductor substrate manufacturing method can be suitably used.

[0157] Examples will be described below. Note that the examples shown below are representative examples of the present invention, and should not be construed as narrowing the scope of the present invention.

[0158] In the present examples, the average molecular weights (Mw) of the compound (a) and the silicon-containing compound (hereinafter also referred to as "compound [A]") as intermediates, the concentration of the compound [A] in solution, and the average thickness of the film were measured by the following methods.

[0159] [Weight-average molecular weight (Mw)] The weight-average molecular weight (Mw) of compounds (a-1) to (a-13) as compound (a) and compound [A] was measured by gel permeation chromatography (GPC) using GPC columns (two "G2000HXL", one "G3000HXL", and one "G4000HXL") manufactured by Tosoh Corporation under the following conditions: Eluent: tetrahydrofuran (Wako Pure Chemical Industries, Ltd.) Flow rate: 1.0 mL / min Sample concentration: 1.0 mass% Sample injection amount: 100 μL Column temperature: 40° C. Detector: differential refractometer Standard material: monodisperse polystyrene

[0160] [Concentration of the Solution of the Compound [A]] 0.5 g of the solution of the compound [A] was baked at 250°C for 30 minutes, and the mass of the residue obtained was measured. The mass of this residue was divided by the mass of the solution of the compound [A] to calculate the concentration (mass %) of the solution of the compound [A].

[0161] [Average Film Thickness] The average film thickness was measured using a spectroscopic ellipsometer (J.A. WOOLLAM "M2000D"). Specifically, the film thickness was measured at nine arbitrary positions at 5 cm intervals including the center of the film formed on the silicon wafer, and the average value of the film thicknesses was calculated to obtain the average thickness.

[0162] <Synthesis of Compounds (a-1) to (a-13)> The monomers used in the synthesis in Synthesis Examples 1-1 to 1-13 (hereinafter also referred to as "monomers (H-1), (S-1) to (S-9)") are shown below.

[0163]

[0164] Synthesis Example 1-1 (Synthesis of Compound (a-1)) 5.83 g of magnesium and 11.12 g of tetrahydrofuran were added to a nitrogen-purged reaction vessel and stirred at 20°C. Next, 17.38 g of monomer (H-1) and 14.94 g of monomer (S-1) (molar ratio: 50 / 50 (mol %)) were dissolved in 111.15 g of tetrahydrofuran to prepare a monomer solution. The temperature inside the reaction vessel was brought to 20°C, and the monomer solution was added dropwise over 1 hour with stirring. The completion of the dropwise addition was designated the start time of the reaction, and the mixture was stirred at 40°C for 1 hour and then at 60°C for 3 hours. Thereafter, 66.69 g of tetrahydrofuran was added, and the mixture was cooled to below 10°C, thereby obtaining a polymerization reaction liquid. Next, 30.36 g of triethylamine was added to this polymerization reaction liquid, and then 9.61 g of methanol was added dropwise over 10 minutes with stirring. The end of the dropwise addition was designated as the start time of the reaction. After stirring at 20°C for 1 hour, the reaction solution was poured into 220 g of diisopropyl ether, and the precipitated salt was filtered off. Next, tetrahydrofuran, diisopropyl ether, triethylamine, and methanol were removed from the filtrate using an evaporator. 50 g of diisopropyl ether was poured into the resulting residue, and the precipitated salt was filtered off. Diisopropyl ether was then added to the filtrate, yielding compound (a-1) with a concentration of 12% by mass. The Mw of compound (a-1) was 850.

[0165] Synthesis Examples 1-2 to 1-13 (Synthesis of Compounds (a-2) to (a-13)) Diisopropyl ether solutions of compounds (a-2) to (a-13) were obtained in the same manner as in Synthesis Example 1-1, except that the types and amounts of each monomer shown in Table 1 below were used. The concentrations (% by mass) and Mw of the obtained solutions of compound (a) are also shown in Table 1. In Table 1, "-" indicates that the corresponding monomer was not used.

[0166]

[0167] <Synthesis of Compound [A]> The monomers used in the synthesis of Synthesis Examples 2-1 to 2-29 (hereinafter also referred to as "monomers (M-1) to (M-10)") are shown below. In the following Synthesis Examples 2-1 to 2-29, mol % refers to a value when the total number of moles of silicon atoms in the compounds (a-1) to (a-13) and monomers (M-1) to (M-10) used is taken as 100 mol %.

[0168]

[0169] Synthesis Example 2-1 (Synthesis of Compound (A-1)) To a reaction vessel were added 23.87 g of the diisopropyl ether solution of compound (a-1) obtained in Synthesis Example 1-1 above and 24.29 g of acetone. The temperature inside the reaction vessel was brought to 30°C, and 1.84 g of a 3.2% by mass aqueous oxalic acid solution was added dropwise over 20 minutes with stirring. The reaction started when the dropwise addition was completed, and the mixture was stirred at 40°C for 4 hours, after which the temperature inside the reaction vessel was cooled to 30°C or below. Next, 25.0 g of diisopropyl ether and 150 g of water were added to the reaction vessel, and extraction was performed. 75 g of propylene glycol monomethyl ether acetate was added to the resulting organic layer, and the water, acetone, diisopropyl ether, alcohols produced by the reaction, and excess propylene glycol monomethyl ether acetate were removed using an evaporator. Next, 5.0 g of trimethyl orthoformate as a dehydrating agent was added to the resulting solution, and the mixture was allowed to react at 40°C for 1 hour, after which the temperature inside the reaction vessel was cooled to 30°C or below. The alcohols, esters, trimethyl orthoformate, and excess propylene glycol monomethyl ether acetate produced by the reaction were removed using an evaporator, yielding a 5% by mass solution of compound (A-1) as compound [A]. The Mw of compound (A-1) was 1,800.

[0170] Synthesis Examples 2-2 to 2-29 (Synthesis of Compounds (A-2) to (A-29)) Solutions of compounds (A-2) to (A-29) as compound [A] in propylene glycol monomethyl ether acetate or propylene glycol monoethyl ether were obtained in the same manner as in Synthesis Example 2-1, except that the types and amounts of each compound and each monomer shown in Table 2 below were used. In Table 2 below, a "-" next to a monomer indicates that the corresponding monomer was not used. The concentrations (% by mass) of the obtained solutions of compound [A] and the Mw of compound [A] are also shown in Table 2.

[0171]

[0172] Comparative Synthesis Example 1-1 Synthesis of Polymer (x-1) 250.0 g of m-cresol, 125.0 g of 37% by mass formalin, and 2 g of anhydrous oxalic acid were added to a reaction vessel under a nitrogen atmosphere, and the mixture was reacted at 100°C for 3 hours and then at 180°C for 1 hour. After that, unreacted monomers were removed under reduced pressure to obtain a polymer (x-1) represented by the following formula (x-1) (hereinafter also referred to as "polymer (x)"). The Mw of the obtained polymer (x-1) was 11,000.

[0173]

[0174] <Preparation of Reverse Pattern Forming Material> The components used in preparing the reverse pattern forming material are shown below. In the following Examples 1-1 to 1-35 and Comparative Example 1-1, unless otherwise specified, parts by mass indicate values ​​when the total mass of the components used is 100 parts by mass.

[0175] [[A] Compounds] A-1 to A-29: Compounds (A-1) to (A-29) synthesized above

[0176] [[x] Polymer] x-1: Compound (x-1) synthesized above

[0177] [B] Solvents: B-1: Propylene glycol monomethyl ether acetate B-2: Propylene glycol monomethyl ether

[0178] [C] Other optional components C-1 (orthoester): trimethyl orthoformate C-2 (acid generator): compound represented by the following formula (C-2) (wherein "Bu" represents an n-butyl group) C-3 (basic compound): compound represented by the following formula (C-3)

[0179]

[0180] Example 1-1 (Preparation of reverse pattern forming material (J-1)) 2.00 parts by mass of (A-1) as the [A] compound (excluding the solvent) and 98.00 parts by mass of (B-1) as the [B] solvent (including the solvent (B-1) contained in the solution of the [A] compound) were mixed, and the resulting solution was filtered through a polytetrafluoroethylene (PTFE) membrane filter having a pore size of 0.2 μm to prepare a reverse pattern forming material (J-1).

[0181] [Examples 1-2 to 1-35, Comparative Example 1-1] (Preparation of reverse pattern forming materials (J-2) to (J-35) and (j-1)) Compositions (J-2) to (J-35) of Examples 1-2 to 1-35 and composition (j-1) of Comparative Example 1-1 were prepared in the same manner as in Example 1-1, except that the types and amounts of each component shown in Table 3 below were used. In Table 3 below, "-" indicates that the corresponding component was not used.

[0182] <Evaluation> Using the reversal pattern forming materials prepared above, etching resistance and rectangularity of the reversal pattern were evaluated by the following methods. The evaluation results are shown in Table 3 below.

[0183] <Preparation of Metal-Containing Resist Forming Material (R-1)>

[0184] [Synthesis of Metal-Containing Compound] Compound (G-1) was synthesized as a metal-containing compound used in preparing metal-containing resist forming material (R-1) by the following procedure. In a reaction vessel, 6.5 parts by mass of isopropyltin trichloride was added to 150 mL of 0.5 N aqueous sodium hydroxide solution while stirring, and the mixture was stirred for 2 hours. The precipitate was collected by filtration, washed twice with 50 parts by mass of water, and then dried to obtain compound (G-1). Compound (G-1) was a hydroxide oxide product (i-PrSnO) of the hydrolysis product of isopropyltin trichloride. （３／２－ｘ／２） (OH) ｘ (where 0<x<3 is the structural unit).

[0185] Two parts by mass of the compound (G-1) synthesized above and 98 parts by mass of propylene glycol monoethyl ether were mixed, and the resulting mixture was passed through an activated 4 Å molecular sieve to remove residual water, followed by filtration through a polytetrafluoroethylene (PTFE) membrane filter with a pore size of 0.2 μm to prepare a metal-containing resist forming material (R-1).

[0186] [Etching Resistance] The prepared reverse pattern forming materials (J-1) to (J-35) and (j-1) were applied onto a 12-inch silicon wafer (substrate) by spin coating using a spin coater (Tokyo Electron Limited's "CLEAN TRACK ACT12"). Next, the wafer was heated at 220°C for 60 seconds in an air atmosphere, and then cooled at 23°C for 60 seconds to form a film with an average thickness of 40 nm, thereby obtaining a film-attached substrate on which a reverse pattern forming film was formed. The film on the obtained film-attached substrate was treated using an etching apparatus (Lam Research Corporation's "Kiyo") under conditions of HBr / Ar = 120 / 40 sccm, PRESS = 30 mTorr, and RF power (plasma generating high frequency power) = 500 W, and the etching rate R was calculated from the average thickness of the film before and after treatment. Ｒ (nm / min) was calculated.

[0187] Next, the metal-containing resist forming material (R-1) was applied onto a 12-inch silicon wafer by a spin coating method using a spin coater (Tokyo Electron Limited's "CLEAN TRACK ACT12"), and after a predetermined time had elapsed, the wafer was heated at 90°C for 60 seconds and then cooled at 23°C for 30 seconds to form a metal-containing resist film having an average thickness of 35 nm. The metal-containing resist film was exposed using an EUV scanner (ASML's "TWINSCAN NXE:3300B" (NA 0.3, sigma 0.9, quadrupole illumination). After exposure, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. The film on the exposed R-1 film-coated substrate obtained above was treated using an etching device (Lam Research Corporation's "Kiyo") under conditions of HBr / Ar = 120 / 40 sccm, PRESS = 30 mTorr, and RF power (high frequency power for plasma generation) = 500 W, and the etching rate R was calculated from the average thickness of the film before and after treatment. Ｍ (nm / min) was calculated.

[0188] Etching rate R of film for forming reverse pattern Ｒ The etching rate R of the metal-containing resist film after exposure Ｍ Ratio to Ｒ / R Ｍ ) is calculated, and the ratio (R Ｒ / RＭ ) was used as a measure of etching resistance. The etching resistance was determined by the above ratio (R Ｒ / R Ｍ ) was rated as "A" (good) when it was 0.5 or less, and "B" (poor) when it was over 0.5.

[0189] [Reverse Pattern Rectangularity (EUV Exposure)] An organic underlayer film-forming material ("HM8006" manufactured by JSR Corporation) was applied onto a 12-inch silicon wafer by a spin coating method using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Limited), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. A metal-containing resist-forming material (R-1) was applied onto this organic underlayer film by the spin coating method using the spin coater, and after a predetermined time had elapsed, the wafer was heated at 90°C for 60 seconds and then cooled at 23°C for 30 seconds to form a metal-containing resist film with an average thickness of 35 nm. The resist film was exposed to light using an EUV scanner (ASML's "TWINSCAN NXE:3300B" (NA 0.3, sigma 0.9, quadrupole illumination, 1:1 line and space mask with on-wafer line width of 25 nm). After exposure, the substrate was heated at 110°C for 60 seconds and then cooled at 23°C for 60 seconds. Thereafter, development was performed by a puddle method using 2-heptanone (20 to 25°C) as a developer to obtain a substrate for evaluation on which a metal-containing resist pattern was formed. The reversal pattern forming material prepared above was applied to the evaluation substrate on which the metal-containing resist pattern was formed, and the substrate was heated at 220°C for 60 seconds and then cooled at 23°C for 30 seconds to form a reversal pattern forming film. The rotation speed of the spin coater when applying the reversal pattern forming material was set to a rotation speed at which the average thickness of the reversal pattern forming film became 40 nm. An etching apparatus (Tokyo Electron Limited's "TACTRAS") was used to perform CF ４ / Ar=110 / 440 sccm, PRESS.=30 mTorr, RF power (high frequency power for generating plasma)=500 W, and the reversal pattern forming film was etched to the height of the metal-containing resist pattern.

[0190] The metal-containing resist pattern was selectively etched and removed using an etching apparatus (Lam Research Corporation's "Kiyo") under the conditions of HBr / Ar = 120 / 40 sccm, PRESS = 30 mTorr, and RF power (plasma generation radio frequency power) = 500 W, to obtain an evaluation substrate on which a reverse pattern was formed. A scanning electron microscope (Hitachi High-Tech Corporation's "SU8220") was used to measure and observe the reverse pattern of the evaluation substrate. The rectangularity of the reverse pattern was evaluated as "A" (good) when the cross-sectional shape of the reverse pattern was rectangular, and as "B" (poor) when the cross-sectional shape of the pattern was tapered.

[0191]

[0192] As is clear from the results in Table 3, the reversal pattern forming materials of the examples provided good results in terms of etching resistance and reversal pattern rectangularity.

[0193] According to the semiconductor substrate manufacturing method of the present invention, a reverse pattern having excellent etching resistance and reverse pattern rectangularity can be formed. Furthermore, the reverse pattern forming material can also form a reverse pattern having excellent etching resistance and reverse pattern rectangularity. Therefore, these can be suitably used in the manufacture of semiconductor devices, which are expected to become even more miniaturized in the future.

[0194] 1; substrate, 10; metal-containing resist film, 11; metal-containing resist pattern, 20; film for forming a reverse pattern, 21; reverse pattern

Claims

1. A method for manufacturing a semiconductor substrate, comprising the steps of: forming a metal-containing resist film directly or indirectly on a substrate using a metal-containing resist forming material; exposing the metal-containing resist film to extreme ultraviolet light; developing the exposed metal-containing resist film; forming a reversal pattern forming film on the metal-containing resist pattern formed by the developing step using a reversal pattern forming material; and removing the metal-containing resist pattern to form a reversal pattern formed by the reversal pattern forming film, wherein the metal-containing resist forming material contains tin atoms and the reversal pattern forming material contains silicon atoms.

2. The method for producing a semiconductor substrate as described in claim 1, wherein the metal-containing resist forming material contains a metal-containing compound (A) containing a tin atom and a solvent, and the content of the metal-containing compound (A) in the components other than the solvent in the metal-containing resist forming material is 50 mass% or more.

3. The method for producing a semiconductor substrate according to claim 1, wherein the metal-containing resist forming material contains a metal-containing compound (B), and the metal-containing resist film is formed by depositing the metal-containing compound (B).

4. The method of claim 3, wherein said deposition is by chemical vapor deposition or atomic layer deposition.

5. The metal-containing resist pattern is removed by H ２ , HBr, NH ３ , H ２ O, hydrocarbon, Cl ２ and BCl ３ The method for producing a semiconductor substrate according to any one of claims 1 to 4, wherein the etching is carried out by using at least one plasma activated reactant selected from the group consisting of:

6. The method for manufacturing a semiconductor substrate according to any one of claims 1 to 4, wherein the reverse pattern forming material contains polysiloxane or polycarbosilane.

7. The method for producing a semiconductor substrate according to claim 6, wherein the polysiloxane has a structural unit represented by the following formula (2-1): (In the above formula (2-1), R １２ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrogen atom. e is an integer of 1 to 3. When e is 2 or more, multiple R １２ are the same or different.) 8. The method for producing a semiconductor substrate according to claim 6, wherein the polycarbosilane has a structural unit represented by the following formula (3-1): (In formula (3-1), R ３１ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrogen atom. h is 1 or 2. When h is 2, two R ３１ are the same or different. ３２ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms bonded to two silicon atoms. q is an integer of 1 to 3. When q is 2 or more, multiple R ３２ are the same or different, provided that h+q is 4 or less.

9. A reversal pattern forming material which is used by being embedded in a metal-containing resist pattern, the metal-containing resist pattern containing tin atoms, and the reversal pattern forming material containing silicon atoms.

10. The reversal pattern forming material according to claim 9, wherein the reversal pattern forming material contains polysiloxane or polycarbosilane.

11. The reversal pattern forming material according to claim 10, wherein the polysiloxane has a structural unit represented by the following formula (2-1): (In the above formula (2-1), R １２ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrogen atom. e is an integer of 1 to 3. When e is 2 or more, multiple R １２ are the same or different.) 12. The reversal pattern forming material according to claim 10, wherein the polycarbosilane has a structural unit represented by the following formula (3-1): (In formula (3-1), R ３１ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, or a hydrogen atom. h is 1 or 2. When h is 2, two R ３１ are the same or different. ３２ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 20 carbon atoms bonded to two silicon atoms. q is an integer of 1 to 3. When q is 2 or more, multiple R ３２ are the same or different, provided that h+q is 4 or less.

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