Microprocessing treatment agent and microprocessing treatment method

Abstract

Provided are a microprocessing treatment agent and a microprocessing treatment method capable of satisfactorily performing selective microprocessing of a silicon oxide film while suppressing microprocessing of a silicon nitride film even when formation of a protective film is omitted for a laminated film including at least a silicon oxide film and a silicon nitride film. The present invention includes (a) hydrogen fluoride in a range of 0.01 mass% to 30 mass%, (b) ammonium fluoride in a range of 0.1 mass% to 40 mass%, (c) a microprocessing inhibitor for suppressing etching of a silicon nitride film, and (d) water, wherein the microprocessing inhibitor includes a sulfo-betaine compound represented by chemical formula (1). (In the formula, R1, R2 and R3 are each independently a chain alkyl group having 17 or less carbon atoms, or a chain alkyl group having 17 or less carbon atoms and containing at least one of a hetero atom or an unsaturated bond. In addition, at least one among R1, R2, and R3 is a chain alkyl group having 5-17 carbon atoms, or a chain alkyl group having 5-17 carbon atoms and containing at least one of a hetero atom or an unsaturated bond. R4 represents a chain alkyl group having 2-4 carbon atoms, or a chain alkyl group having 2-4 carbon atoms and containing at least one of a hetero atom or an unsaturated bond.

Description

Microprocessing agent and microprocessing method

[0001] The present invention relates to a micro-processing treatment agent and a micro-processing method used in micro-processing including etching and cleaning processes in the manufacture of semiconductor devices, liquid crystal display devices, microelectromechanical systems (MEMS) devices, etc., and more particularly to a micro-processing treatment agent and a micro-processing method used in the micro-processing of a laminated film containing at least a silicon oxide film and a silicon nitride film.

[0002] In the manufacturing process of semiconductor devices, one of the most important processes is to pattern and etch silicon oxide films, silicon nitride films, polysilicon films, metal films, etc. formed on the wafer surface into a desired shape. For wet etching, which is one type of etching technology, there is a demand for micro-processing agents that can selectively etch only the specific film to be etched.

[0003] An example of a semiconductor element that can be wet-etched using a micro-processing agent is a dynamic random access memory (DRAM). The semiconductor element that makes up a DRAM has a memory cell region and a peripheral circuit region. The memory cell region is composed of a memory cell selection transistor (MOSFET) and a charge storage capacitor connected in series with the transistor, and multiple memory cells are arranged two-dimensionally.

[0004] DRAM performance has improved through the miniaturization and integration of memory cells, reducing the footprint of various components that make up the device. However, as the footprint shrinks, the capacitor area also decreases, making it difficult to ensure the capacitance required for stable memory operation. Therefore, in recent years, vertically aligned, minute, cylindrical capacitors have become mainstream to ensure the capacitance required for DRAM operation. Other advances include narrowing the separation between adjacent cylinders, thinning the capacitor insulating film, and introducing high-dielectric-constant films.

[0005] When forming a memory cell region in the DRAM manufacturing process, a sacrificial oxide film formed on the capacitor lower electrode is selectively removed to form a space for forming the capacitor (a space for forming the capacitive insulating film and upper electrode that will become the capacitor).

[0006] In addition to hafnium oxide and zirconia oxide, silicon oxide and silicon nitride films are also used as capacitor insulating films. In addition, there is a technique for forming a silicon nitride film as a stopper layer on the lower electrode to form the capacitor.

[0007] Japanese Patent Application Laid-Open No. 2003-144222 discloses that a silicon oxide film such as a BPSG film or a TEOS film is formed as the sacrificial oxide film (mold oxide film).

[0008] When the sacrificial oxide film is etched using conventional fine processing agents such as hydrogen fluoride or ammonium fluoride in forming the capacitor space, the silicon nitride film, which serves as the stopper layer, is simultaneously etched, causing damage to the underlying lower electrode and resulting in deterioration of the capacitor characteristics.

[0009] Examples of micro-processing agents that can solve these problems and selectively etch only silicon oxide films over silicon nitride films include an etching solution containing hydrofluoric acid to which an anionic surfactant such as ammonium lauryl sulfate has been added (Patent Document 2), and an etching composition containing fluoride to which sulfonic acid, phosphonic acid, phosphinic acid, or a mixture of any two or more of these acids has been added (Patent Document 3).

[0010] However, these etching solutions and etching compositions contain strong acids such as hydrofluoric acid and sulfonic acid, resulting in a low pH. As a result, they deteriorate the photoresist masks used in wet etching processes, making them unsuitable for microfabrication in the manufacturing process of semiconductor devices. Furthermore, their etching characteristics, such as the etching suppression effect on silicon nitride films and the etching rate selectivity of silicon oxide films to silicon nitride films (silicon oxide film / silicon nitride film), do not fully satisfy user requirements.

[0011] On the other hand, in order to perform selective etching of a silicon oxide film relative to a silicon nitride film, a method of forming a protective film on the silicon oxide film and then performing etching has also been proposed. Examples of such protective films include those containing water-soluble cellulose (Patent Documents 4 to 6). Furthermore, according to Patent Documents 5 and 6, etching methods using a protective film include (1) a method in which an aqueous solution containing water-soluble cellulose and an acidic etching solution are simultaneously supplied to an inorganic material layer such as a silicon oxide film, and (2) a method in which an aqueous solution containing water-soluble cellulose is supplied and then an acidic etching solution is supplied.

[0012] However, these etching methods all require additional steps such as spin coating, immersion treatment, and drying to form a protective film, which are undesirable because they increase manufacturing costs due to the need for additional equipment and reduced throughput.

[0013] Japanese Patent Application Laid-Open No. 2003-297952 Japanese Patent Application Laid-Open No. 2005-328067 Japanese Patent Application Laid-Open No. 2008-541447 Japanese Patent Application Laid-Open No. 2023-157154 International Publication No. WO2023 / 199900 Japanese Patent Application Laid-Open No. 2023-175389

[0014] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a fine-processing treatment agent and a fine-processing method that can satisfactorily perform selective fine-processing of a silicon oxide film while suppressing fine-processing of the silicon nitride film, even when the formation of a protective film is omitted for a laminated film containing at least a silicon oxide film and a silicon nitride film.

[0015] In order to solve the above-mentioned problems, the fine-processing treatment agent of the present invention is a fine-processing treatment agent used for fine-processing of a laminated film containing at least a silicon oxide film and a silicon nitride film, and comprises: (a) hydrogen fluoride in a content of 0.01 mass % or more and 30 mass % or less relative to the total mass of the fine-processing treatment agent; (b) ammonium fluoride in a content of 0.1 mass % or more and 40 mass % or less relative to the total mass of the fine-processing treatment agent; (c) a fine-processing inhibitor that inhibits fine-processing of the silicon nitride film; and (d) water, wherein the fine-processing inhibitor contains at least one sulfobetaine compound represented by the following chemical formula (1):

[0016] (In the formula, R １ , R ２ and R ３ are each independently a chain alkyl group having 17 or less carbon atoms; or a chain alkyl group having 17 or less carbon atoms and at least one of a heteroatom or an unsaturated bond, and further, R １ , R ２ and R ３ At least one of R is a chain alkyl group having 5 to 17 carbon atoms; or a chain alkyl group having 5 to 17 carbon atoms and at least one of a hetero atom or an unsaturated bond. ４ represents a chain alkyl group having 2 to 4 carbon atoms; or a chain alkyl group having 2 to 4 carbon atoms and at least one of a heteroatom or an unsaturated bond.

[0017] According to the above configuration, by containing 0.01% by mass or more of hydrogen fluoride, the concentration of hydrogen fluoride can be well controlled, and the etching rate variation during micro-machining of a silicon oxide film can be suppressed. On the other hand, by containing 30% by mass or less of hydrogen fluoride, the etching rate during micro-machining of a silicon oxide film can be suppressed from becoming too high. Furthermore, by containing 0.1% by mass or more of ammonium fluoride, the concentration of ammonium fluoride can be well controlled, and the etching rate variation during micro-machining of a silicon oxide film can be suppressed. On the other hand, by containing 40% by mass or less of ammonium fluoride, the precipitation of ammonium fluoride crystals can be prevented. Furthermore, by containing a sulfobetaine compound represented by chemical formula (1) as a micro-machining inhibitor for suppressing micro-machining of a silicon nitride film, micro-machining of a silicon nitride film can be suppressed well. That is, when the fine processing agent having the above-described configuration is used to perform fine processing on a laminated film including at least a silicon oxide film and a silicon nitride film, it is possible to effectively perform selective fine processing on the silicon oxide film while suppressing fine processing on the silicon nitride film.

[0018] In the above-described configuration, the micro-processing inhibitor preferably further contains an anionic water-soluble polymer, which can further suppress micro-processing of silicon nitride films, thereby enabling more favorable selective micro-processing of silicon oxide films.

[0019] Furthermore, in the above-described configuration, it is preferable that the content of the sulfobetaine compound is in the range of 0.0001% by mass or more and 1% by mass or less, based on the total mass of the fine processing treatment agent. By setting the content of the sulfobetaine compound to 0.0001% by mass or more, it is possible to effectively maintain the suppression of the etching rate of the silicon nitride film. On the other hand, by setting the content of the sulfobetaine compound to 1% by mass or less, it is possible to suppress the increase of metal impurities, particles, etc. derived from the sulfobetaine compound in the fine processing treatment agent.

[0020] In the above-mentioned structure, the anionic water-soluble polymer is a polymer or copolymer of a monomer having an anionic group, and the anionic group is a —COOM group, —SO ３ M group, -OSO ３ M group, and -OPO ３ M ２ Preferably, the functional group is at least one selected from the group consisting of groups (wherein M represents any of a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, and an organic ammonium group).

[0021] Furthermore, in the above-described configuration, it is preferable that the content of the anionic water-soluble polymer is in the range of 0.0001% by mass or more and 1% by mass or less, based on the total mass of the fine processing treatment agent. By setting the content of the anionic water-soluble polymer to 0.0001% by mass or more, it is possible to effectively maintain the suppression of the etching rate of the silicon nitride film. On the other hand, by setting the content of the anionic water-soluble polymer to 1% by mass or less, it is possible to suppress the increase of metal impurities and particles derived from the anionic water-soluble polymer in the fine processing treatment agent.

[0022] In order to solve the above-mentioned problems, the micro-processing method of the present invention is a micro-processing method for a laminated film including at least a silicon oxide film and a silicon nitride film, characterized in that the silicon oxide film is selectively micro-processed relative to the silicon nitride film using the above-mentioned micro-processing treatment agent.

[0023] According to the above-mentioned configuration, by performing micro-processing on a laminated film including at least a silicon oxide film and a silicon nitride film using the above-mentioned micro-processing treatment agent, it is possible to suppress micro-processing on the silicon nitride film and to perform selective micro-processing on the silicon oxide film well while suppressing an increase in the variation in the etching rate of the silicon oxide film.

[0024] In the above-mentioned configuration, it is preferable that the selectivity ratio (silicon oxide film / silicon nitride film) representing the ratio of the etching rate of the silicon oxide film to the silicon nitride film when the fine-processing treatment agent is used is 1.4 times or more the selectivity ratio representing the ratio of the etching rates when the fine-processing treatment agent does not contain the fine-processing inhibitor.

[0025] Furthermore, in the above-described structure, it is preferable that the silicon nitride film is formed by low-pressure chemical vapor deposition, and the silicon oxide film is formed by thermal oxidation.

[0026] The present invention achieves the following effects by the means described above: That is, the present invention can provide a fine-processing agent and a fine-processing method that can effectively perform selective fine processing on a silicon oxide film while suppressing fine processing of the silicon nitride film even when the formation of a protective film is omitted for a laminate film including at least a silicon oxide film and a silicon nitride film.

[0027] 1 is a graph showing the relationship between the number of carbon atoms in the alkyl group of a sulfobetaine compound, the etching rate of a silicon nitride film, and the selectivity of the etching rate of a silicon oxide film relative to the silicon nitride film, for the etching solutions of Examples 1 to 5 and Comparative Examples 2 and 3.

[0028] (Fine-processing treatment agent) A fine-processing treatment agent according to one embodiment of the present invention will be described below. The fine-processing treatment agent according to this embodiment contains at least (a) hydrogen fluoride, (b) ammonium fluoride, (c) a fine-processing inhibitor, and (d) water.

[0029] The micro-processing agent of this embodiment is suitable for selective micro-processing of a silicon oxide film relative to a silicon nitride film in a laminate film containing at least a silicon oxide film and a silicon nitride film. Here, in this specification, "micro-processing" means an etching process for micro-processing the surface of a laminate film, and a cleaning process for the surface of a laminate film. When etching a laminate film, the micro-processing agent of this embodiment functions as an etching liquid. When cleaning a laminate film, the micro-processing agent of this embodiment functions as a cleaning liquid.

[0030] The content of hydrogen fluoride, component (a), is in the range of 0.01% by mass or more and 30% by mass or less, preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.05% by mass or more and 10% by mass or less, based on the total mass of the micro-processing agent. By making the hydrogen fluoride content 0.01% by mass or more, it is possible to easily control the hydrogen fluoride concentration, thereby preventing the etching rate of the silicon oxide film from becoming too high. On the other hand, by making the hydrogen fluoride content 30% by mass or less, it is possible to prevent the etching rate of the silicon oxide film from becoming too high, and prevent a decrease in the controllability of micro-processing of the silicon oxide film. The content of hydrogen fluoride is, for example, 0.01, 0.05, 0.1, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 20.0, 25.0, or 30.0 mass% relative to the total mass of the fine processing treatment agent, and may also be within a range between any two of the numerical values ​​exemplified here.

[0031] The content of ammonium fluoride, component (b), is in the range of 0.1% by mass or more and 40% by mass or less, preferably 5% by mass or more and 25% by mass or less, and more preferably 5% by mass or more and 20% by mass or less, based on the total mass of the fine-processing treatment agent. By making the ammonium fluoride content 0.1% by mass or more, it is possible to easily control the ammonium fluoride concentration, thereby preventing the etching rate of the silicon oxide film from varying greatly. On the other hand, by making the ammonium fluoride content 40% by mass or less, it is possible to prevent ammonium fluoride from reaching its saturated solubility and precipitating its crystals in the fine-processing treatment agent, even if the liquid temperature of the fine-processing treatment agent is too low. The content of ammonium fluoride is, for example, 0.1, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 20.0, 25.0, 30.0, 35.0, or 40.0 mass% relative to the total mass of the fine processing treatment agent, and may also be within a range between any two of the numerical values ​​exemplified here.

[0032] The microfabrication inhibitor, component (c), has the function of inhibiting microfabrication of a silicon nitride film. More specifically, the microfabrication inhibitor inhibits etching of a silicon nitride film, and therefore can also be referred to as an etching inhibitor. The microfabrication inhibitor contains at least one sulfobetaine compound represented by the following chemical formula (1):

[0033]

[0034] In the chemical formula (1), R １ , R ２ and R ３ each independently represents a chain alkyl group having 17 or less carbon atoms; or a chain alkyl group having 17 or less carbon atoms and at least one of a hetero atom or an unsaturated bond. １ , R ２ and R ３At least one of R is a chain alkyl group having 5 to 17 carbon atoms; or a chain alkyl group having 5 to 17 carbon atoms and at least one of a heteroatom or an unsaturated bond. ４ represents a chain alkyl group having 2 to 4 carbon atoms; or a chain alkyl group having 2 to 4 carbon atoms and at least one of a hetero atom or an unsaturated bond.

[0035] The R １ , R ２ and R ３ In the formula (I), the chain alkyl groups having 17 or fewer carbon atoms may each independently be either a linear alkyl group or a branched alkyl group. By limiting the number of carbon atoms to 17 or less, excessive reduction in the solubility of the sulfobetaine compound in the fine processing agent can be prevented, and the suppression of the etching rate of the silicon nitride film can be maintained satisfactorily. Furthermore, for chain alkyl groups having 5 to 17 carbon atoms, the number of carbon atoms is preferably in the range of 8 to 16, and more preferably in the range of 12 to 16. By limiting the number of carbon atoms to 5 or more, the effect of suppressing the etching rate of the silicon nitride film can be sufficiently obtained, even when the content of the sulfobetaine compound is, for example, 1 mass% or less relative to the total mass of the fine processing agent. As a result, the increase in metal impurities, particles, etc., in the fine processing agent due to impurities contained in the sulfobetaine compound can be suppressed, making the fine processing agent suitable for use in the manufacturing process of semiconductor devices. Note that, when a range of carbon atoms is expressed in this specification, the range is meant to include all integer carbon numbers within that range. Therefore, for example, an alkyl group having "5 to 7 carbon atoms" means all alkyl groups having 5, 6 and 7 carbon atoms.

[0036] Examples of the linear alkyl group having 17 or less carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, and an n-heptadecyl group.Examples of the branched alkyl group include an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a neohexyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, a neoheptyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, a neooctyl group, an isono nyl group, sec-nonyl group, tert-nonyl group, neononyl group, isodecyl group, sec-decyl group, tert-decyl group, neodecyl group, isoundecyl group, sec-undecyl group, tert-undecyl group, neoundecyl group, isododecyl group, sec-dodecyl group, tert-dodecyl group, neododecyl group, isotridecyl group, sec-tridecyl group, tert-tridecyl group, neotridecyl group, isotetradecyl group, sec-tetradecyl group, tert- Tetradecyl group, neotetradecyl group, isopentadecyl group, sec-pentadecyl group, tert-pentadecyl group, neopentadecyl group, isohexadecyl group, sec-hexadecyl group, tert-hexadecyl group, neohexadecyl group, isoheptadecyl group, sec-heptadecyl group, tert-heptadecyl group, neoheptadecyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1,1,2-trimethylpropyl group Examples of the chain alkyl group having 5 to 17 carbon atoms include a 1,2,2-trimethylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 3-ethylbutyl group, a 1,1-dimethylbutyl group, a 1,2-dimethylbutyl group, a 1,3-dimethylbutyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a 3,3-dimethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group. Examples of the chain alkyl group having 5 to 17 carbon atoms include those of the functional groups exemplified above that have 5 or more carbon atoms.

[0037] The R １ ~R ３In the above, the chain alkyl group having 17 or less carbon atoms and containing a heteroatom refers to the chain alkyl group having 17 or less carbon atoms in which at least one hydrogen atom has been substituted with a substituent such as a hydroxy group, an ether group, a carbonyl group, an oxyethylene group, an oxypropylene group, a sulfone group, a sulfino group, a sulfide group, a sulfonyl group, a thiol group, an amino group, an amide group, a nitro group, a nitroso group, or a phosphoryl group. The heteroatom represents an atom such as oxygen, nitrogen, or sulfur. Furthermore, in the chain alkyl group having 5 to 17 carbon atoms and containing a heteroatom, the number of carbon atoms is preferably in the range of 8 to 16, and more preferably in the range of 12 to 16, as in the case of the chain alkyl group having 5 to 17 carbon atoms described above. Therefore, a detailed description thereof will be omitted.

[0038] The R １ ~R ３ In the above, the chain alkyl group having 17 or less carbon atoms and having an unsaturated bond refers to a linear or branched chain alkyl group having a double bond or triple bond between carbon atoms in the chain alkyl group having 17 or less carbon atoms. The number of unsaturated bonds is preferably in the range of 1 to 5, and more preferably in the range of 1 to 3. Furthermore, in the chain alkyl group having 5 to 17 carbon atoms and having an unsaturated bond, the number of carbon atoms is preferably in the range of 8 to 16, and more preferably in the range of 12 to 16, as in the case of the chain alkyl group having 5 to 17 carbon atoms described above. Therefore, detailed description thereof will be omitted.

[0039] The R ４ In the formula (I), examples of the chain alkyl group having 2 to 4 carbon atoms include linear and branched alkyl groups. Examples of linear alkyl groups include an n-ethyl group, an n-propyl group, and an n-butyl group. Examples of branched alkyl groups include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, and a 1,1-dimethylethyl group.

[0040] The R ４In the above, the chain alkyl group having 2 to 4 carbon atoms and containing a hetero atom refers to the chain alkyl group having 2 to 4 carbon atoms in which at least one hydrogen atom has been substituted with a substituent such as a hydroxy group, an ether group, a carbonyl group, a sulfone group, a sulfino group, a sulfide group, a sulfonyl group, a thiol group, an amino group, an amido group, a nitro group, a nitroso group, or a phosphoryl group. The hetero atom represents an atom such as oxygen, nitrogen, or sulfur.

[0041] The R ４ In the above, the chain alkyl group having 2 to 4 carbon atoms and having an unsaturated bond refers to a linear or branched chain alkyl group having a double bond or a triple bond between carbon atoms in the chain alkyl group having 2 to 4 carbon atoms. The number of unsaturated bonds is preferably in the range of 1 to 2.

[0042] Furthermore, the sulfobetaine compound is preferably at least one compound represented by the following chemical formula (2).

[0043] (In the formula, R １ , R ２ and R ３ are each independently a chain alkyl group having 17 or less carbon atoms, and R １ , R ２ and R ３ At least one of R is a chain alkyl group having 5 to 17 carbon atoms and having at least one of an ether group, a carbonyl group, an oxyethylene group, an oxypropylene group, and an amide group. ５ represents a hydrogen atom or a hydroxy group.

[0044] Specific examples of the sulfobetaine compound of component (c) include the following: 3-[(pentyl)dimethylammonio]-1-propanesulfonate, 3-[(hexyl)dimethylammonio]-1-propanesulfonate, 3-[(heptyl)dimethylammonio]-1-propanesulfonate, 3-[(octyl)dimethylammonio]-1-propanesulfonate, 3-[(nonyl)dimethylammonio]-1-propanesulfonate, 3-[(decyl)dimethylammonio]-1-propanesulfonate, 3-[(undecyl)dimethylammonio]-1-propanesulfonate, 3-[(dodecyl)dimethylammonio]-1-propanesulfonate, 3-[(tridecyl)dimethylammonio]-1-propanesulfonate, 3-[(tetradecyl)dimethylammonio]-1-propanesulfonate, 3-[(pentadecyl)dimethylammonio]-1-propanesulfonate, 3-[(hexadecyl)dimethylammonio]-1-propanesulfonate, 3-[(heptadecyl )dimethylammonio)]-1-propanesulfonate, 3-[(octyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[((nonyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(decyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(undecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(dodecyl)dimethylammonio] dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(tridecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(tetradecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(pentadecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(hexadecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, and the like.

[0045] Also, 3-[[3-(octanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(nonanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(decanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(undecanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(dodecanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(tridecanoylamino)propyl ]dimethylaminio]-1-propanesulfonate, 3-[[3-(tetradecanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(pentadecanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(hexadecanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(heptadecanoylamino)propyl]dimethylaminio]-1-propanesulfonate, 3-[[3-(octadecanoylamino)propyl]dimethylaminio]-1-propanesulfonate 3-[[3-(octanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(nonanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(decanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(undecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(dodecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate [3-(tridecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(tridecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(tetradecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(pentadecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[3-(hexadecanoylamino)propyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, and the like.

[0046] Also, 3-[[(octyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(nonyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(decyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(undecyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(dodecyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(tridecyl) )-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(tetradecyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(pentadecyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(hexadecyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(heptadecyl)-di(2-hydroxyethyl)]ammonio]-1-propanesulfonate, 3-[[(octyl)-di(2 -hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(nonyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(decyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(undecyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(dodecyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1 -propanesulfonate, 3-[[(tridecyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(tetradecyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(pentadecyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, 3-[[(hexadecyl)-di(2-hydroxyethyl)]ammonio]-2-hydroxy-1-propanesulfonate, and the like.

[0047] Also, 3-[(3-oxooctanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxononanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxodecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxoundecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxododecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxotridecanoyl)dimethylaminio]-1-propanesulfonate, dimethylaminio]-1-propanesulfonate, 3-[(3-oxotetradecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxopentadecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxohexadecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxoheptadecanoyl)dimethylaminio]-1-propanesulfonate, 3-[(3-oxooctadecanoyl)dimethylaminio]-1-propanesulfonate ester, 3-[(3-oxooctanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxononanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxodecanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxoundecanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxododecanoyl)dimethylaminio]-2-hydroxy hydroxy-1-propanesulfonate, 3-[(3-oxotridecanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxotetradecanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxopentadecanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[(3-oxohexadecanoyl)dimethylaminio]-2-hydroxy-1-propanesulfonate, and the like.

[0048] Also, 3-[[(3-(octyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(nonyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(decyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(undecyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(dodecyloxy)-3-oxypropyl]dimethylaminio]-1-propane sulfonate, 3-[[(3-(tridecyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(tetradecyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(pentadecyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(hexadecyloxy)-3-oxypropyl]dimethylaminio]-1-propanesulfonate, 3-[[(3-(heptadecyloxy)-3-oxypropyl]dimethylaminio 3-[[(3-(octyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[(3-(nonyloxy)-3-oxypropyl]dimethylaminio]]-2-hydroxy-1-propanesulfonate, 3-[[(3-(decyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[(3-(undecyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate hydroxy-1-propanesulfonate, 3-[[(3-(dodecyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[(3-(tridecyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[(3-(tetradecyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, 3-[[(3-(pentadecyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate,3-[[(3-(hexadecyloxy)-3-oxypropyl]dimethylaminio]-2-hydroxy-1-propanesulfonate, etc.

[0049] Also, 3-[(2-octyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-nonyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-decyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-undecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-dodecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-tridecyloxyethoxy)dimethylammonio] 3-[(2-tetradecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-tetradecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-pentadecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-hexadecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-heptadecyloxyethoxy)dimethylammonio]-1-propanesulfonate, 3-[(2-octadecyloxyethoxy)dimethylammonio]-1-propanesulfonate sulfonate, 3-[(2-octyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-nonyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-decyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-(undecyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-dodecyloxyethoxy)dimethylammonio]- 2-hydroxy-1-propanesulfonate, 3-[(2-tridecyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-tetradecyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-pentadecyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[(2-hexadecyloxyethoxy)dimethylammonio]-2-hydroxy-1-propanesulfonate, and the like.

[0050] Also, 3-[[[2-[2-(2-octyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-nonyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-decyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-undecyloxyethoxy)ethoxy]ethoxy]propyl ]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-dodecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-tridecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-tetradecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-tetradecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate -pentadecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-hexadecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-heptadecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate, 3-[[[2-[2-(2-octadecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-1-propanesulfonate ammonio]-1-propanesulfonate, 3-[[[2-[2-(2-octyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[[2-[2-(2-nonyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[[2-[2-(2-decyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate,3-[[[2-[2-(2-undecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[[2-[2-(2-dodecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[[2-[2-(2-tridecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[[ Examples of sulfobetaine compounds include 2-[2-(2-tetradecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[[2-[2-(2-pentadecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, and 3-[[[2-[2-(2-hexadecyloxyethoxy)ethoxy]ethoxy]propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate. The sulfobetaine compounds exemplified above can be used alone or in combination of two or more.

[0051] Among the sulfobetaine compounds exemplified above, 3-[(octyl)dimethylammonio]-1-propanesulfonate, 3-[(decyl)dimethylammonio]-1-propanesulfonate, 3-[(dodecyl)dimethylammonio]-1-propanesulfonate, 3-[(tetradecyl)dimethylammonio]-1-propanesulfonate, 3-[(hexadecyl)dimethylammonio]-1-propanesulfonate, 3-[(dodecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(tetradecyl)dimethylammonio]-1-propanesulfonate, [methylammonio)]-2-hydroxy-1-propanesulfonate, 3-[(hexadecyl)dimethylammonio)]-2-hydroxy-1-propanesulfonate, 3-[[3-(dodecanoylamino)propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, 3-[[3-(tetradecanoylamino)propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate, and 3-[[3-(hexadecanoylamino)propyl]dimethylammonio]-2-hydroxy-1-propanesulfonate are preferred.

[0052] The content of the sulfobetaine compound in the fine processing inhibitor (component (c)) is preferably in the range of 0.0001% by mass or more and 1% by mass or less, and more preferably in the range of 0.001% by mass or more and 0.1% by mass or less, relative to the total mass of the fine processing treatment agent. By setting the content of the sulfobetaine compound to 0.0001% by mass or more, it is possible to effectively prevent the etching rate of the silicon nitride film from becoming too high. On the other hand, by setting the content of the sulfobetaine compound to 1% by mass or less, it is possible to prevent an increase in metal impurities, particles, etc. derived from the sulfobetaine compound in the fine processing treatment agent. The content of the sulfobetaine compound is, for example, 0.0001, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0% by mass relative to the total mass of the fine processing treatment agent, or may be within a range between any two of the numerical values ​​exemplified here.

[0053] Furthermore, the micro-processing inhibitor, which is the component (c), may further contain an anionic water-soluble polymer (hereinafter referred to as "water-soluble polymer") in addition to the sulfobetaine compound. By including a water-soluble polymer in the micro-processing treatment agent, even if the content of the sulfobetaine compound is reduced, the etching rate of the silicon nitride film is prevented from becoming excessively high, and selective micro-processing of the silicon oxide film can be performed satisfactorily. For example, the sulfobetaine compound may be a compound represented by the formula (1) R １ ~R ３ When a sulfobetaine compound having at least one functional group having 8 or 10 carbon atoms is used, the etching rate of a silicon nitride film can be sufficiently suppressed even when the content of the sulfobetaine compound is 0.1 mass % or less based on the total mass of the fine-processing treatment agent. Furthermore, the inclusion of metal impurities and the like derived from the sulfobetaine compound in the fine-processing treatment agent can be prevented or reduced, thereby achieving a high purity of the fine-processing treatment agent. Furthermore, reducing the content of the sulfobetaine compound also enables cost reduction.

[0054] The water-soluble polymer is preferably a (homo)polymer or copolymer of a monomer having an anionic group. The anionic group is preferably a functional group that exhibits acidity by dissociating and releasing a hydrogen ion. Specific examples of the anionic group include a -COOM group, a -SO ３ M group, -OSO ３ M group, and -OPO ３ M ２ and at least one functional group selected from the group consisting of alkyl ammonium groups (wherein M represents a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, or an organic ammonium group). Examples of alkali metals include lithium, sodium, and potassium. Examples of alkaline earth metals include calcium and magnesium. Examples of organic ammonium groups include alkyl ammonium groups having 1 to 12 carbon atoms, such as monomethyl ammonium groups, dimethyl ammonium groups, trimethyl ammonium groups, and tetramethyl ammonium groups.

[0055] The monomer having an anionic group is not particularly limited and examples thereof include acrylic acid, methyl acrylate, methacrylic acid, methyl methacrylate, maleic acid, fumaric acid, malic acid, acrylamide, vinylphosphonic acid, vinylsulfonic acid, allylsulfonic acid, 2-(methacryloyloxy)ethanesulfonic acid, styrenesulfonic acid, isoprene sulfonic acid, methallylsulfonic acid, acrylamidopropylsulfonic acid, itaconic acid, phosphonic acid, phosphoric acid, vinylphosphoric acid, butadiene-maleic acid, caprolactam etherimide, N-isopropylacrylamide, etc. Furthermore, the monomer having an anionic group may be an alkali metal salt, alkaline earth metal salt, ammonium salt, etc. of these exemplified monomers.

[0056] Specific examples of water-soluble polymers include polyacrylic acid, polymethacrylic acid, polymaleic acid, polyacrylic acid copolymers, polyacrylic acid-maleic acid copolymers, polyacrylic acid-acrylamide copolymers, polyacrylic acid-sulfonic acid copolymers, polystyrene sulfonic acid, polyethylene sulfonic acid, ammonium polystyrene sulfonate, polystyrene sulfonic acid-acrylic acid copolymers, polystyrene sulfonic acid-methacrylic acid copolymers, polystyrene sulfonic acid-maleic acid copolymers, polyisoprene sulfonic acid, polynaphthalene sulfonic acid, polyvinyl sulfonic acid, polymethallyl sulfonic acid, poly(2-(methacrylamido-2-methylpropanesulfonic acid)), poly(2-acrylamido-2-methyl-1-propanesulfonic acid), polyvinyl phosphonic acid, polyphosphoric acid, polyvinyl phosphoric acid, polyphosphonic acid, carboxymethylcellulose, starch phosphate, alginic acid, gum arabic, carrageenan, chondroitin sulfate, hyaluronic acid, gelatin, polyaspartic acid, and sodium dextran sulfate. These polymers can be used alone or in combination of two or more.

[0057] The content of the water-soluble polymer is preferably in the range of 0.0001% by mass or more and 1% by mass or less, and more preferably in the range of 0.001% by mass or more and 0.1% by mass or less, based on the total mass of the fine processing treatment agent. By making the content of the water-soluble polymer 0.0001% by mass or more, it is possible to effectively prevent the etching rate of the silicon nitride film from becoming too high. On the other hand, by making the content of the water-soluble polymer 1% by mass or less, it is possible to prevent an increase in metal impurities, particles, etc. derived from the water-soluble polymer in the fine processing treatment agent. The content of the water-soluble polymer is, for example, 0.0001, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0% by mass relative to the total mass of the micro-processing treatment agent, and may also be within a range between any two of the numerical values ​​exemplified here.

[0058] The microfabrication inhibitor, which is the component (c), may be in an embodiment consisting solely of a sulfobetaine compound, or may be in an embodiment consisting solely of a sulfobetaine compound and a water-soluble polymer.

[0059] The water as component (d) is not particularly limited, but pure water, ultrapure water, etc. are preferred.

[0060] The water content is preferably in the range of 50% by mass or more and 99.8899% by mass or less, more preferably in the range of 55% by mass or more and 95% by mass or less, and even more preferably in the range of 70% by mass or more and 95% by mass or less, based on the total mass of the fine processing treatment agent.

[0061] The microprocessing treatment agent of this embodiment may consist solely of hydrogen fluoride, ammonium fluoride, a microprocessing inhibitor, and water. Furthermore, the microprocessing treatment agent of this embodiment may further contain other additives as long as the effects of the present invention are not impaired. Examples of other additives include surfactants, water-soluble organic solvents, organic acids, hydrogen peroxide, chelating agents, and nonionic water-soluble polymers. Examples of surfactants include ammonium dodecyl sulfate. Examples of water-soluble organic solvents include 2-propanol. Examples of organic acids include acetic acid and methanesulfonic acid. Examples of chelating agents include ethylenediaminetetraacetic acid. Examples of nonionic water-soluble polymers include polyethylene glycol, polyvinyl alcohol, and cellulose. The content of these other additives is not particularly limited and can be appropriately determined depending on the purpose.

[0062] The method for producing the fine processing treatment agent according to the present embodiment is not particularly limited, and various methods can be adopted. For example, the fine processing treatment agent according to the present embodiment can be produced by adding ammonium fluoride, a sulfobetaine compound, an optional water-soluble polymer, and other optional additives to hydrofluoric acid in any order or simultaneously.

[0063] (Micro-processing method) Next, a micro-processing method using the micro-processing treatment agent of this embodiment will be described below. The micro-processing method of this embodiment is suitable for performing micro-processing on a laminated film including at least a silicon oxide film and a silicon nitride film.

[0064] The silicon oxide film is not particularly limited as long as it contains silicon (Si) and oxygen (O). Specific examples include a natural oxide film, a chemical oxide film, a silicon oxide film, a non-doped silicate glass film, a phosphorus-doped silicate glass film, a boron-doped silicate glass film, a boron-phosphorus-doped silicate glass film, a TEOS (Tetraethyl Orthosilicate) film, a fluorine-containing silicon oxide film, a carbon-containing silicon oxide film, a nitrogen-containing silicon oxide film, an SOG (Spin on Glass) film, and an SOD (Spin on Dielectric) film.

[0065] Here, a native oxide film in silicon oxide film refers to a silicon oxide film formed on silicon during exposure to the atmosphere at room temperature. A chemical oxide film refers to a film formed on silicon during chemical treatment with an oxidizing agent, such as sulfuric acid or hydrogen peroxide. A silicon oxide film is a film formed by thermal oxidation at high temperatures, for example, in the range of 800 to 1000°C, while supplying water vapor or oxygen gas. Non-doped silicate glass films, phosphorus-doped silicate glass films, boron-doped silicate glass films, boron-phosphorus-doped silicate glass films, TEOS films, fluorine-containing silicon oxide films, carbon-containing silicon oxide films, and nitrogen-containing silicon oxide films can be formed by supplying a source gas such as silane and depositing the silicon oxide film using a CVD (chemical vapor deposition) method. SOG films and SOD films can be formed by a coating method such as a spin coater.

[0066] The silicon nitride film is not particularly limited as long as it contains silicon (Si) and nitrogen (N). Specific examples include a silicon nitride film, an oxygen-containing silicon nitride film, and a carbon-containing silicon nitride film.

[0067] The method for forming the silicon nitride film is not particularly limited, and examples thereof include CVD methods using silane gas, dichlorosilane gas, ammonia gas, or other source gases. Examples of the CVD methods include low-pressure chemical vapor deposition (LPCVD), plasma-enhanced CVD, atomic layer deposition (ALD), metal-organic chemical vapor deposition (MOCVD), catalytic chemical vapor deposition (Cat-CVD), thermal CVD, and epitaxial CVD.

[0068] The fine processing agent of the present embodiment is used, for example, for wet etching of the laminated film. Wet etching methods include batch and single-wafer processes, and the fine processing agent of the present invention can be used in either method. Batch wet etching methods are superior in terms of throughput because they can wet-etch a large number of wafers at once. Single-wafer wet etching methods can reduce or prevent the problem of cross-contamination in the etching bath.

[0069] Methods for contacting the fine processing treatment agent with the laminated film include immersion and spraying. Of these contact methods, the immersion method is preferred because it can reduce or suppress changes in composition due to evaporation of the fine processing treatment agent during the process.

[0070] When a fine-processing treatment agent is used as an etching solution, the etching temperature (i.e., the liquid temperature of the fine-processing treatment agent) is preferably within the range of 5°C to 50°C, more preferably within the range of 15°C to 35°C, and even more preferably within the range of 20°C to 30°C. By setting the etching temperature at 50°C or below, evaporation of the fine-processing treatment agent can be suppressed, preventing changes in the composition of the fine-processing treatment agent. Furthermore, difficulty in controlling the etching rate due to evaporation of the fine-processing treatment agent can be prevented. On the other hand, by setting the etching temperature at 5°C or above, crystallization of ammonium fluoride and other optional components contained in the fine-processing treatment agent can be reduced or suppressed, preventing an increase in crystallized particles in the fine-processing treatment agent. Furthermore, a decrease in the etching rate can be prevented. The etching rate for each film constituting the stacked film may vary depending on the etching temperature. Therefore, the difference between the etching rates for a silicon oxide film and a silicon nitride film may also be affected.

[0071] Furthermore, in the microprocessing treatment agent of this embodiment, the etching rate of a silicon oxide film at 25°C is preferably in the range of 0.1 nm / min to 5000 nm / min (1 Å / min to 50,000 Å / min), and more preferably in the range of 1 nm / min to 1000 nm / min (10 Å / min to 10,000 Å / min). By setting the etching rate to 0.1 nm / min or more, it is possible to prevent the processing time of microprocessing such as etching from increasing and suppress a decrease in processing efficiency. On the other hand, by setting the etching rate to 5000 nm / min or less, it is possible to prevent a decrease in film thickness controllability after microprocessing and an increase in surface roughness of the substrate surface (the surface opposite to the surface on which a laminated film such as a silicon oxide film is formed), thereby improving yield. The etching rate of the silicon oxide film at 25° C. is, for example, 0.1, 1, 10, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000, 3000, 4000, or 5000 nm / min, or may be within a range between any two of the values ​​exemplified here.

[0072] Furthermore, in the micro-processing agent of this embodiment, the etching rate of a silicon nitride film at 25°C is preferably in the range of 50 nm / min or less (500 Å / min or less), and more preferably in the range of 10 nm / min or less (100 Å / min or less). By setting the etching rate to 50 nm / min or less, micro-processing such as etching of the silicon nitride film can be suppressed, and selective micro-processing of the silicon oxide film can be further improved. The etching rate of a silicon nitride film at 25°C may be, for example, 0.001, 0.01, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, or 50 nm / min, or may be within a range between any two of the values ​​exemplified here.

[0073] When the micro-processing treatment agent of the present embodiment is used to perform micro-processing on a laminated film, the selectivity (silicon oxide film / silicon nitride film), which represents the ratio of the etching rate of a silicon oxide film to that of a silicon nitride film, is preferably 100 or more, more preferably 120 or more, and even more preferably 160 or more.

[0074] Furthermore, the selectivity is preferably 1.2 times or more, more preferably 1.4 times or more, and even more preferably 1.9 times or more, relative to the selectivity representing the ratio of etching rates when the fine processing treatment agent of the present embodiment does not contain a sulfobetaine compound and a water-soluble polymer.

[0075] As described above, the micro-processing agent and micro-processing method according to the present embodiment can effectively perform selective micro-processing on a silicon oxide film in a laminate film containing at least a silicon oxide film and a silicon nitride film while suppressing micro-processing of the silicon nitride film. Furthermore, the step of forming a protective film on the silicon nitride film to prevent micro-processing of the silicon nitride film can be omitted, thereby suppressing increases in manufacturing costs due to reduced equipment installation and throughput. As a result, the micro-processing agent and micro-processing method according to the present embodiment can be suitably applied to micro-processing processes such as wet etching in the manufacturing processes of semiconductor elements, liquid crystal display elements, microelectronic devices, and the like, which are becoming increasingly highly integrated and miniaturized.

[0076] Preferred examples of the present invention are described in detail below. However, the materials and blending amounts described in these examples are not intended to limit the scope of the present invention unless otherwise specified.

[0077] (Examples 1 to 19) Hydrogen fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 50% by mass), ammonium fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 40% by mass), a sulfobetaine compound, and ultrapure water were mixed and stirred to the blending ratios shown in Tables 1 and 2. The temperature of each of these mixed solutions was then adjusted to 25°C, and the solutions were allowed to stand for 3 hours. In this way, etching solutions (micro-processing treatment agents) according to each Example were prepared. The sulfobetaine compounds used in each Example were those shown in Tables 1, 2, and 4, respectively.

[0078] Examples 20 to 23 Hydrogen fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 50% by mass), ammonium fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 40% by mass), several sulfobetaine compounds, and ultrapure water were mixed and stirred to the blending ratios shown in Table 3. Furthermore, the temperature of each of these mixed solutions was adjusted to 25°C, and the solutions were allowed to stand for 3 hours. In this way, etching solutions (micro-processing treatment agents) according to each Example were prepared. Note that the sulfobetaine compounds used in each Example are shown in Tables 3 and 4, respectively.

[0079] (Comparative Examples 1 to 13) Hydrogen fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 50% by mass), ammonium fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 40% by mass), and ultrapure water were mixed and stirred to the blending ratios shown in Table 5. The liquid temperature of this mixture was then adjusted to 25°C and allowed to stand for 3 hours. In this way, etching solutions (micro-processing treatment agents) according to each Comparative Example were prepared.

[0080] (Comparative Examples 14 to 23) Hydrogen fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 50% by mass), ammonium fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 40% by mass), additives, and ultrapure water were mixed and stirred to the blending ratios shown in Table 6. Furthermore, the temperature of each of these mixed solutions was adjusted to 25°C, and the solution was allowed to stand for 3 hours. In this way, etching solutions (micro-processing treatment agents) according to each of Comparative Examples 14 to 23 were prepared. The additives used in each Comparative Example were those shown in Tables 6 and 7, respectively.

[0081] (Solubility Evaluation 1) The etching solutions according to Examples 1 to 23 and Comparative Examples 1 to 23 were visually observed to evaluate the presence or absence of insoluble matter in the etching solution (solubility). The evaluation criteria were as follows. The results are shown in Tables 1 to 3, 5, and 6. ○: The etching solution was transparent or clear, and no insoluble matter was observed. ×: The etching solution was cloudy, or insoluble matter was observed.

[0082] As shown in Tables 1 to 3, no insoluble matter was observed in any of the etching solutions of Examples 1 to 23, confirming that the solubility of ammonium fluoride and the sulfobetaine compound was good. On the other hand, as shown in Table 6, cloudiness or insoluble matter was observed in the etching solutions of Comparative Examples 15, 19, and 20.

[0083] (Evaluation 1 of Etching Rate Selectivity) The etching rate selectivity of a silicon oxide film to a silicon nitride film (silicon oxide film / silicon nitride film) was evaluated for the etching solutions of Examples 1 to 23 and Comparative Examples 1 to 23. The silicon oxide film used was formed by thermal oxidation, and the silicon nitride film used was formed by LPCVD.

[0084] First, the thicknesses of the silicon nitride film and the silicon oxide film before etching were measured using an optical film thickness measuring device (trade name: Nanospec II, manufactured by Onto Innovation Japan, Inc.).

[0085] Next, silicon oxide films and silicon nitride films were etched at an etching temperature of 25°C using the etching solutions of Examples 1 to 23 and Comparative Examples 1 to 23. The thicknesses of the silicon oxide films and silicon nitride films after etching were repeatedly measured at three different etching times to calculate the etching rates. The results are shown in Tables 1 to 3, 5, and 6. The silicon oxide films and silicon nitride films were immersed in each etching solution for etching. Furthermore, the selectivity ratio (silicon oxide film / silicon nitride film) of the etching rate of the silicon oxide film relative to the silicon nitride film was calculated.

[0086] As can be seen from Tables 1 to 3, 5, and 6, the etching solutions of Examples 1 to 23 to which a sulfobetaine compound was added were confirmed to have an improved selectivity ratio (silicon oxy-oxidized film / silicon nitride film) of the etching rate of a silicon oxide film to a silicon nitride film, compared to the etching solutions of Comparative Examples 1 to 13 to which no sulfobetaine compound was added and the etching solutions of Comparative Examples 14 to 23 to which an additive shown in Table 7 was added instead of a sulfobetaine compound.

[0087] Furthermore, in the etching solutions of Comparative Examples 22 and 23, the etching rate of the silicon nitride film was decreased, and although the etching suppression effect was confirmed, the etching rate of the silicon oxide film was also significantly decreased. As a result, the etching selectivity ratio of the silicon oxide film to the silicon nitride film was also decreased, and the expected selective etching performance for the silicon oxide film was not obtained.

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[0092]

[0093]

[0094]

[0095] Here, a graph showing the relationship between the number of carbon atoms in the alkyl group of a sulfobetaine compound, the etching rate of a silicon nitride film, and the selectivity ratio of the etching rate of a silicon oxide film to that of a silicon nitride film is shown in Figure 1. C8, C10, C12, C14, and C16 on the horizontal axis of Figure 1 represent the etching solutions of Examples 1 to 5, respectively, and C4 and C18 represent the etching solutions of Comparative Examples 14 and 15, respectively. Furthermore, "No SB added" represents the etching solution of Comparative Example 1, which does not contain a sulfobetaine compound.

[0096] 1 , when the alkyl group of the sulfobetaine compound has 8 or more carbon atoms, the etching suppression effect on the silicon nitride film and the etching rate selectivity of the silicon oxide film relative to the silicon nitride film were observed to be improved. Furthermore, the etching rate selectivity was best when a sulfobetaine compound with an alkyl group having 16 carbon atoms was used. On the other hand, the etching rate selectivity decreased in Comparative Example 1, in which no sulfobetaine compound was added, Comparative Example 14, in which the alkyl group had 4 carbon atoms, and Comparative Example 15, in which the alkyl group had 18 carbon atoms.

[0097] Examples 24 to 28 Hydrogen fluoride (Semiconductor grade high purity, concentration 50% by mass, manufactured by Stella Chemifa Corporation), ammonium fluoride (Semiconductor grade high purity, concentration 40% by mass, manufactured by Stella Chemifa Corporation), a sulfobetaine compound, ultrapure water, and additives were mixed and stirred to the blending ratios shown in Table 8. The temperature of each of these mixed solutions was adjusted to 25°C and allowed to stand for 3 hours. In this way, etching solutions (micro-processing treatment agents) according to each Example were prepared. The etching solutions according to Examples 24 to 28 differ from the etching solution according to Example 4 in that the additives shown in Table 8 were added and the content of ultrapure water was changed to the value shown in Table 8.

[0098] The sulfobetaine compounds and additives used in each example are shown in Table 8. Details of each additive shown in Table 8 are as follows: Ammonium dodecyl sulfate: manufactured by Sigma-Aldrich LLC; 2-propanol: manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.; Acetic acid: manufactured by Hayashi Pure Chemical Industries, Ltd.; Methanesulfonic acid: manufactured by Hayashi Pure Chemical Industries, Ltd.; Ethylenediaminetetraacetic acid: manufactured by Tokyo Chemical Industry Co., Ltd.

[0099] (Solubility Evaluation 2) The presence or absence of insoluble matter in the etching solutions of Examples 24 to 28 was evaluated by visual observation in the same manner as described above. The results are shown in Table 8.

[0100] (Evaluation 2 of Etching Rate Selectivity) The etching rate selectivity of a silicon oxide film relative to a silicon nitride film (silicon oxide film / silicon nitride film) was evaluated for the etching solutions of Examples 24 to 28 in the same manner as described above. The silicon oxide film used was formed by thermal oxidation, and the silicon nitride film used was formed by LPCVD. The results are shown in Table 8.

[0101] As can be seen from Table 8, the etching solutions of Examples 24 to 28 showed no significant difference in the selectivity of the etching rate compared to the etching solution of Example 4. As a result, it was confirmed that adding ammonium dodecyl sulfate, which is a surfactant, 2-propanol, which is an organic solvent, acetic acid and methanesulfonic acid, which are organic acids, or ethylenediaminetetraacetic acid, which is a chelating agent, to the fine-processing treatment agent of the present invention does not impair the effect of the present invention (i.e., selective fine-processing of silicon oxide films relative to silicon nitride films), and therefore these additives can be added to the fine-processing treatment agent of the present invention.

[0102]

[0103] Examples 29 to 43 Hydrogen fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 50% by mass), ammonium fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 40% by mass), a sulfobetaine compound, an anionic water-soluble polymer, and ultrapure water were mixed and stirred to obtain the blending ratios shown in Tables 9 and 10. Furthermore, the temperature of each of these mixed solutions was adjusted to 25°C, and the solution was allowed to stand for 3 hours. In this way, an etching solution (micro-processing treatment agent) according to each Example was prepared.

[0104] The sulfobetaine compounds and anionic water-soluble polymers used in each example are shown in Tables 9 and 10. Details of each anionic water-soluble polymer shown in Tables 9 and 10 are as follows: Ammonium polystyrene sulfonate: concentration 30% by mass, mass average molecular weight 200,000, manufactured by Sigma-Aldrich LLC. Polystyrene sulfonic acid-methacrylic acid copolymer: mass average molecular weight 20,000, trade name NARLEX D72, manufactured by Nouryon Inc. Polyacrylic acid copolymer: concentration 40% by mass, mass average molecular weight 8,000, trade name A-6114, manufactured by Toagosei Co., Ltd. Polyacrylic acid-sulfonic acid copolymer: concentration 40% by mass, mass average molecular weight 10,000, trade name A-6020, manufactured by Toagosei Co., Ltd. Poly(2-acrylamido-2-methyl-1-propanesulfonic acid): concentration 15% by mass, mass average molecular weight 2,000,000, manufactured by Sigma-Aldrich LLC. Dextran sulfate sodium: mass average molecular weight 1500-1900, sulfur content 15.0-20.0%, product name: Dextran sulfate sodium sulfur-18, manufactured by Meito Sangyo Co., Ltd.

[0105] Examples 44 to 46 Hydrogen fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 50% by mass), ammonium fluoride (manufactured by Stella Chemifa Corporation, high-purity grade for semiconductors, concentration 40% by mass), a sulfobetaine compound, additives, and ultrapure water were mixed and stirred to obtain the blending ratios shown in Table 11. Furthermore, the temperature of each of these mixed solutions was adjusted to 25°C, and the solution was allowed to stand for 3 hours. In this way, an etching solution (micro-processing treatment agent) according to each Example was prepared.

[0106] The sulfobetaine compounds and additives used in each example are shown in Table 11. The details of each additive shown in Table 11 are as follows: Polyethylene glycol (non-ionic): mass average molecular weight 1000, Tokyo Chemical Industry Co., Ltd. Polyvinyl alcohol (non-ionic): mass average molecular weight 500, fully saponified, Fujifilm Wako Pure Chemical Industries, Ltd. Cellulose (non-ionic, microcrystalline): Hayashi Pure Chemical Industries, Ltd.

[0107] (Solubility Evaluation 3) The presence or absence of insoluble matter in the etching solutions of Examples 29 to 46 was evaluated by visual observation in the same manner as described above. The results are shown in Tables 9 to 11.

[0108] (Evaluation 3 of Etching Rate Selectivity) The etching rate selectivity of a silicon oxide film relative to a silicon nitride film (silicon oxide film / silicon nitride film) was evaluated for the etching solutions of Examples 29 to 46 in the same manner as described above. The silicon oxide film used was formed by thermal oxidation, and the silicon nitride film used was formed by LPCVD. The results are shown in Tables 9 to 11.

[0109] As can be seen from Tables 9 and 10, the etching solutions of Examples 29 to 43, which used a sulfobetaine compound and an anionic water-soluble polymer as a microfabrication inhibitor, were able to improve the selectivity ratio of the etching rate of a silicon oxide film to a silicon nitride film (silicon oxide film / silicon nitride film) by 1.5 times or more, compared to Comparative Example 1, which did not contain these microfabrication inhibitors.

[0110] Furthermore, the etching solutions of Examples 29 to 43, which used a sulfobetaine compound and a water-soluble polymer as the microfabrication inhibitor, were able to achieve the same or even better etching rate selectivity as the etching solutions of Examples 1 and 2, which used only a sulfobetaine compound as the microfabrication inhibitor. Furthermore, the etching solutions of Examples 29 to 35 were able to achieve the same or higher etching rate selectivity as the etching solution of Example 1, even when the amount of sulfobetaine compound added was reduced, and it was therefore possible to achieve a high purity microfabrication treatment agent and reduce costs.

[0111] Furthermore, as can be seen from Tables 10 and 11, it was confirmed that the etching solutions of Examples 36 to 43, which used a sulfobetaine compound and an anionic water-soluble polymer as a micro-fabrication inhibitor, were able to further improve the selectivity ratio of the etching rate of a silicon oxide film to a silicon nitride film (silicon oxy-thermalized film / silicon nitride film) compared to the etching solutions of Examples 44 to 46, which used a sulfobetaine compound and a polymer shown in Table 11.

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[0114]

Claims

1. A fine-processing treatment agent used for fine-processing of a laminated film containing at least a silicon oxide film and a silicon nitride film, comprising: (a) hydrogen fluoride in a content of 0.01% by mass or more and 30% by mass or less relative to the total mass of the fine-processing treatment agent; (b) ammonium fluoride in a content of 0.1% by mass or more and 40% by mass or less relative to the total mass of the fine-processing treatment agent; (c) a fine-processing inhibitor that inhibits fine-processing of the silicon nitride film; and (d) water, wherein the fine-processing inhibitor contains at least one sulfobetaine compound represented by the following chemical formula (1): (In the formula, R １ , R ２ and R ３ are each independently a chain alkyl group having 17 or less carbon atoms; or a chain alkyl group having 17 or less carbon atoms and at least one of a heteroatom or an unsaturated bond, and further, R １ , R ２ and R ３ At least one of R is a chain alkyl group having 5 to 17 carbon atoms; or a chain alkyl group having 5 to 17 carbon atoms and at least one of a heteroatom or an unsaturated bond. ４ represents a chain alkyl group having 2 to 4 carbon atoms; or a chain alkyl group having 2 to 4 carbon atoms and at least one of a heteroatom or an unsaturated bond.

2. The micro-processing treatment agent according to claim 1, wherein the micro-processing inhibitor further comprises an anionic water-soluble polymer.

3. The fine processing treatment agent according to claim 1, wherein the content of the sulfobetaine compound is in the range of 0.0001% by mass or more and 1% by mass or less relative to the total mass of the fine processing treatment agent.

4. The anionic water-soluble polymer is a polymer or copolymer of a monomer having an anionic group, and the anionic group is a -COOM group, -SO ３ M group, -OSO ３ M group, and -OPO ３ M ２ 3. The fine processing treatment agent according to claim 2, wherein M is at least one functional group selected from the group consisting of groups (wherein M represents any one of a hydrogen atom, an alkali metal, an alkaline earth metal, an ammonium group, and an organic ammonium group).

5. The fine processing treatment agent according to claim 2, wherein the content of the anionic water-soluble polymer is in the range of 0.0001% by mass or more and 1% by mass or less relative to the total mass of the fine processing treatment agent.

6. A micro-processing method for a laminated film containing at least a silicon oxide film and a silicon nitride film, comprising using a micro-processing treatment agent according to any one of claims 1 to 5 to selectively micro-process the silicon oxide film relative to the silicon nitride film.

7. The fine processing method according to claim 6, wherein a selectivity ratio (silicon oxide film / silicon nitride film) representing the ratio of the etching rate of the silicon oxide film to the silicon nitride film when the fine processing treatment agent is used is 1.4 times or more the selectivity ratio representing the ratio of the etching rates when the fine processing treatment agent does not contain the fine processing inhibitor.

8. The micro-processing method according to claim 7, wherein the silicon nitride film is formed by low-pressure chemical vapor deposition, and the silicon oxide film is formed by thermal oxidation.

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