Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K13/00—Etching, surface-brightening or pickling compositions
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/01—Manufacture or treatment
  • H10D30/019—Manufacture or treatment of FETs having stacked nanowire, nanosheet or nanoribbon channels
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D30/00—Field-effect transistors [FET]
  • H10D30/01—Manufacture or treatment
  • H10D30/021—Manufacture or treatment of FETs having insulated gates [IGFET]
  • H10D30/025—Manufacture or treatment of FETs having insulated gates [IGFET] of vertical IGFETs
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/60—Wet etching
  • H10P50/64—Wet etching of semiconductor materials
  • H10P50/642—Chemical etching
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/69—Etching of wafers, substrates or parts of devices using masks for semiconductor materials
  • H10P50/691—Etching of wafers, substrates or parts of devices using masks for semiconductor materials for Group V materials or Group III-V materials

Definitions

• the present invention relates to an etching solution, an etching method, and a method for manufacturing semiconductor devices.
• a nanosheet or nanowire-like channel is covered with a gate electrode, increasing the contact area between the channel and gate electrode, thereby improving the transistor performance per unit area.
• VFETs have a structure in which nanosheet or nanowire-like channels are stacked vertically, making the area of the standard cell layout smaller than that of a planar transistor (HFET), thereby improving the transistor performance per unit area.
• HFET planar transistor
• Patent Documents 1 and 2 disclose etching solutions that contain alkaline compounds as etching solutions that dissolve silicon.
• Patent Documents 1 and 2 are inferior in selectively dissolving the 110 face of a silicon crystal compared to the 100 face of a silicon crystal.
• the present invention has been made in view of the above problems, and an object of the present invention is to provide an etching solution that has excellent selective dissolution ability for the 110 plane of a silicon crystal relative to the 100 plane of a silicon crystal. Another object of the present invention is to provide an etching method using the etching solution, a method for manufacturing a semiconductor device, a method for manufacturing a vertical transistor, and a method for manufacturing a gate-all-around transistor.
• pigment dispersion methods, dyeing methods, electrodeposition methods, and printing methods have been known as methods for manufacturing color filters used in liquid crystal displays and the like.
• the pigment dispersion method which has excellent characteristics on average in terms of spectral characteristics, durability, pattern shape, accuracy, and the like, is most widely adopted.
• An etching solution comprising an alkaline compound (A), and at least one compound (B) selected from the group consisting of a thiol compound (B1) and a nonionic surfactant (B2) represented by the following formula (1), wherein ER 110 /ER 100 ⁇ 0.5, where ER 110 is the etching rate for the 110 plane of a silicon crystal, and ER 100 is the etching rate for the 100 plane of a silicon crystal.
• R 1 XO-(C m H 2m O) n -R 2 (1)
• R 1 is an alkyl group having 7 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• X in the formula (1) is a phenylene group.
• etching solution according to any one of [1] to [12], wherein the silicon is single crystal silicon.
• An etching method comprising etching a silicon-containing structure using the etching solution according to any one of [1] to [13].
• a method for manufacturing a semiconductor device comprising the step of etching a silicon-containing structure using the etching solution according to any one of [1] to [13].
• a method for manufacturing a vertical transistor comprising the step of etching a silicon-containing structure with the etching solution according to any one of [1] to [13].
• a method for manufacturing a gate-all-around transistor comprising the step of etching a silicon-containing structure with the etching solution according to any one of [1] to [13].
• a method for etching a silicon-containing structure comprising the step of selectively etching a 110 plane of a silicon crystal relative to a 100 plane of the silicon crystal, using an etching solution containing an alkaline compound (A) and at least one compound (B) selected from the group consisting of a thiol compound (B1) and a nonionic surfactant (B2) represented by the following formula (2): R 1 XO-(C m H 2m O) n -R 2 (2)
• R 1 is an alkyl group having 1 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• a method for manufacturing a semiconductor device comprising a step of selectively etching a 110 plane of a silicon crystal relative to a 100 plane of the silicon crystal, using an etching solution containing an alkaline compound (A) and at least one compound (B) selected from the group consisting of a thiol compound (B1) and a nonionic surfactant (B2) represented by the following formula (2): R 1 XO-(C m H 2m O) n -R 2 (2)
• R 1 is an alkyl group having 1 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• the etching solution of the present invention is excellent in selectively dissolving the 110 plane of a silicon crystal relative to the 100 plane of a silicon crystal.
• the etching method of the present invention, the semiconductor device manufacturing method of the present invention, the vertical transistor manufacturing method of the present invention, and the gate-all-around transistor manufacturing method of the present invention have excellent selective solubility of the 110 plane of a silicon crystal relative to the 100 plane of a silicon crystal in the etching step, and therefore can perform highly accurate etching to manufacture desired products with good yields.
• the etching solution of the present invention contains an alkaline compound (A) (hereinafter, sometimes referred to as “component (A)”), and at least one compound (B) (hereinafter, sometimes referred to as “component (B)”) selected from the group consisting of a thiol compound (B1) (hereinafter, sometimes referred to as “component (B1)”) and a nonionic surfactant (B2) (hereinafter, sometimes referred to as “component (B2)”) represented by the following formula (1), and is excellent in selective solubility of the 110 face of a silicon crystal relative to the 100 face of a silicon crystal.
• the etching solution of the present invention preferably further contains water (hereinafter, sometimes referred to as "component (C)").
• R 1 XO-(C m H 2m O) n -R 2 (1)
• R 1 is an alkyl group having 7 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• the reason why the etching solution of the present invention has superior selective solubility in the 110 plane of a silicon crystal relative to the 100 plane of a silicon crystal is believed to be as follows. When silicon crystal is etched using the etching solution of the present invention, the silicon is dissolved by component (A) and the Si ⁇ + on the surface of the silicon crystal is adsorbed and protected by covalent bonds by component (B).
• the adsorption and protection of the surface of the silicon crystal by component (B) is easier for the 100 plane than for the 110 plane.
• the etching solution of the present invention has excellent selective solubility of the 110 plane of the silicon crystal relative to the 100 plane of the silicon crystal.
• the component (A) is an alkaline compound (A).
• the etching liquid of the present invention contains the alkaline compound (A)
• the etching liquid has excellent silicon solubility.
• Component (A) includes, for example, organic alkali compounds such as quaternary ammonium hydroxide compounds, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide; and inorganic alkali compounds such as metal hydroxides, such as sodium hydroxide, potassium hydroxide, and calcium hydroxide.
• organic alkali compounds such as quaternary ammonium hydroxide compounds, such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide
• inorganic alkali compounds such as metal hydroxides, such as sodium hydroxide, potassium hydroxide, and calcium hydroxide.
• quaternary ammonium hydroxide compounds potassium hydroxide, and calcium hydroxide are preferred, since they have a low content of sodium, which is likely to affect transistor performance, and quaternary ammonium hydroxide compounds are more preferred, and tetramethylammonium hydroxide and tetrabutylammonium hydroxide are even more preferred.
• the content of component (A) is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and even more preferably 0.5 mass % or more, in 100 mass % of the etching solution, because component (A) has excellent silicon solubility. Because of its excellent solubility in water, the content of the component (A) is preferably 39.99% by mass or less, more preferably 34.95% by mass or less, and even more preferably 29.92% by mass or less, in 100% by mass of the etching solution.
• the component (B) is at least one compound (B) selected from the group consisting of a thiol compound (B1) and a nonionic surfactant (B2).
• the etching solution of the present invention has excellent selective adsorption properties for the 100-face of silicon crystal.
• the component (B1) is a thiol compound (B1).
• the thiol compound (B1) in the present invention may be one that decomposes in the etching solution to generate a thiol compound, and therefore, a compound that decomposes in the etching solution to generate a thiol compound, such as a disulfide compound, also falls under the component (B1) according to the present invention. That is, the etching solution of the present invention may contain a disulfide compound as the component (B1).
• Component (B1) is preferably a compound having a hydrocarbon group and a thiol group, as this has excellent adsorption stability on the silicon crystal surface, and more preferably a compound having a hydrophobic hydrocarbon group and a thiol group.
• component (B1) examples include thioglycerol, thioglycolic acid, ethanolamine thioglycolate, 8-mercaptooctanoic acid, 1-octanethiol, 1-undecanethiol, 1-dodecanethiol, 11-mercapto-1-undecanol, 11-mercaptoundecanoic acid, 16-mercaptohexadecanoic acid, 4,4'-dithiodibutyric acid, bis(2-hydroxyethyl) disulfide, didodecane disulfide, etc. These components (B1) may be used alone or in combination of two or more.
• thioglycerol, thioglycolic acid, ethanolamine thioglycolate, 1-octanethiol, 1-undecanethiol, 1-dodecanethiol, 11-mercapto-1-undecanol, 11-mercaptoundecanoic acid, and 16-mercaptohexadecanoic acid are preferred because of their excellent solubility in water, with thioglycerol, thioglycolic acid, ethanolamine thioglycolate, 11-mercaptoundecanoic acid, and 16-mercaptohexadecanoic acid being more preferred, and 11-mercaptoundecanoic acid and 16-mercaptohexadecanoic acid being even more preferred.
• the component (B2) is a nonionic surfactant (B) represented by the following formula (1).
• R 1 is an alkyl group having 7 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• R1 is an alkyl group having 7 or more carbon atoms, and is preferably an alkyl group having 7 to 12 carbon atoms because it has excellent hydrophobic adsorptivity to the silicon surface at the hydrogen end.
• R2 is a hydrogen atom or an alkyl group, and is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, because they have excellent solubility in water.
• X is a single bond or a phenylene group, and a phenylene group is preferred because it has excellent adsorption stability on the silicon surface.
• m is an integer of 1 to 6, and preferably 1 to 3 because this provides excellent solubility in water.
• n is from 4 to 25, and preferably from 8 to 25, because this provides excellent solubility in water and excellent adsorption stability on the silicon surface.
• component (B2) examples include octylphenol ethoxylate, polyethylene glycol mono-4-nonylphenyl ether, polyoxyethylene lauryl ether, etc. These components (B2) may be used alone or in combination of two or more. Among these components (B2), octylphenol ethoxylate, polyethylene glycol mono-4-nonylphenyl ether, and polyoxyethylene lauryl ether are preferred because of their excellent hydrophobic adsorption to the silicon surface of the hydrogen terminal, with octylphenol ethoxylate and polyethylene glycol mono-4-nonylphenyl ether being more preferred, and octylphenol ethoxylate being even more preferred.
• the content of component (B) is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and even more preferably 0.08 mass% or more, in 100 mass% of the etching solution, because it has excellent selective adsorption ability for the 100 mass% of silicon crystal. Because of its excellent solubility in water, the content of the component (B) is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less, in 100% by mass of the etching solution.
• the content can be 0.0001 mass % or more, or 0.0002 mass % or more, or 0.0003 mass % or more in 100 mass % of the etching solution, since the component (B2) has excellent selective adsorption ability for the 100-face of silicon crystal.
• its content can be 0.001 mass % or less, or 0.0009 mass % or less, or 0.0008 mass % or less, based on 100 mass % of the etching solution, from the viewpoint of preventing foaming.
• the etching solution of the present invention preferably contains water (component (C)) in addition to the components (A) and (B).
• the content of the component (C) is preferably 60% by mass or more, more preferably 65% by mass or more, and even more preferably 70% by mass or more, in 100% by mass of the etching solution, because the etching solution is easy to produce and the solubility of the components (A) and (B) is excellent. Because the component (C) has excellent silicon solubility, the content of the component (C) is preferably 99.5% by mass or less, more preferably 98% by mass or less, and even more preferably 95% by mass or less, in 100% by mass of the etching solution.
• the etching solution of the present invention may contain other components in addition to the component (A), the component (B), and the component (C) as long as the effects of the present invention are not impaired. However, there may be cases in which the etching solution does not contain any components other than the component (A), the component (B), and the component (C). For example, the content of other components may be 0.001% by mass or less in 100% by mass of the etching solution. In other cases, the etching solution may be substantially free of other components. An etching solution that is substantially free of other components means that the content of other components in 100% by mass of the etching solution is 0% by mass to 0.00001% by mass. Examples of other components that may be contained include a chelating agent, a water-miscible solvent, an oxidizing agent, a cationic surfactant, and an anionic surfactant.
• the etching solution of the present invention contains a chelating agent, which exerts a chelating effect on the adsorption of silicon to each crystal surface.
• chelating agents examples include amine compounds, amino acids, and organic acids. These chelating agents may be used alone or in combination of two or more. Among these chelating agents, amine compounds, amino acids, and organic acids are preferred because of their excellent chelating effect, and amine compounds are more preferred.
• amine compounds include ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, diethylenetriaminepentakis(methylphosphonic acid), ethylenediamine-N,N'-bis[2-(2-hydroxyphenyl)acetic acid], N,N'-bis(3-aminopropane)ethylenediamine, N-methyl-1,3-diaminopropane, 2-aminoethanol, N-methyldiethanolamine, 2-amino-2-methyl-1-propanol, etc.
• amine compounds may be used alone or in combination of two or more.
• amino acids examples include glycine, arginine, histidine, (2-dihydroxyethyl)glycine, etc. These amino acids may be used alone or in combination of two or more. Among these amino acids, glycine, arginine, histidine, and (2-dihydroxyethyl)glycine are preferred because of their excellent chelating effect, and (2-dihydroxyethyl)glycine is more preferred.
• organic acids examples include oxalic acid, citric acid, tartaric acid, malic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid. These organic acids may be used alone or in combination of two or more. Among these organic acids, oxalic acid, citric acid, tartaric acid, malic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid are preferred because of their excellent chelating effect, and citric acid and 2-phosphonobutane-1,2,4-tricarboxylic acid are more preferred.
• the content of the chelating agent is preferably 0.001 mass% or more, more preferably 0.005 mass% or more, and even more preferably 0.01 mass% or more, in terms of excellent chelating effect, based on 100 mass% of the etching solution.
• the content of the chelating agent is preferably 25 mass% or less, more preferably 10 mass% or less, and even more preferably 6 mass% or less, in 100 mass% of the etching solution, because the chelating agent has excellent solubility in water.
• the etching solution of the present invention contains a water-miscible solvent, which has the effect of making hydrophobic substances that are not miscible with water miscible with water.
• the water-miscible solvent may be any solvent having excellent solubility in water, and is preferably a solvent having a solubility parameter (SP value) of 7.0 (cal/cm 3 ) 1/2 or more, more preferably 9.0 (cal/cm 3 ) 1/2 or more.
• SP value solubility parameter
• water-miscible solvents examples include polar protic solvents such as isopropanol, ethylene glycol, propylene glycol, methanol, ethanol, propanol, butanol, glycerol, and 2-(2-aminoethoxyethanol); polar aprotic solvents such as acetone, dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, and acetonitrile; and non-polar solvents such as hexane, benzene, toluene, and diethyl ether. These water-miscible solvents may be used alone or in combination of two or more.
• polar protic solvents such as isopropanol, ethylene glycol, propylene glycol, methanol, ethanol, propanol, butanol, glycerol, and 2-(2-aminoethoxyethanol)
• polar aprotic solvents such as acetone, di
• the content of the water-miscible solvent is preferably 5% by mass or less, more preferably 1% by mass or less, based on 100% by mass of the etching solution, and most preferably does not contain any water-miscible solvent.
• the mass ratio of component (B) to component (A) in the etching solution of the present invention is preferably 0.001 to 2, more preferably 0.003 to 2, even more preferably 0.005 to 1, and even more preferably 0.01 to 0.5, because this provides an excellent balance between the solubility of silicon and the selective adsorption of the 100-face of silicon crystal.
• the mass ratio of component (A) to component (C) is preferably 0.001 to 0.7, more preferably 0.003 to 0.6, and even more preferably 0.005 to 0.5, since this provides excellent silicon solubility.
• the mass ratio of component (B) to component (C) is preferably 0.0001 to 0.08, more preferably 0.0005 to 0.03, and even more preferably 0.001 to 0.01, since this provides excellent selective adsorption of the 100 face of silicon crystal.
• the method for producing the etching solution of the present invention is not particularly limited, and the etching solution can be produced by mixing component (A), component (B), and, if necessary, component (C) and other components.
• the order of mixing is not particularly limited, and all of the components may be mixed at once, or some of the components may be mixed in advance and then the remaining components may be mixed.
• the pH of the etching solution of the present invention is preferably 8 to 14, more preferably 9 to 14, and even more preferably 10 to 14, in view of excellent silicon solubility.
• the oxygen concentration of the etching solution of the present invention is preferably 10 ppm by mass or less, more preferably 5 ppm by mass or less, and even more preferably 1 ppm by mass or less, in order to suppress the complete oxidation of silicon.
• the etching rate ER 110 for the (110) plane of silicon crystal is preferably 1 nm/min or more, more preferably 1.5 nm/min or more, and even more preferably 2 nm/min or more, because this provides excellent efficiency in forming nano shapes in the horizontal direction.
• the etching rate ER 100 for the (100) plane of silicon crystal is preferably 50 nm/min or less, more preferably 30 nm/min or less, and even more preferably 10 nm/min or less, because this provides excellent efficiency in forming nano shapes in the horizontal direction.
• the etching rate ER 111 for the 111 plane of silicon crystal is preferably 0.5 nm/min or more, more preferably 1.0 nm/min or more, and even more preferably 1.5 nm/min or more, because this is excellent for forming a flat facet for the 110 plane of silicon crystal.
• the selective solubility of the 110 face of a silicon crystal relative to the 100 face of a silicon crystal is 0.5 or more, preferably 0.6 to 10, more preferably 0.7 to 7, and even more preferably 0.8 to 5, because the silicon crystal has excellent melt processability in the horizontal direction.
• the selective solubility of the 111 plane of a silicon crystal relative to the 110 plane of a silicon crystal is preferably 0.2 or more, more preferably 0.3 to 5, and even more preferably 0.4 to 3, since this provides excellent flatness of the 110 plane of a silicon crystal.
• etching rate and selective solubility are measured by the method described in the Examples below.
• the etching solution of the present invention has excellent selective solubility for the 110 face of a silicon crystal relative to the 100 face of a silicon crystal, and is therefore suitable as an etching solution for dissolving silicon, and is particularly suitable as an etching solution for dissolving the 110 face of a silicon crystal relative to the 100 face of a silicon crystal.
• the silicon to be etched is preferably single crystal silicon because it has a crystal plane orientation.
• Single crystal silicon can be produced by known methods, and may be produced by cutting a single crystal ingot or by epitaxial growth.
• the etching method of the present invention is a method for etching a silicon-containing structure using the etching solution of the present invention.
• the etching method of the present invention is a method for etching a silicon-containing structure, comprising a step of selectively etching the 110 face of a silicon crystal relative to the 100 face of the silicon crystal using an etching solution containing an alkaline compound (A) and at least one compound (B) selected from the group consisting of a thiol compound (B1) and a nonionic surfactant (B2) represented by the following formula (2): R 1 XO-(C m H 2m O) n -R 2 (2)
• R 1 is an alkyl group having 1 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• the silicon in the silicon-containing structure has a crystal plane orientation, and is therefore preferably single crystal silicon.
• Single crystal silicon can be produced by known methods, and may be produced by cutting a single crystal ingot or by epitaxial growth.
• the silicon-containing structure may also contain a substance other than silicon.
• substances other than silicon include silicon germanium, silicon oxide, silicon nitride, silicon carbonitride, etc.
• a known etching method can be used, such as a batch method or a single wafer method.
• the temperature during etching is preferably 15° C. or higher, and more preferably 20° C. or higher, since this can improve the etching rate.
• the temperature during etching is preferably 100° C. or less, and more preferably 80° C. or less, in order to suppress damage to the substrate and provide excellent etching stability.
• the temperature during etching corresponds to the temperature of the etching solution during etching.
• the etching solution of the present invention has excellent selective solubility for the 110 face of a silicon crystal relative to the 100 face of a silicon crystal, and is therefore suitable as an etching solution for dissolving silicon, and is particularly suitable as an etching solution for dissolving the 110 face of a silicon crystal relative to the 100 face of a silicon crystal. Therefore, the etching liquid of the present invention is suitable for etching a semiconductor device having a silicon-containing structure, is more suitable for a vertical transistor having a silicon-containing structure and a gate-all-around transistor having a silicon-containing structure, and is particularly suitable for a vertical transistor having a silicon-containing structure.
• the method for producing a semiconductor device of the present invention includes a step of etching a silicon-containing structure using the etching solution of the present invention.
• the present invention provides a method for producing a semiconductor device, comprising the step of selectively etching the 110 plane of a silicon crystal relative to the 100 plane of the silicon crystal, using an etching solution containing an alkaline compound (A) and at least one compound (B) selected from the group consisting of a thiol compound (B1) and a nonionic surfactant (B2) represented by the following formula (2): R 1 XO-(C m H 2m O) n -R 2 (2)
• R 1 is an alkyl group having 1 or more carbon atoms
• R 2 is a hydrogen atom or an alkyl group
• X is a single bond or a phenylene group
• m is an integer of 1 to 6
• n is 4 to 25.
• a silicon substrate having silicon crystals with 110 and 100 plane orientations was immersed in a 0.5 mass% hydrofluoric acid aqueous solution for 3 minutes, and then rinsed with ultrapure water.
• the back surface of the silicon substrate was then masked, and the silicon substrate was immersed in the etching solutions obtained in the Examples and Comparative Examples at 60°C for 10 to 60 minutes.
• the film thickness of the silicon substrate before and after immersion was measured with a spectroscopic interference film thickness meter, and the selective solubility of the 110 plane of the silicon crystal relative to the 100 plane of the silicon crystal was calculated using the following formulas (1) to (3).
• ER 110 [nm/min] (film thickness of silicon substrate before immersion [nm] ⁇ film thickness of silicon substrate after immersion [nm]) ⁇ (immersion time [min]) (1)
• ER 100 [nm/min] (film thickness of silicon substrate before immersion [nm] ⁇ film thickness of silicon substrate after immersion [nm]) ⁇ (immersion time [min]) (2)
• Selective solubility ER 110 [nm/min] ⁇ ER 100 [nm/min] (3)
• a silicon substrate having silicon crystals with 111 and 110 plane orientations was immersed in a 0.5 mass% hydrofluoric acid aqueous solution for 3 minutes, and then rinsed with ultrapure water.
• the back surface of the silicon substrate was then masked, and the silicon substrate was immersed in the etching solutions obtained in the Examples and Comparative Examples at 60°C for 10 to 60 minutes.
• the film thickness of the silicon substrate before and after immersion was measured with a spectroscopic interference film thickness meter, and the selective solubility of the 111 plane of the silicon crystal relative to the 110 plane of the silicon crystal was calculated using the following formulas (4) to (6).
• Example 1-1 The components were mixed so that the etching solution contained 0.56 mass% of component (A-1), 0.10 mass% of component (B-1), and the remainder water in 100 mass% of the etching solution, and nitrogen gas was bubbled through the mixture for 5 minutes to obtain an etching solution.
• the evaluation results of the obtained etching solutions are shown in Table 1.
• Example 1-2 Etching solutions were obtained in the same manner as in Example 1-1, except that the types and contents of the components of the etching solution were changed as shown in Table 1. The evaluation results of the obtained etching solutions are shown in Table 1.
• Example 2-1 The components were mixed so that the etching solution was 100% by mass, with 0.56% by mass of component (A-1), 0.10% by mass of component (B-2), and the remainder being water, to obtain an etching solution.
• the evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-2 An etching solution was obtained in the same manner as in Example 2-1, except that after mixing the components, nitrogen gas was bubbled for 5 minutes. The evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-3 Etching solutions were obtained in the same manner as in Example 2-1, except that the types and contents of the components of the etching solution were changed as shown in Table 2. The evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-4 Except for changing the types and contents of the components of the etching solution as shown in Table 2, the same procedure as in Example 2-2 was carried out to obtain etching solutions. The evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-5 Etching solutions were obtained in the same manner as in Example 2-1, except that the types and contents of the components of the etching solution were changed as shown in Table 2. The evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-6 Except for changing the types and contents of the components of the etching solution as shown in Table 2, the same procedure as in Example 2-2 was carried out to obtain etching solutions. The evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-7 Etching solutions were obtained in the same manner as in Example 2-1, except that the types and contents of the components of the etching solution were changed as shown in Table 2. The evaluation results of the obtained etching solutions are shown in Table 2.
• Example 2-8 Except for changing the types and contents of the components of the etching solution as shown in Table 2, the same procedure as in Example 2-2 was carried out to obtain etching solutions. The evaluation results of the obtained etching solutions are shown in Table 2.
• the etching solutions obtained in the examples had excellent selective solubility of the 110 plane of the silicon crystal relative to the 100 plane of the silicon crystal, and the selective solubility of the 111 plane of the silicon crystal relative to the 110 plane of the silicon crystal was also improved.
• the etching solution obtained in the comparative example was inferior in selective dissolution of the 110 plane of silicon crystal relative to the 100 plane of silicon crystal, and in selective dissolution of the 111 plane of silicon crystal relative to the 110 plane of silicon crystal.
• the etching solution of the present invention has excellent selective solubility for the 110 face of a silicon crystal relative to the 100 face of a silicon crystal, and is therefore suitable as an etching solution for dissolving silicon, and is particularly suitable as an etching solution for dissolving the 110 face of a silicon crystal relative to the 100 face of a silicon crystal. Therefore, the etching liquid of the present invention is suitable for etching a semiconductor device having a silicon-containing structure, is more suitable for a vertical transistor having a silicon-containing structure and a gate-all-around transistor having a silicon-containing structure, and is particularly suitable for a vertical transistor having a silicon-containing structure.

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  • 2024-06-27 JP JP2025530208A patent/JPWO2025005206A1/ja active Pending
  • 2024-06-27 KR KR1020257042331A patent/KR20260027162A/ko active Pending
  • 2024-06-27 WO PCT/JP2024/023438 patent/WO2025005206A1/ja not_active Ceased
  • 2024-06-28 TW TW113124278A patent/TW202518579A/zh unknown

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