Method for forming resist pattern, and processing device

Abstract

This method for forming a resist pattern includes, in order: preparing a layered body that has a substrate and a resist film provided on the substrate, said resist film having an exposed section that is a section that has been exposed by pattern exposure, and an unexposed section that is a section other than the exposed section; and forming a resist pattern by development in which a section of the resist film is removed. The development includes supplying a hydrophilic organic solvent to the layered body, and supplying water to the layered body.

Description

Method for forming resist pattern and processing apparatus

[0001] The present disclosure relates to a method for forming a resist pattern and a processing apparatus.

[0002] Patent Document 1 discloses a developing method including a step of supplying a developing solution containing an organic solvent to a substrate on which a metal-containing coating film has been exposed to a predetermined pattern, and a step of supplying a cleaning solution containing an organic solvent to the substrate to which the developing solution has been supplied.

[0003] JP 2022-96081 A

[0004] One aspect of the present disclosure relates to forming a good resist pattern from a resist film containing a metal oxide photoresist material.

[0005] One aspect of the present disclosure relates to a method for forming a resist pattern, the method comprising: preparing a laminate having a substrate and a resist film provided on the substrate, the resist film having an exposed portion that is a portion exposed by patterned exposure and an unexposed portion that is a portion other than the exposed portion; and forming a resist pattern by developing the resist film to remove a portion of the resist film, the resist film including a metal oxide photoresist material. The developing step includes supplying a hydrophilic organic solvent to the laminate and supplying water to the laminate.

[0006] A good resist pattern can be formed from a resist film containing a metal oxide photoresist material.

[0007] Fig. 1 is a flowchart showing an example of a method for forming a resist pattern. Figs. 2(a), 2(b), and 2(c) are process diagrams showing an example of a method for forming a resist pattern. Figs. 3(a) and 3(b) are process diagrams showing an example of a method for forming a resist pattern. Fig. 4 is a flowchart showing an example of a method for forming a resist pattern. Fig. 5 is a flowchart showing an example of a method for forming a resist pattern. Fig. 6 is a schematic diagram showing an example of a processing apparatus. Fig. 7 is a schematic diagram showing an example of a processing apparatus. Fig. 8 is a schematic diagram showing an example of a developing unit.

[0008] Hereinafter, embodiments of the present disclosure will be described in order to explain the present invention. The present invention should not be limited to the following. In the following description, the same elements or elements having the same functions are designated by the same reference numerals, and redundant description may be omitted.

[0009] An example of a method for forming a resist pattern includes preparing a laminate having a substrate and a resist film provided on the substrate, the resist film having exposed portions that are portions exposed by patternwise exposure and unexposed portions that are portions other than the exposed portions, and forming a resist pattern by developing to remove a portion of the resist film. The development includes supplying a hydrophilic organic solvent to the laminate and supplying water to the laminate. The development using a hydrophilic organic solvent and water may be wet development using a developer containing these. The development using a hydrophilic organic solvent and water may be dry development including exposing the laminate to a developing gas containing these. For development, a liquid or gaseous developing material containing a hydrophilic organic solvent and a liquid or gaseous developing material containing water may be supplied separately to the laminate. For development, a liquid or gaseous developing material containing a hydrophilic organic solvent and water may be supplied to the laminate.

[0010] FIG. 1 is a flowchart showing an example of a method for forming a resist pattern, and FIGS. 2 and 3 are process diagrams showing an example of the method for forming a resist pattern in schematic cross-sectional views. The method for forming the resist pattern shown in FIGS. 1 to 3 includes a step S10 of patternwise exposing a resist film 2 containing a metal oxide photoresist material provided on a substrate 1, a post-exposure bake (PEB) step S20 of baking the resist film 2 after patternwise exposure, a development step S31 of supplying a first developing material containing a hydrophilic organic solvent to a laminate 10 including the substrate 1 and the resist film 2, a development step S32 of supplying a second developing material containing water to the laminate 10, a step S40 of washing the resist pattern 3 formed by development with water, and a post-baking step S50 of heating the washed resist pattern. In the example of FIG. 1 , a laminate 10 including a substrate 1 and a resist film provided on the substrate 1 and having an exposed portion formed by patternwise exposure is prepared by the method including steps S10 and S20.

[0011] The substrate 1 may be, for example, a structure including a semiconductor wafer and a film to be etched formed on the semiconductor wafer. The film to be etched may be, for example, an active layer, a lower insulating film, a gate electrode film, or an upper insulating film.

[0012] The resist film 2 in FIG. 2( a) is formed, for example, by a method including applying a photoresist composition containing a metal oxide photoresist material onto the substrate 1 and baking the applied photoresist composition to form the resist film 2. The photoresist composition may further include a solvent. The photoresist composition is applied onto the substrate 1 by, for example, spin coating. A pre-formed resist film 2 may be laminated on the substrate 1. The thickness of the resist film 2 may be, for example, 1 to 5,000 nm, 10 to 1,000 nm, or 30 to 200 nm.

[0013] The metal oxide photoresist material may include, for example, an organometallic compound including a metal oxide containing a metal atom and an organic ligand bonded to the metal atom. The metal oxide photoresist material may be nanoparticles (particles having a maximum width of less than 1 μm). The metal oxide may be a cage compound.

[0014] The metal oxide of the metal oxide photoresist material may contain at least one metal atom selected from the group consisting of Sn, Sb, In, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, and Lu. The organic ligand bonded to the metal atom of the metal oxide may be, for example, a branched or unbranched alkyl group which may have a substituent, or a cycloalkyl group which may have a substituent. The alkyl group and the cycloalkyl group may be bonded to the metal atom at a primary, secondary, or tertiary carbon atom. The alkyl group and the cycloalkyl group may have 1 to 30 carbon atoms. Examples of the alkyl group as the organic ligand include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-octyl group. Examples of the cycloalkyl group as the organic ligand include a cyclobutyl group, a cyclopropyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group. Examples of the substituents that the alkyl group and cycloalkyl group may have include a cyano group, an alkylthio group, a silyl group, an alkyloxy group, an alkylcarbonyl group, an alkylcarbonyl group, and a halogeno group. Nanoparticles containing a cage-like tin oxide and an organic ligand can be, for example, a nanoparticle of the formula: [(SnR) １２ O １４ (OH) ６ ](OH) ２ (R represents an organic ligand).

[0015] 2(b), pattern exposure in which radiation is irradiated onto a portion of the resist film 2 forms exposed portions 2A, which are exposed portions, and unexposed portions 2B, which are the remaining portions, in the resist film 2. For pattern exposure, radiation may be applied through a mask that transmits radiation to the portions corresponding to the exposed portions 2A. The radiation may be ultraviolet light, and in particular, extreme ultraviolet light (EUV) having a wavelength of around 13.5 nm, excimer laser light (ArF excimer laser light) having a wavelength of 193 nm, or excimer laser light (KrF excimer laser light) having a wavelength of 248 nm.

[0016] The exposed portion 2A may include a main portion 2A1 located in the center and an intermediate portion 2A2 surrounding the main portion 2A1. The exposure dose in the intermediate portion 2A2 is relatively smaller than that in the main portion 2A1. In the main portion 2A1, the formation of hydroxyl groups due to the detachment of organic ligands from metal atoms is likely to proceed sufficiently. Therefore, as a condensation reaction in which metal atoms bond to each other proceeds, hydrophobic aggregates or crosslinked structures that are insoluble in developer are likely to be formed. In the intermediate portion 2A2, the exposure dose is relatively small, so some hydroxyl groups bonded to the metal atoms may remain. Therefore, the intermediate portion 2A2 may be more hydrophilic than the main portion 2A1.

[0017] The post-exposure bake (PEB) can promote a condensation reaction that bonds metal atoms together, particularly in the main portion 2A1 of the exposed portion 2A. Heating for the post-exposure bake can be performed in air or in an inert gas atmosphere such as nitrogen and argon. Regarding the post-exposure bake (PEB), the heating temperature may be 50 to 250°C, and the heating time may be 10 to 300 seconds. The post-exposure bake may be omitted.

[0018] Next, a first developing material containing a hydrophilic organic solvent is supplied to the surface of the laminate 10 facing the resist film 2. A first developing solution may be supplied as the first developing material. The first developing solution may be supplied to the center of the surface of the laminate 10 facing the resist film 2 while rotating the laminate 10 around the central axis in the thickness direction of the substrate 1. A first developing gas containing a hydrophilic organic solvent may be supplied as the first developing material. The first developing material mainly dissolves the unexposed portions 2B of the resist film 2, leaving most of the exposed portions 2A on the substrate 1. The remaining resist film 2 (exposed portions 2A) forms a resist pattern 3 having a pattern including openings 5 ​​through which the substrate 1 is exposed. After development with the first developing material, a small amount of the resist film 2 may remain on the substrate 1 as scum 2C in the openings 5.

[0019] The hydrophilic organic solvent may be an organic solvent that is miscible with water in any ratio at 25°C and 1 atmosphere. The hydrophilic organic solvent may include an alcohol such as an alkyl alcohol. The hydrophilic organic solvent may include at least one alkyl alcohol selected from methanol, ethanol, and isopropyl alcohol. The hydrophilic organic solvent may include methanol, ethanol, or a combination thereof. The hydrophilic organic solvent may include methanol.

[0020] The first developing material may further contain components other than the hydrophilic organic solvent (such as water or a base). The proportion of the hydrophilic organic solvent (or alcohol) in the first developing material (e.g., the first developing solution) may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 99% by mass or more, or may be 100% by mass or less, based on the mass of the first developing material (first developing solution). Alternatively, the proportion of the hydrophilic organic solvent (or alcohol) may be 50% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10% by mass or less, or 5% by mass or less, based on the mass of the first developing material (first developing solution).

[0021] Following development with the first developing material, a second developing material containing water is supplied to the surface of the laminate 10 facing the resist film 2. A second developing solution containing water may be supplied as the second developing material. The second developing solution may be supplied to the center of the surface of the laminate 10 facing the resist film 2 while the laminate 10 is rotated around the central axis in the thickness direction of the substrate 1. A second developing gas containing water may be supplied as the second developing material. As shown in FIG. 3A, the second developing material may primarily remove at least a portion of the scum 2C. The second developing solution containing water is compatible with the first developing solution containing a hydrophilic organic solvent. Therefore, the second developing solution may be supplied to the laminate 10 while the first developing solution remains on the laminate 10 (substrate 1 and / or resist film 2). In this case, a heating (baking) step or other process for removing the first developing solution may be omitted. For example, the second developer can be supplied onto the laminate 10 without removing the first developer by heating, centrifugal force, or a combination thereof. If the rotation speed around the central axis in the thickness direction of the substrate 1 is maintained at, for example, 0 rpm or more and 1500 rpm or less during the period from when the first developer is supplied until when the second developer is supplied, the second developer is likely to be supplied while the first developer remains on the laminate 10.

[0022] The second developing material may contain an alkaline component. The second developing material may be a second developer containing water and an alkaline component. A second developing material or second developer containing water and an alkaline component may particularly efficiently remove scum 2C. The alkaline component contained in the second developing material or second developer may be a quaternary ammonium salt, an amine compound having a primary, secondary, or tertiary amino group, ammonia, an alkali metal compound, or a combination thereof. Examples of quaternary ammonium salts include tetramethylammonium hydroxide, tetraethylammonium hydroxide, and choline. Examples of amine compounds include primary amine compounds such as ethylamine and n-propylamine, secondary amine compounds such as diethylamine and di-n-butylamine, tertiary amine compounds such as triethylamine and methyldiethylamine, and alcohol amine compounds such as dimethylethanolamine and triethanolamine. Examples of alkali metal compounds include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, and sodium metasilicate. The second developing solution may be an alkaline aqueous solution containing water and tetramethylammonium hydroxide.

[0023] When the second developing material containing an alkaline component removes a portion of the resist film 2, particularly the intermediate portion 2A2, the width of the formed resist pattern 3 may be smaller than the target width. If the concentration of the alkaline component in the second developing material (second developer) is low, the width of the resist film 2 (resist pattern 3) remaining after development with the second developing material is less likely to decrease. In other words, a decrease in the width of the resist pattern (shrinkage) can be suppressed. Baking the resist film 2 after development with the first developing material can also contribute to suppressing shrinkage, but by using a second developing material (second developer) containing a low concentration of alkaline component, shrinkage of the width of the resist pattern can be effectively suppressed even if such baking is omitted.

[0024] A second developer containing an alkaline component at a low concentration may be supplied onto the resist film 2 while forming the second developer by diluting a solution containing the alkaline component with water. Alternatively, water may be supplied onto the laminate 10 before the second developer containing the alkaline component is supplied onto the laminate 10, thereby diluting the second developer on the laminate 10.

[0025] The concentration of the alkaline component in the second developing material (second developing solution) may be adjusted so that the width of the resist pattern falls within a standard range determined from the target width value. For example, the concentration of the alkaline component in the second developing material (second developing solution) may be adjusted so that the width of the resist pattern falls within a range of 14 nm to 15 nm. Generally, when the concentration of the alkaline component is low, the width of the resist pattern after development with the second developing material tends to increase. The width of the resist pattern refers to the width of the resist pattern in a direction perpendicular to the thickness direction of the substrate.

[0026] The concentration of the alkaline component in the second developing material (second developing solution) may be 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the second developing material (second developing solution). The concentration of the alkaline component in the second developing material (second developing solution) may be 0% by mass or more, 0.0023% by mass or more, 0.010% by mass or more, or 0.10% by mass or more. The concentration of the alkaline component in the second developing material (second developing solution) may be 0% by mass or more and 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less. The concentration of the alkaline component in the second developing material (second developing solution) may be 0.0023% by mass or more and 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less. The concentration of the alkaline component in the second developing material (second developing solution) may be 0.010% by mass or more and 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less.The concentration of the alkaline component in the second developing material (second developing solution) may be 0.10% by mass or more and 5.0% by mass or less, 4.0% by mass or less, 3.0% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less. In particular, when the alkaline component is tetramethylammonium hydroxide, its concentration may be 2.38% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the second developing material (second developing solution). The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) may be 0% by mass or more, 0.0023% by mass or more, 0.010% by mass or more, or 0.10% by mass or more. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) may be 0% by mass or more and 2.38% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) may be 0.0023% by mass or more and 2.38% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less.The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) may be 0.010% by mass or more and 2.38% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) may be 0.10% by mass or more and 2.38% by mass or less, less than 2.38% by mass, 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less. The second developing solution may be pure water (e.g., deionized water).

[0027] After development with the first and second developing materials, water is supplied as a cleaning liquid onto the laminate 10 including the formed resist film 2 (resist pattern 3) and the substrate 1. The water for cleaning may be pure water (e.g., deionized water). In the present disclosure, the water supplied onto the laminate 10 including the resist film 2 (resist pattern 3) following the second developer containing water is considered to be a cleaning liquid rather than a developer. The step S40 of cleaning with water may be omitted.

[0028] After washing with water, the resist pattern 3 is heated in a post-baking step S50. The post-baking removes the water used for washing and may further promote the formation of aggregates or crosslinked structures containing metal atoms in the resist pattern 3. For the post-baking, the heating temperature may be 100 to 400°C, and the heating time may be 1 to 300 seconds. The post-baking step S50 may be omitted.

[0029] 4 is a flowchart showing another example of a method for forming a resist pattern. The method shown in FIG. 4 differs from the method shown in FIG. 1 in that a step S33 is provided in which a mixed developer material containing a mixed solvent containing a hydrophilic organic solvent and water is supplied onto the laminate 10 after post-exposure baking. Development using the mixed developer material can form a good resist pattern with an even fewer number of steps. A mixed developer solution containing a mixed solvent may be supplied as the mixed developer material. The mixed developer solution may be supplied to the center of the surface of the laminate 10 facing the resist film 2 while rotating the laminate 10 (substrate 1 and resist film 2) around the central axis in the thickness direction of the substrate 1. A mixed developer gas containing a mixed solvent may be supplied as the mixed developer material.

[0030] The hydrophilic organic solvent contained in the mixed solvent of the mixed developing material may be the same as the hydrophilic organic solvent that may be contained in the first developing material. For example, the mixed solvent may contain at least one alkyl alcohol selected from methanol, ethanol, and isopropyl alcohol, and water. The mixed solvent may also contain isopropyl alcohol and water. The proportion of water in the mixed solvent may be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, based on the total amount of the mixed solvent. The proportion of water in the mixed solvent may be 50% by mass or less, 40% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total amount of the mixed solvent. The proportion of water in the mixed solvent may be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, and 50% by mass or less, based on the total amount of the mixed solvent. The proportion of water in the mixed solvent may be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, and 40% by mass or less, based on the total amount of the mixed solvent. The proportion of water in the mixed solvent may be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, and 30% by mass or less, based on the total amount of the mixed solvent. The proportion of water in the mixed solvent may be 1% by mass or more, 2% by mass or more, 3% by mass or more, 4% by mass or more, 5% by mass or more, 6% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, and may be 20% by mass or less, based on the total amount of the mixed solvent.

[0031] The mixed developing material containing a hydrophilic organic solvent and water may further contain an alkaline component. The alkaline component contained in the mixed developing material or mixed developer may be the same as the alkaline component that may be contained in the second developing material or second developer.

[0032] The concentration of the alkaline component (or tetramethylammonium hydroxide) in the mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water may be 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the mixed developing material (mixed developing solution). The concentration of the alkaline component (or tetramethylammonium hydroxide) in the mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water may be 0% by mass or more, 0.0023% by mass or more, 0.010% by mass or more, or 0.10% by mass or more, based on the mass of the mixed developing material (mixed developing solution). The concentration of the alkaline component (or tetramethylammonium hydroxide) in the mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water may be 0% by mass or more and 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the mixed developing material (mixed developing solution). The concentration of the alkaline component (or tetramethylammonium hydroxide) in the mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water may be 0.0023% by mass or more and 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the mixed developing material (mixed developing solution). The concentration of the alkaline component (or tetramethylammonium hydroxide) in the mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water may be 0.010% by mass or more and 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the mixed developing material (mixed developing solution).The concentration of the alkaline component (or tetramethylammonium hydroxide) in the mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water may be 0.10% by mass or more and 2.00% by mass or less, 1.50% by mass or less, 1.00% by mass or less, 0.90% by mass or less, 0.80% by mass or less, 0.70% by mass or less, 0.60% by mass or less, 0.50% by mass or less, 0.40% by mass or less, or 0.24% by mass or less, based on the mass of the mixed developing material (mixed developing solution).

[0033] The mixed developing material may contain a hydrophilic organic solvent (e.g., methanol) and an ionic surfactant. A good resist pattern can also be efficiently formed by using a mixed developing material containing a hydrophilic organic solvent and an ionic surfactant. The mixed developing material containing a hydrophilic organic solvent and an ionic surfactant may be substantially free of water, or may further contain water.

[0034] The ionic surfactant may be a cationic surfactant, a betaine surfactant, or a combination thereof. The cationic surfactant may be a quaternary ammonium salt or a pyridinium salt. An example of a cationic surfactant that is a quaternary ammonium salt includes n-hexadecyltrimethylammonium hydroxide. A betaine surfactant has a quaternary ammonium group and an anionic group (e.g., SO ) as its counterion. ３ － The concentration of the ionic surfactant may be, for example, 1% by mass or more and 20% by mass or less based on the mass of the mixed developing material (mixed developing solution).

[0035] Following the step S33 of one development using the mixed developing material, the resist pattern may be washed with water without undergoing development using another developer. In this respect, the mixed developing material can also be advantageous for reducing the number of steps.

[0036] FIG. 5 is a flowchart showing another example of a method for forming a resist pattern. The method shown in FIG. 5 differs from the method shown in FIG. 1 in that a development step S31 in which a first developer material is supplied to the laminate 10 and a development step S31 in which a second developer material is supplied to the laminate 10 are alternately repeated. The number of repetitions of steps S31 and S32, i.e., the number of combinations of steps S31 and S32, may be two or more, three or more, or five or less. In the example of FIG. 5, after the development step S32 with the second developer material, a development step S31 with a first developer material containing a hydrophilic organic solvent is performed, and the resist pattern is then post-baked. The final development step S31 with the first developer material may be omitted, and the final development may be development with a second developer material containing water (e.g., an alkaline aqueous solution). After the final development step S31 with the first developer material or after the development step S32 with the second developer material, which is an alkaline aqueous solution, a water washing step may be performed. When steps S31 and S32 are repeated, the first developing material or first developer liquid may include methanol, and the second developing material or second developer liquid may be water (e.g., deionized water).

[0037] The substrate 1 may be patterned by selectively etching the portions of the substrate 1 exposed in the openings 5 ​​of the formed resist pattern 3. After patterning the substrate 1, the resist pattern 3 may be removed. The method according to the present disclosure can be used, for example, to manufacture a semiconductor device having an integrated circuit including a patterned film.

[0038] 6 and 7 are schematic diagrams showing an example of a processing apparatus for forming a resist pattern. FIG. 6 also shows an example of an exposure apparatus used in combination with the processing apparatus. FIG. 7 shows an example of the internal configuration of the processing apparatus 20 shown in FIG. 6. The processing apparatus 20 shown in FIGS. 6 and 7 includes a carrier block 24, a processing block 25, and an interface block 26. A resist pattern can be formed on a workpiece W by the processing apparatus 20.

[0039] The carrier block 24 is a block configured to introduce the workpiece W into the processing device 20 and to remove the workpiece W from the processing device 20. The carrier block 24 has a transport device A1 including a transfer arm. The transport device A1 removes the workpiece W accommodated in the carrier C and transfers it to the processing block 25, and receives the workpiece W from the processing block 25 and returns it to the carrier C.

[0040] The processing block 25 has processing modules 11, 12, 13, and 14, which are stacked in this order. Each of the processing modules 11, 12, 13, and 14 incorporates a plurality of processing units U1 and U2, and a transport device A3 that transports works W to these processing units.

[0041] The processing module 11 may be configured to form an underlayer film (a film to be etched) on the surface of a substrate (e.g., a semiconductor wafer) serving as the workpiece W. In the processing module 11, for example, the processing unit U1 may be a liquid processing unit that applies a coating liquid for forming the underlayer film to the workpiece W, and the processing unit U2 may be a heat processing unit that heat-treats the applied coating liquid to form the underlayer film.

[0042] The processing module 12 may be configured to form a resist film on an underlying film (film to be etched) of the workpiece W. In the processing module 12, for example, the processing unit U1 may be a coating unit that applies a photoresist composition to the workpiece W, and the processing unit U2 may be a heat treatment unit that bakes the applied photoresist composition to form a resist film. The workpiece W having the resist film may be transported to the exposure device 30 via the interface block 26, where the resist film may be pattern-exposed with radiation.

[0043] The processing module 13 may be configured to bake the resist film after exposure.

[0044] The processing module 14 may be configured to develop the resist film after pattern exposure and baking with a first developing material and a second developing material, or by mixed development, thereby forming a resist pattern. In the processing module 14, for example, the processing unit U1 may be a developing unit for development, and the processing unit U2 may be a thermal processing unit for baking the resist film or the resist pattern.

[0045] Fig. 8 is a cross-sectional view showing an example of a developing unit 200. The developing unit 200 shown in Fig. 8 is mainly composed of a housing 101, a holding section 110 that holds the workpiece W inside the housing 101, a supply section 120 that supplies the developing solution, a cup 130, and a discharge section 140.

[0046] The holder 110 holds the plate-shaped workpiece W substantially horizontally within the housing 101. The holder 110 is provided so as to be rotatable about the vertical direction and movable up and down. By rotating the holder 110, the workpiece W can be rotated about its central axis in the thickness direction.

[0047] The supply unit 120 is configured to be able to supply the developer to the workpiece W within the housing 101. The supply unit 120 has a first nozzle 121, a second nozzle 122, a first tank 123, a second tank 124, a first pipe 125, and a second pipe 126. The first nozzle 121 and the second nozzle 122 are arranged vertically above the holder 110 within the housing 101. A first developer is stored in the first tank 123. A second developer is stored in the second tank 124. The first pipe 125 connects the first nozzle 121 and the first tank 123. The second pipe 126 connects the second nozzle 122 and the second tank 124. The first developer is supplied from the first nozzle to the workpiece W and a laminate including a resist film. A second developer is supplied from a second nozzle to the workpiece W and the laminate including the resist film.

[0048] The cup 130 has a bottom 131 penetrated by the holder 110 and a wall 132 provided on the peripheral edge of the bottom 131. The wall 132 surrounds the periphery of the workpiece W held at the tip of the holder 110. The cup 130 is configured to catch the developing solution that splashes or drops from the workpiece W.

[0049] The discharge unit 140 has a pipe 141, a switching unit 142 connected to the pipe 141, and a first discharge pipe 143 and a second discharge pipe 144 connected to the switching unit 142. The pipe 141 is provided to allow liquid to flow from the bottom 131 of the cup 130 to the outside of the housing 101. The switching unit 142 switches the flow of liquid so that the waste liquid (developer) discharged from the pipe 141 flows to the first discharge pipe 143 or the second discharge pipe 144. The switching unit 142 does not necessarily have to be provided.

[0050] While the workpiece W is held and rotated by the holder 110, a first developer is supplied from the first nozzle 121. Subsequently, a second developer is supplied from the second nozzle 122. After the first developer is supplied, the first developer may be removed by heating, centrifugal force applied by increasing the rotation speed of the workpiece W (holder 110), or a combination of these. Alternatively, the second developer may be supplied from the second nozzle 122 while the first developer remains on the workpiece W and the laminate including the resist film. The rotation speed of the holder 110 and the workpiece W may be maintained at 1500 rpm or less from the time the first developer is supplied until the time the second developer is supplied.

[0051] A pipe connected to the first tank 123 may be connected to a pipe connected to the second tank 124. In this case, a mixed developer formed by mixing the first developer and the second developer may be supplied from the first nozzle 121, the second nozzle 122, or a nozzle provided in place of these.

[0052] The supply unit 120 may have a tank for storing water. In this case, the supply unit 120 may be configured to supply water from the first nozzle 121, the second nozzle 122, or a nozzle provided separately from these. Water may be supplied from the nozzle as a cleaning liquid. Before the second developer containing an alkaline component is supplied onto the laminate including the workpiece W and the resist film, water may be supplied onto the laminate including the workpiece W and the resist film, thereby diluting the second developer on the laminate. The supply unit may be configured to dilute an aqueous solution containing an alkaline component with water in the supply unit to form a second developer containing an alkaline component at a low concentration, and then supply the formed second developer.

[0053] The first developer, the second developer, or the mixed developer is collected on the bottom 131 of the cup 130. The collected developers are discharged to the discharge section 140. When the first developer and the second developer are used, for example, a switching section 142 may be used to discharge waste liquid containing mainly the first developer from a first discharge pipe 143, and waste liquid containing mainly the second developer from a second discharge pipe 144. This switching allows the waste liquids to be more easily separated.

[0054] The processing block 25 further has a shelf unit U10 provided on the carrier block 24 side. The shelf unit U10 is divided into multiple cells lined up in the vertical direction. A transport device A7 including a lifting arm is provided near the shelf unit U10. The transport device A7 raises and lowers the workpiece W between the cells of the shelf unit U10. The processing block 25 has a shelf unit U11 provided on the interface block 26 side. The shelf unit U11 is divided into multiple cells lined up in the vertical direction.

[0055] The interface block 26 is configured to transfer the workpiece W between the processing block 25 and the exposure device 30. The interface block 26 has a built-in transport device A8 (transport unit) including a transfer arm. The transport device A8 transfers the workpiece W placed on the shelf unit U11 to the exposure device 30. The transport device A8 receives the workpiece W from the exposure device 30 and returns it to the shelf unit U11.

[0056] The control device 100 (control unit) controls the units constituting each block so that a desired resist pattern is formed from the resist film on the workpiece W. For example, the control device 100 may be configured to control the developing unit to supply a first developer containing a hydrophilic organic solvent onto the laminate while holding the workpiece W in a holder. The laminate includes a workpiece W (substrate) and a resist film provided on the workpiece W, the resist film containing a metal oxide photoresist material, and the resist film has exposed portions that are portions exposed by pattern exposure and unexposed portions that are portions other than the exposed portions. The control device 100 may be configured to control the developing unit to supply a mixed developer onto the laminate while holding the laminate in a holder.

[0057] The control device 100 may have a storage that stores a program for causing the units constituting each block to execute the above-described method. The storage includes, for example, a computer-readable storage medium that stores the program and a device that reads data from the storage medium. The storage medium is a non-transitory medium, examples of which include a hard disk and a read-only memory (ROM).

[0058] [Verification Example] Examples of development using the processing method according to the present disclosure are shown below, but the present invention is not limited to the following verification example.

[0059] Verification Example 1 Nanoparticles with cage-shaped tin oxide compounds and organic ligands ([(SnR) 12 O 14A photoresist composition was prepared using a 0.01M MOR solution containing [(OH)6](OH)2, where R is an alkyl group (hereinafter referred to as "MOR"). The photoresist composition was applied to a silicon wafer using a spin coater. The solvent was removed by heating the coating to form a 10-nm-thick resist film. The resist film was exposed to extreme ultraviolet (EUV) radiation with a wavelength of 13.5 nm through a mask with a linear pattern corresponding to a 13-nm half-pitch line / space pattern. After exposure, the resist film was baked at 180°C for 60 seconds.

[0060] The resist film and silicon wafer stack after EUV exposure and baking were immersed in methanol (first developer) for 60 seconds. The stack removed from methanol was immersed in a 2.38% by mass or 0.238% by mass TMAH aqueous solution (second developer) for 60 seconds without drying. A resist pattern including a linear portion was formed in the stack removed from the TMAH aqueous solution. The stack was then immersed in deionized water (cleaning liquid, DIW) for 60 seconds without drying. The stack removed from the water was dried by blowing air onto it using a blower. The line width (CD) of the resist pattern was measured by observing the dried resist pattern with a scanning electron microscope (SEM). The SEM image also confirmed the presence or absence of remaining resist film (bridges) connecting the linear portions. The temperatures of the methanol, TMAH aqueous solution, and DIW were approximately 25°C.

[0061]

[0062] The measurement results are shown in Table 1. It was confirmed that successive developments using methanol and a TMAH aqueous solution resulted in the formation of a resist pattern while reducing bridging. Furthermore, a comparison between #1 and #2 revealed that a lower concentration of the TMAH aqueous solution tended to suppress the reduction in the line width (shrinkage) of the resist pattern. For comparison, the resist film (resist pattern) of the laminate immersed in methanol but not in a TMAH aqueous solution was observed with a scanning electron microscope, and many bridging was confirmed.

[0063] Verification Example 2: A laminate including a resist film treated by EUV exposure and subsequent baking and a silicon wafer was prepared in the same manner as in Verification Example 1. The laminate was immersed in methanol for 60 seconds, water for 60 seconds, methanol for 60 seconds, and methanol for 60 seconds, in this order, without drying. The temperature of the methanol and water was approximately 25°C. After immersion, the laminate was dried by blowing air onto it using a blower. The line width (CD) of the resist pattern was measured by observing the formed resist pattern with a scanning electron microscope. The presence or absence of bridging was also confirmed.

[0064]

[0065] The measurement results are shown as #3 together with the evaluation results of #2 in Table 2. It was confirmed that by repeating the development treatment with methanol and water, it is possible to reduce bridging and also suppress shrinkage of the resist pattern.

[0066] Verification Example 3 The following developers were prepared. Developer A: a methanol solution of n-hexadecyltrimethylammonium hydroxide (HDTMAH) (concentration: approximately 5% by mass). Developer B: a solution containing isopropyl alcohol (IPA), water, and TMAH (a mixture of 45 mL of isopropyl alcohol and 5 mL of an aqueous TMAH solution (concentration: 2.38% by mass)).

[0067] A laminate including a resist film treated by EUV exposure and subsequent baking and a silicon wafer was prepared in the same manner as in Verification Example 1. The laminate was immersed in developer A or B for 60 seconds. The laminate removed from developer A or B was immersed in water for 60 seconds. The temperatures of developer A, developer B, and water were approximately 25°C. After immersion, the laminate was dried by blowing air onto it using a blower. The line width (CD) of the resist pattern was measured by observing the dried resist pattern with a scanning electron microscope. The presence or absence of bridges was also confirmed.

[0068]

[0069] The measurement results are shown as #4 or #5 in Table 3 together with the evaluation result of #2. It was confirmed that by using a methanol solution of HDTMAH or a solution containing isopropyl alcohol (IPA), water, and TMAH as the developer, it is possible to reduce bridging and suppress shrinkage of the resist pattern with fewer treatments using the developer.

[0070] The present disclosure includes at least the following aspects: [1] A method for forming a resist pattern, comprising: preparing a laminate having a substrate and a resist film provided on the substrate, the resist film having exposed portions that are portions exposed by patterned exposure and unexposed portions that are portions other than the exposed portions; and forming a resist pattern by developing to remove portions of the resist film, wherein the resist film comprises a metal oxide photoresist material, and the developing comprises supplying a hydrophilic organic solvent to the laminate, and supplying water to the laminate. [2] The method of [1], wherein the developing comprises supplying a first developing material containing the hydrophilic organic solvent to the laminate, and supplying a second developing material containing the water and different from the first developing material to the laminate, in this order. [3] The method of [2], wherein the hydrophilic organic solvent comprises an alcohol. [4] The method according to [2] or [3], wherein a first developer is supplied onto the laminate as the first developing material, and a second developer is supplied onto the laminate as the second developing material. [5] The method according to [4], wherein the second developer is supplied onto the laminate while the first developer remains on the laminate. [6] The method according to [4], wherein the first developer is supplied onto the laminate while rotating the laminate about a central axis in the thickness direction of the substrate, and the rotation speed of the laminate is maintained at 1,500 rpm or less from the time when the first developer is supplied onto the laminate until the second developer is supplied onto the laminate. [7] The method according to any one of [2] to [6], wherein the second developing material further contains an alkaline component. [8] The method according to [7], wherein the alkaline component contains tetramethylammonium hydroxide, and the concentration of the tetramethylammonium hydroxide is 2.00 mass % or less based on the mass of the second developing material. [9] The method according to any one of [2] to [8], wherein at least a portion of the unexposed area is removed by the first developing material, and then at least a portion of the scum remaining on the substrate other than the exposed area is removed by the second developing material.

[10] The method according to any one of [2] to [9], wherein supplying the first developing material to the laminate and supplying the second developing material to the laminate are alternately repeated.

[11] The method according to

[10] , wherein the second developing material is water.

[12] The method according to [1], wherein the developing comprises supplying a mixed developing material containing a mixed solvent containing the hydrophilic organic solvent and water to the laminate.

[13] The method according to

[12] , wherein a mixed developing solution is supplied onto the laminate as the mixed developing material.

[14] The method according to

[12] or

[13] , wherein the hydrophilic organic solvent comprises isopropyl alcohol.

[15] A method for forming a resist pattern, comprising: preparing a laminate having a substrate and a resist film provided on the substrate, the resist film having exposed portions that are portions exposed by patternwise exposure and unexposed portions that are portions other than the exposed portions; and forming a resist pattern by developing to remove portions of the resist film, wherein the resist film comprises a metal oxide photoresist material, and the developing comprises supplying a mixed developing material containing a hydrophilic organic solvent and an ionic surfactant to the laminate.

[16] The method according to

[15] , wherein a mixed developer is supplied onto the laminate as the mixed developing material.

[17] The method according to

[15] or

[16] , wherein the mixed developing material further contains an alkali component.

[18] The method according to any one of

[15] to

[17] , wherein the hydrophilic organic solvent contains methanol.

[19] The method according to any one of

[15] to

[18] , wherein the ionic surfactant is a cationic surfactant.

[20] A processing apparatus comprising: a developing unit having a supply part that supplies a developer and a holding part that holds a substrate; and a control part, wherein the control part is configured to control the developing unit to supply a first developer containing a hydrophilic organic solvent onto the laminate while holding the substrate of the laminate with the holding part, the laminate having a substrate and a resist film provided on the substrate, the resist film containing a metal oxide photoresist material, and the resist film having exposed portions that are portions exposed by patterned exposure and unexposed portions that are portions other than the exposed portions, and then supply a second developer containing water onto the laminate.

[0071] 1...substrate, 2...resist film, 2A...exposed portion, 2B...unexposed portion, 2C...scum, 3...resist pattern, 5...opening, 10...laminated body, 20...processing device, 30...exposure device, 110...holding section, 120...supply section, 130...cup, 140...discharge section, 200...developing unit, W...work

Claims

1. A laminate having a substrate and a resist film provided on the substrate, the resist film having an exposed portion which is a portion exposed by pattern exposure and an unexposed portion which is a portion other than the exposed portion, preparing the laminate, and forming a resist pattern by development for removing a part of the resist film in this order, the resist film containing a metal oxide photoresist material, and the development including supplying a hydrophilic organic solvent to the laminate and supplying water to the laminate. A method for forming a resist pattern.

2. The method according to claim 1, wherein the development includes supplying a first developing material containing the hydrophilic organic solvent to the laminate and supplying a second developing material containing the water and different from the first developing material to the laminate in this order.

3. The method according to claim 2, wherein the hydrophilic organic solvent contains alcohol.

4. The method according to claim 2, wherein a first developer is supplied onto the laminate as the first developing material and a second developer is supplied onto the laminate as the second developing material.

5. The method according to claim 4, wherein the second developer is supplied onto the laminate while the first developer remains on the laminate.

6. The first developer is supplied onto the laminate while rotating the laminate around the central axis in the thickness direction of the substrate, and the rotation speed of the laminate is maintained at 1500 rpm or less between the supply of the first developer onto the laminate and the supply of the second developer onto the laminate. The method according to claim 4.

7. The method according to claim 2, wherein the second developing material further contains an alkaline component.

8. The method according to claim 7, wherein the alkaline component contains tetramethylammonium hydroxide and the concentration of the tetramethylammonium hydroxide is 2.00% by mass or less based on the mass of the second developing material.

9. The method according to claim 8, wherein at least a part of the unexposed portion is removed by the first developing material, and then at least a part of the scum remaining on the substrate other than the exposed portion is removed by the second developing material.

10. The method according to claim 2, wherein supplying the first developing material to the laminate and supplying the second developing material to the laminate are alternately repeated.

11. The method according to claim 10, wherein the second developing material is water.

12. The method according to claim 1, wherein the development includes supplying a mixed developing material containing a mixed solvent including the hydrophilic organic solvent and water to the laminate.

13. The method according to claim 12, wherein a mixed developer is supplied onto the laminate as the mixed developing material.

14. The method according to claim 12, wherein the hydrophilic organic solvent includes isopropyl alcohol.

15. A method of forming a resist pattern, comprising: preparing a laminate having a substrate and a resist film provided on the substrate, the resist film having an exposed portion which is a portion exposed by pattern exposure and an unexposed portion which is a portion other than the exposed portion; and forming a resist pattern by development to remove a part of the resist film, in this order, wherein the resist film contains a metal oxide photoresist material, and the development includes supplying a mixed developing material containing a hydrophilic organic solvent and an ionic surfactant to the laminate.

16. The method according to claim 15, wherein a mixed developer is supplied onto the laminate as the mixed developing material.

17. The method according to claim 15, wherein the mixed developing material further contains an alkaline component.

18. The method according to claim 15, wherein the hydrophilic organic solvent includes alcohol.

19. The method according to claim 15, wherein the ionic surfactant is a cationic surfactant.

20. A processing apparatus, comprising: a developing unit having a supply unit for supplying a developer and a holding unit for holding a substrate; and a control unit, wherein the control unit is configured to control the developing unit to supply a first developer containing a hydrophilic organic solvent onto the laminate while holding the substrate of the laminate having a substrate and a resist film provided on the substrate, the resist film containing a metal oxide photoresist material and having an exposed portion which is a portion exposed by pattern exposure and an unexposed portion which is a portion other than the exposed portion, by the holding unit, and then supply a second developer containing water onto the laminate.

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