Method of forming resist pattern and processing apparatus

Abstract

The method for forming a resist pattern according to the present invention comprises the following steps: preparing a laminate having a substrate and a resist film formed on the substrate, wherein the resist film has 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 the resist pattern by developing a portion of the resist film. The developing process includes supplying a hydrophilic organic solvent to the laminate and supplying water to the laminate.

Description

Technical Field

[0001] The present invention relates to a method and processing apparatus for forming resist patterns. Background Technology

[0002] Patent Document 1 discloses a development method comprising: supplying a developing solution containing an organic solvent to a substrate having a metal-coated film exposed to a predetermined pattern; and supplying a cleaning solution containing an organic solvent to the substrate to which the developing solution has been supplied.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2022-96081 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] One aspect of the present invention relates to a technique for forming a good resist pattern from a resist film comprising a metal oxide photoresist material.

[0008] Technical solutions for solving technical problems

[0009] One aspect of the present invention relates to a method for forming a resist pattern, comprising the steps of: preparing a laminate having a substrate and a resist film formed on the substrate, wherein the resist film has exposed portions that are exposed by pattern exposure and unexposed portions that are portions other than the exposed portions; and forming the resist pattern by developing a portion of the resist film. The resist film comprises a metal oxide photoresist material. The developing process includes supplying a hydrophilic organic solvent to the laminate and supplying water to the laminate.

[0010] Invention Effects

[0011] It is possible to form a good resist pattern from a resist film containing a metal oxide photoresist material. Attached Figure Description

[0012] Figure 1 This is a flowchart illustrating an example of a method for forming a resist pattern.

[0013] Figure 2 of (a) Figure 2 (b) and Figure 2 (c) is a step diagram illustrating an example of a method for forming a resist pattern.

[0014] Figure 3 (a) and Figure 3(b) is a step diagram illustrating an example of a method for forming a resist pattern.

[0015] Figure 4 This is a flowchart illustrating an example of a method for forming a resist pattern.

[0016] Figure 5 This is a flowchart illustrating an example of a method for forming a resist pattern.

[0017] Figure 6 This is a schematic diagram illustrating an example of a processing device.

[0018] Figure 7 This is a schematic diagram illustrating an example of a processing device.

[0019] Figure 8 This is a schematic diagram illustrating an example of a developing unit. Detailed Implementation

[0020] The following examples illustrate embodiments related to the present invention. The present invention should not be limited to the following. In the following description, the same reference numerals are used for the same elements or elements having the same function, and repeated descriptions are omitted.

[0021] In one example of a method for forming a resist pattern, the method includes: preparing a laminate having a substrate and a resist film disposed on the substrate, wherein the resist film has exposed portions that are exposed by pattern exposure and unexposed portions that are portions other than the exposed portions; and forming the resist pattern by developing a portion of the resist film. The developing process includes supplying a hydrophilic organic solvent to the laminate and supplying water to the laminate. The developing process using the hydrophilic organic solvent and water can be wet developing using a developing solution containing the aforementioned components. The developing process using the hydrophilic organic solvent and water can also be dry developing, which includes exposing the laminate to a developing gas containing the aforementioned components. For developing, a liquid or gaseous developing material containing a hydrophilic organic solvent and a liquid or gaseous developing material containing water can be supplied to the laminate. For developing, a liquid or gaseous developing material containing both a hydrophilic organic solvent and water can also be supplied to the laminate.

[0022] Figure 1 This is a flowchart illustrating an example of a method for forming a resist pattern. Figure 2 and Figure 3 This is a schematic cross-sectional view illustrating the steps of an example of a method for forming a resist pattern. Figures 1-3The method for forming a resist pattern includes: a step S10 of pattern exposure on a resist film 2 containing a metal oxide photoresist material disposed on a substrate 1; a post-exposure baking (PEB) step S20 of baking the patterned resist film 2; a step S31 of developing a laminate 10 having a substrate 1 and a resist film 2 by supplying a first developing material containing a hydrophilic organic solvent; a step S32 of developing the laminate 10 by supplying a second developing material containing water; 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. Figure 1 As shown in the example, a laminate 10 having a substrate 1 and a resist film disposed on the substrate 1 is prepared by means of steps S10 and S20. The resist film has an exposure portion formed by pattern exposure.

[0023] The substrate 1 may be, for example, a structure having a semiconductor wafer and an etched film formed on the semiconductor wafer. The etched film may be, for example, an active layer, a lower insulating film, a gate electrode film, or an upper insulating film.

[0024] Figure 2 The resist film 2 of (a) is formed, for example, by the following steps: coating a photoresist composition comprising a metal oxide photoresist material onto a substrate 1; and baking the coated photoresist composition to form the resist film 2. The photoresist composition may also contain a solvent. The photoresist composition may be coated onto the substrate 1, for example, by spin coating. A pre-formed resist film 2 may also be laminated onto the substrate 1. The thickness of the resist film 2 may be, for example, 1–5000 nm, 10–1000 nm, or 30–200 nm.

[0025] Metal oxide photoresist materials may include, for example, metal oxides containing metal atoms; and organometallic compounds containing organic ligands bonded to metal atoms. Metal oxide photoresist materials may be nanoparticles (particles with a maximum width of less than 1 μm). Metal oxides may be cage-like compounds.

[0026] The metal oxide in a metal oxide photoresist material may include at least one metal atom selected from, for example, 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 that may have substituents, or a cycloalkyl group that may have substituents. The alkyl and cycloalkyl groups may be bonded to the metal atom at primary, secondary, or tertiary carbon atoms. The number of carbon atoms in the alkyl and cycloalkyl groups may range from 1 to 30. Examples of alkyl groups as organic ligands include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, and n-octyl. Examples of cycloalkyl groups as organic ligands include cyclobutyl, cyclopropyl, cyclohexyl, 1-adamantyl, and 2-adamantyl. Examples of substituents that the alkyl and cycloalkyl groups may have include cyano, alkylthio, silyl, alkoxy, alkylcarbonyl, alkylcarbonylyl, and haloyl groups. Nanoparticles containing cage-like tin oxide and organic ligands can, for example, be made of the formula [(SnR)]. 12 O 14 Compounds represented by [(OH)6](OH)2 (R represents an organic ligand).

[0027] Pattern exposure of a portion of the resist film 2 by irradiating it with radiation lines, such as Figure 2 As shown in (b), an exposed portion 2A, which is the exposed portion, and an unexposed portion 2B, which is the remaining portion, are formed within the resist film 2. For pattern exposure, radiation can be irradiated onto the portion corresponding to the exposed portion 2A via a mask through which radiation can be transmitted. The radiation can be ultraviolet light, particularly extreme ultraviolet light (EUV) with a wavelength of approximately 13.5 nm, an excimer laser (ArF excimer laser) with a wavelength of 193 nm, or an excimer laser (KrF excimer laser) with a wavelength of 248 nm.

[0028] The exposure section 2A may include a main section 2A1 located at its center and an intermediate section 2A2 surrounding the main section 2A1. The exposure amount of the intermediate section 2A2 is relatively small compared to that of the main section 2A1. In the main section 2A1, the reaction in which organic ligands detach from metal atoms to form hydroxyl groups readily proceeds sufficiently. Therefore, through condensation reactions involving bonding between metal atoms, hydrophobic aggregates or cross-linked structures that are insoluble in the developer are easily formed. In the intermediate section 2A2, due to the relatively small exposure amount, there may be some residual hydroxyl groups bonded to metal atoms. Therefore, the intermediate section 2A2 may be more hydrophilic than the main section 2A1.

[0029] Post-exposure baking (PEB), particularly in the main section 2A1 of the exposed section 2A, enables a condensation reaction that bonds metal atoms together. Heating for PEB can be performed in the atmosphere or under an inert gas atmosphere such as nitrogen or argon. The heating temperature for PEB can be 50–250°C, and the heating time can be 10–300 seconds. Alternatively, PEB can be omitted.

[0030] Next, a first developing material containing a hydrophilic organic solvent is supplied to the surface of the laminate 10 on one side of the resist film 2. A first developing solution can be supplied as the first developing material. The first developing solution can be supplied to the center of the surface of the laminate 10 on one side of the resist film 2 while rotating the laminate 10 about the central axis in the thickness direction of the substrate 1. A first developing gas containing a hydrophilic organic solvent can be supplied as the first developing material. The first developing material mainly dissolves the unexposed portion 2B of the resist film 2, while most of the exposed portion 2A remains on the substrate 1. The resist pattern 3 is formed by the retained resist film 2 (exposed portion 2A), wherein the resist pattern 3 has a pattern including the opening 5 exposed on the substrate 1. After development using the first developing material, a small amount of resist film 2 may remain on the substrate 1 in the form of residue 2C within the opening 5.

[0031] A hydrophilic organic solvent can be an organic solvent that is miscible with water in any proportion at 25°C and 1 atmosphere. A hydrophilic organic solvent may contain alcohols such as alkyl alcohols. A hydrophilic organic solvent may contain at least one alkyl alcohol selected from methanol, ethanol, and isopropanol. A hydrophilic organic solvent may also contain methanol, ethanol, or combinations thereof. A hydrophilic organic solvent may also contain methanol.

[0032] The first developing material may also contain components other than hydrophilic organic solvents (such as water, alkali, etc.). The proportion of hydrophilic organic solvents (or alcohols) in the first developing material (e.g., the first developing solution), based on the mass of the first developing material (first developing solution), can be 50% or more by mass, 60% or more by mass, 70% or more by mass, 80% or more by mass, 90% or more by mass, 95% or more by mass, or 99% or more by mass, or less than 100% by mass. Alternatively, the proportion of hydrophilic organic solvents (or alcohols), based on the mass of the first developing material (first developing solution), can be less than 50% by mass, less than 40% by mass, less than 30% by mass, less than 20% by mass, less than 10% by mass, or less than 5% by mass.

[0033] After development using the first developing material, a second developing material containing water is supplied to the surface of the laminate 10 on the side of the resist film 2. The second developing material can be a second developing solution containing water. The second developing solution can be supplied to the center of the surface of the laminate 10 on the side of the resist film 2 while rotating the laminate 10 about the central axis in the thickness direction of the substrate 1. A second developing gas containing water can be supplied as the second developing material. Using the second developing material, such as... Figure 3 As shown in (a), at least a portion of the residue 2C can be removed. The second developer, which contains water, is well miscible with the first developer, which contains a hydrophilic organic solvent. Therefore, the second developer can be supplied to the laminate 10 while the first developer remains on the laminate 10 (substrate 1 and / or resist film 2). In this case, steps such as heating (baking) to remove the first developer can be omitted. For example, the second developer can be supplied directly to the laminate 10 without removing the first developer by heating, centrifugation, or a combination thereof. During the period from the supply of the first developer to the supply of the second developer, if the rotational speed around the central axis in the thickness direction of the substrate 1 is maintained at, for example, 0 rpm to 1500 rpm, it is easy to supply the second developer while the first developer remains on the laminate 10.

[0034] The second developing material may contain an alkaline component. The second developing material may be a second developing solution containing water and an alkaline component. A second developing material or second developing solution containing water and an alkaline component is particularly effective at removing residual 2C. The alkaline component contained in the second developing material or second developing solution may be a quaternary ammonium salt, an amine compound having primary, secondary, or tertiary amines, 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 alkanolamine 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 aqueous alkaline solution containing water and tetramethylammonium hydroxide.

[0035] When the resist film 2, particularly a portion of the middle section 2A2, is removed using a second developing material containing an alkaline component, the width of the resulting resist pattern 3 may be smaller than the target width. If the concentration of the alkaline component in the second developing material (second developing solution) is low, the width of the remaining resist film 2 (resist pattern 3) after development with the second developing material is less likely to decrease. In other words, the reduction (shrinkage) of the resist pattern width can be suppressed. Although baking the resist film 2 after development with the first developing material also helps to suppress shrinkage, by using a second developing material (second developing solution) containing a low concentration of alkaline component, even omitting such baking can effectively suppress the width shrinkage of the resist pattern.

[0036] The second developer, containing a low concentration of alkaline components, can be supplied to the resist film 2 while simultaneously diluting the solution containing the alkaline components with water to form a second developer. Alternatively, water can be supplied to the laminate 10 before supplying the second developer containing the alkaline components to the laminate 10, thereby diluting the second developer on the laminate 10.

[0037] The concentration of the alkaline component in the second developing material (second developing solution) can be adjusted so that the width of the resist pattern is within a reference range specified according to the target width value. For example, the concentration of the alkaline component in the second developing material (second developing solution) can be adjusted so that the width of the resist pattern is within the range of 14 nm to 15 nm. Generally speaking, the lower the concentration of the alkaline component, the wider the resist pattern tends to be after development using the second developing material. The width of the resist pattern refers to the width of the resist pattern in the direction perpendicular to the thickness direction of the substrate.

[0038] The concentration of the alkaline component in the second developing material (second developing solution), based on the mass of the second developing material (second developing solution), can be less than 5.0% by mass, less than 4.0% by mass, less than 3.0% by mass, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of the alkaline component in the second developing material (second developing solution) can be more than 0% by mass, more than 0.0023% by mass, more than 0.010% by mass, or more than 0.10% by mass. The concentration of the alkaline component in the second developing material (second developing solution) can be above 0% by mass, and below 5.0% by mass, below 4.0% by mass, below 3.0% by mass, less than 2.38% by mass, below 2.00% by mass, below 1.50% by mass, below 1.00% by mass, below 0.90% by mass, below 0.80% by mass, below 0.70% by mass, below 0.60% by mass, below 0.50% by mass, below 0.40% by mass, or below 0.24% by mass. The concentration of the alkaline component in the second developing material (second developing solution) can be 0.0023% by mass or more, and is less than 5.0% by mass, less than 4.0% by mass, less than 3.0% by mass, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of the alkaline component in the second developing material (second developing solution) can be 0.010% by mass or more, and is less than 5.0% by mass, less than 4.0% by mass, less than 3.0% by mass, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of the alkaline component in the second developing material (second developing solution) can be 0.10% by mass or more, and is less than 5.0% by mass, less than 4.0% by mass, less than 3.0% by mass, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass.In particular, when the alkali component is tetramethylammonium hydroxide, its concentration, based on the mass of the second developing material (second developing solution), can 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. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) can 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) can be 0% by mass or more, and is 2.38% by mass or less, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) can be 0.0023% by mass or more, and is 2.38% by mass or less, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) can be 0.010% by mass or more, and is 2.38% by mass or less, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of tetramethylammonium hydroxide in the second developing material (second developing solution) can be 0.10% by mass or more, and is 2.38% by mass or less, less than 2.38% by mass, less than 2.38% by mass, less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The second developer can also be pure water (e.g., deionized water).

[0039] After development using the first and second developing materials, water, as a cleaning solution, is supplied to the laminate 10 containing the formed resist film 2 (resist pattern 3) and the substrate 1. The water used for cleaning can be pure water (e.g., deionized water). In this invention, the water supplied to the laminate 10 containing the resist film 2 (resist pattern 3) after the second developing solution containing water is considered as a cleaning solution rather than a developing solution. The cleaning step S40 using water can also be omitted.

[0040] After cleaning with water, the resist pattern 3 is heated in the post-baking step S50. Post-baking removes the water used for cleaning and allows for the further formation of aggregates or cross-linked structures containing metal atoms within the resist pattern 3. The heating temperature for post-baking can be 100–400°C, and the heating time can be 1–300 seconds. Post-baking step S50 can also be omitted.

[0041] Figure 4 This is a flowchart illustrating another example of a method for forming a resist pattern. Figure 4 The method shown is the same as Figure 1 The method differs in that, after exposure and baking, a step S33 is provided whereby a mixed developing material containing a mixed solvent of a hydrophilic organic solvent and water is supplied to the laminate 10. By using the mixed developing material, a good resist pattern can be formed with fewer steps. The mixed developing material can be a mixed developing solution containing a mixed solvent. The mixed developing solution can be supplied to the center of the surface of the laminate 10 on one side of 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 developing gas containing a mixed solvent can also be supplied as the mixed developing material.

[0042] 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 isopropanol, and water. The mixed solvent may also contain isopropanol and water. The proportion of water in the mixed solvent, based on the total amount of the mixed solvent, may be 1% or more by mass, 2% or more by mass, 3% or more by mass, 4% or more by mass, 5% or more by mass, 6% or more by mass, 7% or more by mass, 8% or more by mass, 9% or more by mass, or 10% or more by mass. The proportion of water in the mixed solvent, based on the total amount of the mixed solvent, may be less than 50% by mass, less than 40% by mass, less than 30% by mass, or less than 20% by mass. The proportion of water in the mixed solvent, based on the total amount of the mixed solvent, may be 1% or more by mass, 2% or more by mass, 3% or more by mass, 4% or more by mass, 5% or more by mass, 6% or more by mass, 7% or more by mass, 8% or more by mass, 9% or more by mass, or 10% or more by mass, and less than 50% by mass. The proportion of water in the mixed solvent, based on the total amount of the mixed solvent, can be 1% or more by mass, 2% or more by mass, 3% or more by mass, 4% or more by mass, 5% or more by mass, 6% or more by mass, 7% or more by mass, 8% or more by mass, 9% or more by mass, or 10% or more by mass, and is less than 40% by mass. The proportion of water in the mixed solvent, based on the total amount of the mixed solvent, can be 1% or more by mass, 2% or more by mass, 3% or more by mass, 4% or more by mass, 5% or more by mass, 6% or more by mass, 7% or more by mass, 8% or more by mass, 9% or more by mass, or 10% or more by mass, and is less than 30% by mass. The proportion of water in the mixed solvent, based on the total amount of the mixed solvent, can be 1% or more by mass, 2% or more by mass, 3% or more by mass, 4% or more by mass, 5% or more by mass, 6% or more by mass, 7% or more by mass, 8% or more by mass, 9% or more by mass, or 10% or more by mass, and is less than 20% by mass.

[0043] The mixed developing material, comprising a hydrophilic organic solvent and water, may also contain an alkaline component. The alkaline component contained in the mixed developing material or mixed developing solution may be the same as the alkaline component that may be contained in the second developing material or second developing solution.

[0044] The concentration of the alkaline component (or tetramethylammonium hydroxide) in a mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water, based on the mass of the mixed developing material (mixed developing solution), can be less than 2.00% by mass, less than 1.50% by mass, less than 1.00% by mass, less than 0.90% by mass, less than 0.80% by mass, less than 0.70% by mass, less than 0.60% by mass, less than 0.50% by mass, less than 0.40% by mass, or less than 0.24% by mass. The concentration of the alkaline component (or tetramethylammonium hydroxide) in a mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water, based on the mass of the mixed developing material (mixed developing solution), can be more than 0% by mass, more than 0.0023% by mass, more than 0.010% by mass, or more than 0.10% by mass. The concentration of the alkaline component (or tetramethylammonium hydroxide) in a mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water, based on the mass of the mixed developing material (mixed developing solution), can be above 0% by mass and below 2.00% by mass, below 1.50% by mass, below 1.00% by mass, below 0.90% by mass, below 0.80% by mass, below 0.70% by mass, below 0.60% by mass, below 0.50% by mass, below 0.40% by mass, or below 0.24% by mass. The concentration of the alkaline component (or tetramethylammonium hydroxide) in a mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water, based on the mass of the mixed developing material (mixed developing solution), can 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. The concentration of the alkaline component (or tetramethylammonium hydroxide) in a mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water, based on the mass of the mixed developing material (mixed developing solution), can 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. The concentration of the alkaline component (or tetramethylammonium hydroxide) in a mixed developing material or mixed developing solution containing a hydrophilic organic solvent and water, based on the mass of the mixed developing material (mixed developing solution), can 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.

[0045] Hybrid developing materials can also contain hydrophilic organic solvents (such as methanol) and ionic surfactants. By using hybrid developing materials containing hydrophilic organic solvents and ionic surfactants, it is also possible to effectively form good resist patterns. Hybrid developing materials containing hydrophilic organic solvents and ionic surfactants may be substantially water-free or may contain water.

[0046] Ionic surfactants can be cationic surfactants, betaine-type surfactants, or combinations thereof. Cationic surfactants can be quaternary ammonium salts or pyridinium salts. An example of a cationic surfactant as a quaternary ammonium salt is hexadecyltrimethylammonium hydroxide. Betaine-type surfactants can have a quaternary ammonium group and an anionic group (e.g., SO3) as their counterion. － The concentration of ionic surfactants is based on the mass of the mixed developing material (mixed developing solution), for example, it can be more than 1% by mass and less than 20% by mass.

[0047] After step S33, which involves developing the image using a mixed developing material, the resist pattern can be cleaned with water without further development using other developing solutions. In this respect, using a mixed developing material is advantageous for reducing the number of steps.

[0048] Figure 5 This is a flowchart illustrating another example of a method for forming resist patterns. Figure 5 The method shown is the same as Figure 1 The difference in the method shown is that the steps S31 (developing the laminate 10 by supplying a first developing material) and S32 (developing the laminate 10 by supplying a second developing material) are performed alternately and repeatedly. The number of repetitions of steps S31 and S32, i.e., the number of combinations of steps S31 and S32, can be more than two times, more than three times, or less than five times. Figure 5 In the example, after step S32 of developing with the second developing material, there is a step S31 of developing with the first developing material containing a hydrophilic organic solvent, followed by post-baking of the resist pattern. Alternatively, step S31 of final developing with the first developing material can be omitted, and the final developing can be done with the second developing material containing water (e.g., an alkaline aqueous solution). After step S31 of final developing with the first developing material, or after step S32 of developing with the second developing material as an alkaline aqueous solution, a rinsing step with water can be provided. When steps S31 and S32 are repeated, the first developing material or first developing solution may contain methanol, and the second developing material or second developing solution may be water (e.g., deionized water).

[0049] The substrate 1 can be patterned by selectively etching the portion of the substrate 1 exposed within the openings 5 ​​of the formed resist pattern 3. After patterning the substrate 1, the resist pattern 3 can be removed. The method of the present invention can, for example, be used to manufacture semiconductor devices having integrated circuits comprising patterned films.

[0050] Figure 6 and Figure 7 This is a schematic diagram illustrating an example of a processing apparatus used to form a resist pattern. Figure 6 An example of an exposure apparatus used in combination with a processing device is also shown in the illustration. Figure 7 It shows Figure 6 An example of the internal structure of the processing device 20 shown. Figure 6 and Figure 7 The processing apparatus 20 shown includes a carrier block 24, a processing block 25, and an interface block 26. Using the processing apparatus 20, a resist pattern can be formed on the workpiece W.

[0051] The carrier block 24 is configured to allow workpiece W to be introduced into the processing device 20 and to be removed from the processing device 20 to the outside. The carrier block 24 has a conveying device A1 including a transfer arm. The conveying device A1 removes the workpiece W stored in the carrier C and delivers it to the processing block 25, and receives the workpiece W from the processing block 25 and puts it back into the carrier C.

[0052] 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 has multiple processing units U1 and U2 and a conveying device A3 for transporting the workpiece W to these processing units.

[0053] The processing module 11 can be configured to form a lower layer film (etched film) on the surface of a substrate (e.g., a semiconductor wafer) serving as a workpiece W. In the processing module 11, for example, processing unit U1 can be a liquid treatment unit that applies a coating liquid for forming the lower layer film to the workpiece W, and processing unit U2 can be a heat treatment unit that heat-treats the applied coating liquid to form the lower layer film.

[0054] Processing module 12 can be configured to form a photoresist film on the lower layer (etched film) of workpiece W. In processing module 12, for example, processing unit U1 can be a coating unit that applies a photoresist composition to workpiece W, and processing unit U2 can be a heat treatment unit that bakes the applied photoresist composition to form a photoresist film. Alternatively, the workpiece W with the photoresist film can be transported to exposure apparatus 30 via interface block 26, where the photoresist film is patterned using radiation.

[0055] The processing module 13 can be configured to bake the exposed resist film.

[0056] The processing module 14 can be configured to develop the resist film after pattern exposure and baking using a first developing material and a second developing material, or by mixed developing, thereby forming a resist pattern. In the processing module 14, for example, processing unit U1 can be a developing unit for developing, and processing unit U2 can be a heat treatment unit for baking the resist film or resist pattern.

[0057] Figure 8 This is a cross-sectional view schematically representing an example of a developing unit. Figure 8 The developing unit 200 shown mainly consists of a housing 101, a holding part 110 that holds the workpiece W inside the housing 101, a supply part 120 that supplies developing solution, a cup-shaped body 130, and a discharge part 140.

[0058] The holding part 110 holds the plate-shaped workpiece W substantially horizontally within the housing 101. The holding part 110 is configured to be rotatable and movable in the vertical direction. The workpiece W can rotate about its central axis in the thickness direction by rotating the holding part 110.

[0059] The supply unit 120 is configured to supply developer to the workpiece W within the housing 101. The supply unit 120 includes a first nozzle 121, a second nozzle 122, a first reservoir 123, a second reservoir 124, a first pipe 125, and a second pipe 126. The first nozzle 121 and the second nozzle 122 are located within the housing 101 and are positioned vertically above the holding unit 110. The first reservoir 123 contains the first developer. The second reservoir 124 contains the second developer. The first pipe 125 connects the first nozzle 121 to the first reservoir 123. The second pipe 126 connects the second nozzle 122 to the second reservoir 124. The first developer is supplied from the first nozzle to the laminate having the workpiece W and a resist film. The second developer is supplied from the second nozzle to the laminate having the workpiece W and a resist film.

[0060] The cup-shaped body 130 has a bottom 131 through which the holding part 110 passes, and a wall part 132 provided on the periphery of the bottom 131. The wall part 132 surrounds the workpiece W held by the front end of the holding part 110. The cup-shaped body 130 is configured to catch developing solution that spills or falls from the workpiece W.

[0061] The discharge section 140 includes a pipe 141, a switching section 142 connected to the pipe 141, and a first discharge pipe 143 and a second discharge pipe 144 connected to the switching section 142. The pipe 141 is configured to allow liquid to flow from the bottom 131 of the cup-shaped body 130 to the outside of the housing 101. The switching section 142 switches the liquid flow so that waste liquid (developer) discharged from the pipe 141 flows into the first discharge pipe 143 or the second discharge pipe 144. Alternatively, the switching section 142 may not be provided.

[0062] While holding and rotating the workpiece W using the holding part 110, a first developing solution is supplied from the first nozzle 121. Then, a second developing solution is supplied from the second nozzle 122. After the first developing solution is supplied, it can be removed by heating, centrifugal force generated by increasing the rotational speed of the workpiece W (holding part 110), or a combination thereof. Alternatively, the second developing solution can be supplied from the second nozzle 122 while the first developing solution still remains on the workpiece W and the laminate with the resist film. From the time the first developing solution is supplied until the second developing solution is supplied, the rotational speed of the holding part 110 and the workpiece W can be maintained at 1500 rpm or less.

[0063] The piping connected to the first storage tank 123 and the piping connected to the second storage tank 124 can also be interconnected. In this case, the mixed developer formed by mixing the first developer and the second developer can be supplied from the first nozzle 121, the second nozzle 122, or a nozzle provided to replace these nozzles.

[0064] The supply unit 120 may have a storage tank for collecting 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 separately provided to distinguish it from these nozzles. Water may be supplied from the nozzle as a cleaning fluid. Alternatively, water may be supplied to the laminate having the workpiece W and the resist film before supplying the second developer containing an alkaline component to the laminate having the workpiece W and the resist film, thereby diluting the second developer on the laminate. The supply unit may be configured to supply the formed second developer while diluting the aqueous solution containing an alkaline component with water in the supply unit to form a second developer containing a low concentration of alkaline component.

[0065] The first developer, the second developer, or a mixed developer are recovered at the bottom 131 of the cup-shaped body 130. These recovered developers are discharged to the discharge section 140. When using both the first and second developers, for example, the switching section 142 can be used to discharge waste liquid containing the first developer primarily from the first discharge pipe 143, and waste liquid containing the second developer primarily from the second discharge pipe 144. This switching facilitates easier separation of the waste liquids.

[0066] Processing block 25 also has a shelf unit U10 disposed on the side of carrier block 24. The shelf unit U10 is divided into multiple cells arranged in the vertical direction. Near the shelf unit U10, a conveying device A7 including a lifting arm is disposed. The conveying device A7 lifts and lowers the workpiece W between the cells of the shelf unit U10. Processing block 25 also has a shelf unit U11 disposed on the side of interface block 26. The shelf unit U11 is divided into multiple cells arranged in the vertical direction.

[0067] Interface block 26 is configured to transfer workpiece W between processing block 25 and exposure device 30. Interface block 26 has a built-in conveying device A8 (conveyor unit) including a transfer arm. Conveyor A8 delivers workpiece W, which is disposed in shelf unit U11, to exposure device 30. Conveyor A8 receives workpiece W from exposure device 30 and returns it to shelf unit U11.

[0068] The control device 100 (control unit) controls the units constituting each block to form a target resist pattern from the resist film on the workpiece W. For example, the control device 100 may be configured to control the developing unit so that while the workpiece W, as a laminate, is held by a holding portion, a first developing solution containing a hydrophilic organic solvent is supplied to the laminate, followed by a second developing solution containing water. The laminate is a laminate having the workpiece W and a resist film disposed on the workpiece W. The resist film contains a metal oxide photoresist material and has exposed portions (areas exposed by pattern exposure) and unexposed portions (areas other than the exposed portions). The control device 100 may also be configured to control the developing unit so that while the laminate is held by a holding portion, a mixed developing solution is supplied to the laminate.

[0069] The control device 100 may have a memory storing programs for causing the units constituting each block to perform the methods described above. The memory may include, for example, a computer-readable storage medium for storing programs and means for reading data from the storage medium. The storage medium is a non-transitory medium; examples include hard disks and read-only memory (ROM).

[0070] [Verification Example]

[0071] The following examples illustrate development using the processing method of the present invention. The present invention is not limited to the following verification examples.

[0072] Verification Example 1

[0073] Nanoparticles containing cage-like tin oxide compounds and organic ligands ([(SnR)]) 12 O 14 A photoresist composition was prepared by mixing [(OH)6](OH)2, where R is an alkyl group (hereinafter sometimes referred to as "MOR"), and a solvent (propylene glycol monomethyl ether acetate (PGMEA)), with a MOR concentration of 0.01 M. The photoresist composition was applied to a silicon wafer using a spin coater. The solvent was removed by heating the coated film, forming a photoresist film with a thickness of 10 nm. The photoresist film was exposed to extreme ultraviolet (EUV) light at a wavelength of 13.5 nm using a mask with a line pattern corresponding to a line / space half-pitch of 13 nm. After exposure, the photoresist film was baked at 180 °C for 60 seconds.

[0074] The resist film, after EUV exposure and baking, and the laminated silicon wafer were immersed in methanol (first developer) for 60 seconds. The laminate was removed from the methanol and, without drying, immersed in a 2.38% by mass or 0.238% by mass TMAH aqueous solution (second developer) for 60 seconds. Upon removal from the TMAH aqueous solution, the laminate had formed a resist pattern including linear portions. Next, without drying, the laminate was immersed in deionized water (cleaning solution, DIW) for 60 seconds. The laminate, after being removed from the water, was dried using a blower. The linewidth (CD) of the dried resist pattern was measured by observing it with a scanning electron microscope (SEM). Furthermore, the presence of residual resist film (bridging) connecting the linear portions was confirmed in the SEM images. The temperature of the methanol, TMAH aqueous solution, and DIW was approximately 25°C.

[0075] Table 1

[0076]

[0077] The measurement results are shown in Table 1. It was confirmed that continuous development using methanol and TMAH aqueous solution can reduce bridging while forming a resist pattern. Furthermore, by comparing #1 and #2, the following trend was observed: when the concentration of the TMAH aqueous solution is lower, the reduction (shrinkage) of the resist pattern linewidth is suppressed. For comparison, the resist film (resist pattern) of the laminate immersed in methanol but not in TMAH aqueous solution was observed using scanning electron microscopy, and the results confirmed high bridging.

[0078] Verification Example 2

[0079] Using the same method as in Verification Example 1, a laminate consisting of a resist film treated with EUV exposure and subsequent baking and a silicon wafer was prepared. The laminate was continuously immersed in methanol for 60 seconds, water for 60 seconds, methanol for 60 seconds, and methanol for 60 seconds, without drying. The temperature of the methanol and water was approximately 25°C. The laminate was dried by blowing air onto it using a blower. The linewidth (CD) of the formed resist pattern was measured by observing it with a scanning electron microscope. The presence of bridging was also confirmed.

[0080] Table 2

[0081]

[0082] The measurement result is #3, and is shown in Table 2 along with the evaluation results for #2. It has been confirmed that repeated development using methanol and water can reduce bridging while suppressing resist pattern shrinkage.

[0083] Verification Example 3

[0084] The following developer solution was prepared.

[0085] Developer A: A methanol solution of hexadecyltrimethylammonium hydroxide (HDTMAH) (concentration: approximately 5% by mass)

[0086] Developer B: A solution containing isopropanol (IPA), water, and TMAH (a mixture of 45 mL of isopropanol and 5 mL of TMAH aqueous solution (concentration 2.38% by mass)).

[0087] Using the same method as in Verification Example 1, a laminate consisting of a resist film treated with EUV exposure and subsequent baking and a silicon wafer was prepared. The laminate was immersed in developer A or B for 60 seconds. The laminate, removed from developer A or B, was then immersed in water for 60 seconds. The temperatures of developer A, developer B, and water were approximately 25°C. The laminate was dried by blowing air onto it using a blower. The linewidth (CD) of the dried resist pattern was measured by observing it with a scanning electron microscope. The presence of bridging was also confirmed.

[0088] Table 3

[0089]

[0090] The measurement results are #4 or #5, and are shown in Table 3 along with the evaluation results for #2. It has been confirmed that by using a methanol solution as HDTMAH, or a solution containing isopropanol (IPA), water, and TMAH as the developer, it is possible to reduce bridging and suppress resist pattern shrinkage by using fewer processing steps with the developer.

[0091] The present invention includes at least the following aspects.

[0092] [1] A method for forming a resist pattern, comprising the following steps:

[0093] The step of preparing a laminate having a substrate and a resist film formed on the substrate, wherein the resist film has exposed portions that are exposed by pattern exposure and unexposed portions that are portions other than the exposed portions; and

[0094] The step of forming a resist pattern by developing a process that removes a portion of the resist film described above.

[0095] The aforementioned photoresist film contains a metal oxide photoresist material.

[0096] The above-mentioned development includes:

[0097] The steps of supplying a hydrophilic organic solvent to the above-mentioned laminate; and

[0098] The steps of supplying water to the above-mentioned laminated body.

[0099] [2] According to the method described in [1], where,

[0100] The above development includes, in sequence:

[0101] The steps of supplying the above-mentioned laminate with a first developing material comprising the above-mentioned hydrophilic organic solvent; and

[0102] The step of supplying the above-mentioned laminate with a second developing material that contains the above-mentioned water and is different from the above-mentioned first developing material.

[0103] [3] According to the method described in [2], where,

[0104] The aforementioned hydrophilic organic solvents include alcohols.

[0105] [4] According to the method described in [2] or [3], where,

[0106] The first developer is supplied to the laminate as the first developing material, and the second developer is supplied to the laminate as the second developing material.

[0107] [5] According to the method described in [4], where,

[0108] While the first developer remains on the laminate, the second developer is supplied to the laminate.

[0109] [6] According to the method described in [4], where,

[0110] While rotating the laminate around the central axis of the substrate in the thickness direction, the first developer is supplied to the laminate.

[0111] After the first developer is supplied to the laminate, and during the period between the supply of the second developer to the laminate, the rotational speed of the laminate is maintained at 1500 rpm or less.

[0112] [7] According to any one of the methods described in [2] to [6], wherein,

[0113] The aforementioned second developing material also contains an alkaline component.

[0114] [8] According to the method described in [7], where,

[0115] The aforementioned alkaline component includes tetramethylammonium hydroxide, and the concentration of the aforementioned tetramethylammonium hydroxide, based on the mass of the aforementioned second developing material, is less than 2.00% by mass.

[0116] [9] According to any one of the methods described in [2] to [8], wherein,

[0117] At least a portion of the unexposed portion is removed by the first developing material, and subsequently, at least a portion of the residue remaining on the substrate other than the exposed portion is removed by the second developing material.

[0118]

[10] According to any one of the methods described in [2] to [9], wherein,

[0119] The steps of supplying the first developing material to the laminate and supplying the second developing material to the laminate are performed alternately and repeatedly.

[0120]

[11] According to the method described in

[10] , wherein,

[0121] The second developing material mentioned above is water.

[0122]

[12] According to the method described in [1], where,

[0123] The aforementioned development includes the step of supplying the aforementioned laminate with a mixed developing material comprising a mixed solvent, wherein the mixed solvent contains the aforementioned hydrophilic organic solvent and the aforementioned water.

[0124]

[13] According to the method described in

[12] , wherein,

[0125] The mixed developer solution is supplied to the laminate as the mixed developer material.

[0126]

[14] According to the method described in

[12] or

[13] , wherein,

[0127] The aforementioned hydrophilic organic solvents include isopropanol.

[0128]

[15] A method for forming a resist pattern, comprising, in sequence:

[0129] The step of preparing a laminate having a substrate and a resist film formed on the substrate, wherein the resist film has exposed portions that are exposed by pattern exposure and unexposed portions that are portions other than the exposed portions; and

[0130] The step of forming a resist pattern by developing a portion of the resist film described above;

[0131] The aforementioned photoresist film contains a metal oxide photoresist material.

[0132] The above-mentioned development includes the step of supplying the above-mentioned laminate with a mixed developing material comprising a hydrophilic organic solvent and an ionic surfactant.

[0133]

[16] According to the method described in

[15] , wherein,

[0134] The mixed developer solution is supplied to the laminate as the mixed developer material.

[0135]

[17] According to the method described in

[15] or

[16] , wherein,

[0136] The aforementioned mixed developing material also contains an alkaline component.

[0137]

[18] According to any one of the methods described in

[15] to

[17] , wherein,

[0138] The aforementioned hydrophilic organic solvents include methanol.

[0139]

[19] According to any one of the methods described in

[15] to

[18] , wherein,

[0140] The aforementioned ionic surfactants are cationic surfactants.

[0141]

[20] A processing apparatus comprising:

[0142] A developing unit having a supply section for supplying developing solution and a holding section for holding the substrate; and

[0143] Control Department

[0144] The control unit is configured to control the developing unit so that while holding the substrate of the laminate using the holding portion, a first developing solution containing a hydrophilic organic solvent is supplied to the laminate, and subsequently, a second developing solution containing water is supplied to the laminate. The laminate has a substrate and a photoresist film formed on the substrate. The photoresist film contains a metal oxide photoresist material and has an exposed portion, which is a portion exposed by pattern exposure, and an unexposed portion, which is a portion other than the exposed portion.

[0145] Explanation of reference numerals in the attached figures

[0146] 1…substrate, 2…resist film, 2A…exposure section, 2B…unexposed section, 2C…residue, 3…resist pattern, 5…opening, 10…layer, 20…processing device, 30…exposure device, 110…holding section, 120…supply section, 130…cup-shaped body, 140…discharge section, 200…developing unit, W…workpiece.

Claims

1. A method for forming a resist pattern, characterized in that, In order, they include: The step of preparing a laminate having a substrate and a resist film formed on the substrate, wherein the resist film has exposed portions that are exposed by pattern exposure and unexposed portions that are portions other than the exposed portions; and The step of forming a resist pattern by developing a portion of the resist film; The resist film comprises a metal oxide photoresist material. The developing process includes: The step of supplying a hydrophilic organic solvent to the laminate; and The step of supplying water to the laminated body.

2. The method according to claim 1, characterized in that: The developing process includes, in sequence: The steps of supplying the laminate with a first developing material comprising the hydrophilic organic solvent; and The step of supplying the laminate with a second developing material that contains the water and is different from the first developing material.

3. The method according to claim 2, characterized in that: The hydrophilic organic solvent includes alcohols.

4. The method according to claim 2, characterized in that: The first developing solution is supplied to the laminate as the first developing material, and the second developing solution is supplied to the laminate as the second developing material.

5. The method according to claim 4, characterized in that: While the first developer remains on the laminate, the second developer is supplied to the laminate.

6. The method according to claim 4, characterized in that: While rotating the laminate around the central axis of the substrate in the thickness direction, the first developer is supplied to the laminate. After the first developer is supplied to the laminate, and during the period between the supply of the second developer to the laminate, the rotational speed of the laminate is maintained below 1500 rpm.

7. The method according to claim 2, characterized in that: The second developing material also contains an alkaline component.

8. The method according to claim 7, characterized in that: The alkaline component includes tetramethylammonium hydroxide, and the concentration of the tetramethylammonium hydroxide, based on the mass of the second developing material, is less than 2.00% by mass.

9. The method according to claim 8, characterized in that: At least a portion of the unexposed portion is removed by the first developing material, and subsequently, at least a portion of the residue remaining on the substrate other than the exposed portion is removed by the second developing material.

10. The method according to claim 2, characterized in that: The steps of supplying the first developing material to the laminate and supplying the second developing material to the laminate are performed alternately and repeatedly.

11. The method according to claim 10, characterized in that: The second developing material is water.

12. The method according to claim 1, characterized in that: The developing process includes the step of supplying the laminate with a mixed developing material comprising a mixed solvent, wherein the mixed solvent contains the hydrophilic organic solvent and the water.

13. The method according to claim 12, characterized in that: The mixed developer solution is supplied to the laminate as the mixed developer material.

14. The method according to claim 12, characterized in that: The hydrophilic organic solvent includes isopropanol.

15. A method for forming a resist pattern, characterized in that, In order, they include: The step of preparing a laminate having a substrate and a resist film formed on the substrate, wherein the resist film has an exposed portion as a portion exposed by pattern exposure and an unexposed portion as a portion other than the exposed portion; as well as The step of forming a resist pattern by developing a portion of the resist film; The resist film comprises a metal oxide photoresist material; The developing process includes the step of supplying the laminate with a mixed developing material comprising a hydrophilic organic solvent and an ionic surfactant.

16. The method according to claim 15, characterized in that: The mixed developer solution is supplied to the laminate as the mixed developer material.

17. The method according to claim 15, characterized in that: The mixed developing material also contains an alkaline component.

18. The method according to claim 15, characterized in that: The hydrophilic organic solvent includes alcohols.

19. The method according to claim 15, characterized in that: The ionic surfactant is a cationic surfactant.

20. A processing apparatus, characterized in that, include: The developing unit has a supply section for supplying developing solution and a holding section for holding the substrate; as well as Control Department The control unit is configured to control the developing unit such that while holding the substrate of the laminate using the holding portion, a first developing solution containing a hydrophilic organic solvent is supplied to the laminate, and subsequently, a second developing solution containing water is supplied to the laminate. The laminate has a substrate and a photoresist film formed on the substrate. The photoresist film contains a metal oxide photoresist material and has an exposed portion, which is a portion exposed by pattern exposure, and an unexposed portion, which is a portion other than the exposed portion.

Images