Method for forming a pattern

Abstract

To provide a pattern forming method capable of forming an inverted pattern.SOLUTION: In one exemplary embodiment, a method for forming a pattern includes (a) forming, on a substrate, a first pattern having an opening and containing a first material, (b) forming a filling portion in the opening, the filling portion containing a second material different from the first material, and (c) removing the first pattern so that the filling portion remains as a second pattern inverted with respect to the first pattern. At least one of the first material and the second material contains tin.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a method of forming a pattern.

Background Art

[0002] Patent Document 1 discloses a method for patterning a substrate. In this method, first, a substrate having a radiation-sensitive layer is received. Then, a patterned resist mask is formed on the substrate by developing a pattern transferred to the radiation-sensitive layer via an extreme ultraviolet lithography process. Then, the patterned resist mask is overcoated with an image reversal material. Then, the upper portion of the image reversal material is removed. Then, a patterned image reversal material mask is formed by removing the patterned resist mask.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a pattern formation method capable of forming an inverted pattern.

Means for Solving the Problems

[0005] In one exemplary embodiment, a method of forming a pattern includes: (a) forming, on a substrate, a first pattern having an opening and including a first material; (b) forming, in the opening, a filling portion including a second material different from the first material; and (c) removing the first pattern so that the filling portion remains as a second pattern inverted with respect to the first pattern, wherein at least one of the first material and the second material contains tin.

Effects of the Invention

[0006] According to one exemplary embodiment, a pattern forming method capable of forming an inverted pattern is provided.

Brief Description of the Drawings

[0007]

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[0008] Hereinafter, various exemplary embodiments will be described.

[0009] In one exemplary embodiment, a method of forming a pattern includes: (a) forming a first pattern including a first material and having an opening on a substrate; (b) forming a filling portion including a second material different from the first material in the opening; and (c) removing the first pattern so that the filling portion remains as a second pattern inverted with respect to the first pattern, wherein at least one of the first material and the second material contains tin.

[0010] According to the above method, the pattern can be inverted from the first pattern to the second pattern.

[0011] The first material may contain tin. In this case, the pattern can be inverted from the first pattern containing tin to the second pattern.

[0012] The first material may contain tin oxide.

[0013] The second material may contain at least one of an organic substance, silicon, and a metal.

[0014] In (c), the first pattern may be removed using hydrogen bromide gas. In this case, since the first pattern can be removed without using plasma, the etching selectivity of the first pattern with respect to the filling portion can be increased.

[0015] The second material may contain tin. In this case, the pattern can be inverted from the first pattern to the second pattern containing tin.

[0016] The second material may contain tin oxide.

[0017] The first material may contain at least one of an organic substance, silicon, and a metal.

[0018] The first material contains tin, the second material contains at least one of an organic substance, silicon, and a metal, and in the step (c), the first pattern may be removed using at least one of hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, hydrogen iodide gas, fluorine gas, chlorine gas, bromine gas, iodine gas, boron trichloride gas, helium gas, neon gas, argon gas, xenon gas, nitrogen gas, hydrocarbon gas, and methanol gas.

[0019] The first material contains tin oxide, and the second material may contain at least one of an organic substance and silicon.

[0020] In the step (c), the first pattern may be removed using at least one of hydrogen bromide gas and hydrocarbon gas.

[0021] The first material contains an organic substance, the second material contains tin, and in the step (c), the first pattern may be removed using at least one of an oxygen-containing gas, a fluorine-containing gas, and a nitrogen-containing gas.

[0022] The first material contains silicon, the second material contains tin, and in the step (c), the first pattern may be removed using a fluorine-containing gas.

[0023] The first material contains tin, the second material contains tin oxide, the oxygen concentration of the second material is higher than that of the first material, and in (c), at least one of hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, hydrogen iodide gas, fluorine gas, chlorine gas, bromine gas, iodine gas, boron trichloride gas, helium gas, neon gas, argon gas, xenon gas, nitrogen gas, hydrocarbon gas, and methanol gas may be used to remove the first pattern.

[0024] Among the first pattern and the second pattern, the pattern containing tin may be formed from a CVD film or an ALD film.

[0025] The CVD film or the ALD film may be a photoresist film containing tin.

[0026] The photoresist film may be a photoresist film for EUV exposure.

[0027] The unexposed portion of the photoresist film contains tin, the exposed portion of the photoresist film contains tin oxide, and the oxygen concentration of the exposed portion may be higher than that of the unexposed portion.

[0028] (a) may include: (a1) forming a mask pattern corresponding to the first pattern on an underlying film provided on the substrate; and (a2) etching the underlying film using the mask pattern to form the first pattern. In this case, a pattern corresponding to the first pattern can be formed from the underlying film.

[0029] The underlying film may include at least one of a silicon-containing film and an organic film.

[0030] The filling part is the first filling part, and the method may further include: (d) forming a second filling part including a third material different from the first material and the second material in the opening of the second pattern; and (e) removing the second pattern so that the second filling part remains as a third pattern corresponding to the first pattern. In this case, a third pattern having the same shape but different material from the first pattern can be obtained.

[0031] The filling part is the first filling part, and before the step (a), the method may further include: (f) forming a third pattern having an opening and including a third material on the substrate, where the third material is different from the first material and the second material; and (g) forming a second filling part including the first material in the opening of the third pattern. In the step (a), the second filling part may remain as the first pattern by removing the third pattern. In this case, a second pattern having the same shape but different material from the third pattern can be obtained.

[0032] Hereinafter, various exemplary embodiments will be described in detail with reference to the drawings. The same or corresponding parts in each drawing will be denoted by the same reference numerals.

[0033] FIG. 1 is a flowchart of a pattern forming method according to an exemplary embodiment. The method shown in FIG. 1 (hereinafter referred to as "method MT") includes step ST1, step ST2, and step ST3. Steps ST1 to ST3 can be executed in order. Hereinafter, method MT of the first embodiment to method MT of the fourth embodiment will be described.

[0034] (First Embodiment) FIGS. 2(a) to 2(c) and FIGS. 3(a) to 3(c) are cross-sectional views showing some steps of the pattern forming method according to the first embodiment. Hereinafter, method MT of the first embodiment will be described with reference to FIGS. 1 to 3.

[0035] In step ST1, as shown in FIG. 2, a pattern PT1 (first pattern) having an opening OP1 is formed on a substrate W. Pattern PT1 contains a first material. In this embodiment, the first material contains tin (Sn). The first material may contain tin oxide (SnO). Examples of the first material include tin-containing resist materials. The opening OP1 is, for example, a hole. Step ST1 can be carried out as follows.

[0036] First, as shown in FIG. 2(a), a photoresist film 18 is formed on the substrate W. The substrate W may include a silicon-containing film 10 and a oxide film 12. The oxide film 12 is disposed between the silicon-containing film 10 and the photoresist film 18. The oxide film 12 is, for example, a silicon oxide film. An underlayer film UR may be provided on the substrate W. The underlayer film UR may include a first layer 14 and a second layer 16. The first layer 14 is disposed between the oxide film 12 and the second layer 16. The first layer 14 may be an organic film such as a carbon film. The second layer 16 may be a silicon-containing film. Examples of the silicon-containing film include silicon oxide film (SiO x ), silicon nitride film (SiN), silicon carbide film (SiC), and silicon oxynitride film (SiON).

[0037] The photoresist film 18 can be formed on the underlayer film UR. The photoresist film 18 contains tin. The photoresist film 18 may be a negative resist film. The photoresist film 18 can be formed by a wet process or a dry process. Examples of the wet process include coating. The photoresist film 18 can be formed, for example, by coating a tin-containing resist material on the substrate W. Examples of the dry process include CVD. The photoresist film 18 can be formed by CVD using a tin-containing gas. Examples of the tin-containing gas include organic tin compound gas, SnCl4 gas, Sn(CH3)4 gas, and SnH4 gas.

[0038] Next, as shown in FIG. 2(b), for example, the photoresist film 18 is exposed using a photomask. By the exposure, an exposed portion 18a and an unexposed portion 18b are formed from the photoresist film 18. Tin oxide may be generated in the exposed portion 18a by the exposure. In the exposure, extreme ultraviolet light (EUV) or other light may be used.

[0039] Next, as shown in FIG. 2(c), by development, the non-exposed portion 18b is removed to form the opening OP1. As a result, the exposed portion 18a remains as the pattern PT1. The non-exposed portion 18b can be removed by a wet process or a dry process. In the dry process, the temperature may be -60°C or higher and 120°C or lower, and the pressure may be 0.1 mTorr (0.01333 Pa) or higher and 760 mTorr (101.308 kPa) or lower. The non-exposed portion 18b can be removed by a substance containing at least one of hydrogen and halogen. Examples of substances containing halogen include fluorine gas (F2), chlorine gas (Cl2), bromine gas (Br2), iodine gas (I2), and boron trichloride gas (BCl3). The non-exposed portion 18b is removed by a substance containing at least one of, for example, hydrogen, chlorine, and bromine. The substance containing hydrogen can be a hydrogen-containing gas or a hydrogen-containing liquid. Examples of hydrogen-containing gases include hydrogen (H2) gas, hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, hydrogen fluoride (HF) gas, and hydrogen iodide (HI) gas. Examples of hydrogen-containing liquids include hydrochloric acid (HCl), hydrobromic acid (HBr), and nitric acid (HNO3). The substance containing chlorine can be a chlorine-containing gas. Examples of chlorine-containing gases include Cl2 and BCl3. The substance containing bromine can be a bromine-containing gas. Examples of bromine-containing gases include Br2. The non-exposed portion 18b may be removed using at least one of helium gas, neon gas, argon gas, xenon gas, nitrogen gas, hydrocarbon gas, and methanol (CH3OH) gas. The non-exposed portion 18b may be removed by plasma (ashing) generated from a gas containing at least one of hydrogen, chlorine, and bromine, or may be removed by a gas containing at least one of hydrogen, chlorine, and bromine without using plasma. When using hydrogen bromide gas, the non-exposed portion 18b can be removed without using plasma.

[0040] In process ST2, as shown in FIGS. 3(a) and 3(b), a filling portion FL1 (first filling portion) is formed in the opening OP1. The filling portion FL1 contains a second material different from the first material. The second material may not contain tin. The second material may contain at least one of an organic substance, silicon, and a metal. Examples of the organic substance include spin-on carbon (SOC) and the like. The metal may be a metal other than tin. Examples of the metal include aluminum (Al), tungsten (W), titanium (Ti), hafnium (Hf), zirconium (Zr), and the like. The second material may contain a silicon-containing substance such as silicon oxide. Examples of the silicon-containing substance include spin-on glass (SOG) and the like. When the first material contains tin, the second material may contain tin oxide. The oxygen concentration of the second material may be higher than the oxygen concentration of the first material. The first material may not contain oxygen. Process ST2 can be implemented as follows.

[0041] First, as shown in FIG. 3(a), a filling film FL1a to be filled in the opening OP1 is formed on the substrate W. The filling film FL1a may be formed to cover the pattern PT1. The filling film FL1a can be formed by a wet process or a dry process.

[0042] Examples of the wet process include coating. For example, a liquid second material is applied onto the substrate W using a spin coater. Thereafter, the liquid second material is solidified by exposure or baking. Thereby, the filling film FL1a can be formed.

[0043] Examples of the dry process include CVD. When the filling film FL1a contains, for example, silicon, the filling film FL1a can be formed by CVD using a silicon-containing gas. Examples of the silicon-containing gas include SiCl4 gas, Si2Cl6 gas, and SiBr4 gas. The silicon-containing gas vaporizes under high-temperature or low-pressure conditions and liquefies under low-temperature or high-pressure conditions. Therefore, by adjusting at least one of the temperature and the pressure, a liquid second material can be formed on the substrate W. Thereafter, the liquid second material is solidified by oxidation or chlorine desorption. Thereby, the filling film FL1a can be formed.

[0044] Next, as shown in FIG. 3(b), if necessary, the upper portion of the filling film FL1a is removed, for example, by etching or CMP. Thereby, the filling portion FL1 is formed from the filling film FL1a. When the filling film FL1a is, for example, an organic film, the filling film FL1a can be etched with, for example, a mixed gas of nitrogen gas and hydrogen gas, or an oxygen-containing gas. Examples of the oxygen-containing gas include oxygen gas. When the filling film FL1a is, for example, a silicon-containing film, the filling film FL1a can be etched with, for example, a fluorine-containing gas. The fluorine-containing gas may contain carbon. Examples of the fluorine-containing gas include fluorocarbon (C x F y ) gas.

[0045] In step ST3, as shown in FIG. 3(c), by removing the pattern PT1, the filling portion FL1 remains as a pattern PT2 (second pattern) inverted with respect to the pattern PT1. When using a substance containing at least one of hydrogen, chlorine, and bromine, the pattern PT1 can be etched with a high selectivity with respect to the filling portion FL1. When removing the pattern PT1 using hydrogen bromide gas, the pattern PT1 can be removed without using plasma, so the etching selectivity of the pattern PT1 with respect to the filling portion FL1 can be increased.

[0046] Examples of the substance for removing the pattern PT1 are the same as the examples of the substance for removing the non-exposed portion 18b in step ST1. The pattern PT1 can be removed using at least one of hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, hydrogen iodide gas, fluorine gas, chlorine gas, bromine gas, iodine gas, boron trichloride gas, helium gas, neon gas, argon gas, xenon gas, nitrogen gas, hydrocarbon gas, and methanol (CH3OH) gas. The pattern PT1 may be removed by plasma (ashing) generated from a gas containing at least one of hydrogen, chlorine, and bromine, or may be removed by a gas containing at least one of hydrogen, chlorine, and bromine without using plasma.

[0047] After the process ST3, the underlying film UR may be etched using the pattern PT2 as a mask. As a result, a pattern corresponding to the pattern PT2 is formed from the underlying film UR. Thereafter, the oxide film 12 may be etched using the resulting pattern as a mask. As a result, a pattern is formed from the oxide film 12. Thereafter, the silicon-containing film 10 may be etched using the pattern obtained from the oxide film 12 as a mask.

[0048] According to the method MT of the present embodiment, a pattern can be inverted from the pattern PT1 to the pattern PT2. Usually, since a photoresist film containing tin is a negative resist film, it is difficult to reduce the size of the pattern formed from the photoresist film containing tin. However, according to the method MT of the present embodiment, by reducing the size of the opening OP1 of the pattern PT1, a pattern PT2 having a relatively small size can be formed. Therefore, by etching using the pattern PT2 as a mask, a contact hole having a relatively small size can be formed in the silicon-containing film 10. Further, in the method MT of the present embodiment, by using a substance containing at least one of hydrogen, chlorine, and bromine in the process ST3, the pattern PT1 containing tin can be selectively removed while leaving the filling portion FL1. A material containing tin has a special property of reacting easily with a substance containing at least one of hydrogen, chlorine, and bromine as compared with many other materials. Therefore, when the pattern PT1 containing tin is used, the choice of materials for the filling portion FL1 is expanded.

[0049] (Second Embodiment) FIGS. 4(a) to 4(d) are cross-sectional views showing some steps of a pattern forming method according to the second embodiment. Hereinafter, the method MT of the second embodiment will be described with reference to FIGS. 1, 2, and 4.

[0050] In the present embodiment, in the process ST1, as shown in FIG. 4(a), a pattern PT11 (first pattern) having an opening OP2 is formed on the substrate W. The pattern PT11 contains the same first material as the pattern PT1. The process ST1 can be carried out as follows.

[0051] In step ST1, first, as shown in FIG. 2, a pattern PT1 (mask pattern) corresponding to the pattern PT11 is formed on the underlayer film UR provided on the substrate W. The pattern PT1 can be formed in the same manner as in the first embodiment.

[0052] Next, as shown in FIG. 4(a), by etching the underlayer film UR using the pattern PT1 as a mask, the pattern PT11 is formed. For example, the pattern 14a and the pattern 16a are formed from the first layer 14 and the second layer 16, respectively. The pattern PT11 may include the pattern PT1, the pattern 14a, and the pattern 16a.

[0053] In step ST2, as shown in FIGS. 4(b) and (c), a filling portion FL2 is formed in the opening OP2. The filling portion FL2 contains the same second material as the filling portion FL1. Step ST2 can be carried out as follows.

[0054] First, as shown in FIG. 4(b), a filling film FL2a to be filled in the opening OP2 is formed on the substrate W. The filling film FL2a may be formed so as to cover the pattern PT11. The filling film FL2a can be formed in the same manner as the filling film FL1a.

[0055] Next, as shown in FIG. 4(c), if necessary, the upper portion of the filling film FL2a may be removed. Thereby, the filling portion FL2 is formed from the filling film FL2a. The upper portion of the filling film FL2a can be removed in the same manner as the upper portion of the filling film FL1a.

[0056] In step ST3, as shown in FIG. 4(d), by removing the pattern PT11, the filling portion FL2 remains as a pattern PT12 (second pattern) inverted with respect to the pattern PT11. The pattern PT1 in the pattern PT11 can be removed by etching similar to the etching in step ST3 of the first embodiment. The patterns 14a and 16a in the pattern PT11 are removed by etching similar to the etching of the underlayer film UR in step ST1 of the present embodiment.

[0057] According to the method MT of this embodiment, the aspect ratio of the pattern PT12 can be increased compared to the pattern PT2 of the first embodiment. Therefore, when etching the oxide film 12 using the pattern PT12 as a mask, a good etching selectivity can be obtained.

[0058] (Third Embodiment) Figs. 5(a) to (c) and Figs. 6(a) to (c) are cross-sectional views showing some steps of the pattern forming method according to the third embodiment. Hereinafter, the method MT of the third embodiment will be described with reference to Figs. 1, 5 and 6.

[0059] In step ST1, as shown in Fig. 5, a pattern PT21 (first pattern) having an opening OP3 is formed on a substrate W. The pattern PT21 contains a first material. In this embodiment, the first material may contain at least one of an organic substance, silicon, and a metal. The first material may not contain tin. The first material of this embodiment may be the same as the second material of the first embodiment. The opening OP3 is, for example, a hole. Step ST1 can be implemented as follows.

[0060] First, as shown in Fig. 5(a), a photoresist film 28 is formed on the substrate W. The photoresist film 28 can be formed on an underlayer film UR. The photoresist film 28 may contain at least one of an organic substance, silicon, and a metal. The photoresist film 28 may be a positive resist film or a negative resist film. The photoresist film 28 can be formed by a wet process or a dry process. Examples of the wet process include coating. Examples of the dry process include CVD.

[0061] Next, as shown in Fig. 5(b), the photoresist film 28 is exposed using, for example, a photomask. By the exposure, an exposed portion 28a and a non-exposed portion 28b are formed from the photoresist film 28.

[0062] Next, as shown in FIG. 5(c), the exposed portion 28a is removed by development to form the opening OP3. As a result, the pattern PT21 is formed from the unexposed portion 28b. In this case, the photoresist film 28 is a positive resist film. If the photoresist film 28 is a negative resist film, the unexposed portion 28b is removed, so that the pattern PT21 is formed from the exposed portion 28a.

[0063] In step ST2, as shown in FIGS. 6(a) and 6(b), a filling portion FL3 (first filling portion) is formed in the opening OP3. The filling portion FL3 contains a second material different from the first material. The second material contains tin. The second material may contain tin oxide. Examples of the second material include tin-containing organic materials and the like. The second material of the present embodiment may be the same as the first material of the first embodiment. Step ST2 can be implemented as follows.

[0064] First, as shown in FIG. 6(a), a filling film FL3a to be filled in the opening OP3 is formed on the substrate W. The filling film FL3a may be formed so as to cover the pattern PT21. The filling film FL3a can be formed by a wet process or a dry process. Examples of the wet process include coating. Examples of the dry process include CVD. The filling film FL3a can be formed by CVD using a tin-containing gas. Examples of the tin-containing gas include organotin compound gas, SnCl4 gas, Sn(CH3)4 gas, and SnH4 gas. The tin-containing gas vaporizes under high-temperature or low-pressure conditions and liquefies under low-temperature or high-pressure conditions. Therefore, by adjusting at least one of the temperature and the pressure, the opening OP3 can be filled with the liquid second material. Thereafter, the liquid second material is solidified by oxidation or chlorine elimination. Thereby, the filling film FL3a can be formed.

[0065] Next, as shown in FIG. 6(b), if necessary, the upper part of the filling film FL3a is removed, for example, by etching or CMP. Thereby, the filling portion FL3 is formed from the filling film FL3a. The filling film FL3a may be removed by plasma (ashing) generated from a gas containing at least one of hydrogen, chlorine, and bromine, or may be removed by a gas containing at least one of hydrogen, chlorine, and bromine without using plasma.

[0066] In step ST3, as shown in FIG. 6(c), by removing the pattern PT21, the filling portion FL3 remains as a pattern PT22 (second pattern) inverted with respect to the pattern PT21. When a substance containing no hydrogen, chlorine, and bromine is used, the pattern PT21 can be etched with a high selectivity with respect to the filling portion FL3.

[0067] When the pattern PT21 contains, for example, an organic substance, examples of the substance containing no hydrogen, chlorine, and bromine include an oxygen-containing gas, a fluorine-containing gas, and a nitrogen-containing gas. Examples of the oxygen-containing gas include oxygen gas, carbonyl sulfide (COS) gas, and sulfur dioxide (SO2) gas. Examples of the fluorine-containing gas include fluorocarbon (C x F y ) gas, hydrofluorocarbon (C x H y F z ) gas, and nitrogen trifluoride (NF3 gas). Examples of the nitrogen-containing gas include nitrogen gas.

[0068] When the pattern PT21 contains, for example, silicon, examples of the substance containing no hydrogen, chlorine, and bromine include a fluorine-containing gas. The fluorine-containing gas may contain carbon or nitrogen. Examples of the fluorine-containing gas include fluorocarbon (C x F y ) gas, hydrofluorocarbon (C x H y F z ) gas, and NF3 gas.

[0069] When the pattern PT21 contains, for example, a metal excluding tin, examples of substances that do not contain hydrogen, chlorine, and bromine include fluorine-containing gases. Examples of fluorine-containing gases include hydrogen fluoride (HF) gas, fluorocarbon (C x F y ) gas, NF3 gas, and SF6 gas. The pattern PT21 can be removed as follows. First, the surface of the pattern PT21 is fluorinated using a fluorine-containing gas. Then, the fluorinated surface of the pattern PT21 is exposed to a metal-containing precursor containing a metal complex. Examples of the metal-containing precursor include tin(II) acetylacetonate (Sn(acac)2). By ligand exchange between the metal fluoride and the metal complex, another highly volatile metal complex is formed. Thereby, the pattern PT21 is etched.

[0070] According to the method MT of the present embodiment, the pattern can be inverted from the pattern PT21 to the pattern PT22. Usually, since a photoresist film containing tin is a negative resist film, it is difficult to reduce the dimensions of the pattern formed from the photoresist film containing tin. However, according to the method MT of the present embodiment, by reducing the dimension of the opening OP3 of the pattern PT21, a pattern PT22 having relatively small dimensions can be formed. Therefore, by etching using the pattern PT22 as a mask, a contact hole having relatively small dimensions can be formed in the silicon-containing film 10. Further, in the method MT of the present embodiment, by using a substance that does not contain hydrogen, chlorine, and bromine in the step ST3, the pattern PT21 can be selectively removed while leaving the filling portion FL3 containing tin. A material containing tin has a special property that it is difficult to react with substances that do not contain hydrogen, chlorine, and bromine compared to many other materials. Therefore, when using the filling portion FL3 containing tin, the options for the material of the pattern PT21 are expanded.

[0071] (Fourth Embodiment) FIGS. 7(a) and (b) and FIGS. 8(a) to (c) are cross-sectional views showing some steps of a pattern forming method according to the fourth embodiment. Hereinafter, the method MT of the fourth embodiment will be described with reference to FIGS. 1, 5, 7, and 8.

[0072] In this embodiment, in step ST1, as shown in FIG. 7, a pattern PT31 (first pattern) having an opening OP4 is formed on a substrate W. The pattern PT31 contains a first material. In this embodiment, the first material may contain at least one of an organic substance, silicon, and a metal. The first material may not contain tin. Step ST1 can be implemented as follows.

[0073] In step ST1, first, as shown in FIG. 5, a pattern PT21 (mask pattern) corresponding to the pattern PT31 is formed on an underlayer film UR provided on the substrate W. The pattern PT21 can be formed in the same manner as in the third embodiment.

[0074] Next, as shown in FIG. 7, the underlayer film UR is etched using the pattern PT21 as a mask to form the pattern PT31. For example, a pattern 14b and a pattern 16b are formed from the first layer 14 and the second layer 16, respectively. When etching the underlayer film UR, the pattern PT21 may disappear. The pattern PT31 may include the pattern 14b and the pattern 16b.

[0075] In step ST2, as shown in FIGS. 8(a) and 8(b), a filling portion FL4 is formed in the opening OP4. The filling portion FL4 contains a second material similar to the filling portion FL3. Step ST2 can be implemented as follows.

[0076] First, as shown in FIG. 8(a), a filling film FL4a to be filled in the opening OP4 is formed on the substrate W. The filling film FL4a may be formed so as to cover the pattern PT31. The filling film FL4a can be formed in the same manner as the filling film FL3a.

[0077] Next, as shown in FIG. 8(b), if necessary, the upper portion of the filling film FL4a may be removed. Thereby, the filling portion FL4 is formed from the filling film FL4a. The upper portion of the filling film FL4a can be removed in the same manner as the upper portion of the filling film FL3a.

[0078] In step ST3, as shown in FIG. 8(c), by removing the pattern PT31, the filling portion FL4 remains as a pattern PT32 (second pattern) that is inverted with respect to the pattern PT31. The pattern PT31 is removed by an etching similar to the etching of the underlying film UR in step ST1.

[0079] According to the method MT of the present embodiment, the aspect ratio of the pattern PT32 can be increased compared to the pattern PT22 of the third embodiment. Therefore, when etching the oxide film 12 using the pattern PT32 as a mask, a good etching selectivity can be obtained.

[0080] (Fifth Embodiment) FIG. 9 is a flowchart of a pattern formation method according to one exemplary embodiment. The method shown in FIG. 9 (hereinafter referred to as "method MT1") further includes steps ST4 and ST5 in addition to steps ST1, ST2, and ST3. Steps ST4 and ST5 can be executed after each step ST3 of the first to fourth embodiments. Step ST5 can be executed after step ST4. Hereinafter, the method MT1 will be described.

[0081] FIGS. 10(a) to (c) are cross-sectional views showing some steps of the pattern formation method according to the fifth embodiment. In the present embodiment, steps ST4 and ST5 can be performed after step ST3 shown in FIG. 3(c).

[0082] In step ST4, as shown in FIGS. 10(a) and (b), a filling portion FL11 (second filling portion) is formed in the opening OP11 of the pattern PT2. The filling portion FL11 contains a third material different from the first material and the second material. When the first material and the second material are the first material and the second material of the first embodiment, examples of the third material include organic substances, silicon, and metals (excluding tin).

[0083] Step ST4 can be implemented in the same manner as step ST2. First, as shown in FIG. 10(a), a filling film FL11a to be filled in the opening OP11 is formed on the substrate W. The filling film FL11a may be formed to cover the pattern PT2. Next, as shown in FIG. 10(b), if necessary, for example, by etching or CMP, the upper part of the filling film FL11a is removed. Thereby, the filling portion FL11 is formed from the filling film FL11a.

[0084] In step ST5, as shown in FIG. 10(c), by removing the pattern PT2, the filling portion FL11 remains as a pattern PT3 (third pattern) corresponding to the pattern PT1. Step ST5 can be implemented in the same manner as step ST3.

[0085] When the pattern PT2 contains an organic substance and the filling portion FL11 contains a metal other than tin or silicon, the pattern PT2 can be removed by an oxygen-containing gas or a nitrogen-containing gas. Examples of the oxygen-containing gas include oxygen gas, carbonyl sulfide (COS) gas, and sulfur dioxide (SO2) gas. Examples of the nitrogen-containing gas include nitrogen gas.

[0086] When the pattern PT2 contains silicon and the filling portion FL11 contains an organic substance, the pattern PT2 can be removed by a halogen-containing gas. Examples of the halogen-containing gas include fluorocarbon (C x F y ) gas, hydrofluorocarbon (C x H y F z ) gas, NF3 gas, hydrogen fluoride gas, hydrogen chloride gas, and hydrogen bromide gas.

[0087] When the pattern PT2 contains silicon and the filling portion FL11 contains a metal other than tin, the pattern PT2 can be removed by a fluorine-containing gas. Examples of the fluorine-containing gas include fluorocarbon (C x F y ) gas, hydrofluorocarbon (C x H y F z ) gas, and NF3 gas.

[0088] When the pattern PT2 contains a metal other than tin and the filling portion FL11 contains an organic substance or silicon, the pattern PT2 can be removed by a hydrogen-containing gas or a halogen-containing gas. Examples of the hydrogen-containing gas include hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, and hydrogen gas. The halogen-containing gas includes chlorine gas and bromine gas.

[0089] According to the method MT1 of the present embodiment, a pattern PT3 having the same shape as the pattern PT1 and containing a material different from the pattern PT1 can be formed.

[0090] (Sixth Embodiment) FIG. 11 is a flowchart of a pattern formation method according to one exemplary embodiment. The method shown in FIG. 11 (hereinafter referred to as "method MT2") further includes steps ST6 and ST7 in addition to steps ST1, ST2, and ST3. Steps ST6 and ST7 can be executed before each step ST1 of the first to fourth embodiments. Step ST6 can be executed before step ST7. Hereinafter, the method MT2 will be described.

[0091] FIGS. 12(a) to 12(c) are cross-sectional views showing some steps of the pattern formation method according to the sixth embodiment. In the present embodiment, steps ST6 and ST7 can be performed before step ST1 shown in FIG. 5(c).

[0092] In step ST6, as shown in FIG. 12(a), a pattern PT4 (third pattern) having an opening OP12 is formed on a substrate W. The pattern PT4 contains a third material different from the first material and the second material. When the first material and the second material are the first material and the second material of the third embodiment, examples of the third material include an organic substance, silicon, and a metal (excluding tin). Step ST6 can be performed in the same manner as step ST1.

[0093] In step ST7, a filling portion FL12 (second filling portion) is formed in the opening OP12 of the pattern PT4. The filling portion FL12 contains the first material.

[0094] Step ST7 can be implemented in the same manner as step ST2. First, as shown in FIG. 12(b), a filling film FL12a to be filled in the opening OP12 is formed on the substrate W. The filling film FL12a may be formed so as to cover the pattern PT4. Next, as shown in FIG. 12(c), if necessary, for example, the upper portion of the filling film FL12a is removed by etching or CMP. Thereby, the filling portion FL12 is formed from the filling film FL12a.

[0095] After step ST7, in step ST1, by removing the pattern PT4, the filling portion FL12 remains as the pattern PT21 (first pattern) as shown in FIG. 5(c).

[0096] When the pattern PT4 contains an organic substance and the filling portion FL12 contains a metal other than tin or silicon, the pattern PT4 can be removed by an oxygen-containing gas or a nitrogen-containing gas. Examples of the oxygen-containing gas include oxygen gas, carbonyl sulfide (COS) gas, and sulfur dioxide (SO2) gas. Examples of the nitrogen-containing gas include nitrogen gas.

[0097] When the pattern PT4 contains silicon and the filling portion FL12 contains an organic substance, the pattern PT4 can be removed by a halogen-containing gas. Examples of the halogen-containing gas include fluorocarbon (C x F y ) gas, hydrofluorocarbon (C x H y F z ) gas, NF3 gas, hydrogen fluoride gas, hydrogen chloride gas, and hydrogen bromide gas.

[0098] When the pattern PT4 contains silicon and the filling portion FL12 contains a metal other than tin, the pattern PT4 can be removed by a fluorine-containing gas. Examples of the fluorine-containing gas include fluorocarbon (C x F y ) gas, hydrofluorocarbon (C x H y F z ) gas, and NF3 gas.

[0099] When pattern PT4 contains a metal other than tin and filling portion FL12 contains an organic substance or silicon, pattern PT4 can be removed by a hydrogen-containing gas or a halogen-containing gas. Examples of the hydrogen-containing gas include hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, and hydrogen gas. The halogen-containing gas includes chlorine gas and bromine gas.

[0100] According to method MT2 of this embodiment, a pattern PT22 can be formed that contains a material different from pattern PT4 and has the same shape as pattern PT4.

[0101] In each embodiment, the pattern containing tin may be a Sn-containing film. The Sn-containing film can be formed by a dry process or a wet process. The Sn-containing film may be a Sn film or a SnO film. The Sn-containing film may be a photoresist film or a non-photoresist film. The pattern containing tin may be formed from any one of a CVD film, an ALD film, and a PVD film. The pattern containing tin can be formed by CVD or ALD using, for example, t-butyltris(dimethylamino)tin as a precursor and, for example, H2O as an oxidant. The CVD film, ALD film, and PVD film may be formed by plasma energy. The CVD film and ALD film may be formed by thermal energy. The CVD film or ALD film may be a photoresist film containing tin. The photoresist film may be a photoresist film for EUV exposure. When the non-exposed portion of the photoresist film contains tin and the exposed portion of the photoresist film contains tin oxide, the oxygen concentration of the exposed portion may be higher than that of the non-exposed portion. The non-exposed portion may not contain oxygen.

[0102] FIG. 13 is a diagram schematically showing an apparatus for implementing a pattern formation method according to one exemplary embodiment. Method MT of each of the above embodiments can be implemented using apparatus 100 shown in FIG. 13. Apparatus 100 may include a coating and developing apparatus 110, an exposure apparatus 120, a coating apparatus 130, an etching apparatus 140, an asher 150, and an etching apparatus 160.

[0103] The coating and developing apparatus 110 and the exposure apparatus 120 can constitute the pattern forming apparatus 101. The substrate W can be conveyed between the coating and developing apparatus 110 and the exposure apparatus 120. The process ST1 can be carried out using the pattern forming apparatus 101. In the process ST1, the pattern PT1, the pattern PT11, the pattern PT21 or the pattern PT31 can be formed using the pattern forming apparatus 101. After the process ST1, the substrate W can be conveyed from the coating and developing apparatus 110 to the coating apparatus 130.

[0104] The process ST2 can be carried out using the coating apparatus 130 and the etching apparatus 140. The coating apparatus 130 may be, for example, a spin coater or a slit coater. The apparatus 100 may be provided with a CVD apparatus instead of the coating apparatus 130. The apparatus 100 may be provided with a CMP apparatus instead of the etching apparatus 140. In the process ST2, the substrate W can be conveyed from the coating apparatus 130 to the etching apparatus 140. In the process ST2, the filling portions FL1, FL2, FL3 and FL4 can be formed. After the process ST2, the substrate W can be conveyed from the etching apparatus 140 to the asher 150.

[0105] The process ST3 can be carried out using the asher 150. The apparatus 100 may be provided with a cleaning apparatus instead of the asher 150. In the process ST3, the pattern PT1, the pattern PT11, the pattern PT21 or the pattern PT31 can be removed using the asher 150. As a result, the pattern PT2, the pattern PT12, the pattern PT22 or the pattern PT32 can be formed. After the process ST3, the substrate W can be conveyed from the asher 150 to the etching apparatus 160. The etching apparatus 160 can be used for etching the oxide film 12 of the substrate W.

[0106] FIG. 14 is a diagram schematically showing an apparatus for implementing a pattern formation method according to another exemplary embodiment. The method MT of each of the above embodiments may be implemented using the apparatus 200 shown in FIG. 14. By using the apparatus 200, the method MT of each embodiment can be performed only by a dry process. The apparatus 200 may include a CVD apparatus 210, an exposure apparatus 220, an etching apparatus 230, a CVD apparatus 240, an etching apparatus 250, an asher 260, and an etching apparatus 270.

[0107] The CVD apparatus 210, the exposure apparatus 220, and the etching apparatus 230 may constitute a pattern formation apparatus 201. The substrate W may be transported from the CVD apparatus 210 through the exposure apparatus 220 to the etching apparatus 230. The step ST1 may be implemented using the pattern formation apparatus 201. In the step ST1, the pattern PT1, the pattern PT11, the pattern PT21, or the pattern PT31 may be formed using the pattern formation apparatus 201. After the step ST1, the substrate W may be transported from the etching apparatus 230 to the CVD apparatus 240.

[0108] The step ST2 may be implemented using the CVD apparatus 240 and the etching apparatus 250. In the step ST2, the substrate W may be transported from the CVD apparatus 240 to the etching apparatus 250. In the step ST2, the filling portions FL1, FL2, FL3, and FL4 may be formed. After the step ST2, the substrate W may be transported from the etching apparatus 250 to the asher 260.

[0109] The step ST3 may be implemented using the asher 260. After the step ST3, the substrate W may be transported from the asher 260 to the etching apparatus 270. The etching apparatus 270 may be used for etching the oxide film 12 of the substrate W.

[0110] As described above, various exemplary embodiments have been described, but the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and changes may be made. Also, it is possible to combine elements in different embodiments to form other embodiments.

[0111] From the above description, it will be understood that the various embodiments of the present disclosure are described herein for purposes of illustration and that various changes can be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, and the true scope and spirit are indicated by the appended claims.

Explanation of Reference Numerals

[0112] FL1, FL2, FL3, FL4... filling parts, MT... method, OP1, OP2, OP3, OP4... openings, PT1... pattern (first pattern), PT2, PT12, PT22, PT32... patterns (second pattern), PT11, PT31... patterns (first pattern), PT21... pattern (first pattern), W... substrate.

Claims

1. A method of forming a pattern, comprising: (a) forming, by a dry process, a first pattern having openings and including a first material on a substrate; (b) forming a filling portion including a second material different from the first material in the openings; (c) removing the first pattern so that the filling portion remains as a second pattern inverted with respect to the first pattern; wherein the first material contains tin, and in (a), the openings are formed by removing the non-exposed portion of a photoresist film including an exposed portion and a non-exposed portion.

2. The method according to claim 1, wherein the first material contains tin oxide.

3. The method according to claim 1 or 2, wherein the second material contains at least one of an organic substance, silicon, and a metal.

4. The method according to claim 3, wherein in (c), the first pattern is removed using hydrogen bromide gas.

5. the second material contains at least one of an organic substance, silicon, and a metal, and in (c), the first pattern is removed using at least one of hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, hydrogen iodide gas, fluorine gas, chlorine gas, bromine gas, iodine gas, boron trichloride gas, helium gas, neon gas, argon gas, xenon gas, nitrogen gas, hydrocarbon gas, and methanol gas.

6. the first material contains tin oxide, and the second material contains at least one of an organic substance and silicon.

7. The method according to claim 6, wherein in (c), the first pattern is removed using at least one of hydrogen bromide gas and hydrocarbon gas.

8. the second material contains tin oxide, the oxygen concentration of the second material is higher than the oxygen concentration of the first material, and in (c), the first pattern is removed using at least one of hydrogen fluoride gas, hydrogen chloride gas, hydrogen bromide gas, hydrogen iodide gas, fluorine gas, chlorine gas, bromine gas, iodine gas, boron trichloride gas, helium gas, neon gas, argon gas, xenon gas, nitrogen gas, hydrocarbon gas, and methanol gas.

9. The method according to any one of claims 5 to 8, wherein the first pattern is formed from a CVD film or an ALD film.

10. The method according to claim 9, wherein the CVD film or the ALD film is the photoresist film containing tin.

11. The method according to claim 10, wherein the photoresist film is a photoresist film for EUV exposure.

12. The method according to claim 10, wherein the unexposed portion of the photoresist film contains tin, the exposed portion of the photoresist film contains tin oxide, and the oxygen concentration of the exposed portion is higher than the oxygen concentration of the unexposed portion.

13. The step (a) includes: (a1) forming a mask pattern corresponding to the first pattern on an underlayer film provided on the substrate; and (a2) forming the first pattern by etching the underlayer film using the mask pattern. The method according to any one of claims 1 to 12, comprising the above steps.

14. The method according to claim 13, wherein the underlayer film includes at least one of a silicon-containing film and an organic film.

15. A method for forming a pattern, comprising: (a) forming a first pattern including a first material and having an opening on a substrate; and (b) forming a first filling portion including a second material different from the first material in the opening. and (c) removing the first pattern so that the first filling portion remains as a second pattern inverted with respect to the first pattern. and (d) forming a second filling portion including a third material different from the first material and the second material in the opening of the second pattern. and (e) removing the second pattern so that the second filling portion remains as a third pattern corresponding to the first pattern. The method includes: at least one of the first material and the second material contains tin.

16. A method for forming a pattern, comprising: and (a) forming a first pattern including a first material and having an opening on a substrate; and (b) forming a first filling portion including a second material different from the first material in the opening. and (c) removing the first pattern so that the first filling portion remains as a second pattern inverted with respect to the first pattern. The method includes: at least one of the first material and the second material contains tin, before the step (a), the method further includes: and (f) forming a third pattern including a third material and having an opening on the substrate, wherein the third material is different from the first material and the second material. (g) forming a second filling portion containing the first material within the opening of the third pattern; further comprising; in the step (a), by removing the third pattern, the second filling portion remains as the first pattern, the method.

17. (a) preparing a substrate having a photoresist film containing tin, the photoresist film including an exposed portion and a non-exposed portion; (b) removing the non-exposed portion by a dry process to form an opening; (c) forming a filling portion containing a second material different from the first material constituting the photoresist film containing tin within the opening; (d) removing the photoresist film containing tin; including, the method.

18. In the step (b), the method according to claim 17, wherein the non-exposed portion is removed by a substance containing at least one of hydrogen and halogen.

19. The substance is fluorine (F ２ ), chlorine (Cl ２ ), bromine (Br ２ ), iodine (I ２ ), boron trichloride (BCl ３ ), hydrogen (H ２ ), hydrogen chloride (HCl) gas, hydrogen bromide (HBr) gas, hydrogen fluoride (HF) gas, and hydrogen iodide (HI) gas, and the method according to claim 18, comprising at least one of them.

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