Pattern formation method

Abstract

To provide a pattern forming method in which a fine pattern can be formed easily and efficiently without damaging a substrate.SOLUTION: In a pattern forming method, an organic lower layer film, a tin-containing intermediate film and an upper layer resist film are formed on a substrate to be processed; an upper layer resist pattern is formed; the upper layer resist pattern is transferred onto the tin-containing intermediate film; an organic lower layer film pattern in which a part of the tin-containing intermediate film remains on an upper part of the pattern is formed; a part of the tin-containing intermediate film is removed by dry etching; an inorganic silicon-containing film is formed so as to cover the organic lower layer film pattern; an upper part of the organic lower layer film pattern is exposed; the organic lower layer film pattern is removed to form an inorganic silicon-containing film pattern in which a pattern pitch is 1 / 2 the upper layer resist pattern; and the substrate to be processed is processed by using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pattern forming method by a sidewall spacer method.

Background Art

[0002] As exposure light used for forming a resist pattern, in the 1980s, optical exposure using g-line (436 nm) or i-line (365 nm) of a mercury lamp as a light source was widely used. As a means for further miniaturization, a method of shortening the exposure wavelength has been considered effective. In mass production processes after 64M-bit (processing dimension of 0.25 μm or less) DRAM (Dynamic Random Access Memory) in the 1990s, a short wavelength KrF excimer laser (248 nm) has been used as an exposure light source instead of i-line (365 nm).

[0003] However, for the production of DRAMs with a higher integration of 256M and 1G or more that require a finer processing technology (processing dimension of 0.2 μm or less), a light source with a shorter wavelength is required. Since about 10 years ago, photolithography using an ArF excimer laser (193 nm) has been seriously studied. Initially, ArF lithography was supposed to be applied from the production of 180 nm node devices, but KrF excimer lithography was extended until the mass production of 130 nm node devices, and the full-scale application of ArF lithography started from the 90 nm node. Furthermore, in combination with a lens with an increased NA up to 0.9, mass production of 65 nm node devices is being carried out. For the next 45 nm node devices, shortening of the exposure wavelength has been promoted, and F2 lithography with a wavelength of 157 nm has been proposed as a candidate. However, due to various problems such as an increase in the cost of the scanner due to the large amount of expensive CaF2 single crystal used for the projection lens, changes in the optical system due to the introduction of a hard pellicle due to the extremely low durability of the soft pellicle, and a decrease in the etching resistance of the resist film, the development of F2 lithography was discontinued, and ArF immersion lithography was introduced.

[0004] In ArF immersion lithography, water with a refractive index of 1.44 is inserted between the projection lens and the wafer using a partial-fill method, enabling high-speed scanning. This allows for the mass production of 45nm node devices using lenses with an NA of 1.3.

[0005] While vacuum ultraviolet (EUV) lithography with a wavelength of 13.5 nm has been put into practical use as a lithography technology at the 32 nm node, the optical exposure technology used as a general-purpose technique is approaching the intrinsic resolution limit inherent in the wavelength of the light source.

[0006] Therefore, one of the miniaturization technologies that has attracted attention in recent years is the double patterning process, in which a pattern is formed with the first exposure and development, and a pattern is formed exactly in the space of the first pattern with the second exposure (Non-Patent Literature 1). Many processes have been proposed for double patterning. For example, (1) a photoresist pattern with a line-to-space ratio of 1:3 is formed with the first exposure and development, the underlying hard mask is processed by dry etching, another hard mask is laid on top, a line pattern is formed in the space area of ​​the first exposure by exposure and development of the photoresist film, and the hard mask is processed by dry etching to form a line-and-space pattern with half the pitch of the initial pattern. Also, (2) a photoresist pattern with a space-to-line ratio of 1:3 is formed with the first exposure and development, the underlying hard mask is processed by dry etching, a photoresist film is applied on top, a second space pattern is exposed to the area where the hard mask remains, and the hard mask is processed by dry etching. In both cases, the hard mask is processed by two dry etchings.

[0007] The former method requires laying a hard mask twice, while the latter method only requires one hard mask layer, but it requires forming a trench pattern, which is more difficult to resolve than a line pattern. Furthermore, the latter method involves using negative resist material to form the trench pattern. This method allows the use of the same high-contrast light as when forming lines with a positive-developed pattern, but the dissolution contrast of negative resist material is lower than that of positive resist material. Therefore, when comparing forming lines with positive resist material and forming trench patterns of the same size with negative resist material, the negative resist material results in lower resolution. In the latter method, it is conceivable to apply thermal flow methods, where a wide trench pattern is formed using positive resist material and then the substrate is heated to shrink the trench pattern, or the RELACS method, where a water-soluble film is coated onto the developed trench pattern and then heated to crosslink the resist film surface and shrink the trenches. However, these methods suffer from drawbacks such as a deterioration of proximity bias and increased process complexity, leading to reduced throughput.

[0008] In both methods, etching is required twice for substrate processing, which leads to problems such as reduced throughput and deformation or misalignment of the pattern due to the two etching processes.

[0009] To complete etching in a single pass, one method involves using a negative resist material in the first exposure and a positive resist material in the second exposure. Another method involves using a positive resist material in the first exposure and then using a negative resist material dissolved in a higher alcohol with 4 or more carbon atoms (which does not dissolve the positive resist material) in the second exposure. In these cases, a degradation in resolution occurs because a negative resist material with low resolution is used.

[0010] Another proposed method involves treating the pattern formed by the first exposure and development with a reactive metal compound to insolubilize the pattern, and then forming a second pattern between the first and second patterns by exposure and development (Patent Document 1).

[0011] In this type of double patterning, the most critical issue is the alignment accuracy between the first and second patterns. The magnitude of the misalignment results in variations in line dimensions; for example, to form a 32nm line with 10% accuracy, an alignment accuracy of within 3.2nm is required. Current scanners have an alignment accuracy of around 8nm, so a significant improvement in accuracy is necessary.

[0012] Due to issues with scanner alignment accuracy and the difficulty of dividing one pattern into two, methods for halving the pitch in a single exposure are being considered. For example, a sidewall spacer method has been proposed in which a film is attached to the side walls on both sides of a line pattern to halve the pitch (Non-Patent Literature 2). As part of this sidewall spacer method, two methods have been proposed: the spacer space method, which uses the hard mask of the resist layer beneath it, the film attached to its side walls, and a film embedded in the space between the films as etching patterns, and the spacer line method, which uses a film attached to the side walls of the hard mask of the resist layer beneath it as an etching pattern (Non-Patent Literature 3).

[0013] As a sidewall spacer method, a method has been proposed in which sidewalls are formed on the core pattern using CVD with materials such as SiO2, α-Si, and α-C, and then the core pattern is removed by dry etching, thereby using the sidewalls as the pattern and halving the pattern pitch. In a multilayer resist method using an organic resist underlayer and a silicon-containing interlayer, a resist pattern can be transferred to a core material consisting of the organic underlayer by dry etching, then sidewalls are formed on the core material to which the pattern has been transferred, and then the core material is removed to form a pattern with half the pattern pitch. However, when the core material that is no longer needed after sidewall formation is removed by dry etching, the silicon-containing interlayer remains on top of the organic underlayer, and dry etching using fluorine gas is required to remove the silicon-containing interlayer. The substrate is damaged during this dry etching process to remove the silicon-containing interlayer. This leads to problems such as failure to meet product performance targets and reduced yield.

[0014] As a method for removing silicon-containing interlayers remaining on an organic underlayer without damaging the substrate, a method has been proposed in which the silicon-containing interlayer remaining on top of the organic underlayer is washed away with a stripping solution that does not damage the organic underlayer or the substrate, thereby forming an inorganic silicon film pattern (sidewall pattern) with a pattern pitch of half that of the upper resist pattern (Patent Document 2). On the other hand, when forming finer patterns, wet stripping carries the risk of pattern collapse, and there is a need for a highly practical pattern formation method using dry etching. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] Japanese Patent Publication No. 2008-33174 [Patent Document 2] Japanese Patent Publication No. 2020-111727 [Non-patent literature]

[0016] [Non-Patent Document 1] Proc.SPIE Vol.5754p1508(2005) [Non-Patent Document 2] J.Vac.Sci.Technol.B17(6), Nov / Dec1999 [Non-Patent Document 3] 4th Immersion Symposium (2007), Presentation Number: PR-01, Title: Implementation of Immersion Lithography to NAND / CMOS Lithography to NAND / CMOS Device Manufacturing [Overview of the Initiative] [Problems that the invention aims to solve]

[0017] The sidewall spacer method using an organic resist underlayer as the core material is useful for forming fine patterns, but in the combination of an organic resist underlayer and a silicon-containing interlayer, which is the mainstream of multilayer resist methods, the method of removing the silicon-containing interlayer remaining on the organic resist underlayer remains a challenge.

[0018] The present invention aims to improve upon the above-mentioned situation and provide a pattern formation method that can easily and efficiently form finer patterns with higher smoothness without damaging the substrate. [Means for solving the problem]

[0019] To solve the above problems, the present invention provides a method for forming a pattern on a substrate to be processed, (i-1) A step of forming an organic underlayer film on a substrate to be processed, forming a tin-containing interlayer film on the organic underlayer film, and further forming an upper resist film on the tin-containing interlayer film. (i-2) A step of pattern exposure of the upper resist film, then developing it to form an upper resist pattern, (i-3) A step of transferring the upper resist pattern to the tin-containing interlayer by dry etching the tin-containing interlayer using the upper resist pattern as a mask, and further forming an organic underlayer pattern in which a portion of the tin-containing interlayer remains on the upper part of the pattern by dry etching the organic underlayer using the tin-containing interlayer on which the upper resist pattern has been transferred as a mask. (i-4) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (i-5) A step of forming an inorganic silicon-containing film made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof, by CVD or ALD, so as to cover the organic underlayer film pattern. (i-6) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the organic underlayer film pattern. (i-7) Removing the organic lower layer film pattern to form an inorganic silicon-containing film pattern having a pattern pitch that is 1 / 2 of the upper layer resist pattern, and (i-8) Processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed provided is a patterning method characterized by including the above.

[0020] With such a patterning method, without damaging the inorganic silicon-containing film or the substrate forming the sidewalls, the tin-containing intermediate film and the organic lower layer film forming the core material can be removed by dry etching. Therefore, without causing problems such as product performance shortfalls or yield reduction, it becomes possible to simply and efficiently form an inorganic silicon-containing film pattern (sidewall pattern) having a pattern pitch that is 1 / 2 of the upper layer resist pattern.

[0021] Further, in the present invention, a method for forming a pattern on a substrate to be processed, comprising: (ii-1) Forming an organic lower layer film on the substrate to be processed, forming a tin-containing intermediate film on the organic lower layer film, and further forming an upper layer resist film on the tin-containing intermediate film; (ii-2) Pattern-exposing the upper layer resist film and then developing it to form an upper layer resist pattern; (ii-3) Transferring the upper layer resist pattern to the tin-containing intermediate film by dry-etching the tin-containing intermediate film using the upper layer resist pattern as a mask, and further dry-etching the organic lower layer film using the tin-containing intermediate film onto which the upper layer resist pattern has been transferred as a mask, thereby forming an organic lower layer film pattern in which a part of the tin-containing intermediate film remains on the upper part of the pattern; (ii-4) Forming an inorganic silicon-containing film made of any one of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide or a composite material thereof by CVD method or ALD method so as to cover the part of the tin-containing intermediate film and the organic lower layer film pattern; (ii-5) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the portion of the tin-containing interlayer film. (ii-6) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (ii-7) A step of removing the organic underlayer film pattern by dry etching to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (ii-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method characterized by including the following:

[0022] With this pattern formation method, the tin-containing interlayer and organic underlayer forming the core material can be removed by dry etching without damaging the inorganic silicon-containing film forming the sidewall or the substrate. Therefore, it becomes possible to easily and efficiently form an inorganic silicon-containing film pattern (sidewall pattern) with a pattern pitch of half that of the upper resist pattern without causing problems such as underperformance of the product or reduced yield.

[0023] In step (i-4) or (ii-6) above, it is preferable to etch the tin-containing interlayer with a plasma formed in an H2-containing gas.

[0024] By using an H2-containing gas, the tin-containing interlayer can be removed without damaging the inorganic silicon-containing film or substrate forming the sidewall.

[0025] It is preferable to form the tin-containing interlayer film by a spin-coating method using a tin-containing interlayer film forming composition.

[0026] If the method for forming the tin-containing interlayer is a spin-coating method using a tin-containing interlayer formation composition, then the tin-containing interlayer can be formed at low cost and efficiently.

[0027] It is preferable to form the tin-containing interlayer from a tin-containing interlayer-forming composition containing a compound having a crosslinkable organic structure.

[0028] By using a tin-containing interlayer formed with a tin-containing interlayer-forming composition containing a compound having a crosslinkable organic structure, a highly smooth pattern can be transferred to the organic underlying film, thus offering an advantage in forming fine patterns.

[0029] In this case, the crosslinkable organic structure is, Hydroxyl group, Organic groups in which a protecting group is removed by the action of acid and / or heat to generate one or more hydroxyl groups or carboxyl groups, and Organic groups represented by any of the following general formulas (a-1) to (a-3) and (b-1) to (b-4) It is preferable to use the compound having one or more selected from the group consisting of the following. [ka] (In the above general formulas (a-1) to (a-3), R1 is a hydrogen atom or Number of carbon atoms (A monovalent organic group with values ​​from 1 to 10, where q represents 0 or 1, and * represents a bond.) [ka] (In the general formulas (b-1) and (b-3) above, R1' is a hydrogen atom or a methyl group, and they may be the same or different from each other within the same formula. In (b-3) to (b-4), R2 is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. * represents a bond.)

[0030] By using compounds having such crosslinkable organic structures, it is possible to transfer patterns with higher smoothness to the organic underlayer film, thus providing an even greater advantage in forming fine patterns.

[0031] In step (i-1) or (ii-1), it is preferable to further form a water-repellent coating film on the upper resist film.

[0032] When forming the upper resist pattern, if a protective film of the upper resist is required for use with immersion lithography, this type of pattern formation method can be used.

[0033] In step (i-1) or (ii-1), it is preferable to form an organic adhesion film between the tin-containing interlayer and the upper resist film.

[0034] By forming an organic adhesion film between the tin-containing interlayer and the upper resist film, a good pattern shape can be obtained in the pattern formation of the upper resist film, and the collapse of fine patterns can be suppressed. [Effects of the Invention]

[0035] As described above, the pattern formation method of the present invention is a fine pattern formation method using a sidewall spacer process. Because it can remove the tin-containing interlayer and organic underlayer that form the core material by dry etching without damaging the inorganic silicon-containing film forming the sidewall or the substrate, it is possible to easily and efficiently form an inorganic silicon-containing film pattern (sidewall pattern) with a pattern pitch of half that of the upper resist pattern without causing problems such as failure to meet product performance targets or reduced yield. This provides a highly practical pattern formation method. [Brief explanation of the drawing]

[0036] [Figure 1] This is an explanatory diagram of an example of a first embodiment of the pattern forming method according to the present invention. [Figure 2] This is an explanatory diagram of an example of a second embodiment of the pattern forming method according to the present invention. [Modes for carrying out the invention]

[0037] As mentioned above, with the recent miniaturization of pattern rules, there has been a need for a highly practical pattern formation method that can easily and efficiently form finer patterns and can be applied to semiconductor manufacturing processes.

[0038] As a result of diligent research to achieve the above objective, the inventors have discovered that by using a tin-containing interlayer film and an organic resist underlayer film that can be easily removed by dry etching, it is possible to easily and efficiently form an inorganic silicon-containing film pattern (sidewall pattern) with a pattern pitch of half that of the upper resist pattern without damaging the inorganic silicon-containing film forming the sidewall or the substrate, thereby providing a highly practical pattern formation method and completing the present invention.

[0039] That is, a first aspect of the present invention is a method for forming a pattern on a substrate to be processed, (i-1) A step of forming an organic underlayer film on a substrate to be processed, forming a tin-containing interlayer film on the organic underlayer film, and further forming an upper resist film on the tin-containing interlayer film. (i-2) A step of pattern exposure of the upper resist film, then developing it to form an upper resist pattern, (i-3) A step of transferring the upper resist pattern to the tin-containing interlayer by dry etching the tin-containing interlayer using the upper resist pattern as a mask, and further forming an organic underlayer pattern in which a portion of the tin-containing interlayer remains on the upper part of the pattern by dry etching the organic underlayer using the tin-containing interlayer on which the upper resist pattern has been transferred as a mask. (i-4) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (i-5) A step of forming an inorganic silicon-containing film made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof, by CVD or ALD, so as to cover the organic underlayer film pattern. (i-6) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the organic underlayer film pattern. (i-7) A step of removing the organic underlayer film pattern to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (i-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. This is a pattern formation method characterized by including [a specific element].

[0040] Furthermore, a second aspect of the present invention is a method for forming a pattern on a substrate to be processed, (ii-1) A step of forming an organic underlayer film on a substrate to be processed, forming a tin-containing interlayer film on the organic underlayer film, and further forming an upper resist film on the tin-containing interlayer film. (ii) A step of pattern exposure of the upper resist film, and then developing it to form an upper resist pattern, (ii-3) A step of forming an organic underlayer film pattern in which a portion of the tin-containing film remains on the upper part of the pattern by dry etching the tin-containing underlayer film using the upper layer resist pattern as a mask, thereby transferring the upper layer resist pattern to the tin-containing underlayer film, and further forming an organic underlayer film pattern in which a portion of the tin-containing underlayer film remains on the upper part of the pattern by dry etching the tin-containing underlayer film using the tin-containing underlayer film on which the upper layer resist pattern has been transferred, (ii-4) A step of forming an inorganic silicon-containing film made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof, by CVD or ALD, so as to cover the part of the tin-containing interlayer film and the organic underlayer film pattern. (ii-5) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the portion of the tin-containing interlayer film. (ii-6) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (ii-7) A step of removing the organic underlayer film pattern by dry etching to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (ii-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. This is a pattern formation method characterized by including [a specific element].

[0041] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0042] <Pattern Formation Method> A first aspect of the pattern forming method according to the present invention includes the above steps (i-1) to (i-8).

[0043] This pattern formation method provides a highly practical method for easily and efficiently forming inorganic silicon-containing film patterns (sidewall patterns) with a pattern pitch of half that of the upper resist pattern, without damaging the inorganic silicon-containing film forming the sidewalls or the substrate.

[0044] Furthermore, a second embodiment of the pattern forming method according to the present invention includes the above steps (ii-1) to (ii-8).

[0045] Such a pattern formation method provides a highly practical method for forming inorganic silicon-containing film patterns (sidewall patterns) with a pattern pitch of half that of the upper resist pattern, without damaging the inorganic silicon-containing film forming the sidewalls or the substrate being processed. Furthermore, in (ii-6) and (ii-7), the tin-containing interlayer and the organic underlayer can be removed simultaneously (continuously) by dry etching, which is preferable from the standpoint of productivity.

[0046] The following describes each process in detail, referring to the drawings. Note that processes (i-1) to (i-3) in the first embodiment are the same as processes (ii-1) to (ii-3) in the second embodiment. Therefore, these processes will be explained together first.

[0047] [Process (i-1) and (ii-1)] Steps (i-1) and (ii-1) are steps in which an organic underlayer film 3 is formed on a workpiece substrate 10, a tin-containing interlayer film 4 is formed on the organic underlayer film 3, and an upper resist film 5 is formed on the tin-containing interlayer film 4, as shown in Figures 1(A) and 2(A). Figures 1(A) and 2(A) show an example in which a workpiece layer 2 is formed on a substrate 1 to form a workpiece substrate 10, and the organic underlayer film 3 is formed on the workpiece layer 2 of this workpiece substrate 10.

[0048] <Processed substrate> For example, a semiconductor manufacturing substrate can be used as the substrate 1. As the workpiece layer (workpiece portion) 2 on the substrate 1, a metal film, metal carbide film, metal oxide film, metal nitride film, or a composite of these films can be used.

[0049] While silicon substrates are commonly used as semiconductor manufacturing substrates, they are not particularly limited, and materials such as Si, amorphous silicon (α-Si), p-Si, SiO2, SiN, SiON, W, TiN, and Al, which are different in material from the layer being processed, may also be used.

[0050] The metal constituting the workpiece layer 2 can be silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, aluminum, and iron, or an alloy thereof. Examples of such metals used in the workpiece layer 2 include Si, SiO2, SiN, SiON, SiOC, p-Si, α-Si, TiN, WSi, BPSG, SOG, Cr, CrO, CrON, MoSi, W, W-Si, Al, Cu, Al-Si, and various low-dielectric films and their etching stopper films, and can be formed to a thickness of typically 50 to 10,000 nm, particularly 100 to 5,000 nm.

[0051] <Organic lower layer film> When forming an organic underlayer film (e.g., a resist underlayer film) 3 on the substrate 10 to be processed, the organic underlayer film 3 can be formed by a spin coating method using a coating-type organic underlayer film material, or by a CVD method or ALD method.

[0052] Examples of coated organic underlayer materials include WO2007-105776, WO2009-72465, WO2010-61774, WO2010-147155, WO2011-125839, WO2012-50064, WO2012-77640, WO2013-5797, WO2013-47106, WO2013-47516, WO2013-80929, WO2013-115097, WO2013-146670, WO2014-24836, WO2014-208324, WO2014-208499, and WO2 015-170736, WO2015-194273, WO2016-147989, JP 2001-40293, JP 2002-214777, JP 2002-296789, JP 2004-205685, JP 2004-264710, JP 2005-0 Japanese Patent Publication No. 43471, JP 2005-250434, JP 2005-128509, JP 2006-259249, JP 2006-285046, JP 2007-171895, JP 2007-199653, JP 2007-293294, JP 2008-65303 , JP 2008-65081, JP 2008-274250, JP 2009-14816, JP 2009-229666, JP 2009-251130, JP 2010-122656, JP 2010-15112, JP 2010-271654, JP 2011 -107684, JP 2011-170059, JP 2012-1687, JP 2012-77295, JP 2012-214720, JP 2012-215842, JP 2013-83939, JP 2014-24831, JP 2014-157169, Examples of resins and compositions shown in Japanese Patent Publication Nos. 2015-131954, 2015-183406, 2016-29160, 2016-44272, 2016-60886, 2016-145849, 2016-167047, 2016-216367, 2017-3959, 2017-119670, 2017-119671, Japanese Patent Publication No. 2013-516643, Japanese Patent Publication No. 2015-515112, Japanese Patent Publication No. 2017-119671, Japanese Patent Publication No. 2019-44022, etc., can be cited.In the present invention, it is preferable to use a resin containing aromatic skeleton-containing compounds such as naphthalene skeleton-containing compounds, fluorene skeleton-containing compounds, carbazole skeleton-containing compounds, acenaphthylene skeleton-containing compounds, naphthol skeleton-containing compounds, and bisnaphthol skeleton-containing compounds.

[0053] When forming the above-mentioned organic underlayer film 3 by spin coating, it is preferable to evaporate the solvent after spin coating and perform baking (heat treatment) to promote the crosslinking reaction in order to prevent mixing with the upper resist film 5 and the intermediate film (for example, a tin-containing intermediate film or any organic adhesive film). Baking is preferably performed at a temperature of 100°C to 600°C for 10 to 600 seconds, and more preferably at a temperature of 200°C to 500°C for 10 to 300 seconds. Considering the impact on device damage and wafer deformation, the upper limit of the heating temperature in the lithography wafer process is preferably 600°C or lower, and more preferably 500°C or lower.

[0054] Alternatively, an organic underlayer film 3 can be formed by coating the substrate 10 with an organic underlayer film-forming composition using a spin coating method or the like described above, and then curing the organic underlayer film-forming composition by firing it in an atmosphere with an oxygen concentration of 0.1% to 21% by volume.

[0055] By firing the organic underlayer film-forming composition in such an oxygen atmosphere, a sufficiently cured organic underlayer film 3 can be obtained. While air may be used as the atmosphere during baking, it is preferable to seal in an inert gas such as N2, Ar, and He to reduce oxygen levels and prevent oxidation of the organic underlayer film 3. To prevent oxidation, it is necessary to control the oxygen concentration, which is preferably 1000 ppm or less, more preferably 100 ppm or less (by volume). Preventing oxidation of the organic underlayer film 3 during baking is preferable because it prevents increased absorption and decreased etching resistance.

[0056] <Tin-containing interlayer film> The tin-containing interlayer 4 can be easily removed by dry etching. Unlike the case where a silicon-containing interlayer is used as the interlayer, this tin-containing interlayer 4 can be easily removed by dry etching without damaging the workpiece substrate, or the inorganic silicon-containing film forming the workpiece substrate and sidewalls, as will be explained in detail below. Therefore, problems such as product performance degradation and yield reduction can be eliminated.

[0057] The tin-containing interlayer 4 used in the pattern formation method of the present invention is not particularly limited, but since it is necessary to form an upper resist film 5 on the tin-containing interlayer 4, it is preferable that the tin-containing interlayer 4 has excellent heat resistance, solvent resistance, and adhesion to the upper resist film 5. The tin-containing interlayer 4 can be formed by a method using a coating-type tin-containing interlayer forming composition, or by CVD or ALD methods. A spin-coating method using a coating-type tin-containing interlayer forming composition is preferred because it can be formed at low cost and efficiently.

[0058] As a coating-type tin-containing interfilm-forming composition, it is preferable to use one that contains a compound having a crosslinkable organic structure.

[0059] By using a tin-containing interlayer-forming composition containing a compound having a crosslinkable organic structure, it is possible to improve the heat resistance and solvent resistance required during the formation of the upper resist film 5, as well as the adhesion with the upper resist film 5.

[0060] As the aforementioned crosslinkable organic structure, Hydroxyl group, Organic groups in which a protecting group is removed by the action of acid and / or heat to generate one or more hydroxyl groups or carboxyl groups, and Organic groups represented by any of the following general formulas (a-1) to (a-3) and (b-1) to (b-4) It is preferable to use the compound having one or more selected from the group consisting of the following. [ka] (In the above general formulas (a-1) to (a-3), R1 is a hydrogen atom or Number of carbon atoms (A monovalent organic group with values ​​from 1 to 10, where q represents 0 or 1, and * represents a bond.) [ka] (In the general formulas (b-1) and (b-3) above, R1' is a hydrogen atom or a methyl group, and they may be the same or different from each other within the same formula. In (b-3) to (b-4), R2 is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. * represents a bond.)

[0061] In the above general formulas (a-1) to (a-3), R1 is preferably a hydrogen atom or a methyl group, and q is preferably 0 or 1. In addition, in the above general formulas (b-1) and (b-3), R1' is preferably a hydrogen atom.

[0062] By using a compound having such a crosslinkable organic structure, the heat resistance and solvent resistance required when forming the upper resist film 5, as well as the adhesion to the upper resist film 5, can be further improved.

[0063] Examples of compounds having the above-mentioned crosslinkable organic structure include the following compounds, but the compounds used in the present invention are not limited to these.

[0064] [ka] (In the above formula, Q is a hydrocarbon group having 1 to 20 carbon atoms.)

[0065] [ka] (In the above formula, Q is a hydrocarbon group having 1 to 20 carbon atoms.)

[0066] [ka] (In the above formula, n is between 1 and 30, Q is a hydrocarbon group having 1 to 20 carbon atoms, and * represents a bond.)

[0067] [ka] (In the above formula, Q is a hydrocarbon group having 1 to 20 carbon atoms.)

[0068] In the above formula, Q is preferably an n-butyl group or an n-octyl group.

[0069] Furthermore, examples include those represented by the following compounds described in WO2018-123388, Japanese Patent No. 6591058, Japanese Patent No. 7096814, and Japanese Unexamined Patent Publication No. 2021-179606.

[0070] [ka]

[0071] When forming the above-mentioned tin-containing interlayer film by spin coating, after spin coating, the solvent is evaporated and a bake (heat treatment) is performed to promote the crosslinking reaction in order to prevent mixing with the upper resist film and the resist interlayer film. The bake is preferably performed at a temperature of 100°C to 600°C for 10 to 600 seconds, and more preferably at a temperature of 150°C to 500°C for 10 to 300 seconds. Considering the impact on device damage and wafer deformation, the upper limit of the heating temperature in the lithography wafer process is preferably 600°C or lower, and more preferably 500°C or lower.

[0072] <Upper resist film> The upper resist film 5 that can be used in the pattern formation method of the present invention is not particularly limited, and any of the various conventionally known resist films can be used. Figures 1 and 2 show an example in which a positive-type upper resist film 5 is used, but the upper resist film 5 can be either positive-type or negative-type, and the same material as that used in conventional photoresist compositions can be used.

[0073] When forming the upper resist film 5 by spin coating, pre-baking is performed after resist coating, preferably at a temperature of 60 to 180°C for 10 to 300 seconds. The thickness of the upper resist film 5 is not particularly limited, but 10 to 500 nm, and especially 20 to 400 nm, is preferred.

[0074] <Water repellent coating film> Furthermore, when forming the upper resist pattern in step (i-2) or step (ii-2) described below, if a protective film for the upper resist film 5 is required for immersion lithography, a water-repellent coating film may be formed on top of the upper resist film 5 in step (i-1) or step (ii-1). The water-repellent coating film is not particularly limited, and various types can be used.

[0075] <Organic adhesive film> In step (i-1) or (ii-1), it is preferable to form an organic adhesion film between the tin-containing interlayer film 4 and the upper resist film 5.

[0076] By forming an organic adhesion film between the tin-containing interlayer 4 and the upper resist film 5, a good pattern shape can be obtained in the pattern formation of the upper resist film 5, and the collapse of fine patterns can be suppressed.

[0077] Conventional organic adhesion films can be used.

[0078] [Processes (i-2) and (ii-2)] Steps (i-2) and (ii-2) are steps in which the upper resist film 5 is pattern-exposed as shown in Figures 1(B) and 2(B), and then developed to form the upper resist pattern 5a as shown in Figures 1(C) and 2(C).

[0079] These processes can be carried out according to conventional methods. For example, exposure, post-exposure baking (PEB), and development can be performed to obtain the upper resist pattern 5a with a pattern pitch P1.

[0080] Examples of exposure light include high-energy rays with wavelengths of 300 nm or less, specifically excimer lasers with wavelengths of 248 nm, 193 nm, and 157 nm, soft X-rays, electron beams, and X-rays with wavelengths of 3 to 20 nm.

[0081] As a method for forming the pattern of the above-mentioned upper resist film, it is preferable to use photolithography with a wavelength of 5 nm to 300 nm, direct writing with an electron beam, nanoimprinting, or a combination thereof.

[0082] Furthermore, it is preferable that the development method in the pattern formation method be alkaline development or development with an organic solvent.

[0083] In Figures 1(B) and (C), and Figures 2(B) and (C), this development process removes the exposed portion 6 shown in Figures 1(B) and 2(B), and rinsing is performed to form the upper resist pattern 5a.

[0084] [Processes (i-3) and (ii-3)] Steps (i-3) and (ii-3) are steps in which the tin-containing interlayer 4 is dry-etched using the upper resist pattern 5a as a mask to transfer the upper resist pattern 5a to the tin-containing interlayer 4 as shown in Figures 1(D) and 2(D), and further, the organic underlayer 3 is dry-etched using the tin-containing interlayer 4 (tin-containing interlayer pattern 4a) on which the upper resist pattern 5a has been transferred as a mask to form an organic underlayer pattern 3a in which a portion 4b of the tin-containing interlayer remains on the upper part of the pattern as shown in Figures 1(E) and 2(E).

[0085] In steps (i-3) and (ii-3), by using the upper resist pattern 5a as an etching mask and etching the tin-containing interlayer 4 under dry etching conditions where the etching rate of the tin-containing interlayer 4 is significantly higher than that of the upper resist pattern 5a, for example, by dry etching with plasma formed in an H2-containing gas, the upper resist pattern 5a can be transferred to the tin-containing interlayer 4 with almost no influence from pattern changes due to side etching of the upper resist pattern 5a, thereby obtaining the tin-containing interlayer pattern 4a.

[0086] Next, a substrate having a tin-containing interlayer 4 (tin-containing interlayer pattern 4a) onto which the upper resist pattern 5a has been transferred is subjected to dry etching conditions in which the etching rate of the organic underlayer 3a is significantly higher than that of the tin-containing interlayer 4, such as reactive dry etching using an oxygen-containing gas plasma, and the organic underlayer 3 can be etched as shown in Figures 1(E) and 2(E).

[0087] This etching process yields an organic underlayer pattern 3a, but at the same time, the top layer resist layer 5 is usually lost. On the other hand, a portion 4b of the tin-containing interlayer 4, which served as the etching mask, is left on top of the organic underlayer pattern 3a.

[0088] The subsequent steps differ between the first and second embodiments. Therefore, we will first explain each step of the first embodiment, and then explain each step of the second embodiment.

[0089] <First aspect> In the first embodiment, after step (i-3), steps (i-4) to (i-8) described below are performed.

[0090] [Process (i-4)] Step (i-4) is a step in which a portion 4b of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern 3a is removed by dry etching, as shown in Figure 1(F).

[0091] In step (i-4), the removal of a portion 4b of the tin-containing interlayer remaining on the organic underlayer pattern 3a can be carried out, for example, by dry etching using plasma formed in an H2-containing gas, under conditions that allow for the selective removal of a portion 4b of the tin-containing interlayer without damaging the substrate (workpiece substrate 10).

[0092] [Process (i-5)] Step (i-5) is a step in which an inorganic silicon-containing film 7 made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof is formed by CVD or ALD so as to cover the organic underlayer film pattern 3a, as shown in Figure 1(G).

[0093] [Process (i-6)] Step (i-6) involves removing a portion of the inorganic silicon-containing film by dry etching, exposing the upper part of the organic underlayer film pattern 3a, as shown in Figure 1(H). This step leaves the remaining portion 7a of the inorganic silicon-containing film in a patterned form.

[0094] The dry etching conditions at this time are not particularly limited, and the gas conditions, etc., can be determined by the composition of the inorganic silicon-containing film.

[0095] [Process (i-7)] Step (i-7) is a step in which the organic underlayer pattern 3a is removed to form an inorganic silicon-containing film pattern 7a, as shown in Figure 1(I), in which the pattern pitch P2 is 1 / 2 of that of the upper resist pattern 5a (1 / 2 of the pattern pitch P1).

[0096] Furthermore, in step (i-7), the organic underlayer pattern 3a can be selectively removed without damaging the sidewalls formed by the inorganic silicon-containing film 7, for example, by dry etching with an oxygen-containing gas plasma.

[0097] [Process (i-8)] Step (i-8) is a step in which the substrate 10 to be processed is processed using the inorganic silicon-containing film pattern 7a as a mask to form a pattern 2a on the substrate 10 as shown in Figure 1(J).

[0098] The processing of the substrate 10 is not particularly limited as long as the dry etching conditions are significantly better than those for the inorganic silicon-containing film pattern, and can be carried out by conventional methods. For example, if the workpiece is SiO2, SiN, or a silica-based low dielectric constant insulating film, etching is performed mainly using a fluorocarbon gas.

[0099] <Second aspect> In the second embodiment, steps (ii-4) to (ii-8) are performed after step (ii-3).

[0100] [Step (ii-4)] Step (ii-4) is a step in which an inorganic silicon-containing film 7 made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof is formed by CVD or ALD so as to cover a portion 4b of the tin-containing interlayer film 4 and the organic underlayer film pattern 3a, as shown in Figure 2(F).

[0101] [Step (ii-5)] Step (ii-5) involves removing a portion of the inorganic silicon-containing film 7 by dry etching, exposing the upper part of a portion 4b of the tin-containing interlayer, as shown in Figure 2(G). This step leaves a pattern of the remaining portion 7a of the inorganic silicon-containing film.

[0102] The dry etching conditions at this time are not particularly limited, and the gas conditions, etc., can be determined by the composition of the inorganic silicon-containing film 7.

[0103] [Step (ii-6)] Step (ii-6) is a step in which a portion 4b of the tin-containing interlayer remaining on the upper part 3a of the organic underlayer pattern is removed by dry etching, as shown in Figure 2(H).

[0104] In step (ii-6), the removal of a portion 4b of the tin-containing interlayer remaining on the organic underlayer pattern 3a can be performed under conditions that do not damage the sidewall formed by the inorganic silicon-containing film, for example, by dry etching with a gas plasma containing H2.

[0105] [Step (ii-7)] Step (ii-7) is a step in which the organic underlayer pattern 3a is removed by dry etching to form an inorganic silicon-containing film pattern 7a in which the pattern pitch P2 is 1 / 2 of that of the upper resist pattern 5a (1 / 2 of that of pattern P1), as shown in Figure 2(I).

[0106] Furthermore, in step (ii-7), the organic underlayer pattern 3a can be selectively removed without damaging the sidewalls formed by the inorganic silicon-containing film 7a, for example, by dry etching with an oxygen-containing gas plasma.

[0107] [Step (ii-8)] Step (ii-8) is a step in which the substrate 10 to be processed is processed using the inorganic silicon-containing film pattern 7a as a mask to form a pattern 2a on the substrate 10 as shown in Figure 2(J).

[0108] This step (ii-8) is the same as step (i-8) of the first embodiment.

[0109] In the pattern formation method of the present invention described above, it is possible to form an inorganic silicon-containing film pattern (sidewall pattern) without damaging the sidewalls or substrate, whether or not there is residue of the masking material after pattern transfer by dry etching.

[0110] Furthermore, in actual semiconductor device manufacturing processes, the dry etching method used for pattern transfer of multilayer resists often involves leaving a portion of the mask pattern material on top of the transferred pattern to ensure the rectangular shape of the pattern after dry etching. That is, in the pattern formation method of the present invention, when transferring a pattern to the tin-containing interlayer 4 using the upper resist pattern 5a as a mask by dry etching, the process can be carried out under the condition that a portion of the upper resist film 5 is left behind in order to ensure the rectangular shape of the cross-sectional shape of the pattern 4a of the tin-containing interlayer 4. Similarly, when transferring a pattern to the organic underlayer 3 using the tin-containing interlayer pattern 4a as a mask, the pattern transfer process can be carried out with a portion of the tin-containing interlayer 4b left on top of the organic underlayer pattern 3a in order to ensure the rectangular shape of the cross-sectional shape of the pattern 3a of the organic underlayer 3. Then, using this organic underlayer pattern 3a as a core material, the sidewall spacer method is used to form a sidewall with the inorganic silicon-containing film 7, and after that, the organic underlayer pattern 3a is removed to form the pattern 7a of the inorganic silicon-containing film 7. Unlike the case where a silicon-containing interlayer is used as the interlayer, the tin-containing interlayer residue 4b remaining on top of the organic underlayer pattern 3a does not damage the sidewalls formed by the inorganic silicon-containing film 7 or the workpiece substrate 10, and can be easily removed by dry etching, thus eliminating problems of product performance degradation and yield reduction. [Examples]

[0111] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these descriptions.

[0112] The molecular weight and dispersion were measured by the following method: The weight-average molecular weight (Mw) and dispersion (Mw / Mn) in polystyrene equivalent were determined by gel permeation chromatography (GPC) using tetrahydrofuran as the eluent.

[0113] [Example of combination] The following synthesis examples used the compound group G: (G1) to (G14) and the tin compound group S: (S1) to (S3) shown below.

[0114] Compound group G: (G1) to (G14) are shown below.

[0115] [ka]

[0116] The tin compound group S:(S1)~(S3) is shown below. (S1): Dibutyltin oxide (S2): Dibenzyl tin oxide (S3): Dioctyl tin oxide

[0117] [Synthesis Example 1] Synthesis of tin-containing interfilm-forming compound (A-1) 5.0 g of dibutyltin oxide (S1), 11.0 g of carboxylic acid (G1), and 100 g of toluene were added, and the mixture was refluxed for 7 hours while removing water. After the reaction, the solvent was removed under reduced pressure, and the mixture was filtered and washed with hexane. The recovered solid was vacuum-dried at 70°C to obtain a tin-containing interfilm-forming compound (A-1). (A-1): Mw=254, Mw / Mn=1.18

[0118] [ka]

[0119] [Synthesis Example 2] Synthesis of tin-containing interfilm-forming compounds (A-2) to (A-13) The tin-containing interfilm-forming compounds (A-2) to (A-13) shown in Tables 1 and 2 were obtained under the same reaction conditions as in Synthesis Example 1, except that one of the compounds from compound group G and one of the compounds from tin compound group S were used in the amounts shown in Tables 1 and 2. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) of these compounds were determined. The results are shown in Table 3.

[0120] [Table 1]

[0121] [Table 2]

[0122] [Table 3]

[0123] [Preparation of tin-containing interlayer-forming composition (UDL-1)] A tin-containing interfilm-forming compound (A-1) was dissolved in a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and cyclohexanone (CyHO) containing 0.5% by mass of surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 4, and the mixture was filtered through a 0.02 μm membrane filter to prepare a tin-containing interfilm-forming composition (UDL-1).

[0124] [Preparation of tin-containing interlayer-forming compositions (UDL-2~13)] Except for the types and contents of each component shown in Table 4, the tin-containing interfilm-forming compositions (UDL-2 to UDL-13) were prepared in the same manner as UDL-1.

[0125] [Table 4]

[0126] <Pattern Formation Method 1> [Examples 1-1 to 1-13] As an organic underlayer, ODL-306 manufactured by Shin-Etsu Chemical Co., Ltd. was applied to a Si wafer substrate by spin coating and baked at 350°C for 60 seconds to produce a carbon film with a thickness of 80 nm. The carbon ratio of the carbon film was 88%. On top of that, as a tin-containing interlayer, one of the tin-containing interlayer-forming compositions (UDL-1 to UDL-13) shown in Table 6 below was applied to the organic underlayer by spin coating and baked at 250°C for 60 seconds to produce a tin-containing interlayer with a thickness of 20 nm.

[0127] Furthermore, a composition for forming an upper resist film, containing polymer 1, an acid generator (PAG1), a basic compound (Quencher 1), and an organic solvent, was applied by spin coating onto a tin-containing interlayer and baked at 110°C for 60 seconds to produce an upper resist film. The thickness of the upper resist film was 120 nm.

[0128] Polymer 1 Molecular weight (Mw)=8,100 Dispersity (Mw / Mn)=1.77 [ka]

[0129] Acid generator: PAG1 [ka]

[0130] Basic compound: Quencher1 [ka]

[0131] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) CyH (Cyclohexanone)

[0132] This is an ArF excimer laser scanner (Nikon Corporation, NSR-S307E, N A0.85, σ0.93 / 0.69, 20-degree dipole illumination, 6% halftone phase shift Exposure is performed using a tomask, and immediately after exposure, it is baked at 100°C for 60 seconds, resulting in 2.38 mass. Develop with a 1% aqueous solution of tetramethylammonium hydroxide for 30 seconds, and the dimensions are 5 A positive-type isolated pattern (upper resist pattern) with a pitch of 130 nm was obtained at 0 nm.

[0133] Using the above upper resist pattern as a mask, the tin-containing interlayer was processed by dry etching under the following conditions (1), and then the pattern was transferred to the organic underlayer under the following conditions (2). At this time, a portion of the tin-containing interlayer was left on the organic underlayer pattern.

[0134] (1) Etching conditions with H2 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (1): Chamber pressure: 100mT RF Power (Top): 300W RF Power (Bottom): 500W H2 gas flow rate: 200 sccm CHF3 gas flow rate: 30 sccm Processing time: 20 seconds

[0135] (2) Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (2): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0136] The tin-containing interlayer remaining on the obtained organic underlayer pattern was removed by dry etching under the following conditions (3).

[0137] Etching conditions (3): Chamber pressure: 100mT RF Power (Top): 300W RF Power (Bottom): 500W H2 gas flow rate: 200 sccm Ar gas flow rate: 100 sccm Processing time: 20 seconds

[0138] Next, a silicon oxide film (ALD film) with a thickness of 30 nm was formed on the obtained organic underlayer film pattern using an ALD apparatus in accordance with the method described in Examples

[0043] to

[0053] of Japanese Patent Application Publication No. 2005-197561. Subsequently, in order to expose the upper part of the organic underlayer film pattern, the ALD film was dry-etched under the following conditions (4) to obtain a test wafer in which the core material (organic underlayer film pattern) was exposed.

[0139] (4) Etching conditions with CHF3 / CF4 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (4): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0140] The obtained test wafer was dry-etched under the following conditions (5) to remove the organic underlayer pattern and form an ALD film pattern (silicon-containing film pattern). Subsequently, the ALD film pattern and the cross-sectional shape of the processed substrate were observed using a Hitachi High-Technologies Corporation (S-4700) instrument.

[0141] (5) Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (5): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0142] [Comparative Example 1-1] In Comparative Example 1-1, a silicon-containing interlayer was used instead of a tin-containing interlayer. Specifically, a silicon atom-containing resist interlayer material (SOG-1) made from the following raw materials was used as the silicon-containing interlayer. This was applied to an organic underlayer by spin coating and baked at 220°C for 60 seconds to produce a silicon-containing interlayer with a thickness of 20 nm. In Comparative Example 1-1, the same process as in Example 1-1 was performed to form a pattern, except that a silicon-containing interlayer was used instead of a tin-containing interlayer. The results are shown in Table 6 below.

[0143] As the silicon atom-containing resist interlayer material (SOG-1), a polymer represented by ArF silicon-containing interlayer polymer (SiP1) and a crosslinking catalyst (CAT1) were dissolved in propylene glycol monoethyl ether, an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Co., Ltd.), in the proportions shown in Table 5, and the mixture was filtered through a fluororesin filter with a pore size of 0.1 μm to prepare the silicon atom-containing resist interlayer material (SOG-1).

[0144] [Table 5]

[0145] The structural formulas of the ArF silicon-containing interlayer polymer (SiP1) and crosslinking catalyst (CAT1) used are shown below.

[0146] [ka]

[0147] [Comparative Example 1-2] In Comparative Example 1-2, a silicon-containing interlayer was used instead of a tin-containing interlayer. Specifically, the same material used in Comparative Example 1-1 was used as the silicon-containing interlayer, which was applied to the organic underlayer by spin coating and baked at 220°C for 60 seconds to produce a silicon-containing interlayer with a thickness of 20 nm.

[0148] Furthermore, an upper resist film similar to that in Example 1-1 was applied to the silicon-containing interlayer by spin coating and baked at 110°C for 60 seconds to obtain a resist film thickness of 120 nm.

[0149] This is an ArF excimer laser scanner (Nikon Corporation, NSR-S307E, N A0.85, σ0.93 / 0.69, 20-degree dipole illumination, 6% halftone phase shift Exposure is performed using a tomask, and immediately after exposure, it is baked at 100°C for 60 seconds, resulting in 2.38 mass. Develop with a 1% aqueous solution of tetramethylammonium hydroxide for 30 seconds, and the dimensions are 5 A positive-type isolated pattern (upper resist pattern) with a pitch of 130 nm was obtained at 0 nm.

[0150] Using the above upper resist pattern as a mask, the silicon-containing interlayer was processed by dry etching under the following conditions (1'), and then the pattern was transferred to the organic underlayer under the following conditions (2'). At this time, a portion of the silicon-containing interlayer was left on the organic underlayer pattern.

[0151] (1') Etching conditions with CHF3 / CF4 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (1'): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0152] (2') Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (2'): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0153] The silicon-containing interlayer remaining on the obtained organic underlayer pattern was processed by dry etching under the following conditions (3').

[0154] Etching conditions (3'): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0155] Next, a silicon oxide film (ALD film) with a thickness of 30 nm was formed on the obtained organic underlayer film pattern using an ALD apparatus in accordance with the method described in Examples

[0043] to

[0053] of Japanese Patent Application Publication No. 2005-197561. Subsequently, in order to expose the upper part of the organic underlayer film pattern, the ALD film was dry-etched under the following conditions (4') to obtain a test wafer in which the core material (organic underlayer film pattern) was exposed.

[0156] (4') Etching conditions with CHF3 / CF4 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (4'): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0157] The obtained test wafer was dry-etched under the following conditions (5') to remove the organic underlayer pattern and form an ALD film pattern (silicon-containing film pattern). Subsequently, the ALD film pattern and the cross-sectional shape of the processed substrate were observed using a Hitachi High-Technologies Corporation (S-4700) instrument.

[0158] (5') Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (5'): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0159] The results for Examples 1-1 to 1-13, and Comparative Examples 1-1 and 1-2 are shown in Table 6 below.

[0160] [Table 6]

[0161] In Examples 1-1 to 1-13, the shape of the sidewall (ALD film) pattern after core material removal showed a good vertical shape, and no damage to the sidewall pattern or substrate was observed, indicating that the pattern formation method of the present invention is useful for forming fine patterns. Furthermore, the pitch of the sidewall pattern could be set to 65 nm, which is half the pitch of the upper resist pattern. On the other hand, in Comparative Example 1-1, in which a silicon-containing interlayer was used instead of a tin-containing interlayer and the same treatment as in Example 1-1 was performed, the silicon-containing interlayer did not have selectivity for H2-based gases, unlike the tin-containing interlayer, so the organic underlayer pattern of the core material could not be removed, and an inorganic silicon film pattern (sidewall pattern) with a pattern pitch of half that of the upper resist pattern could not be formed. In Comparative Example 1-2, in which a silicon-containing interlayer was used instead of a tin-containing interlayer and dry etching containing CF4 gas was used to remove the silicon-containing interlayer, damage to the substrate was observed, and the shape of the sidewall pattern after core material removal lacked smoothness. It is presumed that the shape of the organic underlayer pattern changed when the silicon-containing interlayer remaining on the core material's organic underlayer pattern was removed by dry etching. At the same time, it is presumed that the exposed substrate being processed was etched and damaged.

[0162] <Pattern Formation Method 2> [Examples 2-1 to 2-13] As an organic underlayer film, ODL-306 manufactured by Shin-Etsu Chemical Co., Ltd. was applied by spin coating onto a Si wafer substrate, and baked at 350°C for 60 seconds to produce a carbon film with a thickness of 80 nm. The carbon ratio of the carbon film was 88%. On top of that, as a tin-containing interlayer film, one of the tin-containing interlayer film forming compositions (UDL-1 to UDL-13) shown in Table 7 below was applied by spin coating onto the organic underlayer film, and baked at 250°C for 60 seconds to produce a tin-containing interlayer film with a thickness of 20 nm.

[0163] Furthermore, an upper resist film with the same composition as in Example 1-1 was applied to the silicon-containing interlayer by spin coating and baked at 110°C for 60 seconds to obtain a resist film thickness of 120 nm.

[0164] This is an ArF excimer laser scanner (Nikon Corporation, NSR-S307E, N A0.85, σ0.93 / 0.69, 20-degree dipole illumination, 6% halftone phase shift Exposure is performed using a tomask, and immediately after exposure, it is baked at 100°C for 60 seconds, resulting in 2.38 mass. Develop with a 1% aqueous solution of tetramethylammonium hydroxide for 30 seconds, and the dimensions are 5 A positive-type isolated pattern (upper resist pattern) with a pitch of 130 nm was obtained at 0 nm.

[0165] Using the above upper resist pattern as a mask, the tin-containing interlayer was processed by dry etching under the following conditions (6), and then the pattern was transferred to the organic underlayer under the following conditions (7). At this time, a portion of the tin-containing interlayer was left on the organic underlayer pattern.

[0166] (6) Etching conditions with H2 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (6): Chamber pressure: 100mT RF Power (Top): 300W RF Power (Bottom): 500W H2 gas flow rate: 200 sccm CHF3 gas flow rate: 30 sccm Processing time: 20 seconds

[0167] (7) Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (7): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0168] A silicon oxide film (ALD film) with a thickness of 30 nm was formed on the obtained organic underlayer film pattern and on a portion of the tin-containing interlayer film using an ALD apparatus, according to the method described in Examples

[0043] to

[0053] of Japanese Patent Application Publication No. 2005-197561. Subsequently, in order to expose the upper part of a portion of the tin-containing interlayer film, the ALD film was dry-etched under the following conditions (8) to obtain a test wafer in which a portion of the tin-containing interlayer film was exposed.

[0169] (8) Etching conditions with CHF3 / CF4 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (8): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0170] The obtained test wafer was dry-etched under the following conditions (9) to remove the tin-containing interlayer on the organic underlayer pattern. Subsequently, dry-etching was performed under the following conditions (10) to remove the organic underlayer pattern and form an ALD film pattern (silicon-containing film pattern). The cross-sectional shape of the ALD film pattern and the processed substrate was observed using a Hitachi High-Technologies Corporation (S-4700) instrument. As a result, no damage to the sidewall pattern or the processed substrate was observed during the removal of the core material (organic underlayer pattern). The results are summarized in Table 7 below.

[0171] (9) Etching conditions with H2 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (9): Chamber pressure: 100mT RF Power (Top): 300W RF Power (Bottom): 500W H2 gas flow rate: 200 sccm Ar gas flow rate: 100 sccm Processing time: 20 seconds

[0172] (10) Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (10): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0173] [Comparative Example 2-1] In Comparative Example 2-1, a silicon-containing interlayer was used instead of a tin-containing interlayer. Specifically, the silicon atom-containing resist interlayer material (SOG-1) described below was used as the silicon-containing interlayer, which was applied to the organic underlayer by spin coating and baked at 220°C for 60 seconds to produce a silicon-containing interlayer with a thickness of 20 nm. In Comparative Example 2-1, the same process as in Example 2-1 was performed to form a pattern, except that a silicon-containing interlayer was used instead of a tin-containing interlayer.

[0174] For the silicon atom-containing resist interlayer material (SOG-1), the same silicon atom-containing resist interlayer material (SOG-1) as in Comparative Example 1-1 was used.

[0175] [Comparative Example 2-2] In Comparative Example 2-2, a silicon-containing interlayer was used instead of a tin-containing interlayer. Specifically, the silicon-containing interlayer was made using the same material as used in Comparative Example 2-1, applied by spin coating onto the organic underlayer, and baked at 220°C for 60 seconds to produce a silicon-containing interlayer with a thickness of 20 nm.

[0176] Furthermore, an upper resist film similar to that in Example 2-1 was applied to the silicon-containing interlayer by spin coating, baked at 110°C for 60 seconds, and the thickness of the resist film was reduced to 120 nm.

[0177] This is an ArF excimer laser scanner (Nikon Corporation, NSR-S307E, N A0.85, σ0.93 / 0.69, 20-degree dipole illumination, 6% halftone phase shift Exposure is performed using a tomask, and immediately after exposure, it is baked at 100°C for 60 seconds, resulting in 2.38 mass. Develop with a 1% aqueous solution of tetramethylammonium hydroxide for 30 seconds, and the dimensions are 5 A positive-type isolated pattern (upper resist pattern) with a pitch of 130 nm was obtained at 0 nm.

[0178] Using the resist pattern as a mask, the silicon-containing intermediate film was processed by dry etching under the following conditions (6’), and then the pattern was transferred to the organic underlayer film under the following conditions (7’). At this time, a part of the silicon-containing intermediate film was left on the organic underlayer film pattern.

[0179] (6’) Etching conditions with CHF3 / CF4-based gas Equipment: Dry etching equipment Telius SP manufactured by Tokyo Electron Limited Etching conditions (6’): Chamber pressure: 50 mT RF power (upper): 200 W RF power (lower): 100 W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20 sec

[0180] (7’) Etching conditions with O2-based gas Equipment: Dry etching equipment Telius SP manufactured by Tokyo Electron Limited Etching conditions (7’): Chamber pressure: 10 mT RF power (upper): 1,000 W RF power (lower): 300 W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50 sec

[0181] On the obtained organic underlayer film pattern and a part of the silicon-containing intermediate film, a silicon oxide film (ALD film) with a thickness of 30 nm was formed using an ALD apparatus by the method described in Examples

[0043] to

[0053] of JP-A-2005-197561. Subsequently, in order to expose a part of the upper portion of the silicon-containing intermediate film, the ALD film was dry-etched under the following conditions (8’) to obtain a test wafer in which a part of the silicon-containing intermediate film was exposed.

[0182] (8') Etching conditions with CHF3 / CF4 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (8'): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0183] The obtained test wafer was dry-etched under the following conditions (9') to remove the silicon-containing interlayer film on the organic underlayer pattern. Subsequently, dry-etching was performed under the following conditions (10') to remove the organic underlayer film and form an ALD film pattern (silicon-containing film pattern). After that, the cross-sectional shape of the ALD film pattern and the processed substrate was observed using a Hitachi High-Technologies Corporation (S-4700) instrument. As a result, damage to the sidewall pattern and the substrate during core material removal was confirmed.

[0184] (9') Etching conditions with CHF3 / CF4 gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (9'): Chamber pressure: 50mT RF Power (Top): 200W RF Power (Bottom): 100W CHF3 gas flow rate: 50 sccm CF4 gas flow rate: 50 sccm Ar gas flow rate: 100 sccm Time: 20sec

[0185] (10') Etching conditions with O2-based gas Equipment: Telius SP dry etching system manufactured by Tokyo Electron Ltd. Etching conditions (10'): Chamber pressure: 10mT RF Power (Top): 1,000W RF Power (Bottom): 300W CO2 gas flow rate: 320 sccm N2 gas flow rate: 80 sccm Time: 50sec

[0186] [Table 7]

[0187] In Examples 2-1 to 2-13, the shape of the sidewall (ALD film) pattern after core material removal showed a good vertical shape, and no damage to the sidewall pattern or substrate was observed, indicating that the pattern formation method of the present invention is useful for forming fine patterns. Furthermore, the pitch of the sidewall pattern could be set to 65 nm, which is half the pitch of the upper resist pattern. On the other hand, in Comparative Example 2-1, in which a silicon-containing interlayer was used instead of a tin-containing interlayer and the same treatment as in Example 2-1 was performed, the silicon-containing interlayer did not have selectivity for H2-based gases, unlike the tin-containing interlayer, so the organic underlayer pattern of the core material could not be removed, and an inorganic silicon film pattern (sidewall pattern) with a pattern pitch of half that of the upper resist pattern could not be formed. In Comparative Example 2-2, in which a silicon-containing interlayer was used instead of a tin-containing interlayer and dry etching containing CF4 gas was used to remove the silicon-containing interlayer, damage to the substrate was observed, and the shape of the sidewall pattern after core material removal lacked smoothness. It is presumed that the shape of the organic underlayer pattern changed when the silicon-containing interlayer remaining on the core material's organic underlayer pattern was removed by dry etching. At the same time, it is presumed that the exposed substrate being processed was etched and damaged.

[0188] From the above, in the method for forming a fine pattern using the sidewall spacer process of the present invention, without damaging the inorganic silicon-containing film forming the sidewall or the substrate to be processed, the organic lower layer film pattern forming the core material, or a part of the organic lower layer film pattern and the tin-containing intermediate film can be removed by dry etching. Therefore, without causing problems such as product performance failure or yield reduction, it is possible to provide a highly practical pattern forming method capable of simply and efficiently forming an inorganic silicon-containing film pattern (sidewall pattern) having a pattern pitch of 1 / 2 of the upper layer resist pattern.

[0189] This specification includes the following aspects. [1] A method for forming a pattern on a substrate to be processed, comprising: (i-1) forming an organic lower layer film on the substrate to be processed, forming a tin-containing intermediate film on the organic lower layer film, and further forming an upper layer resist film on the tin-containing intermediate film; (i-2) pattern-exposing the upper layer resist film and then developing it to form an upper layer resist pattern; (i-3) using the upper layer resist pattern as a mask to dry-etch the tin-containing intermediate film to transfer the upper layer resist pattern to the tin-containing intermediate film, and further using the tin-containing intermediate film onto which the upper layer resist pattern has been transferred as a mask to dry-etch the organic lower layer film to form an organic lower layer film pattern in which a part of the tin-containing intermediate film remains on the upper part of the pattern; (i-4) removing the part of the tin-containing intermediate film remaining on the upper part of the organic lower layer film pattern by dry etching; (i-5) forming an inorganic silicon-containing film made of any one of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or a composite material thereof on the organic lower layer film pattern by CVD or ALD; (i-6) removing a part of the inorganic silicon-containing film by dry etching to expose the upper part of the organic lower layer film pattern; (i-7) A step of removing the organic underlayer film pattern to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (i-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by including the following. [2] A method for forming a pattern on a substrate to be processed, (ii-1) A step of forming an organic underlayer film on a substrate to be processed, forming a tin-containing interlayer film on the organic underlayer film, and further forming an upper resist film on the tin-containing interlayer film. (ii) A step of pattern exposure of the upper resist film, and then developing it to form an upper resist pattern, (ii-3) A step of forming an organic underlayer film pattern in which a portion of the tin-containing film remains on the upper part of the pattern by dry etching the tin-containing underlayer film using the upper layer resist pattern as a mask, thereby transferring the upper layer resist pattern to the tin-containing underlayer film, and further forming an organic underlayer film pattern in which a portion of the tin-containing underlayer film remains on the upper part of the pattern by dry etching the tin-containing underlayer film using the tin-containing underlayer film on which the upper layer resist pattern has been transferred, (ii-4) A step of forming an inorganic silicon-containing film made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof, by CVD or ALD, so as to cover the part of the tin-containing interlayer film and the organic underlayer film pattern. (ii-5) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the portion of the tin-containing interlayer film. (ii-6) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (ii-7) A step of removing the organic underlayer film pattern by dry etching to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (ii-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by including the following. [3] The pattern forming method according to [1] or [2], characterized in that in step (i-4) or (ii-6), the tin-containing interlayer is etched with plasma formed in an H2-containing gas. [4] The pattern formation method according to any one of [1] to [3], characterized in that the tin-containing interlayer is formed by a spin-coating method using a tin-containing interlayer forming composition. [5] The pattern forming method according to any one of [1] to [4], characterized in that the tin-containing interlayer is formed from a tin-containing interlayer forming composition containing a compound having a crosslinkable organic structure. [6] As the crosslinkable organic structure, Hydroxyl group, Organic groups in which a protecting group is removed by the action of acid and / or heat to generate one or more hydroxyl groups or carboxyl groups, and Organic groups represented by any of the following general formulas (a-1) to (a-3) and (b-1) to (b-4) The pattern formation method according to [5], characterized in that it uses the compound having one or more selected from the group consisting of the following. [ka] (In the above general formulas (a-1) to (a-3), R1 is a hydrogen atom or Number of carbon atoms (A monovalent organic group with values ​​from 1 to 10, where q represents 0 or 1, and * represents a bond.) [ka] (In the general formulas (b-1) and (b-3) above, R1' is a hydrogen atom or a methyl group, and they may be the same or different from each other within the same formula. In (b-3) to (b-4), R2 is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. * represents a bond.) [7] A pattern formation method according to any one of [1] to [6], characterized in that a water-repellent coating film is further formed on the upper resist film in step (i-1) or (ii-1). [8] A pattern formation method according to any one of [1] to [7], characterized in that an organic adhesion film is formed between the tin-containing interlayer film and the upper resist film in step (i-1) or (ii-1).

[0190] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention. [Explanation of Symbols]

[0191] 1...Substrate, 2...Layer to be processed, 2a...Pattern (pattern formed on the layer to be processed), 3...Organic underlayer film, 3a...Organic underlayer film pattern, 4...Tin-containing interlayer film, 4a...Tin-containing interlayer film pattern, 4b...Part of the tin-containing interlayer film, 5...Upper resist film, 5a...Upper resist film pattern, 6...Exposed area, 7...Inorganic silicon-containing film, 7a...Inorganic silicon-containing film pattern, 10...Substrate to be processed.

Claims

1. A method for forming a pattern on a substrate to be processed, (i-1) A step of forming an organic underlayer film on a substrate to be processed, forming a tin-containing interlayer film on the organic underlayer film, and further forming an upper resist film on the tin-containing interlayer film. (i-2) A step of pattern exposure of the upper resist film, and then developing it to form an upper resist pattern. (i-3) A step of transferring the upper resist pattern to the tin-containing interlayer by dry etching the tin-containing interlayer using the upper resist pattern as a mask, and further forming an organic underlayer pattern in which a portion of the tin-containing interlayer remains on the upper part of the pattern by dry etching the organic underlayer using the tin-containing interlayer on which the upper resist pattern has been transferred as a mask. (i-4) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (i-5) A step of forming an inorganic silicon-containing film made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof, by CVD or ALD, so as to cover the organic underlayer film pattern. (i-6) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the organic underlayer film pattern. (i-7) A step of removing the organic underlayer film pattern to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (i-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. Includes, The tin-containing interlayer is formed from a tin-containing interlayer forming composition containing a compound having a crosslinkable organic structure. A pattern-forming method characterized by using the compound having one or more organic groups selected from the group consisting of any of the following general formulas (a-1) to (a-3) and (b-1) to (b-4) as the crosslinkable organic structure. 【Chemistry 1】 (In the above general formulas (a-1) to (a-3), R1 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) 【Chemistry 2】 (In the above general formulas (b-1) and (b-3), R1' is a hydrogen atom or a methyl group, and they may be the same or different from each other within the same formula. In (b-3) to (b-4), R2 is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. * represents a bond.)

2. A method for forming a pattern on a substrate to be processed, (ii-1) A step of forming an organic underlayer film on a substrate to be processed, forming a tin-containing interlayer film on the organic underlayer film, and further forming an upper resist film on the tin-containing interlayer film. (ii-2) A step of pattern exposure of the upper resist film, and then developing it to form an upper resist pattern, (ii-3) A step of transferring the upper layer resist pattern to the tin-containing interlayer by dry etching the tin-containing interlayer using the upper layer resist pattern as a mask, and further forming an organic underlayer pattern in which a portion of the tin-containing interlayer remains on the upper part of the pattern by dry etching the organic underlayer using the tin-containing interlayer on which the upper layer resist pattern has been transferred as a mask. (ii-4) A step of forming an inorganic silicon-containing film made of polysilicon, amorphous silicon, silicon oxide, silicon nitride, silicon oxidnitride, silicon carbide, or a composite material thereof, by CVD or ALD, so as to cover the part of the tin-containing interlayer film and the organic underlayer film pattern. (ii-5) A step of removing a portion of the inorganic silicon-containing film by dry etching to expose the upper part of the portion of the tin-containing interlayer film. (ii-6) A step of removing the portion of the tin-containing interlayer remaining on the upper part of the organic underlayer pattern by dry etching. (ii-7) A step of removing the organic underlayer film pattern by dry etching to form an inorganic silicon-containing film pattern whose pattern pitch is half that of the upper resist pattern, and (ii-8) A step of processing the substrate to be processed using the inorganic silicon-containing film pattern as a mask to form a pattern on the substrate to be processed. Includes, The tin-containing interlayer is formed from a tin-containing interlayer forming composition containing a compound having a crosslinkable organic structure. A pattern-forming method characterized by using the compound having one or more organic groups selected from the group consisting of any of the following general formulas (a-1) to (a-3) and (b-1) to (b-4) as the crosslinkable organic structure. 【Transformation 3】 (In the above general formulas (a-1) to (a-3), R1 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) 【Chemistry 4】 (In the above general formulas (b-1) and (b-3), R1' is a hydrogen atom or a methyl group, and they may be the same or different from each other within the same formula. In (b-3) to (b-4), R2 is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms. * represents a bond.)

3. In the above step (i-4) or (ii-6), H ２ The pattern forming method according to claim 1 or 2, characterized by comprising etching the tin-containing interlayer with plasma formed in a gas-containing environment.

4. The pattern forming method according to claim 1 or 2, characterized in that the tin-containing interlayer is formed by a spin-coating method using a tin-containing interlayer forming composition.

5. The pattern forming method according to claim 1 or 2, characterized in that a water-repellent coating film is further formed on the upper resist film in step (i-1) or (ii-1).

6. The pattern forming method according to claim 1 or 2, characterized in that an organic adhesion film is formed between the tin-containing interlayer film and the upper resist film in step (i-1) or (ii-1).

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