Composition for forming organic film, method for forming organic film and patterning process

Abstract

To provide a composition for forming an organic film, which is excellent in film-formability on a substrate and in filling property, excellent in hump suppression property during an EBR process, and capable of forming an organic film having an excellent process margin when used as an organic film for a multilayer resist.SOLUTION: A composition for forming an organic film comprises (A) a resin or compound for forming an organic film, (B) a fluorine-containing compound represented by formula (1), and (C) a solvent. (L represents a single bond or an n1-valent organic group having 1 to 50 carbon atoms. R1 represents a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, the organic group R1 having at least one specific fluorine-containing structure).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for forming an organic film, a method for forming an organic film using the composition, and a method for forming a pattern using the composition. [Background technology]

[0002] In recent years, with the increasing integration and speed of semiconductor devices, there has been a demand for finer pattern rules. In light of this, in lithography, which is currently used as a general-purpose technology using optical exposure, various technological developments have been carried out to enable finer and more accurate pattern processing using the light source used.

[0003] As a light source for lithography used in forming resist patterns, light exposure using mercury lamp g-line (436 nm) or i-line (365 nm) light sources is widely used in areas with low integration. On the other hand, in areas with high integration and requiring finer detail, lithography using shorter wavelength KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) has also been put to practical use, and for the most advanced generation requiring even finer detail, extreme ultraviolet (EUV, 13.5 nm) lithography is approaching practical use.

[0004] As resist patterns become thinner, the ratio of pattern height to pattern linewidth (aspect ratio) increases in the single-layer resist method, a typical method for forming resist patterns, and it is well known that this causes pattern collapse during development due to the surface tension of the developer. Therefore, multilayer resist methods, in which films with different dry etching properties are stacked to form patterns, are known to be superior for forming high-aspect-ratio patterns on uneven substrates. Two-layer resist methods have been developed, including a silicon-containing photosensitive polymer photoresist layer and an organic polymer lower layer, such as a novolac polymer, whose main constituent elements are carbon, hydrogen, and oxygen (Patent Document 1), and a three-layer resist method, in which a single-layer resist photoresist layer is combined with a silicon-based polymer or silicon-based CVD film intermediate layer and an organic polymer lower layer (Patent Document 2).

[0005] In this three-layer resist method, for example, an organic film such as novolac is uniformly formed on a substrate to be processed as a resist underlayer, a silicon-containing resist intermediate film is formed on top of that as a resist intermediate film, and a conventional organic photoresist film is formed on top of that as a resist upper layer. Because the organic resist upper layer has a favorable etching selectivity relative to the silicon-containing resist intermediate film when dry-etched with a fluorine-based gas plasma, the resist pattern can be transferred to the silicon-containing resist intermediate film by dry-etching with a fluorine-based gas plasma. This method allows for pattern transfer to the silicon-containing resist intermediate film even when using a resist composition that is difficult to form a pattern with a thickness sufficient for direct processing of the substrate to be processed or a resist composition that does not have sufficient dry-etching resistance for substrate processing. Subsequent pattern transfer using dry-etching with an oxygen-based gas plasma allows for the formation of a pattern in an organic film (e.g., a novolac film or other resist underlayer) with sufficient dry-etching resistance for processing.

[0006] Although many technologies for the organic underlayer film described above are already known (for example, Patent Document 3), with the recent advances in miniaturization, there is an increasing need for excellent filling properties in addition to dry etching properties. There is a need for organic underlayer film materials that can be uniformly formed on the underlying substrate to be processed, even on substrates or materials with complex shapes, and that have filling properties that enable the necessary patterns to be filled without voids.

[0007] The organic underlayer film described above is formed using a coater / developer capable of spin coating, EBR, baking, and other processes when manufacturing semiconductor substrates, etc. The EBR (Edge Bead Removal) process is a process in which, after a coating is formed on a substrate (wafer) by spin coating, the coating on the edge of the substrate is removed with a remover to prevent contamination of the coater / developer's substrate transfer arm. The remover used in the EBR process is, for example, a mixture of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether (30% by mass:70% by mass). This remover is widely used in the EBR process of resist films, resist underlayer films (e.g., organic underlayer films), and resist interlayer films (e.g., silicon-containing resist interlayer films).

[0008] The remover used in the EBR process can cause a thick film thickness (hump) on the outer periphery of the organic underlayer film. Because humps can cause defects in the dry etching process used in substrate processing, there is a demand for organic underlayer films that suppress hump formation.

[0009] Furthermore, after forming a spin-coated organic underlayer film, it is baked to form a hardened film for use in a multilayer resist process. This is because the organic underlayer film must be insoluble and infusible so that a silicon-containing resist interlayer can be applied as an upper layer. The organic film surface formed by the bake process has a hydrophobic surface due to the surfactant contained in the organic film-forming composition, which can cause coating abnormalities in the silicon-containing resist interlayer. Control of the contact angle of the organic underlayer film surface is required to improve the coatability of the silicon-containing resist interlayer and expand the process tolerance. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 6-118651 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-128509 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-205685 Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition for forming an organic film that is excellent in film-forming properties (in-plane uniformity) and filling properties on a substrate (wafer), is excellent in suppressing humps during an EBR process, and can form an organic film that has excellent process tolerance when used as an organic film for a multilayer resist, as well as a method for forming an organic film and a method for forming a pattern using the composition. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides a composition for forming an organic film, comprising: (A) an organic film-forming resin or compound; (B) a fluorine-containing compound represented by the following general formula (1), and (C) Solvent The present invention provides a composition for forming an organic film, which comprises: [ka] (In the formula, L is a single bond or an n1-valent organic group having 1 to 50 carbon atoms. R1 is a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, and the organic group R1 has at least one fluorine-containing structure represented by any one of the following formulas (2). R2 is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. n1 represents an integer of 2 to 8.) [ka] (* indicates a bond in the organic group represented by R1, and the organic group R1 may have two or more types of structures represented by the above formula (2), or may have two or more of the same structure.)

[0013] Such an organic film-forming composition makes it possible to form an organic film that has excellent in-plane uniformity and filling properties and that suppresses the formation of humps due to the effects of the remover in the EBR process. Furthermore, by incorporating a structure having multiple fluorine atoms as a partial structure into the (B) fluorine-containing compound, when used as an organic underlayer film, the compound is volatilized from the organic film surface and removed from the film by baking during cured film formation, resulting in an organic film-forming composition with excellent process tolerance and allowing the formation of an organic film with excellent coatability of the silicon-containing intermediate film.

[0014] It is preferable that R1 in the general formula (1) has a structure represented by any one of the following general formulas (3). [ka] (* represents a bond in the organic group represented by R1, and n2, n3, and n4 each represent an integer of 1 to 10.)

[0015] A composition for forming an organic film containing a fluorine-containing compound (B) having such a partial structure can improve film-forming properties during application by having an appropriate fluorine content, and can control volatility during baking to an appropriate temperature range.

[0016] Furthermore, it is preferable that L in the general formula (1) is an organic group represented by any one of the following general formulas (4). [ka] (* indicates a bond to a terminal structure including OR1 and OR2. n5, n6, and n7 each represent an integer of 1 to 10.)

[0017] In the case of an organic film-forming composition containing a compound having an organic group L of such a structure, decomposition products generated during baking do not impair the in-plane uniformity of the film, and insoluble matters are not formed due to reactions between decomposition products, etc. Therefore, when used as an organic underlayer film, the process margin is not narrowed, and problems such as equipment contamination do not occur.

[0018] R2 in the general formula (1) is preferably a hydrogen atom.

[0019] An organic film-forming composition containing a compound having such a structure contains a hydrophilic hydroxyl group, so that the surfactant effect of the compound can be controlled and poor film formation that occurs when the organic film-forming composition is applied to form an organic film can be prevented.

[0020] The weight average molecular weight of the fluorine-containing compound (B) represented by the general formula (1) is preferably 300 to 1,500.

[0021] The fluorine-containing compound (B) having a weight-average molecular weight within this range makes it possible to more reliably form an organic film having excellent film-forming and filling properties. Furthermore, the contact angle of the film surface after film formation can be controlled within an appropriate range, making it possible to form an organic underlayer film that is more suitable for use in a multilayer resist process.

[0022] The ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn of the fluorine-containing compound (B) represented by the general formula (1) in terms of polystyrene, as determined by gel permeation chromatography, is preferably 1.00≦Mw / Mn≦1.10.

[0023] When the (B) fluorine-containing compound having a ratio of weight-average molecular weight Mw to number-average molecular weight Mn within the above range is contained, it is possible to reliably form a good organic film without generating foreign matter that may cause film formation defects or impurities after film formation.

[0024] When the content of the (A) organic film-forming resin or compound is taken as 100 parts by mass, the content of the (B) fluorine-containing compound is preferably 0.01 to 5 parts by mass.

[0025] A composition for forming an organic film containing the fluorine-containing compound (B) in such an amount is preferable because the formed organic film has better in-plane uniformity.

[0026] The present invention also provides a method for forming an organic film used in a manufacturing process of a semiconductor device, comprising the steps of: The composition for forming an organic film of the present invention is spin-coated on a substrate to be processed to obtain a coating film; The coating film is heat-treated at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds to form a cured film, thereby providing a method for forming an organic film.

[0027] The composition for forming an organic film of the present invention can sufficiently fill patterns of complex shapes on a substrate to be processed by spin coating, and can form an organic film with excellent in-plane uniformity, and is particularly useful when removing an organic film from the edge while suppressing humps in the EBR process.

[0028] Further, the present invention provides a pattern forming method, comprising the steps of: forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming a resist upper layer film on the resist intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; Furthermore, the present invention provides a pattern forming method, which comprises using the organic underlayer film onto which the pattern has been transferred as a mask to transfer the pattern to the workpiece by etching.

[0029] Further, the present invention provides a pattern forming method, comprising the steps of: forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming an organic anti-reflective film or an adhesion film on the resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the organic anti-reflective film or adhesive film and the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; Furthermore, the present invention provides a pattern forming method, which comprises using the organic underlayer film onto which the pattern has been transferred as a mask to transfer the pattern to the workpiece by etching.

[0030] Further, the present invention provides a pattern forming method, comprising the steps of: forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film; forming a resist upper layer film on the inorganic hard mask using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the inorganic hard mask by etching; the pattern is transferred to the organic underlayer film by etching using the inorganic hard mask to which the pattern has been transferred as a mask; Furthermore, the present invention provides a pattern forming method, which comprises using the organic underlayer film onto which the pattern has been transferred as a mask to transfer the pattern to the workpiece by etching.

[0031] A pattern formation method, comprising: forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film; forming an organic anti-reflective film or an adhesion film on the inorganic hard mask; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; using the resist upper layer film on which the circuit pattern has been formed as a mask, to transfer the pattern to the organic anti-reflective film or adhesion film and the inorganic hard mask by etching; the pattern is transferred to the organic underlayer film by etching using the inorganic hard mask to which the pattern has been transferred as a mask; Furthermore, the present invention provides a pattern forming method, which comprises using the organic underlayer film onto which the pattern has been transferred as a mask to transfer the pattern to the workpiece by etching.

[0032] As described above, the organic film-forming composition of the present invention can be suitably used in various pattern formation methods, such as a three-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask, or a four-layer resist process using an organic antireflective film in addition to these. Such a pattern formation method of the present invention makes it possible to transfer and form the circuit pattern of the resist upper layer film onto the workpiece with high precision.

[0033] The inorganic hard mask is preferably formed by a CVD method or an ALD method.

[0034] In the pattern formation method of the present invention, for example, an inorganic hard mask can be formed by such a method.

[0035] In forming the circuit pattern, it is preferable to form the circuit pattern by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct drawing with an electron beam, nanoimprinting, or a combination thereof.

[0036] In forming the circuit pattern, it is preferable to develop the circuit pattern using an alkali developer or an organic solvent.

[0037] In the pattern forming method of the present invention, such circuit pattern forming means and developing means can be suitably used.

[0038] Furthermore, it is preferable that the workpiece is a semiconductor device substrate, or a semiconductor device substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film is formed.

[0039] Furthermore, the metal constituting the workpiece is preferably silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

[0040] The pattern forming method of the present invention makes it possible to form a pattern by processing the above-mentioned workpiece. [Effects of the Invention]

[0041] As described above, the organic film-forming composition of the present invention can provide an organic film-forming composition that exhibits excellent film-forming properties (in-plane uniformity) and filling characteristics on a substrate (wafer), and that exhibits excellent film-forming properties for an intermediate film on the organic film when used as an organic underlayer film, as well as excellent hump suppression during the EBR process. The organic film-forming composition of the present invention exhibits excellent film-forming properties, filling characteristics, and suppression of hump generation during the EBR process. When used as an organic underlayer film, it exhibits excellent film-forming properties for an intermediate film on the organic film, i.e., excellent process tolerance. Therefore, it is extremely useful as an organic underlayer film material for multilayer resist processes, such as a two-layer resist process, a three-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask, or a four-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask and an organic anti-reflective film, or for forming an organic film for semiconductor device manufacturing. Furthermore, the organic film-forming method of the present invention can form an organic film with suppressed hump generation, thereby enabling the efficient manufacture of semiconductor devices and the like. [Brief explanation of the drawings]

[0042] [Figure 1] 1A to 1C are explanatory diagrams illustrating an example of a pattern formation method using a three-layer resist process according to the present invention. [Figure 2] 10 is an example of a graph showing the height of a hump measured using a contact profiler in Example 2. [Figure 3] 10 is an example of a graph showing the height of a hump measured using a contact profiler in Comparative Example 2. [Figure 4] FIG. 1 is an explanatory diagram of a method for evaluating filling characteristics in an example. DETAILED DESCRIPTION OF THE INVENTION

[0043] As described above, there has been a need for the development of a composition for forming an organic film that has excellent film-forming properties (in-plane uniformity) and filling properties on a substrate (wafer) and that can form an organic film that suppresses humps during the EBR process.

[0044] Typically, when forming an organic film, a resin for forming the organic film and additives are dissolved in an organic solvent to form a composition, which is then applied to a substrate on which structures, wiring, etc. are formed using a coater and developer.The composition is spread as the substrate rotates, and the composition at the edges is removed in an EBR process, followed by baking to form the organic film.

[0045] If the fluidity of the above composition is insufficient, voids will occur when filling holes or trenches with very high aspect ratios, and if the resin or additives used to form the organic film have poor solubility in the remover used in the EBR process, humps will occur on the periphery of the organic film.

[0046] The inventors further conducted extensive research and discovered that by incorporating a compound having a specific substituent into a composition for forming an organic film, a composition for forming an organic film can be obtained that combines excellent film-forming properties with advanced filling properties and is also excellent in suppressing humps during the EBR process, and thus completed the present invention.

[0047] That is, the present invention provides a composition for forming an organic film, (A) an organic film-forming resin or compound; (B) a fluorine-containing compound represented by the following general formula (1), and (C) Solvent The organic film-forming composition is characterized by comprising: [ka] (In the formula, L is a single bond or an n1-valent organic group having 1 to 50 carbon atoms. R1 is a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, and the organic group R1 has at least one fluorine-containing structure represented by any one of the following formulas (2). R2 is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. n1 represents an integer of 2 to 8.) [ka] (* indicates a bond in the organic group represented by R1, and the organic group R1 may have two or more types of structures represented by the above formula (2), or may have two or more of the same structure.)

[0048] The present invention will be described in detail below, but the present invention is not limited thereto.

[0049] [Composition for organic film formation] The organic film-forming composition of the present invention comprises (A) an organic film-forming resin or compound, a fluorine-containing compound represented by the above general formula (1), and (C) a solvent. The organic film-forming composition of the present invention is a composition for forming, for example, an organic film for a multilayer resist for microfabrication in the production of semiconductor devices, etc., or an organic film for planarization in the production of semiconductor devices, etc.

[0050] In addition, the composition for forming an organic film of the present invention can use one type alone or two or more types in combination of the (B) fluorine-containing compound, the (A) organic film-forming resin or compound, and the (C) solvent.

[0051] Hereinafter, the fluorine-containing compound (B), which is a feature of the composition for forming an organic film of the present invention, will be first described in more detail, followed by a description of other components of the composition for forming an organic film of the present invention.

[0052] [(B) Fluorine-containing compound] The fluorine-containing compound (B) contained in the organic film-forming composition of the present invention is a compound represented by the following general formula (1). [ka] (In the formula, L is a single bond or an n1-valent organic group having 1 to 50 carbon atoms. R1 is a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, and the organic group R1 has at least one fluorine-containing structure represented by any one of the following formulas (2). R2 is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. n1 represents an integer of 2 to 8.) [ka] (* indicates a bond in the organic group represented by R1, and the organic group R1 may have two or more types of structures represented by the above formula (2), or may have two or more of the same structure.)

[0053] The fluorine-containing compound (B) contained in the organic film-forming composition of the present invention is a compound with a low molecular weight structure and multiple fluorine substituents, which decomposes or sublimes to become volatile when exposed to heat or other factors. For example, when a high-molecular-weight polymer is used, such polymers generally have lower volatility and sublimability than low-molecular-weight compounds, and therefore the polymer or decomposition products remain in or on the film surface during baking. When such a polymer is used as a material for forming an organic underlayer film, it can affect the etching resistance and the coatability of the silicon-containing intermediate film formed on the organic underlayer film. The fluorine-containing compound (B) contained in the organic film-forming composition of the present invention is designed to have an appropriately designed terminal substituent structure that reduces the intermolecular forces between compounds so that the compound does not remain on the film surface or within the film after heat treatment. The compound is also designed to have an appropriate fluorine structure that prevents thermal sublimation or decomposition from affecting film properties.

[0054] Furthermore, the fluorine-containing compound (B) contained in the organic film-forming composition of the present invention functions as a surfactant. By introducing multiple substituents containing an appropriate fluorine-containing structure into the terminal structure of the compound, it is possible to impart the compound with the ability to reduce surface tension and function as a surfactant for achieving excellent uniform coating properties (leveling properties) of organic films. Therefore, the organic film-forming compound of the present invention containing such a fluorine-containing compound (B) can be suitably used not only for organic underlayer films but also for general organic film materials, such as general photolithography coating materials (photosensitive resist materials, materials for forming top coats on resist films, etc.). Furthermore, such a fluorine-containing compound (B) can be applied not only to organic film-forming materials but also to silicon-containing resist underlayer films, and can be used as a surfactant suitable for exhibiting highly versatile film-forming properties that can be applied to various film-forming materials.

[0055] In other words, in the organic film-forming composition of the present invention, the fluorine-containing compound (B) functions as a surfactant that imparts excellent film-forming properties and high leveling performance. Its applications are not limited to organic underlayer films, but can be used in general coating materials for photolithography, such as photosensitive resist materials and materials for forming top coats formed on resist films.

[0056] In the organic film-forming composition of the present invention, the (B) fluorine-containing compound can be used alone or in combination of two or more. The amount of these compounds added is preferably such that the content of the (B) fluorine-containing compound is 0.01 to 5 parts by mass per 100 parts by mass of the (A) organic film-forming resin or compound. This content provides the formed organic film with better in-plane uniformity.

[0057] Examples of the fluorine-containing compound (B) of the general formula (1) include the following: In the following formula, R1 and R2 are the same as above.

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] Among the above examples, from the viewpoint of improving thermal decomposition property, a structure in which the organic group L does not contain an aromatic ring is preferred, and from the viewpoint of surface activity, a structure without nitrogen is preferred. Examples that satisfy these requirements include a structure linked by a glyme chain of the following general formula (4) or one having an alkylene group in the organic group (linking group) L.

[0062] [ka] (* indicates a bond to a terminal structure including OR1 and OR2. n5, n6, and n7 each represent an integer of 1 to 10.)

[0063] R1 in the above general formula (1) is a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, and the organic group R1 has at least one fluorine-containing structure represented by any one of the following formulas (2). Specific examples of the substituent having at least one structure represented by general formula (2) include the following: (n1 represents an integer of 2 to 8, and n2, n3, and n6 to n9 each represent an integer of 1 to 10.)

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] Among the above examples, from the viewpoint of surface activity, it is preferable that R1 has a structure represented by any of the following general formulas (3). If the (B) compound having any of these structures is included, the introduction of a fluorine structure with an appropriate fluorine content can be expected to improve film-forming properties. Furthermore, among these, those having trifluoromethoxybenzene are more preferable not only from the viewpoint of surface activity but also from the viewpoint of reducing the environmental impact of compounds having a fluorine structure.

[0068] [ka] (* represents a bond in the organic group represented by R1, and n2, n3, and n4 each represent an integer of 1 to 10.)

[0069] A composition for forming an organic film containing a fluorine-containing compound (B) having such a partial structure can improve film-forming properties during application by having an appropriate fluorine content, and can control volatility during baking to an appropriate temperature range.

[0070] In the general formula (1), R2 is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms, and specific examples include the following: In the following formula, n14 represents an integer of 0 to 29, and n15 represents 0 to 20.

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] (* indicates a bond in the organic group represented by R2)

[0075] Among the above, from the viewpoint of imparting a surface active effect, R2 is preferably a hydrogen atom or one having the partial structure shown below, and from the viewpoint of affinity to organic solvents, it is more preferably a hydrogen atom.

[0076] [ka]

[0077] If the composition contains the fluorine-containing compound (B) having the structure described above, the thermal decomposition property, sublimation property, surfactant effect, and fluidity can be adjusted, and the composition can have both excellent film-forming properties and high embedding properties.

[0078] The weight-average molecular weight of the (B) fluorine-containing compound is preferably 300 to 1500. If the weight-average molecular weight is 300 or more, it is possible to prevent a decrease in the blending effect due to evaporation or the like, and a sufficient blending effect can be obtained. Furthermore, if the weight-average molecular weight is 1500 or less, it is possible to prevent the surfactant from remaining in the film, and it is possible to form an organic film with even better process tolerance. Furthermore, it is preferable that the weight-average molecular weight is 1000 or less. If the weight-average molecular weight is 1000 or less, it is possible to further reduce the risk of the surfactant remaining in the film.

[0079] The ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of the fluorine-containing compound (B) in terms of polystyrene as determined by gel permeation chromatography is preferably 1.00≦Mw / Mn≦1.10.

[0080] Normally, for a single compound, the ratio Mw / Mn is theoretically 1.00, but considering that, for example, the fluorine-containing compound (B) contained in the organic film-forming composition of the present invention may combine multiple types of organic group R1 structures and multiple types of group R2 structures, and that in gel permeation chromatography, the separation performance of compounds is affected by compound properties such as polarity and errors in measurement conditions such as column temperature and pressure, it is difficult to achieve a Mw / Mn of 1.00 strictly even for a single compound. Therefore, in order to distinguish from compounds having a distribution in the ratio Mw / Mn, the above range is defined as an index showing monomolecularity.

[0081] [(B) Method for producing fluorine-containing compounds] The fluorine-containing compound (B) having the structure represented by the general formula (1) can be produced by selecting an optimal method depending on the structure. For example, when the group R2 is a hydrogen atom, the fluorine-containing compound (B) can be obtained by an addition reaction (STEP 1) between an epoxy compound having an organic group L as a partial structure and a compound having an organic group R1 as a partial structure and a hydroxyl group. Alternatively, when the group R2 is not a hydrogen atom, the fluorine-containing compound (B) can be obtained by the addition reaction (STEP 1) followed by an acylation reaction (STEP 2) using an acylating agent corresponding to the introduction of the organic group R2. Examples of the compound having a hydroxyl group include carboxylic acids, alcohols, and phenols. Examples of the acylating agent include acid anhydrides and acid chlorides.

[0082] In the following formula, R1 and R2 are the same as defined above.

[0083] [ka]

[0084] [ka]

[0085] In the reaction of an epoxy compound with a compound having a hydroxyl group shown in STEP 1 above, when the molar amount of epoxy in the epoxy compound is taken as 1 mole, the amount of the compound having a hydroxyl group charged is preferably 0.3 to 4.0 moles, more preferably 0.5 to 2.0 moles, and even more preferably 0.75 to 1.25 moles. If the amount of the compound having a hydroxyl group charged relative to the epoxy unit is within the above preferred range, unreacted epoxy groups can be prevented from remaining, ensuring storage stability. Furthermore, if the amount of the compound having a hydroxyl group charged relative to the epoxy unit is within the above preferred range, unreacted hydroxyl groups can be prevented from remaining in the system, avoiding the problem of outgassing.

[0086] Furthermore, a compound having a hydroxyl group and a group other than the organic group R1 can also be used as an ultraviolet light absorbing group to improve antireflection ability and solvent solubility. Examples of such a compound include aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, palmitic acid, and stearic acid; alicyclic carboxylic acids such as cyclohexanecarboxylic acid and norbornenecarboxylic acid; aromatic carboxylic acids such as benzoic acid, naphthalenecarboxylic acid, and anthracenecarboxylic acid; alcohols such as methanol, ethanol, and benzyl alcohol; and phenols such as phenol and naphthol. The amount of the compound is preferably 0.1 to 50 mol %, more preferably 1 to 30 mol %, based on the total amount of the compound having a hydroxyl group.

[0087] The compound synthesized from the above-mentioned raw materials can usually be obtained by reacting an epoxy compound with a compound having a hydroxyl group in a solvent or solvents in the presence of a reaction catalyst at room temperature or, if necessary, under cooling or heating.

[0088] Examples of the solvent to be used include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, and diacetone alcohol; ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; lactones such as γ-butyrolactone; and aprotic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. As the solvent, one of these can be used alone, or a mixture of two or more can be used. These solvents can be used in an amount of, for example, 0 to 2000 parts by mass per 100 parts by mass of the reaction raw materials.

[0089] Examples of reaction catalysts include benzyltriethylammonium chloride, benzyltriethylammonium bromide, benzyltrimethylammonium chloride, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetramethylammonium hydroxide, tetraethylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrabutylammonium hydrogen sulfate, trioctylmethylammonium chloride, tributylbenzylammonium chloride, trimethylbenzylammonium chloride, trimethylammonium chloride, Examples of catalysts include quaternary ammonium salts such as benzyl ammonium hydroxide, N-lauryl pyridinium chloride, N-lauryl 4-picolinium chloride, N-lauryl picolinium chloride, trimethylphenyl ammonium bromide, and N-benzyl picolinium chloride; quaternary phosphonium salts such as tetrabutyl phosphonium chloride, tetrabutyl phosphonium bromide, and tetraphenyl phosphonium chloride; tertiary amines such as tris[2-(2-methoxyethoxy)ethyl]amine, tris(3,6-dioxaheptyl)amine, and tris(3,6-dioxaoctyl)amine; potassium tert-butoxide; and sodium hydride. The amount of catalyst used is 0.001 to 100% by weight, preferably 0.005 to 50% by weight, based on the raw materials. The reaction temperature is preferably from -50°C to the boiling point of the solvent, more preferably from room temperature to 150°C. The reaction time is appropriately selected from the range of 0.1 to 100 hours.

[0090] The reaction method is not limited, but examples include a method in which the epoxy compound, the compound having a hydroxyl group, and the catalyst are charged all at once, a method in which the epoxy compound and the compound having a hydroxyl group are dispersed or dissolved in a solvent, and then the catalyst is added all at once or diluted with a solvent and added dropwise, or a method in which the catalyst is dispersed or dissolved in a solvent, and then the epoxy compound and the compound having a hydroxyl group are added all at once or diluted with a solvent and added dropwise. After completion of the reaction, the reaction product may be used as is without purification, or, in order to remove unreacted raw materials, catalyst, etc. present in the system, the reaction product may be diluted with an organic solvent and then subjected to separation and washing to recover a highly pure product.

[0091] The organic solvent used in this purification is not particularly limited as long as it can dissolve the reaction product and separate into two layers when mixed with water. Examples include hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, methyl t-butyl ether, and ethylcyclopentyl methyl ether; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; and mixtures thereof. The washing water used in this process is typically what is known as deionized water or ultrapure water. The number of washes may be one or more times, but washing more than 10 times will not provide the desired effect, so washing is preferably performed about 1 to 5 times.

[0092] During separation and washing, washing may be performed with a basic aqueous solution to remove unreacted compounds having hydroxyl groups or acidic components. Examples of bases include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, ammonia, and organic ammonium.

[0093] Furthermore, during separation washing, washing with an acidic aqueous solution may be performed to remove metal impurities or basic components from the system. Examples of acids include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropolyacids, and organic acids such as oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0094] The separation washing with a basic aqueous solution and an acidic aqueous solution may be carried out either alone or in combination. From the viewpoint of removing metal impurities, the separation washing is preferably carried out in the order of the basic aqueous solution and then the acidic aqueous solution.

[0095] After the separation washing with the basic aqueous solution and the acidic aqueous solution, washing with neutral water may be carried out subsequently. The washing may be carried out once or more times, preferably about 1 to 5 times. The neutral water may be deionized water or ultrapure water as described above. The washing may be carried out once or more times, but if the washing is carried out too few times, the basic components and acidic components cannot be removed, and even if washing is carried out 10 times or more, the effect of washing alone cannot be obtained, so the washing is preferably carried out about 1 to 5 times.

[0096] Furthermore, the reaction product after the separation operation can be recovered as a powder by concentrating the solvent to dryness or crystallizing it under reduced pressure or normal pressure, but it can also be left in a solution state of a moderate concentration to improve operability when preparing an organic film-forming composition. The concentration in this case is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by weight. At such a concentration, the viscosity is unlikely to increase, preventing a loss of operability, and the amount of solvent is not excessive, making it economical.

[0097] The solvent used here is not particularly limited as long as it can dissolve the resulting compound, but specific examples include ketones such as cyclohexanone and methyl 2-amyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate. These solvents may be used alone or in combination of two or more.

[0098] The reaction represented by STEP 2 can be easily carried out by known methods. The acylating agent is preferably an acid chloride or an acid anhydride corresponding to the partial structure of the organic group R2. When an acid chloride is used, the reaction can be carried out without a solvent or in a solvent such as methylene chloride, acetonitrile, toluene, or hexane by sequentially or simultaneously adding the compound obtained in STEP 1, the acid chloride, and a base such as triethylamine, pyridine, or 4-dimethylaminopyridine, followed by cooling or heating as needed. When an acid anhydride is used, the reaction can be carried out by sequentially or simultaneously adding the compound obtained in STEP 1 and a base such as triethylamine, pyridine, or 4-dimethylaminopyridine, followed by cooling or heating as needed, followed by heating as needed. The resulting reaction product can be purified, such as by washing with water, and recovered as a powder or solution. Examples of solvents used in this reaction include those listed above. The concentration of the solvent is preferably 0.1 to 50% by weight, more preferably 0.5 to 30% by weight.

[0099] To prepare the fluorine-containing compound (B) used in the organic film-forming composition obtained by this method, various compounds having hydroxyl groups can be used, allowing the compound structure and terminal group structure ratio to be appropriately selected and adjusted to suit the required performance. For example, it is possible to arbitrarily combine compounds having side chain structures that contribute to improving planarization characteristics, or fluorine-containing substituents that control surface tension and other properties to change surfactant properties. Therefore, when an organic film-forming composition using these compounds is used in an organic underlayer film, it becomes possible to achieve a high level of compatibility between various performances such as film-forming ability and embedding ability.

[0100] [(A) Organic film-forming resin or compound] The (A) organic film-forming resin or compound used in the organic film-forming composition of the present invention is not particularly limited as long as it is a resin or compound that satisfies the film-forming properties and curing properties of spin coating. However, from the viewpoints of etching resistance, optical properties, heat resistance, etc., a resin or compound containing an aromatic skeleton (different from the (B) fluorine-containing compound) is more preferred.

[0101] Examples of the aromatic skeleton include benzene, naphthalene, anthracene, pyrene, indene, fluorene, furan, pyrrole, thiophene, phosphole, pyrazole, oxazole, isoxazole, thiazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, and carbazole. Among these, benzene, naphthalene, fluorene, and carbazole are particularly preferred.

[0102] The (A) organic film-forming resin or compound used in the organic film-forming composition of the present invention is not limited to a resin or compound for forming an organic underlayer film, but may also be, for example, a resin or compound for forming a resist upper layer film.

[0103] Examples of the organic film-forming resin or compound (A) used in the present invention include resins containing the following structures described in JP-A Nos. 2012-001687 and 2012-077295.

[0104] [ka] (In formula (1), the ring structures Ar1 and Ar2 each independently represent a benzene ring or a naphthalene ring. X represents a single bond or an alkylene group having 1 to 20 carbon atoms. m represents 0 or 1. n represents any natural number such that the molecular weight is 100,000 or less. Note that the definitions of the symbols in the formula apply only to this formula.)

[0105] [ka] (In formula (2), the ring structures Ar1 and Ar2 each independently represent a benzene ring or a naphthalene ring. n represents any natural number such that the weight average molecular weight, as measured by gel permeation chromatography in terms of polystyrene, is 100,000 or less. The definitions of the symbols in the formula apply only to this formula.)

[0106] Further examples of the (A) organic film-forming resin or compound used in the present invention include resins containing the following structures described in JP-A Nos. 2004-264710, 2005-043471, 2005-250434, 2007-293294, and 2008-065303.

[0107] [ka] (In formula (3) and formula (4), R 1 and R 2 each independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an aryl group; R 3 represents an alkyl group having 1 to 3 carbon atoms, a vinyl group, an allyl group, or an aryl group which may be substituted, n represents 0 or 1, and m represents 0, 1, or 2. The definitions of the symbols in the formula apply only to this formula.

[0108] [ka] (In formula (5), R1 is a monovalent atom or group other than a hydrogen atom, and n is an integer of 0 to 4. However, when n is 2 to 4, multiple R1s may be the same or different. R2 and R3 are each independently a monovalent atom or group. X is a divalent group. Note that the definitions of the symbols in the formula apply only to this formula.)

[0109] [ka] In formula (6), R1 is a hydrogen atom or a methyl group. R2 is a single bond, a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms, or an arylene group having 6 to 10 carbon atoms, and may have any of ether, ester, lactone, and amide. R 3 , R 4 are each a hydrogen atom or a glycidyl group. X represents a polymer of any one of hydrocarbons containing an indene skeleton, cycloolefins having 3 to 10 carbon atoms, and maleimide, and may have any one of ethers, esters, lactones, and carboxylic acid anhydrides. R 5 , R 6 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 7 is a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a hydroxy group, or an alkoxycarbonyl group. p and q are each an integer of 1 to 4. r is an integer of 0 to 4. a, b, and c are in the ranges of 0.5≦a+b+c≦1, 0≦a≦0.8, 0≦b≦0.8, 0.1≦a+b≦0.8, and 0.1≦c≦0.8, respectively. The definitions of the symbols in the formula apply only to this formula.

[0110] [ka] (In formula (7), R1 represents a hydrogen atom or a monovalent organic group, and R2 and R3 each independently represent a monovalent atom or a monovalent organic group. The definitions of the symbols in the formula apply only to this formula.)

[0111] Further specific examples of the (A) organic film-forming resin or compound used in the present invention include resins containing the following structures described in JP-A Nos. 2004-205685, 2007-171895, and 2009-014816.

[0112] [ka] (In formula (8) and formula (9), R 1 ~R 8 are each independently a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group having 1 to 6 carbon atoms, an optionally substituted alkoxy group having 1 to 6 carbon atoms, an optionally substituted alkoxycarboxyl group having 2 to 6 carbon atoms, an optionally substituted aryl group having 6 to 10 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an isocyanate group, or a glycidyl group. m and n are positive integers. Note that the definitions of the symbols in the formula apply only to this formula.

[0113] [ka] (In formula (10), R 1 and R 6 are each independently a hydrogen atom or a methyl group. 2 , R 3 and R 4 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acetoxy group, or an alkoxycarbonyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R 5 is a condensed polycyclic hydrocarbon group having 13 to 30 carbon atoms, -OR 7 , -C(=O)-OR 7 , -OC(=O)-R 7 or -C(=O)-NR 8 -R 7 where m is 1 or 2, n is an integer of 0 to 4, and p is an integer of 0 to 6. 7 is an organic group having 7 to 30 carbon atoms, and R 8is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Z is any one of a methylene group, -O-, -S-, and -NH-. a, b, c, d, e are in the ranges of 0 < a < 1.0, 0 ≦ b ≦ 0.8, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.8, and 0 < b + c + d + e < 1.0. Note that the definitions of the symbols in the formula are applicable only within this formula.)

[0114]

Chemical formula

[0115] Examples of the resin represented by formula (11) include, for example, the following resins.

[0116]

Chemical formula

[0117]

Chemical formula

[0118] Further examples of the (A) organic film-forming resin or compound used in the present invention include resins containing the following structures described in JP-A Nos. 2007-199653, 2008-274250, and 2010-122656.

[0119] [ka] (In formula (12), R 1 and R 2 are each independently the same or different hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, and R 3 is a single bond or an alkylene group having a linear, branched or cyclic structure and having 1 to 30 carbon atoms, which may have a bridged cyclic hydrocarbon group, a double bond, a heteroatom or an aromatic group having 6 to 30 carbon atoms; R 4 and R 5 are each independently a hydrogen atom or a glycidyl group, and n is an integer of 1 to 4. The definitions of the symbols in the formula apply only to this formula.

[0120] [ka] (In formula (13), R 1 and R 2 are each independently the same or different and represent a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; R 3 is a single bond or an alkylene group having a linear, branched or cyclic structure and having 1 to 30 carbon atoms, which may have a bridged cyclic hydrocarbon group, a double bond, a heteroatom or an aromatic group having 6 to 30 carbon atoms; R 4 and R 5 are each independently a hydrogen atom or a glycidyl group, and R 6 is a single bond or a linear or branched alkylene group having 1 to 10 carbon atoms. The definitions of the symbols in the formula apply only to this formula.

[0121]

Chem.

[0122]

Chem.

[0126] [ka]

[0127] [ka]

[0128] Further examples of the (A) organic film-forming resin or compound used in the present invention include resins containing the following structure described in JP-A No. 2012-214720.

[0129] [ka] (In formula (16), the ring structures Ar1 and Ar2 each independently represent a benzene ring or a naphthalene ring. x and z each independently represent 0 or 1. The definitions of the symbols in the formula apply only within this formula.)

[0130] Examples of the (A) organic film-forming resin or compound used in the present invention include resins described in JP-A-2014-29435.

[0131] [ka] (In formula (17), A represents a structure having carbazole, B represents a structure having an aromatic ring, C represents a structure having a hydrogen atom, an alkyl group, or an aromatic ring, and B and C may form a ring together. The combined structure of A, B, and C has 1 to 4 carboxyl groups or salts thereof, or carboxylate ester groups. Note that the definitions of the symbols in the formula apply only to this formula.)

[0132] Further examples of the organic film-forming resin or compound (A) used in the present invention include polymers described in WO 2012 / 077640, which contain a unit structure represented by the following formula (18) and a unit structure represented by the following formula (19), and in which the molar ratio of the unit structure represented by formula (18) to the unit structure represented by formula (19) is 3 to 97:97 to 3.

[0133] [ka]

[0134] In formula (18), R1 and R2 each independently represent a hydrogen atom, a halogen atom, a nitro group, an amino group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination of these groups which may contain an ether bond, a ketone bond, or an ester bond. R3 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination of these groups which may contain an ether bond, a ketone bond, or an ester bond. R4 represents a hydrogen atom, or an aryl group having 6 to 40 carbon atoms which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group, or a heterocyclic group; R5 represents a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group, or an aryl group having 6 to 40 carbon atoms, or a heterocyclic group; R4 and R5 may together form a ring; n1 and n2 each represent an integer of 1 to 3; and the definitions of the symbols in the formula apply only to this formula.

[0135] [ka] In formula (19), Ar represents an aromatic ring group having 6 to 20 carbon atoms, R6 represents a hydroxy group, R7 represents a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination of these groups which may contain an ether bond, a ketone bond, or an ester bond, and R8 represents a hydrogen atom, or a carbon atom which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group. R8 represents an aryl group or heterocyclic group having 6 to 40 carbon atoms, R9 represents a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group, or an aryl group or heterocyclic group having 6 to 40 carbon atoms, and R8 and R9 may together form a ring. n6 represents an integer of 1 to p, and n7 represents an integer of p-n6, where p represents the maximum number of atoms which may be substituted on the aromatic ring group Ar. The definitions of the symbols in the formula apply only to this formula.

[0136] Further examples of the organic film-forming resin or compound (A) used in the present invention include polymers containing a unit structure represented by the following formula (20) described in WO 2010 / 147155.

[0137] [ka] In formula (20), R1 and R2 are each independently selected from the group consisting of a hydrogen atom, a halogen group, a nitro group, an amino group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, and a combination thereof, and the alkyl group, the alkenyl group, or the aryl group may contain an ether bond, a ketone bond, or an ester bond; R3 is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, and a combination thereof, and the alkyl group, the alkenyl group, or the aryl group may contain an ether bond, a ketone bond, or an ester bond; The group or the aryl group represents a group which may contain an ether bond, a ketone bond, or an ester bond; R4 represents an aryl group or heterocyclic group having 6 to 40 carbon atoms which may be substituted with a halogen group, a nitro group, an amino group, or a hydroxy group; R5 represents a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms, an aryl group or a heterocyclic group having 6 to 40 carbon atoms which may be substituted with a halogen group, a nitro group, an amino group, or a hydroxy group; R4 and R5 may form a ring together with the carbon atoms to which they are bonded; and n1 and n2 are each an integer of 1 to 3. Note that the definitions of the symbols in the formula apply only to this formula.

[0138] Further examples of the (A) organic film-forming resin or compound used in the present invention include novolak resins obtained by reacting one or more phenols, such as phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyquinol, and phloroglucinol, with one or more aldehyde sources, such as formaldehyde, paraformaldehyde, and trioxane, using an acidic catalyst; and resins containing a repeating unit structure represented by the following formula (21), which are described in WO 2012 / 176767.

[0139] [ka] (In formula (21), A represents a hydroxy-substituted phenylene group derived from polyhydroxybenzene, and B represents a monovalent fused aromatic hydrocarbon ring group in which 2 to 6 benzene rings are fused. Note that the definitions of the symbols in the formula apply only to this formula.)

[0140] Further examples of the (A) organic film-forming resin or compound used in the present invention include novolak resins having a fluorene or tetrahydrospirobiindene structure described in JP-A Nos. 2005-128509, 2006-259249, 2006-259482, 2006-293298, and 2007-316282, and resins containing a repeating unit structure represented by the following formula (22-1) or (22-2):

[0141] [ka] (In formula (22-1) and formula (22-2), R 1 , R 2 , R 6 and R 7 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an allyl group, or a halogen atom; R 3 , R 4 , R 8 and R 9 are each independently a hydrogen atom, a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a glycidyl group; R 5 and R 14 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. n, m, p and q are integers of 1 to 3. R 10 ~R 13are each independently a hydrogen atom, a halogen atom, a hydroxy group, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear, branched or cyclic alkoxy group having 1 to 6 carbon atoms. The definitions of the symbols in the formula apply only to this formula.)

[0142] Further examples of the organic film-forming resin or compound (A) used in the present invention include reaction products obtained by the method described in JP 2012-145897 A. More specifically, examples include polymers obtained by condensing one or more compounds represented by the following general formula (23-1) and / or (23-2) with one or more compounds represented by the following general formula (24-1) and / or (24-2) and / or equivalents thereof.

[0143] [ka] (In the general formula (23-1) and the general formula (23-2), R 1 ~R 8 are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an isocyanato group, a glycidyloxy group, a carboxyl group, an amino group, an alkoxy group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 1 to 30 carbon atoms, an alkanoyloxy group having 1 to 30 carbon atoms, or an optionally substituted saturated or unsaturated organic group having 1 to 30 carbon atoms. 1 ~R 4 or R 5 ~R 8 Two substituents arbitrarily selected from the following may be bonded to form a cyclic substituent. The definitions of the symbols in the formula apply only to this formula.)

[0144] [ka] (In general formula (24-1) and general formula (24-2), Q is an organic group having 1 to 30 carbon atoms which may be substituted, and two Qs arbitrarily selected in the molecule may be bonded to form a cyclic substituent. n1 to n6 are the number of each substituent, and n1 to n6 are 0, 1, or 2, and in formula (24-1), hydroxybenzaldehyde is excluded. In addition, in formula (24-2), the relationships 0≦n3+n5≦3, 0≦n4+n6≦4, and 1≦n3+n4≦4 are satisfied. Note that the definitions of the symbols in the formulas apply only within this formula.)

[0145] Further, examples of the polymers include those obtained by condensing one or more compounds represented by the above general formula (23-1) and / or (23-2), one or more compounds represented by the above general formula (24-1) and / or (24-2) and / or equivalents thereof, and one or more compounds represented by the following general formula (25) and / or equivalents thereof.

[0146] [ka] (In formula (25), Y is a hydrogen atom or a monovalent organic group having 30 or less carbon atoms which may have a substituent, and formula (25) is different from general formula (24-1) and general formula (24-2). Note that the definitions of the symbols in the formula apply only to this formula.)

[0147] Further examples of the (A) organic film-forming resin or compound used in the present invention include compounds having the following structure described in JP-A-2017-119671.

[0148] [ka] (In formula (26-1), R is a single bond or an organic group having 1 to 50 carbon atoms, X is a group represented by the following general formula (26-2), and m1 is an integer satisfying 2≦m1≦10. Note that the definitions of the symbols in the formula apply only within this formula.)

[0149] [ka] (In the formula, X 2 is a divalent organic group having 1 to 10 carbon atoms, n1 is 0 or 1, n2 is 1 or 2, and X 3 is a group represented by the following general formula (26-3), and n5 is 0, 1, or 2. The definitions of the symbols in the formula apply only to this formula.

[0150] [ka] (In the formula, R 10 is a hydrogen atom or a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, and the hydrogen atom on the benzene ring in the formula may be substituted with a methyl group or a methoxy group. The definitions of the symbols in the formula apply only to this formula.

[0151] Examples of compounds containing the above structure include the following compounds.

[0152] [ka]

[0153] Further examples of the organic film-forming resin or compound (A) used in the present invention include polymers having a repeating unit represented by the following general formula (27-1), which are described in JP-A-2019-044022.

[0154] [ka] In formula (27-1), AR1 and AR2 are benzene rings or naphthalene rings which may have a substituent, and R 1 and R 2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms, and R 1 and R 2 When and are organic groups, R 1 and R 2may form a cyclic organic group by bonding intramolecularly. n is 0 or 1, and when n=0, AR1 and AR2 do not form a bridged structure between the aromatic rings of AR1 and AR2 via Z, and when n=1, AR1 and AR2 form a bridged structure between the aromatic rings of AR1 and AR2 via Z, and Z is either a single bond or a group represented by the following formula (27-2). Y is a group represented by the following formula (27-3). Note that the definitions of the symbols in the formula apply only within this formula.

[0155] [ka] (In formula (27-3), R 3 is a single bond or a divalent organic group having 1 to 20 carbon atoms, and R 4 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and the dashed line represents a bond. The definitions of the symbols in the formula apply only to this formula.

[0156] Examples of polymers having a repeating unit represented by the above general formula (27-1) include the following polymers. [ka]

[0157] [ka]

[0158] The (A) organic film-forming resin or compound may be synthesized by a known method, or a commercially available product may be used.

[0159] The amount of the (A) organic film-forming resin or compound is not particularly limited as long as the organic film-forming composition satisfies the film-forming properties of spin coating. Preferably, the amount of the (A) organic film-forming resin or compound is 10 to 40 parts by weight, more preferably 10 to 30 parts by weight, and even more preferably 10 to 25 parts by weight, per 100 parts by weight of the organic film-forming composition. For example, when filling holes or trenches with extremely high aspect ratios in 3D NAND memory architectures with an organic film-forming composition, a large amount of the organic film-forming resin is required. However, such organic film-forming compositions have high viscosity, which can degrade the in-plane uniformity and filling characteristics after spin coating. Even with the above-mentioned ratio of the (A) organic film-forming resin or compound, the organic film-forming composition of the present invention can be suitably applied because it can form organic films with excellent in-plane uniformity and filling characteristics.

[0160] Furthermore, it is preferable that the content of the fluorine-containing compound (B) is 0.01 to 5 parts by mass per 100 parts by mass of the resin or compound (A) for forming an organic film. When the composition for forming an organic film contains a polymer in such a content, the formed organic film has better in-plane uniformity.

[0161] [(C) Solvent] The solvent (C) that can be used in the organic film-forming composition of the present invention is not particularly limited as long as it can dissolve the (A) organic film-forming resin or compound and the (B) fluorine-containing compound, and is preferably one that can also dissolve the acid generator, crosslinking agent, and additional surfactant, which will be described later. Specifically, solvents with a boiling point of less than 180°C, such as those described in paragraphs (0091) and (0092) of JP-A No. 2007-199653, can be used. Among these, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and mixtures of two or more of these are preferably used.

[0162] The content of the (C) solvent is preferably 200 to 10,000 parts by mass, more preferably 300 to 5,000 parts by mass, per 100 parts by mass of the (A) organic film-forming resin or compound. By setting the content within this range, the concentration can be adjusted according to the film thickness to be consumed.

[0163] Furthermore, in the organic film-forming material of the present invention, as the organic solvent (C), a high-boiling solvent having a boiling point of 180°C or higher can be added to the above-mentioned solvent having a boiling point of less than 180°C (a mixture of a solvent having a boiling point of less than 180°C and a solvent having a boiling point of 180°C or higher). The high-boiling organic solvent is not particularly limited as long as it can dissolve (A) the organic film-forming resin or compound and (B) the fluorine-containing compound, and includes hydrocarbons, alcohols, ketones, esters, ethers, chlorine-based solvents, etc. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-Hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, n-nonyl acetate, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol butyl methyl ether, triethylene Glycol diacetate, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,Examples include 6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate, and these may be used alone or in combination.

[0164] The boiling point of the high-boiling solvent may be appropriately selected according to the temperature at which (A) the organic film-forming resin or compound is heat-treated, and the boiling point of the high-boiling solvent to be added is preferably 180°C to 300°C, and more preferably 200°C to 300°C. Such a boiling point prevents the solvent from volatilizing too quickly during baking (heat treatment) due to a boiling point that is too low, thereby ensuring sufficient thermal fluidity. Furthermore, such a boiling point is so high that the solvent does not remain in the film after baking without volatilizing, and therefore does not adversely affect film properties such as etching resistance.

[0165] Furthermore, when using the high-boiling point solvent, the blending amount of the high-boiling point solvent is preferably 1 to 30 parts by mass per 100 parts by mass of the solvent having a boiling point of less than 180° C. Such a blending amount can impart sufficient thermal fluidity during baking, and is unlikely to remain in the film, leading to deterioration of film properties such as etching resistance.

[0166] In such an organic film-forming composition, the addition of a high-boiling point solvent to the (A) organic film-forming resin or compound provides thermal fluidity, thereby providing an organic film-forming composition that has both high embedding properties and excellent planarization properties.

[0167] [Other ingredients] Furthermore, an acid generator or a crosslinking agent may be added to the organic film-forming composition of the present invention in order to further accelerate the crosslinking reaction.

[0168] Acid generators include those that generate acid by thermal decomposition and those that generate acid by light irradiation, and either can be added. Specific examples of acid generators include those described in paragraphs

[0061] to

[0085] of JP 2007-199653 A. The acid generators can be used alone or in combination of two or more. When an acid generator is added, the amount added is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the (A) organic film-forming resin or compound. This amount promotes the crosslinking reaction and enables the formation of a dense film.

[0169] Specific examples of crosslinking agents include those described in paragraphs

[0055] to

[0060] of JP 2007-199653 A. Crosslinking agents can be used singly or in combination of two or more. The amount of crosslinking agent added is preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass of (A) organic film-forming resin or compound. This amount enhances curability and further suppresses intermixing with the overlying film.

[0170] Furthermore, to further improve the in-plane uniformity in spin coating, the organic film-forming composition of the present invention may contain an additional surfactant other than the fluorine-containing compound (B) of the present invention. Specific examples of such additional surfactants include those described in paragraphs

[0142] to

[0147] of JP 2009-269953 A. The aforementioned additional surfactants may be used singly or in combination of two or more. When an additional surfactant is added, the amount added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the organic film-forming resin or compound (A). This amount enables the formation of an organic film with excellent in-plane uniformity.

[0171] Furthermore, a basic compound can be added to the organic film-forming composition of the present invention to improve storage stability. The basic compound acts as an acid quencher to prevent a small amount of acid generated by the acid generator from promoting a crosslinking reaction. Specific examples of such basic compounds include those described in paragraphs

[0086] to

[0090] of JP 2007-199653 A. The basic compounds can be used alone or in combination of two or more. When an acid generator is added, the amount added is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the (A) organic film-forming resin or compound. This amount can improve the storage stability of the organic film-forming composition.

[0172] Such an organic film-forming composition makes it possible to form an organic film that has excellent in-plane uniformity and filling properties and that suppresses the formation of humps due to the effects of the remover in the EBR process. Furthermore, by incorporating a structure having multiple fluorine atoms as a partial structure into the fluorine-containing compound (B), when used as an organic underlayer film, the fluorine-containing compound (B) is volatilized from the organic film surface and removed from the film by baking during cured film formation, thereby forming an organic film with excellent coatability for the silicon-containing intermediate film, resulting in an organic film-forming composition with excellent process tolerance.

[0173] In particular, as described above, the organic film-forming composition of the present invention is an organic film-forming composition that is excellent in suppressing humps during the EBR process. Therefore, the organic film-forming composition of the present invention is extremely useful as a resist underlayer film material (organic film material) for multilayer resist processes such as a two-layer resist process, a three-layer resist process using a silicon-containing resist interlayer or a silicon-containing inorganic hard mask interlayer, and a four-layer resist process using a silicon-containing resist interlayer or a silicon-containing inorganic hard mask interlayer and an organic antireflective film or adhesive film.

[0174] [Organic film formation method] The present invention provides a method for forming an organic film used in the manufacturing process of a semiconductor device, which method comprises spin-coating the organic film-forming composition of the present invention onto a substrate to be processed to obtain a coating film, and then heat-treating the coating film at a temperature of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film.

[0175] In this organic film formation method, the organic film-forming composition of the present invention is first spin-coated onto a substrate to be processed. By using the spin-coating method, excellent embedding properties can be obtained. After removing the coating from the edges in the EBR process, baking (heat treatment) is performed to promote the crosslinking reaction. This baking process also evaporates the solvent in the composition, preventing mixing even when forming a resist top layer or a silicon-containing resist intermediate layer on the organic film.

[0176] Baking is performed at a temperature of 100°C to 600°C for 10 to 600 seconds, preferably at a temperature of 200°C to 500°C for 10 to 300 seconds. Considering the effects on device damage and wafer deformation, the upper limit of the heating temperature in the lithography wafer process is preferably 600°C or less, more preferably 500°C or less. Heat treatment under these conditions promotes the crosslinking reaction, making it possible to form an organic film that does not mix with the film formed on top.

[0177] [Pattern formation method] A pattern forming method using the organic film-forming composition of the present invention will be described below.

[0178] [Trilayer resist process using silicon-containing resist interlayer] In the present invention, there is provided a pattern forming method, comprising the steps of: forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming a resist upper layer film on the resist intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; Furthermore, the present invention provides a pattern forming method, which comprises using the organic underlayer film onto which the pattern has been transferred as a mask to transfer the pattern to the workpiece by etching.

[0179] The workpiece is preferably, for example, a semiconductor device substrate, or the semiconductor device substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal carbide oxide film, and a metal oxynitride film is formed. More specifically, although not limited to, substrates such as Si, α-Si, p-Si, SiO, SiN, SiON, W, TiN, and Al, or the substrate on which any of the above metal films is formed as a workpiece layer, may be used.

[0180] The work layer may be a low-k film or a stopper film thereof, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, or Al-Si, and may be formed to a thickness of typically 50 to 10,000 nm, particularly 100 to 5,000 nm. When forming the work layer, the substrate and the work layer are made of different materials.

[0181] It is preferable to use a metal constituting the workpiece that includes silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

[0182] When forming an organic film on a workpiece using the organic film-forming composition of the present invention, the above-described organic film-forming method of the present invention may be applied, for example, but is not limited to this.

[0183] Next, a resist interlayer (silicon-containing resist interlayer) is formed on the organic underlayer using a resist interlayer material containing silicon atoms. A polysiloxane-based interlayer material is preferred as the silicon-containing resist interlayer material. By imparting anti-reflective properties to the silicon-containing resist interlayer, reflection can be reduced. For 193 nm exposure, in particular, using an organic film-forming composition containing many aromatic groups and exhibiting high etching selectivity with the substrate increases the k value and increases substrate reflection. However, by providing the silicon-containing resist interlayer with an appropriate k value, reflection can be reduced, reducing substrate reflection to 0.5% or less. For silicon-containing resist interlayers with anti-reflective properties, preferred are polysiloxanes that have anthryl groups in their pendant structures for 248 nm or 157 nm exposure, and phenyl groups or light-absorbing groups with silicon-silicon bonds for 193 nm exposure, and that crosslink with acid or heat.

[0184] Next, a resist top layer film is formed on the silicon-containing resist intermediate film using a resist top layer film material composed of a photoresist composition. The resist top layer film material may be either positive or negative, and the same materials as commonly used photoresist compositions can be used. After spin-coating the resist top layer film material, it is preferable to prebake at 60 to 180°C for 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, followed by post-exposure baking (PEB) and development to obtain a resist top layer film pattern. The thickness of the resist top layer film is not particularly limited, but is preferably 30 to 500 nm, and particularly preferably 50 to 400 nm.

[0185] Next, a circuit pattern (resist upper layer film pattern) is formed on the resist upper layer film, preferably by lithography using light with a wavelength of 10 nm or more and 300 nm or less, direct writing with an electron beam, nanoimprinting, or a combination thereof.

[0186] Examples of exposure light include high-energy rays with a wavelength of 300 nm or less, specifically far ultraviolet rays, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F2 laser light (157 nm), Kr2 laser light (146 nm), Ar2 laser light (126 nm), soft X-rays (EUV) of 3 to 20 nm, electron beams (EB), ion beams, and X-rays.

[0187] In forming the circuit pattern, it is preferable to develop the circuit pattern using an alkali developer or an organic solvent.

[0188] Next, the resist top layer film on which the circuit pattern is formed is used as a mask to etch the silicon-containing resist intermediate film, and the pattern is transferred to the silicon-containing resist intermediate film. The etching of the silicon-containing resist intermediate film using the resist top layer film pattern as a mask is preferably carried out using a fluorocarbon gas. This allows the pattern (silicon-containing resist intermediate film pattern) to be transferred to the silicon-containing resist intermediate film.

[0189] Next, the pattern is transferred to the organic underlayer film by etching using the silicon-containing resist intermediate film (silicon-containing resist intermediate film pattern) as a mask. Because the silicon-containing resist intermediate film exhibits etching resistance to oxygen gas or hydrogen gas, the etching of the organic film using the silicon-containing resist intermediate film pattern as a mask is preferably carried out using an etching gas mainly composed of oxygen gas or hydrogen gas. This allows the pattern (organic film pattern) to be transferred to the organic underlayer film.

[0190] Next, a pattern is formed on the workpiece by etching using the organic underlayer film (organic underlayer film pattern) onto which the pattern has been transferred as a mask.

[0191] The next etching of the workpiece (processing layer) can be performed using conventional methods. For example, if the workpiece is SiO2, SiN, or a silica-based low-dielectric-constant insulating film, etching is performed primarily with fluorocarbon-based gases; if it is p-Si, Al, or W, etching is performed primarily with chlorine- or bromine-based gases. When substrate processing is performed using etching with fluorocarbon-based gases, the silicon-containing resist underlayer film pattern is stripped simultaneously with processing of the workpiece. On the other hand, if the workpiece is processed using etching with chlorine- or bromine-based gases, a separate dry etching stripping process using fluorocarbon-based gases must be performed after processing of the workpiece in order to strip the silicon-containing resist intermediate film pattern.

[0192] The organic underlayer film obtained by using the organic film-forming composition of the present invention can have excellent etching resistance when etching the workpiece as described above.

[0193] [Four-layer resist process using silicon-containing resist interlayer and organic anti-reflective or adhesive coating] The present invention also provides a pattern formation method, comprising the steps of forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention, forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms, forming an organic antireflective film or an adhesive film on the resist intermediate film, forming a resist upper layer film on the organic antireflective film or adhesive film using a resist upper layer film material comprising a photoresist composition, forming a circuit pattern on the resist upper layer film, transferring the pattern to the organic antireflective film or adhesive film and the resist intermediate film by etching using the resist upper layer film on which the circuit pattern has been formed as a mask, transferring the pattern to the organic underlayer film by etching using the resist intermediate film on which the pattern has been transferred as a mask, and further transferring the pattern to the workpiece by etching using the organic underlayer film on which the pattern has been transferred as a mask.

[0194] This method can be performed in the same manner as the three-layer resist process using the silicon-containing resist intermediate film described above, except that an organic antireflective coating (BARC) or an adhesion film is formed between the silicon-containing resist intermediate film and the resist top layer film.

[0195] The organic anti-reflection film and the adhesive film can be formed by spin coating using known organic anti-reflection film materials.

[0196] [Trilayer resist process using inorganic hard mask intermediate film] The present invention also provides a pattern formation method, comprising the steps of forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention, forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film, forming a resist upper layer film on the inorganic hard mask using a resist upper layer film material comprising a photoresist composition, forming a circuit pattern on the resist upper layer film, transferring the pattern to the inorganic hard mask by etching using the resist upper layer film on which the circuit pattern has been formed as a mask, transferring the pattern to the organic underlayer film by etching using the inorganic hard mask on which the pattern has been transferred as a mask, and further transferring the pattern to the workpiece by etching using the organic underlayer film on which the pattern has been transferred as a mask.

[0197] This method can be performed in the same manner as the three-layer resist process using the silicon-containing resist intermediate film described above, except that an inorganic hard mask intermediate film is formed on the organic underlayer film instead of the silicon-containing resist intermediate film.

[0198] An inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film (SiON film) can be formed by, for example, a CVD method or an ALD method. Methods for forming a silicon nitride film are described, for example, in JP-A No. 2002-334869 and WO 2004 / 066377. The thickness of the inorganic hard mask intermediate film is preferably 5 to 200 nm, more preferably 10 to 100 nm. As the inorganic hard mask intermediate film, a SiON film is most preferably used because of its high anti-reflection effect.

[0199] [Four-layer resist process using inorganic hard mask intermediate film and organic anti-reflective or adhesive film] The present invention also provides a pattern formation method, comprising the steps of forming an organic underlayer film on a workpiece using the organic film-forming composition of the present invention, forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film, forming an organic antireflective film or an adhesive film on the inorganic hard mask, forming a resist upper layer film on the organic antireflective film or adhesive film using a resist upper layer film material comprising a photoresist composition, forming a circuit pattern on the resist upper layer film, transferring the pattern to the organic antireflective film or adhesive film and the inorganic hard mask by etching using the resist upper layer film on which the circuit pattern has been formed as a mask, transferring the pattern to the organic underlayer film by etching using the inorganic hard mask on which the pattern has been transferred as a mask, and further transferring the pattern to the workpiece by etching using the organic underlayer film on which the pattern has been transferred as a mask.

[0200] This method can be performed in the same manner as the above-mentioned three-layer resist process using an inorganic hard mask intermediate film, except that an organic antireflective coating (BARC) or an adhesion film is formed between the inorganic hard mask intermediate film and the resist top layer film.

[0201] In particular, when a SiON film is used as the inorganic hard mask intermediate film, the two-layer anti-reflection coating of the SiON film and BARC makes it possible to suppress reflection even in immersion lithography with a high NA exceeding 1.0. Another benefit of forming a BARC is that it reduces the footing of the resist top layer pattern directly above the SiON film.

[0202] An example of a pattern formation method using the three-layer resist process of the present invention is shown in Figures 1(A) to 1(F). In the three-layer resist process, as shown in Figure 1(A), an organic film-forming composition of the present invention is used to form an organic underlayer film 3 on a workpiece (workpiece) 2 formed on a substrate 1. A silicon-containing resist intermediate film 4 is then formed on the organic underlayer film 3, and a resist upper layer film 5 is then formed thereon. Next, as shown in Figure 1(B), the exposed portion 6 of the resist upper layer film 5 is exposed to light, followed by PEB (post-exposure bake). Next, as shown in Figure 1(C), development is performed to form a resist upper layer film pattern 5a. Next, as shown in Figure 1(D), using the resist upper layer film pattern 5a as a mask, the silicon-containing resist intermediate film 4 is dry-etched using a fluorocarbon-based gas to form a silicon-containing resist intermediate film pattern 4a. Next, the resist upper layer film pattern 5a is removed, and then, as shown in Figure 1(E), the organic underlayer film 3 is oxygen plasma etched using the silicon-containing resist intermediate film pattern 4a as a mask to form an organic underlayer film pattern 3a.Furthermore, as shown in Figure 1(F), the silicon-containing resist intermediate film pattern 4a is removed, and then, using the organic underlayer film pattern 3a as a mask, the processable layer 2 is etched to form a pattern 2a.

[0203] In the pattern formation method of this example, humps are suppressed during the formation of the organic film 3, making it possible to reduce defects caused by humps in the organic underlayer film during the dry etching process of Figures 1(D), (E), and (F).

[0204] When an inorganic hard mask intermediate film is formed, the silicon-containing resist intermediate film 4 can be replaced with an inorganic hard mask intermediate film, and when a BARC or adhesion film is formed, the BARC or adhesion film can be formed between the silicon-containing resist intermediate film 4 and the resist upper layer film 5. Etching of the BARC or adhesion film can be performed consecutively prior to etching of the silicon-containing resist intermediate film 4, or etching of the silicon-containing resist intermediate film 4 can be performed after etching of the BARC or adhesion film alone, by changing the etching apparatus, for example.

[0205] As described above, the pattern formation method of the present invention makes it possible to form a fine pattern on a workpiece with high precision using a multilayer resist process, and also to reduce defects caused by humps in the organic underlayer film by suppressing hump formation in the organic film. [Example]

[0206] The present invention will be explained in more detail below with reference to Synthesis Examples, Comparative Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited thereto. The molecular weight was measured specifically as follows: The weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene were determined by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent (solvent), and the polydispersity (Mw / Mn) was also determined.

[0207] [Synthesis of compounds (B1) to (B29)] The fluorine-containing compounds (B1) to (B29) used to prepare the organic film-forming compositions (UDL-1 to ULD-56) of the examples of the present invention were synthesized using the epoxy compounds (E1) to (E9) and hydroxyl-containing compounds (alcohol compounds or carboxylic acid compounds) (F1) to (F13) shown below. Regarding the synthesis method of the fluorine-containing compounds (B1 to B27), the synthesis methods for the fluorine-containing compounds (B1) to (B2), (B4) to (B13), (B15) to (B18), (B20), (B22), (B25), and (B26) containing an ether structure differ from those for the fluorine-containing compounds (B3), (B14), (B19), (B21), (B23), (B24), and (B27) containing an ester structure, and are shown below.

[0208] (epoxy compounds) [ka]

[0209] Hydroxyl-containing compounds (alcohol compounds or carboxylic acid compounds)

[0210] [ka]

[0211] [Synthesis Example 1] Synthesis of fluorine-containing diol compound (B1) containing an ether structure [ka]

[0212] Under a nitrogen atmosphere, 100.0 g of THF (tetrahydrofuran) and 32.1 g (190.9 mmol) of alcohol compound (F1) were mixed and stirred in an ice bath to obtain a homogeneous solution. To the homogeneous solution, 21.4 g (190.9 mmol) of potassium t-butoxide was added and stirred to obtain a homogeneous solution. A mixture of 20.0 g (63.6 mmol) of epoxy compound (E1) and 20.0 g of THF was then added dropwise over 30 minutes, and the reaction was carried out at an internal temperature of 60°C for 24 hours. After cooling the reaction solution to room temperature, the reaction was quenched with 100 ml of ultrapure water. The reaction solution was then diluted with 300 ml of toluene, and the separated lower layer was removed. The residue was washed twice with 100 g of 5% potassium hydroxide aqueous solution, 100 ml of ultrapure water, twice with 100 ml of 3.0% nitric acid aqueous solution, and five times with 100 g of ultrapure water, in this order. The organic layer was then evaporated to dryness under reduced pressure to obtain compound (B1).

[0213] [Synthesis Example 2] Synthesis of fluorine-containing diol compound (B3) containing an ester structure [ka]

[0214] Under a nitrogen atmosphere, 20.0 g (63.6 mmol) of epoxy compound (E1), 28.6 g (133.6 mmol) of carboxylic acid compound (F4), 1.5 g (6.4 mmol) of benzyltriethylammonium chloride, and 100 g of 2-methoxy-1-propanol were mixed and heated to an internal temperature of 80°C to form a homogeneous solution. The homogeneous solution was further stirred at an internal temperature of 100°C for 24 hours. After cooling to room temperature, 200 ml of toluene was added to the homogeneous solution. The homogeneous solution was then washed twice with 100 g of 3% aqueous NaHCO3 solution, 100 g of ultrapure water, twice with 100 g of 3% aqueous nitric acid solution, and five times with 100 g of ultrapure water, in this order. The organic layer was then evaporated to dryness under reduced pressure. Thus, compound (B3) was obtained.

[0215] Fluorine-containing diol compounds (B2), (B4), and (B5) to (B27) were obtained as products under the same reaction conditions as in Synthesis Example 1 or Synthesis Example 2, except that the epoxy compounds and hydroxyl group-containing compounds shown in Table 1 were used. The synthesis method (Synthesis Example 1 or 2) used to synthesize the compounds is also shown in the table.

[0216] [Table 1]

[0217] (Synthesis Example 3) Synthesis of fluorine-containing compounds (B28) [ka]

[0218] 10.0 g of fluorine-containing compound (B5), 5.8 g of pyridine, and 50 g of N-methylpyrrolidone were mixed and prepared into a homogeneous solution in an ice bath under a nitrogen atmosphere. 14.1 g of 4-(trifluoromethoxy)benzoyl chloride was slowly added dropwise to the homogeneous solution. The mixture was then stirred in an ice bath for 1 hour. The temperature was then raised to 40°C in an oil bath, and the reaction was carried out for 12 hours. After the reaction was completed, 100 ml of IPE (diisopropyl ether) was added to the reaction solution, and then 50 g of ultrapure water was slowly added while cooling in an ice bath to quench the reaction. After quenching, the reaction solution was transferred to a separatory funnel, the aqueous layer was removed, and the organic layer was washed twice with 50 g of 2% aqueous NaHCO3 solution, twice with 50 g of 3% aqueous nitric acid solution, and six times with 50 g of pure water. The organic layer was then evaporated to dryness under reduced pressure. Thus, fluorine-containing compound (B28) was obtained.

[0219] (Synthesis Example 4) Synthesis of fluorine-containing compounds (B29) [ka]

[0220] 10.0 g of fluorine-containing compound (B22), 5.4 g of pyridine, and 50 g of tetrahydrofuran were mixed and heated in an ice bath under a nitrogen atmosphere to form a homogeneous solution. 13.0 g of 4-(trifluoromethoxy)benzoyl chloride was slowly added dropwise to the homogeneous solution. The mixture was then stirred in an ice bath for 1 hour. The mixture was then heated to 50°C in an oil bath and reacted for 12 hours. After the reaction was completed, 100 ml of IPE (diisopropyl ether) was added to the reaction solution, and 50 g of ultrapure water was slowly added while cooling in an ice bath to quench the reaction. After quenching, the reaction solution was transferred to a separatory funnel and the aqueous layer was removed. The organic layer was then washed twice with 50 g of 2% aqueous NaHCO3, twice with 50 g of 3% aqueous nitric acid, and six times with 50 g of pure water. The organic layer was then evaporated to dryness under reduced pressure. Thus, fluorine-containing compound (B29) was obtained.

[0221] The structural formulas of the fluorine-containing compounds (B1) to (B29) obtained in the synthesis examples described above are shown below. Table 2 also shows the Mw and Mw / Mn ratios of the fluorine-containing compounds (B1) to (B29) obtained.

[0222] [ka]

[0223] [ka]

[0224] [Table 2]

[0225] [Synthesis of comparative polymers (R1) to (R5)] The comparative polymers (R1) to (R5) used to prepare the organic film-forming compositions of the comparative examples (Comparative UDL-1 to 10) were synthesized using the following monomers (b1) to (b6).

[0226] [ka]

[0227] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer (R1) [ka]

[0228] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. To this was added dropwise a mixture of 3.44 g (0.011 mol) of monomer (b1), 7.46 g (0.034 mol) of monomer (b3), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA over 4 hours. After further heating and stirring for 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R1) was obtained.

[0229] The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained. (R1): Mw = 9500, Mw / Mn = 1.20

[0230] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer (R2) [ka]

[0231] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. To this was added dropwise a mixture of 1.43 g (0.005 mol) of monomer (b1), 5.76 g (0.041 mol) of monomer (b4), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA over 4 hours. After heating and stirring for an additional 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R2) was obtained.

[0232] The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained. (R2): Mw = 5800, Mw / Mn = 1.42

[0233] [Comparative Synthesis Example 3] Synthesis of Comparative Polymer (R3) [ka]

[0234] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. To this was added dropwise a mixture of 7.00 g (0.032 mol) of monomer (b2), 1.92 g (0.014 mol) of monomer (b3), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA over 4 hours. After heating and stirring for an additional 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R3) was obtained.

[0235] The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained. (R3): Mw = 6200, Mw / Mn = 1.33

[0236] [Comparative Synthesis Example 4] Synthesis of Comparative Polymer (R4) [ka]

[0237] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. To this was added dropwise a mixture of 5.00 g (0.023 mol) of monomer (b2), 3.20 g (0.023 mol) of monomer (b5), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA over 4 hours. After heating and stirring for an additional 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R4) was obtained.

[0238] The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained. (R4): Mw = 8300, Mw / Mn = 1.33

[0239] [Comparative Synthesis Example 5] Synthesis of Comparative Polymer (R5) [ka] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. To this was added dropwise a mixture of 2.00 g (0.009 mol) of monomer (b2), 5.41 g (0.036 mol) of monomer (b6), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA over 4 hours. After heating and stirring for an additional 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R5) was obtained. The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained. (R5): Mw = 3800, Mw / Mn = 1.44

[0240] [(A) Organic film-forming resin or compound] A1: a resin represented by the following formula (A1): A2: a resin represented by the following formula (A2): A3: A compound represented by the following formula (A3): A4: A compound represented by the following formula (A4): A5: Resin represented by the following formula (A5): A6: Resin represented by the following formula (A6):

[0241] [ka]

[0242] [solvent] (C1): Propylene glycol monomethyl ether acetate (C2): Propylene glycol monoethyl ether

[0243] [Preparation of Organic Film-Forming Compositions (UDL-1 to 56, Comparative UDL-1 to 16)] Each of the fluorine-containing compounds (B1) to (B29) and comparative polymers (R1) to (R5), or each of the organic film-forming resins or compounds (A1) to (A6) was dissolved in solvent (C1) and / or (C2) in the proportions shown in Tables 3 and 4, and the mixture was filtered through a 0.1 μm fluororesin filter to prepare each of the organic film compositions (resist underlayer film materials: UDL-1 to 56, comparative examples UDL-1 to 10). Each of the organic film-forming resins or compounds (A1) to (A6) was dissolved in solvent (C1) in the proportions shown in Table 4, and the mixture was filtered through a 0.1 μm fluororesin filter to prepare each of the organic film compositions (resist underlayer film materials: comparative examples UDL-11 to 16).

[0244] [Table 3]

[0245] [Table 4]

[0246] [Preparation of Silicon Wafers with Organic Underlayer Films Formed Using Organic Film-Forming Compositions (UDL-1 to 56, Comparative UDL-1 to 16)] Using a Tokyo Electron Limited coater / developer "CLEAN TRACK LITHIUS Pro AP," 2 mL of each of the organic film-forming compositions (UDL-1 to 56, Comparative UDL-1 to 16) prepared above was dispensed onto the center of a silicon wafer. The wafer was then rotated at a speed sufficient to achieve the average film thickness shown in Tables 5 and 6 after baking, forming a coating of the organic film-forming composition. While the silicon wafer was being rotated at 1000 rpm, the remover discharge nozzle was moved at a speed of 5 mm / s from the outer periphery of the silicon wafer to a position 3 mm toward the center, discharging the remover (a mixture of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether (30:70, mass ratio)) at a rate of 2 mL / s. The nozzle then continued to dispense the remover at a rate of 2 mL / s for 5 seconds. Discharge of the remover was then stopped, and the silicon wafer was rotated at 1000 rpm for an additional 30 seconds. Next, the silicon wafer was heated at 350° C. for 60 seconds to obtain a silicon wafer on which the organic underlayer film (cured organic film) of each example was formed.

[0247] [Solvent Resistance Evaluation: Examples 1-1 to 1-56, Comparative Examples 1-1 to 1-16] Using the above method, organic underlayer films were formed on silicon wafers using each organic film-forming composition (UDL-1 to 56, Comparative UDL-1 to 16), and their thicknesses were measured. Next, PGMEA solvent was dispensed onto each organic underlayer film, left for 30 seconds, spin-dried, and baked at 100°C for 60 seconds to evaporate the PGMEA, and the film thickness was measured. The film thickness before dispensing the PGMEA solvent was defined as X, and the film thickness after dispensing the PGMEA solvent was defined as X1. The absolute value of the value calculated by (X1 - X) / X × 100 was used as the film thickness change rate (%). A film thickness change rate of less than 0.5% was considered good, and a film thickness change rate of 0.5% or greater was considered poor. The results are shown in Tables 5 and 6 below.

[0248] [In-plane uniformity evaluation: Examples 1-1 to 1-56, Comparative Examples 1-1 to 1-16] Using the above method, an organic underlayer film was formed on a silicon wafer using each organic film-forming composition (UDL-1 to 56, comparative UDL-1 to 16), and the film thickness within a radius of 145 mm from the center of the organic underlayer film was measured. The maximum film thickness Xmax, minimum film thickness Xmin, and average film thickness X average As, (X max -X min ) / X average The value obtained by the above was taken as the in-plane uniformity (%). When the in-plane uniformity was less than 2%, it was rated as A (good), when it was 2% or more but less than 3%, it was rated as B, and when it was 3% or more, it was rated as C (poor). The results are shown in Tables 5 and 6 below.

[0249] [Contact Angle Evaluation: Examples 1-1 to 1-56, Comparative Examples 1-1 to 1-16] Using the above method, organic underlayer films were formed on silicon wafers using each organic film-forming composition (UDL-1 to 56, comparative UDL-1 to 16), and the contact angle of each organic underlayer film with pure water was measured. Note that UDL-11 to 16 were not measured due to poor in-plane uniformity. The results are shown in Tables 5 and 6 below.

[0250] [Table 5]

[0251] [Table 6]

[0252] As shown in Tables 5 and 6, Examples 1-1 to 1-56, which used the organic film-forming composition of the present invention, provided organic underlayer films with both good solvent resistance and in-plane uniformity, and with contact angles with pure water of 60 to 67 degrees. Organic underlayer films exhibiting such contact angles provide excellent coating properties for silicon-containing resist interlayer films. On the other hand, among Comparative Examples 1-1 to 1-16, which used compositions that did not contain the fluorine-containing compound contained in the organic film-forming composition of the present invention, Comparative Examples 1-11 to 1-16 exhibited poor in-plane uniformity. Therefore, in the following evaluation, we investigated UDL-1 to 56 and Comparative UDL-1 to 10, which exhibited good solvent resistance and in-plane uniformity. Furthermore, the organic underlayer films of Comparative Examples 1-1 to 1-10 exhibited contact angles with pure water of 74 degrees or more, which were so high that they were highly hydrophobic and therefore poorly coated with silicon-containing resist interlayer films. By controlling the film surface conditions to an appropriate contact angle in this way, an organic underlayer film with excellent film-forming properties for the silicon-containing intermediate film can be formed.

[0253] [Hump suppression evaluation: Examples 2-1 to 2-56, Comparative Examples 2-1 to 2-10] Using the method described above, organic underlayer films were formed on silicon wafers using each organic film-forming composition (UDL-1 to 56, comparative UDL-1 to 1-10), and the height change from the outer periphery of the organic underlayer film to 1000 μm toward the center of the silicon wafer was measured using an Alpha-Step D-600 (contact profiler) manufactured by KLA-Tencor. Assuming the height of the silicon wafer was 0, the maximum height was rated A (good) if it was less than 110% of the film thickness, as shown in Figure 2; B if it was 110% or more but less than 150%; and C (poor) if there was a region where the height was 150% or more, as shown in Figure 3.

[0254] [Evaluation of Filling Characteristics: Examples 2-1 to 2-56, Comparative Examples 2-1 to 2-10] As shown in Figure 4, a resist underlayer film (organic underlayer film) 8 was formed on a SiO2 wafer substrate having a dense hole pattern (hole diameter 0.2 μm, hole depth 1.0 μm, center-to-center distance between adjacent two holes 0.4 μm) using each of the organic film-forming compositions (UDL-1 to 56, comparative UDL-1 to 10) by the above method. The substrate used was a base substrate (SiO2 wafer substrate) 7 having a dense hole pattern as shown in Figure 4(G) (overhead view) and (H) (cross-sectional view). The cross-section of each wafer substrate was observed using a scanning electron microscope (SEM) to confirm whether the holes were filled with the resist underlayer film without any voids. When an organic film-forming composition with poor filling properties was used, voids were generated within the holes. When an organic film-forming composition with good filling properties was used, the holes were filled with the organic underlayer film without any voids, as shown in Figure 4(I). If no voids were generated, the sample was evaluated as good, and if voids were generated, the sample was evaluated as poor.

[0255] [Evaluation of Coatability of Silicon-Containing Resist Interlayer: Examples 2-1 to 2-56, Comparative Examples 2-1 to 2-10] Using the above method, an organic underlayer film was formed on a silicon wafer substrate using each organic film-forming composition (UDL-1 to 56, Comparative UDL-1 to 10). The silicon-containing resist intermediate film material (SOG1) described below was applied to the formed organic underlayer film and baked at 200°C for 60 seconds to form a silicon-containing resist intermediate film. The state of the silicon-containing resist intermediate film coating was then visually observed and evaluated.

[0256] The silicon-containing resist intermediate film was rated as good if its coating condition was good, and rated as poor if dewetting occurred. The results are shown in Tables 8 and 9 below.

[0257] In this evaluation, in order to evaluate the superiority or inferiority of the coating properties of the silicon-containing resist interlayer, the thickness of the silicon-containing resist interlayer was set to 5 nm, which was a special and strict evaluation condition.

[0258] The silicon-containing resist interlayer material (SOG1) was prepared by dissolving the polymer (SP1), crosslinking catalyst, and acid in an organic solvent and water in the proportions shown in Table 7, and then filtering the mixture through a 0.1 μm fluororesin filter.

[0259] [Table 7]

[0260] The polymer (SP1) is shown below.

[0261] [ka]

[0262] TMPANO3: Trimethylphenylammonium nitrate PGEE: Propylene glycol ethyl ether

[0263] [Table 8]

[0264] [Table 9]

[0265] As shown in Tables 8 and 9, it was confirmed that the organic film-forming compositions (UDL-1 to 56) of the examples of the present invention are excellent in solvent resistance, in-plane uniformity, hump suppression, embedding properties, and coating properties of silicon-containing resist-containing intermediate films.

[0266] [Pattern formation test: Examples 3-1 to 3-56] Using the above method, an organic underlayer film was formed on a SiO2 wafer substrate using each organic film-forming composition (UDL-1 to 56). Next, the following silicon-containing resist intermediate film material (SOG2) was applied onto the organic underlayer film and baked at 200°C for 60 seconds to form a 35 nm-thick silicon-containing resist intermediate film. Next, the following ArF single-layer resist was applied as a resist upper layer film material onto the silicon-containing resist intermediate film and baked at 105°C for 60 seconds to form a 100 nm-thick photoresist film. Next, the following immersion protective film material (TC-1) was applied onto the photoresist film and baked at 90°C for 60 seconds to form a 50 nm-thick protective film.

[0267] The silicon-containing resist underlayer film material (SOG2) was prepared by dissolving the polymer (SP1), crosslinking catalyst, and acid in an organic solvent and water in the proportions shown in Table 10, and filtering the solution through a 0.1 μm fluororesin filter.

[0268] [Table 10]

[0269] The resist top layer film material (ArF single-layer resist) was prepared by dissolving a polymer (RP1), an acid generator (PAG1), and a basic compound (Amine1) in a solvent containing 0.1 mass% of FC-430 (manufactured by Sumitomo 3M Limited) in the proportions shown in Table 11, and filtering the resulting mixture through a 0.1 μm fluororesin filter.

[0270] [Table 11]

[0271] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) are shown below.

[0272] [ka]

[0273] The immersion protective film material (TC-1) was prepared by dissolving the polymer (PP1) in an organic solvent in the proportions shown in Table 12 and filtering the resulting mixture through a 0.1 μm fluororesin filter.

[0274] [Table 12]

[0275] The polymer (PP1) is shown below.

[0276] [ka]

[0277] The resist was then exposed using an ArF immersion exposure system (Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% halftone phase-shift mask), baked at 100°C for 60 seconds (PEB), and developed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) for 30 seconds to obtain a 55 nm 1:1 positive line-and-space pattern (resist upper layer film pattern).

[0278] Next, using a Tokyo Electron etching device Telius, the resist upper layer film pattern was used as a mask to dry etch (pattern transfer) the silicon-containing resist intermediate film to obtain a silicon-containing resist intermediate film pattern, and the resulting silicon-containing resist intermediate film pattern was used as a mask to dry etch (pattern transfer) the organic film to obtain an organic underlayer film pattern, and the resulting organic underlayer film pattern was used as a mask to dry etch (pattern transfer) the SiO2 wafer substrate (SiO2 film). The etching conditions are as shown below.

[0279] (Conditions for transferring the resist top layer pattern to the silicon-containing resist intermediate film) Chamber pressure 10.0Pa RF power 1,500W CF4 gas flow rate: 75mL / min O2 gas flow rate 15mL / min Time 15sec

[0280] (Conditions for transferring silicon-containing resist intermediate film pattern to organic underlayer film) Chamber pressure 2.0Pa RF power 500W Ar gas flow rate: 75 mL / min O2 gas flow rate: 45mL / min Time 120sec

[0281] (Conditions for transferring organic underlayer film patterns onto SiO2 wafer substrates) Chamber pressure 2.0Pa RF power 2,200W C5F 12 Gas flow rate: 20 mL / min C2F6 gas flow rate 10mL / min Ar gas flow rate: 300 mL / min O2 gas flow rate 60mL / min Time 90sec

[0282] The cross section of the obtained pattern was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. The results are shown in Tables 13 and 14.

[0283] [Table 13]

[0284] [Table 14]

[0285] As shown in Tables 13 and 14, in Examples 3-1 to 3-56, in which the organic film-forming compositions (UDL-1 to 56) of the present invention were used, the resist upper layer film pattern was successfully transferred to the SiO2 wafer substrate, confirming that the organic film-forming compositions of the present invention are suitable for use in microfabrication using the multilayer resist method.

[0286] [Preparation of resist top layer materials (ArFPR1-29, comparative ArFPR)] The previously described polymer (RP1; organic film-forming resin), acid generator (PAG1), basic compound (Amine1), and fluorine-containing compounds (B1 to B29) were dissolved in a solvent in the proportions shown in Tables 15 and 16, and the resulting mixture was filtered through a 0.1 μm fluororesin filter to prepare resist top layer film materials (ArFPR1 to 29). A comparative resist top layer film material (Comparative ArFPR) was also prepared in the same manner as the resist top layer film material (ArFPR1), except that the fluorine-containing compound (A1) was not used.

[0287] [Table 15]

[0288] [Table 16]

[0289] [Preparation of silicon wafers with resist top layer films formed using resist top layer materials (ArFPR1-29, comparative ArFPR)] Using a Tokyo Electron Co., Ltd. coater / developer "CLEAN TRACK LITHIUS Pro AP," 2 ml of each of the resist top layer film materials (ArFPR1-29, comparative ArFPR) prepared above was dispensed onto the center of a silicon wafer and baked. The wafer was then rotated at a speed that resulted in an average film thickness of 100 nm, spreading the coating to form each resist top layer film precursor. Next, the silicon wafers coated with the resist top layer film precursors were heated at 105°C for 60 seconds to obtain silicon wafers coated with resist top layer films.

[0290] [Evaluation of in-plane uniformity of resist top layer film: Examples 4-1 to 4-29] The thickness of each resist top layer (ArFPR1-29, comparative ArFPR) formed on a silicon wafer using the above method was measured within a radius of 145 mm from the center, and the maximum thickness Xmax, minimum thickness Xmin, and average thickness X average As, (X max -X min ) / X average The value obtained by the above formula was taken as the in-plane uniformity (%). In-plane uniformity of less than 3% was considered good, and in-plane uniformity of 3% or more was considered poor. The results are shown in Table 17 below.

[0291] [Table 17]

[0292] As shown in Table 17, the resist top layer film materials (ArFPR1 to 29) of the examples of the present invention have excellent in-plane uniformity, which indicates that the (B) fluorine-containing compound of the present invention functions as a surfactant that imparts excellent leveling performance and can be used in various organic film-forming compositions regardless of the type of (A) organic film-forming resin or compound to be combined.

[0293] From the above, the organic film-forming composition of the present invention has excellent film-forming properties, high-level filling properties, and hump suppression properties, and has excellent coatability for silicon-containing resist intermediate films, i.e., excellent process tolerance, and is therefore extremely useful as an organic film material for use in multilayer resist processes.Furthermore, the pattern formation method of the present invention using this composition is capable of filling holes and trenches with very high aspect ratios without voids, and is also capable of forming fine patterns with high precision.It is also possible to form an organic film (e.g., an organic underlayer film or a resist overlayer film) with suppressed humps, and therefore semiconductor elements and the like can be efficiently manufactured.

[0294] The present specification includes the following aspects. [1] A composition for forming an organic film, (A) an organic film-forming resin or compound; (B) a fluorine-containing compound represented by the following general formula (1), and (C) Solvent A composition for forming an organic film, comprising: [ka] (In the formula, L is a single bond or an n1-valent organic group having 1 to 50 carbon atoms. R1 is a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, and the organic group R1 has at least one fluorine-containing structure represented by any one of the following formulas (2). R2 is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. n1 represents an integer of 2 to 8.) [ka] (* indicates a bond in the organic group represented by R1, and the organic group R1 may have two or more types of structures represented by the above formula (2), or may have two or more of the same structure.) [2] The composition for forming an organic film according to [2], wherein R1 in the general formula (1) has a structure represented by any one of the following general formulas (3): [ka] (* represents a bond in the organic group represented by R1, and n2, n3, and n4 each represent an integer of 1 to 10.) [3] The composition for forming an organic film according to [1] or [2], wherein L in the general formula (1) is an organic group represented by any one of the following general formulas (4): [ka] (* indicates a bond to a terminal structure including OR1 and OR2. n5, n6, and n7 each represent an integer of 1 to 10.) [4] The composition for forming an organic film according to any one of [1] to [3], wherein R2 in the general formula (1) is a hydrogen atom. [5] The composition for forming an organic film according to any one of [1] to [4], wherein the weight average molecular weight of the fluorine-containing compound (B) represented by the general formula (1) is 300 to 1500. [6] The compound for forming an organic film according to any one of [1] to [5], characterized in that the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn in terms of polystyrene, as determined by gel permeation chromatography, of the fluorine-containing compound (B) represented by the general formula (1) satisfies 1.00≦Mw / Mn≦1.10. [7] The composition for forming an organic film according to any one of [1] to [6], characterized in that the content of the (A) organic film-forming resin or compound is 0.01 to 5 parts by mass. [8] A method for forming an organic film used in a manufacturing process of a semiconductor device, comprising: A composition for forming an organic film according to any one of [1] to [7] is spin-coated on a substrate to be processed to obtain a coating film; The organic film forming method is characterized in that a cured film is formed by heat-treating the coating film at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds. [9] A pattern forming method, forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of [1] to [7]; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming a resist upper layer film on the resist intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

[10] A pattern forming method, forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of [1] to [7]; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming an organic anti-reflective film or an adhesion film on the resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the organic anti-reflective film or adhesive film and the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

[11] A pattern forming method, forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of [1] to [7]; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film; forming a resist upper layer film on the inorganic hard mask using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the inorganic hard mask by etching; the pattern is transferred to the organic underlayer film by etching using the inorganic hard mask to which the pattern has been transferred as a mask; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

[12] A pattern forming method, forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of [1] to [7]; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film; forming an organic anti-reflective film or an adhesion film on the inorganic hard mask; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; using the resist upper layer film on which the circuit pattern has been formed as a mask, to transfer the pattern to the organic anti-reflective film or adhesion film and the inorganic hard mask by etching; the pattern is transferred to the organic underlayer film by etching using the inorganic hard mask to which the pattern has been transferred as a mask; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

[13] The pattern forming method according to

[11] or

[12] , wherein the inorganic hard mask is formed by a CVD method or an ALD method.

[14] The pattern forming method according to any one of [9] to

[13] , characterized in that in forming the circuit pattern, the circuit pattern is formed by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct writing with an electron beam, nanoimprinting, or a combination thereof.

[15] The pattern forming method according to any one of [9] to

[14] , wherein the circuit pattern is developed using an alkali developer or an organic solvent.

[16] The pattern forming method according to any one of [9] to

[15] , wherein the workpiece is a semiconductor device substrate, or a semiconductor device substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film is formed.

[17] The pattern formation method according to

[16] , wherein the metal constituting the workpiece is silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

[0295] The present invention is not limited to the above-described embodiments. The above-described embodiments are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits similar effects is included within the technical scope of the present invention. [Explanation of symbols]

[0296] 1...substrate, 2...processed layer, 2a...pattern (pattern formed on the processed layer), 3...organic underlayer film, 3a...organic underlayer film pattern, 4...silicon-containing resist intermediate film, 4a...silicon-containing resist intermediate film pattern, 5...resist upper layer film, 5a...resist upper layer film pattern, 6...exposed portion, 7...underlying substrate, 8...organic film.

Claims

1. An organic film-forming composition, (A) an organic film-forming resin or compound; (B) a fluorine-containing compound represented by the following general formula (1), and (C) Solvent A composition for forming an organic film, comprising: 【Chemical 1】 (In the formula, L is a single bond or an n1-valent organic group having 1 to 50 carbon atoms. R １ is a saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, and the organic group R １ R has at least one fluorine-containing structure represented by any one of the following formulas (2): ２ is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. n1 is an integer of 2 to 8. 【Chemistry 2】 (* indicates R １ and the organic group R １ may have two or more types of structures represented by the above formula (2), or may have two or more of the same structure.

2. R in the general formula (1) １ The organic film-forming composition according to claim 1, wherein the organic film-forming composition has a structure represented by any one of the following general formulas (3): 【Chemistry 3】 (* indicates R １ and n2, n3, and n4 each represent an integer of 1 to 10.

3. 2. The organic film-forming composition according to claim 1, wherein L in the general formula (1) is an organic group represented by any one of the following general formulas (4): 【Chemistry 4】 (* indicates OR １ and OR ２ n5, n6, and n7 each represent an integer of 1 to 10.

4. R in the general formula (1) ２ 2. The organic film-forming composition according to claim 1, wherein is a hydrogen atom.

5. 2. The organic film-forming composition according to claim 1, wherein the weight average molecular weight of the fluorine-containing compound (B) represented by the general formula (1) is 300 to 1,500.

6. 2. The compound for forming an organic film according to claim 1, wherein the ratio Mw / Mn of the weight average molecular weight Mw and the number average molecular weight Mn of the fluorine-containing compound (B) represented by the general formula (1) in terms of polystyrene, as determined by gel permeation chromatography, is 1.00≦Mw / Mn≦1.

10.

7. The composition for forming an organic film according to claim 1, characterized in that the content of the (B) fluorine-containing compound is 0.01 parts by mass to 5 parts by mass when the content of the (A) organic film-forming resin or compound is 100 parts by mass.

8. A method for forming an organic film used in a manufacturing process of a semiconductor device, comprising: A composition for forming an organic film according to any one of claims 1 to 7 is spin-coated on a substrate to be processed to obtain a coating film, The organic film forming method is characterized in that the coating film is heat-treated at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds to form a cured film.

9. A pattern formation method, comprising: forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming a resist upper layer film on the resist intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

10. A pattern formation method, comprising: forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming a resist intermediate film on the organic underlayer film using a resist intermediate film material containing silicon atoms; forming an organic anti-reflective film or an adhesion film on the resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the organic anti-reflective film or adhesive film and the resist intermediate film by etching; the resist intermediate film onto which the pattern has been transferred is used as a mask to transfer the pattern to the organic underlayer film by etching; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

11. A pattern formation method, comprising: forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film; forming a resist upper layer film on the inorganic hard mask using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the inorganic hard mask by etching; the pattern is transferred to the organic underlayer film by etching using the inorganic hard mask to which the pattern has been transferred as a mask; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

12. A pattern formation method, comprising: forming an organic underlayer film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic underlayer film; forming an organic anti-reflective film or an adhesion film on the inorganic hard mask; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; using the resist upper layer film on which the circuit pattern has been formed as a mask, to transfer the pattern to the organic anti-reflective film or adhesion film and the inorganic hard mask by etching; the pattern is transferred to the organic underlayer film by etching using the inorganic hard mask to which the pattern has been transferred as a mask; The pattern forming method further comprises transferring the pattern to the workpiece by etching using the organic underlayer film onto which the pattern has been transferred as a mask.

13. 12. The pattern formation method according to claim 11, wherein the inorganic hard mask is formed by a CVD method or an ALD method.

14. 10. The pattern forming method according to claim 9, wherein the circuit pattern is formed by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct writing with an electron beam, nanoimprinting, or a combination thereof.

15. 10. The pattern forming method according to claim 9, wherein the circuit pattern is developed using an alkali developer or an organic solvent.

16. 10. The pattern forming method according to claim 9, wherein the workpiece is a semiconductor device substrate, or a semiconductor device substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film is formed.

17. 17. The pattern formation method according to claim 16, wherein the metal constituting the workpiece is silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

Images