Planarizing agent for forming an organic film, composition for forming an organic film, method for forming an organic film, and pattern forming method

Abstract

To provide a flattening agent for organic film formation from which a composition for organic film formation having high flattening characteristics is given, a composition for organic film formation containing the flattening agent, an organic film formation method using the composition, and a pattern formation method.SOLUTION: A flattening agent for organic film formation is composed of an aromatic-containing compound having a molecular weight represented by the molecular formula of 200-500, wherein the flattering agent for organic film formation is blended with a composition containing a resin for organic film formation and a solvent having complex viscosity of 1.0 Pa s or more in a temperature range of 175°C or higher, and thereby the complex viscosity of the composition becomes less than 1.0 Pa s in the temperature range of 175°C or higher.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a planarizing agent for forming an organic film for a multilayer resist for microfabrication in the manufacture of semiconductor devices and the like, an organic film for planarization in the manufacture of semiconductor devices and the like, an organic film-forming composition containing the compound, an organic film-forming method using the composition, and a pattern-forming method using the composition.

Background Art

[0002] In recent years, with the high integration and high speed of semiconductor elements, as the miniaturization of pattern rules is required, in lithography using optical exposure, which is currently a general-purpose technology, various technological developments have been carried out on how to perform finer and more accurate pattern processing with respect to the light source used.

[0003] As a light source for lithography used in forming a resist pattern, in parts with low integration, optical exposure using the g-line (436 nm) or i-line (365 nm) of a mercury lamp as a light source is widely used. On the other hand, in parts with high integration and the need for miniaturization, lithography using a shorter wavelength KrF excimer laser (248 nm) or ArF excimer laser (193 nm) has also been put into practical use, and in the most advanced generations where further miniaturization is required, lithography using extreme ultraviolet light (EUV, 13.5 nm) is also approaching practical use.

[0004] As the line width of the resist pattern is reduced in this way, in the single-layer resist method, which is a typical resist pattern formation method, the ratio of the pattern height to the pattern line width (aspect ratio) increases, and it is well known that pattern collapse occurs due to the surface tension of the developer during development. Therefore, it is known that the multilayer resist method, in which films with different dry etching characteristics are laminated to form a pattern, is excellent for forming a pattern with a high aspect ratio on a stepped substrate. Examples include a two-layer resist method (Patent Document 1) that combines a photoresist layer made of a silicon-containing photosensitive polymer and a lower layer made of an organic polymer having carbon, hydrogen, and oxygen as main constituent elements, such as a novolak-based polymer, and a three-layer resist method (Patent Document 2) that combines a photoresist layer made of an organic photosensitive polymer used in the single-layer resist method, an intermediate layer made of a silicon-based polymer or a silicon-based CVD film, and a lower layer made of an organic polymer.

[0005] In this three-layer resist method, for example, an organic film made of novolak or the like is formed as an organic lower layer film on a substrate to be processed, a silicon-containing film is formed as a resist intermediate film thereon, and a normal organic photoresist film is formed as a resist upper layer film thereon. For dry etching with a fluorine-based gas plasma, the organic resist upper layer film has a good etching selectivity with respect to the silicon-containing resist intermediate film, so the resist pattern is transferred to the silicon-containing resist intermediate film by using dry etching with a fluorine-based gas plasma. According to this method, even if a resist composition that is difficult to form a pattern with a sufficient film thickness for directly processing the substrate to be processed or a resist composition that does not have sufficient dry etching resistance for processing the substrate is used, a pattern can be transferred to the silicon-containing film. Subsequently, if pattern transfer is performed using dry etching with an oxygen-based gas plasma, a novolak film with sufficient dry etching resistance for processing can be obtained. etc. of the pattern can be obtained.

[0006] Although many techniques for the organic underlayer film as described above are already known (for example, Patent Document 3), in recent years, in addition to dry etching characteristics, the need for excellent embedding characteristics or planarization characteristics has been increasing. For example, when there are minute pattern structures such as holes and trenches in the underlying substrate to be processed, embedding characteristics for filling the inside of the pattern with a film without voids are required. Further, when there are steps in the underlying substrate to be processed, or when a pattern-dense portion and a pattern-free region exist on the same wafer, it is necessary to planarize the film surface with the underlayer film. By planarizing the underlayer film surface, it is possible to suppress the film thickness variation of the intermediate layer and photoresist formed thereon, and to expand the focus margin of lithography and the margin of the subsequent processing steps of the substrate to be processed.

[0007] As a method for improving the planarization characteristics of the underlayer film material, a method of adding a solvent having a high boiling point has been proposed (Patent Document 4). However, when the pattern region existing in the substrate to be processed is wide, it is more difficult to planarize the step with the pattern-free region, and these methods are insufficient.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to provide a planarizing agent for forming an organic film that gives an organic film-forming composition having high planarization characteristics, an organic film-forming composition containing this planarizing agent, an organic film-forming method using this composition, and a patterning method.

Means for Solving the Problems

[0010] In order to solve the above problems, in the present invention, there is provided a planarizing agent for forming an organic film, The planarizing agent for forming an organic film is composed of an aromatic-containing compound having a molecular weight represented by a molecular formula of 200 to 500, By blending the planarizing agent for forming an organic film into a composition containing an organic film-forming resin and a solvent having a complex viscosity of 1.0 Pa·s or more in a temperature range of 175°C or higher, the composition has a temperature range in which the complex viscosity is less than 1.0 Pa·s in a temperature range of 175°C or higher. A planarizing agent for forming an organic film is provided.

[0011] With such a planarizing agent for forming an organic film, since it has good thermal fluidity during heat-assisted film formation, high planarization becomes possible. In addition, since it is an aromatic-containing compound, film formation defects are less likely to occur in the organic film.

[0012] It is preferable that the weight loss rate of the planarizing agent for forming an organic film is less than 15% from 30°C to 190°C, and the weight loss rate is 98% or more between 30°C and 350°C.

[0013] With such a planarizing agent for forming an organic film, it has good thermal fluidity during heat-assisted film formation, and since the remaining amount in the film of the planarizing agent for forming an organic film after heat-assisted film formation is further reduced, high planarization can be achieved without further impairing the etching resistance of the organic film-forming resin.

[0014] It is preferable that the planarizing agent for forming an organic film is an aromatic-containing compound containing an oxygen atom.

[0015] Such a planarizing agent for forming an organic film is less likely to cause film formation defects on the substrate to be processed.

[0016] It is more preferable that the aromatic ring contained in the aromatic-containing compound is a benzene ring.

[0017] Such a planarizing agent for forming an organic film has excellent solubility in a solvent because the aromatic ring contained in the planarizing agent for forming an organic film is a benzene ring.

[0018] Furthermore, it is more preferable that the planarizing agent for forming an organic film is a compound having two or more benzene rings or containing one benzene ring and a structure represented by the following general formula (A).

Chemical formula

[0019] Such a planarizing agent for forming an organic film has even better solubility in a solvent.

[0020] Moreover, it is preferable that the planarizing agent for forming an organic film is one or more compounds selected from the following general formulas (I) to (III).

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0021] By including such a compound, the compatibility with the resin for forming an organic film is excellent, and film formation defects such as pinholes are less likely to occur during film formation.

[0022] If it is a planarizing agent for forming an organic film as described above, the effects of the present invention are sufficiently exhibited.

[0023] Further, the present invention provides an organic film-forming composition comprising an organic film-forming resin, the planarizing agent for forming an organic film of the present invention, and a solvent.

[0024] If it is such an organic film-forming composition, it will have high planarization characteristics.

[0025] Further, it is preferable that the organic film-forming resin has an aromatic skeleton.

[0026] Such a composition for forming an organic film can provide an organic film having excellent etching resistance and optical properties.

[0027] Furthermore, it is preferable that the skeleton of the resin for forming the organic film is any one of benzene, naphthalene, and fluorene.

[0028] Such a composition for forming an organic film is preferable for providing an organic film having excellent etching resistance, optical properties, and heat resistance.

[0029] If it is a composition for forming an organic film as described above, the effects of the present invention are sufficiently exhibited.

[0030] The present invention also provides a method for forming an organic film that functions as an organic planarization film used in the manufacturing process of a semiconductor device. The method includes spin-coating the above-described composition for forming an organic film on a substrate to be processed, and heat-treating the substrate coated with the composition for forming an organic film at a temperature of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film.

[0031] The present invention also provides a method for forming an organic film that functions as an organic planarization film used in the manufacturing process of a semiconductor device. The method includes spin-coating the above-described composition for forming an organic film on a substrate to be processed, heat-treating the substrate coated with the composition for forming an organic film at a temperature of 100°C or higher and 350°C or lower for 10 to 600 seconds, and further heat-treating at a temperature of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film.

[0032] Thus, in the method for forming an organic film of the present invention, it is possible to promote planarization by thermal flow and crosslinking reaction by performing single-step baking, or to perform two-step baking to advance planarization by thermal flow in the first baking and cause a crosslinking reaction in the second baking.

[0033] In this case, it is preferable to use a substrate to be processed having a structure or step with a height of 20 nm or more as the substrate to be processed.

[0034] Since the composition for forming an organic film of the present invention has excellent planarization characteristics, it is particularly useful when forming a flat organic film on such a substrate to be processed.

[0035] Furthermore, the present invention provides a pattern forming method, which comprises forming an organic film on a substrate to be processed using the above composition for forming an organic film, forming a resist intermediate film on the organic film using a resist intermediate film material containing a silicon atom, forming a resist upper layer film on the resist intermediate film using a resist upper layer film material composed of a photoresist composition, forming a circuit pattern on the resist upper layer film, transferring the pattern to the resist intermediate film by etching using the resist upper layer film on which the circuit pattern is formed as a mask, transferring the pattern to the organic film by etching using the resist intermediate film on which the pattern is transferred as a mask, and further transferring the pattern to the substrate to be processed by etching using the organic film on which the pattern is transferred as a mask.

[0036] Also, the present invention provides a pattern forming method, which comprises forming an organic film on a substrate to be processed using the above composition for forming an organic film, forming a resist intermediate film on the organic film using a resist intermediate film material containing a silicon atom, forming an organic antireflection film or an adhesion film on the resist intermediate film, forming a resist upper layer film on the organic antireflection film or the adhesion film using a resist upper layer film material composed of a photoresist composition, forming a circuit pattern on the resist upper layer film, transferring the pattern to the organic antireflection film or the adhesion film and the resist intermediate film by etching using the resist upper layer film on which the circuit pattern is formed as a mask, transferring the pattern to the organic film by etching using the resist intermediate film on which the pattern is transferred as a mask, and further transferring the pattern to the substrate to be processed by etching using the organic film on which the pattern is transferred as a mask.

[0037] Also, an organic film is formed on a workpiece using the above composition for forming an organic film, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the organic film, a resist upper layer film is formed on the inorganic hard mask using a resist upper layer film material composed of a photoresist composition, a circuit pattern is formed in the resist upper layer film, the inorganic hard mask is etched to transfer the pattern using the resist upper layer film having the circuit pattern formed thereon as a mask, the organic film is etched to transfer the pattern using the inorganic hard mask having the pattern transferred thereon as a mask, and further, the workpiece is etched to transfer the pattern using the organic film having the pattern transferred thereon as a mask. A pattern forming method is also provided.

[0038] Also, an organic film is formed on a workpiece using the above composition for forming an organic film, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the organic film, an organic antireflection film or an adhesion film is formed on the inorganic hard mask, a resist upper layer film is formed on the organic antireflection film or the adhesion film using a resist upper layer film material composed of a photoresist composition, a circuit pattern is formed in the resist upper layer film, the organic antireflection film or the adhesion film and the inorganic hard mask are etched to transfer the pattern using the resist upper layer film having the circuit pattern formed thereon as a mask, the organic film is etched to transfer the pattern using the inorganic hard mask having the pattern transferred thereon as a mask, and further, the workpiece is etched to transfer the pattern using the organic film having the pattern transferred thereon as a mask. A pattern forming method is also provided.

[0039] Thus, the composition for forming an organic film of the present invention can be suitably used in various pattern forming methods such as a three-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask, and a four-layer resist process using an organic antireflection film or an adhesion film in addition to these. With such a pattern forming method of the present invention, the circuit pattern of the resist upper layer film can be transferred and formed on the workpiece with high precision.

[0040] Further, it is preferable to form the inorganic hard mask by a CVD method or an ALD method.

[0041] In the pattern formation method of the present invention, an inorganic hard mask can be formed by such a method, for example.

[0042] Further, in the formation of 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 by an electron beam, nanoimprinting, or a combination thereof.

[0043] Further, in the formation of the circuit pattern, it is preferable to develop the circuit pattern by alkali development or an organic solvent.

[0044] In the pattern formation method of the present invention, such circuit pattern formation means and development means can be suitably used.

[0045] Further, it is preferable that the workpiece is a semiconductor device substrate or a substrate obtained by forming any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxynitride film, and a metal oxynitride film on the semiconductor device substrate.

[0046] Further, it is preferable that 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.

[0047] In the pattern formation method of the present invention, a pattern can be formed by processing the workpiece as described above.

Advantages of the Invention

[0048] As described above, according to the present invention, it is possible to provide a planarizing agent for forming an organic film that imparts high planarization characteristics and a composition for forming an organic film having high planarization characteristics. Further, such a composition for forming an organic film of the present invention has excellent planarization characteristics and is also excellent in other characteristics such as heat resistance and etching resistance. Therefore, for example, it is extremely useful as an organic film material used in a multilayer resist process 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 antireflection film or an adhesion film, or as a planarizing material for manufacturing semiconductor devices. Further, according to the method for forming an organic film of the present invention, an organic film having sufficient organic solvent resistance and being very flat can be formed on a substrate to be processed. Further, according to the pattern forming method of the present invention, a fine pattern can be formed on an object to be processed with high precision by a multilayer resist process.

Brief Description of Drawings

[0049]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0050] As described above, there has been a demand for the development of a composition for forming an organic film having advanced embedding / planarization characteristics and a compound for forming an organic film useful for the composition.

[0051] Generally, when forming an organic film, a resin for forming an organic film is dissolved in an organic solvent to form a composition, which is applied onto a substrate on which a structure and wiring of a semiconductor device are formed, and then fired to form an organic film. Immediately after the application of the composition, a coating film conforming to the shape of the structure on the substrate is formed. However, when the coating film is fired, most of the organic solvent evaporates before curing, and the uneven shape immediately after application is flattened by the thermal flow of the resin for forming an organic film remaining on the substrate. On the other hand, a resin with high etching resistance generally has poor thermal fluidity and is difficult to flatten the uneven shape, while a resin with high thermal fluidity has poor etching resistance in a flexible low carbon density structure, such as an alkyl chain structure, and it has been difficult to achieve both etching resistance and flatness.

[0052] The present inventors have further intensively studied and found that by incorporating an aromatic-containing compound having a molecular weight represented by a molecular formula of 200 to 500 into a composition for forming an organic film, which is a planarizing agent for forming an organic film and contains a resin for forming an organic film and a solvent, and having a complex viscosity of 1.0 Pa·s or more in a temperature range of 175°C or higher, a temperature range in which the complex viscosity is less than 1.0 is generated, and the thermal fluidity is improved, thereby providing a composition for forming an organic film having advanced planarization characteristics, and thus completed the present invention.

[0053] That is, the present invention relates to a planarizing agent for forming an organic film, wherein the planarizing agent for forming an organic film is composed of an aromatic-containing compound having a molecular weight represented by a molecular formula of 200 to 500, and by incorporating the planarizing agent for forming an organic film into a composition containing a resin for forming an organic film and a solvent, which has a complex viscosity of 1.0 Pa·s or more in a temperature range of 175°C or higher, the composition has a temperature range in which the complex viscosity is less than 1.0 in a temperature range of 175°C or higher. The planarizing agent for forming an organic film is characterized by this.

[0054] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0055] [Planarizing agent for organic film formation] A planarizing agent for organic film formation is a compound that is blended in a composition for organic film formation in addition to a resin for organic film formation and a solvent, and has an effect of improving planarization characteristics. The planarizing agent for organic film formation of the present invention is composed of an aromatic-containing compound having a molecular weight represented by a molecular formula of 200 to 500, and the planarizing agent for organic film formation is used in a composition containing a resin for organic film formation and a solvent having a complex viscosity of 1.0 Pa·s or more in a temperature range of 175 °C or higher. By blending, the composition has a temperature range in which the complex viscosity of the composition is less than 1.0 Pa·s in a temperature range of 175 °C or higher.

[0056] Here, with reference to FIGS. 1 and 2, the planarizing agent for organic film formation will be described. Details of the composition corresponding to FIGS. 1 and 2 will be described later. In a composition (hereinafter referred to as an organic film-forming pre-composition) composed of an organic film-forming resin and a solvent without the planarizing agent for organic film formation of the present invention, the graph of the complex viscosity measured in the range of 50°C or higher and 300°C or lower is shown in FIG. 1, and the graph of the complex viscosity measured in the range of 50°C or higher and 300°C or lower in the organic film-forming composition containing the planarizing agent for organic film formation of the present invention is shown in FIG. 2. When heating the organic film-forming pre-composition without the planarizing agent for organic film formation, as shown in FIG. 1, an increase in the complex viscosity starts in the range of 50°C or higher and 100°C or lower. This increase in the complex viscosity is considered to be due to the evaporation of the solvent. Further, in a higher temperature region, when heating is continued, the viscosity further increases due to the cross-linking reaction of the organic film-forming resin. On the other hand, when heating the organic film-forming compound containing the planarizing agent for organic film formation of the present invention, as shown in FIG. 2, after maintaining a relatively low state of the complex viscosity until around 180°C, an increase in viscosity starts due to cross-linking. The planarizing agent for organic film formation of the present invention has a function of suppressing an increase in the complex viscosity by heat treatment by being blended in the organic film-forming composition in this way, and is composed of an aromatic-containing compound having a molecular weight represented by a molecular formula of 200 to 500. By blending the planarizing agent for organic film formation into a composition containing an organic film-forming resin and a solvent having a complex viscosity of 1.0 Pa·s or more in a temperature range of 175°C or higher, the composition has a temperature range in which the complex viscosity of the composition is less than 1.0 Pa·s in a temperature range of 175°C or higher.

[0057] The complex viscosity of the organic film-forming compound can be easily measured with a commercially available general measuring device. Examples of the measuring device include, for example, the MCR rheometer manufactured by Anton Paar, and the ARES viscoelastic measuring system manufactured by Rheometric Scientific. Examples of the measuring procedure include a method of setting the organic film-forming composition in the measuring device and measuring the complex viscosity between 50°C and 300°C. In the present invention, the complex viscosity of the composition and the corresponding temperature are determined by the following measuring method. [Measuring Method] When measuring using a dynamic viscoelasticity measuring device (MCR rheometer MCR302 manufactured by Anton Paar), a measuring jig with an outer diameter of 20 mm is used, and the complex viscosity is measured from 50°C to 300°C at a strain of 1%, a frequency of 1 Hz, and a heating rate of 5°C / min.

[0058] The planarizing agent for organic film formation of the present invention can achieve a high degree of planarization because it imparts good thermal fluidity to the organic film-forming composition.

[0059] When forming an organic film or the like, after the organic film-forming composition is spin-coated on a stepped substrate, it is usually heat-cured by baking (Hard Bake) at approximately 250 to 400°C to obtain a cured film. Therefore, if it is possible to maintain a low complex viscosity up to a high temperature range, the thermal fluidity until curing is promoted, and a high degree of planarization of the stepped substrate can be achieved.

[0060] In addition, the molecular weight based on the molecular formula indicating the planarizing agent for organic film formation is 200 to 500, and since it has sufficient thermal fluidity during baking, it has a high degree of planarization characteristics and less residue of the planarizing agent for organic film formation in the film after baking. The molecular weight based on the molecular formula indicating the planarizing agent for organic film formation is preferably 240 to 450, and particularly preferably 300 to 400.

[0061] On the other hand, when the planarizing agent for organic film formation has a molecular weight of less than 200, the planarizing agent for organic film formation is easily reduced by evaporation or the like during heat treatment, resulting in poor thermal fluidity and insufficient planarization characteristics. When the molecular weight exceeds 500, evaporation of the planarizing agent for organic film formation during heat treatment is suppressed, so the in-plane uniformity deteriorates due to the simultaneous occurrence of the cross-linking reaction of the organic film-forming resin and the evaporation of the planarizing agent. In addition, the etching resistance also deteriorates due to the remaining of the planarizing agent in the film.

[0062] Furthermore, a planarizing agent for forming an organic film, having a weight loss rate of less than 15% from 30°C to 190°C and a weight loss rate of 98% or more from 30°C to 350°C, is preferable because evaporation during heat treatment is suppressed, sufficiently maintaining a low complex viscosity, having excellent thermal fluidity, and having little residue of the planarizing agent for forming an organic film in the film after firing. In this specification, the weight loss rate is based on a value determined by TG (thermogravimetry) measurement using a differential thermal balance.

[0063] The upper limit of the temperature range in which the weight loss rate of the planarizing agent for forming an organic film is less than 15% is more preferably 210°C, and even more preferably 230°C. By setting the temperature range in which the weight loss rate of the planarizing agent for forming an organic film is less than 15% to the above temperature range, the planarization characteristics can be further improved.

[0064] As the temperature at which the weight loss rate of the planarizing agent for forming an organic film becomes 98% or more, 330°C is more preferable, and 310°C is particularly preferable. By setting the temperature at which the weight loss rate of the planarizing agent for forming an organic film becomes 98% or more to the above temperature range, the residue of the planarizing agent for forming an organic film in the film after firing can be made even less.

[0065] By blending the planarizing agent for forming an organic film as described above, the film thermal fluidity of the organic forming composition from the start of heat treatment to curing by crosslinking reaction is improved, resulting in excellent planarization characteristics. On the other hand, the planarizing agent for forming an organic film is reduced by heat treatment, such as evaporation, and does not impair etching resistance and optical properties.

[0066] In the present invention, the planarization property refers to the performance of planarizing the surface of a substrate. For a composition containing the planarizing agent for forming an organic film of the present invention, for example, as shown in FIG. 3, by applying the composition 3' for forming an organic film on the substrate 1 and heating to form the organic film 3, it is possible to reduce the step of 115 nm on the substrate 1 to less than 115 nm. Note that the step shape shown in FIG. 3 shows a typical example of the step shape in a substrate for manufacturing a semiconductor device, and the step shape of the substrate that can be planarized by the composition containing the compound for forming an organic film of the present invention is of course not limited to this.

[0067] A more preferable embodiment of the planarizing agent for forming an organic film includes those containing an oxygen atom.

[0068] The surface of the substrate to be processed is one on which Si, α-Si, p-Si, SiO 2 , SiN, SiON, W, TiN, Al, etc. are formed. Therefore, for such a planarizing agent for forming an organic film containing an oxygen atom, it is possible to improve the wettability of the composition for forming an organic film with respect to the substrate to be processed during spin coating or heat treatment of the composition for forming an organic film on the substrate to be processed, and it is possible to reduce film formation defects such as dewetting.

[0069] The planarizing agent for forming an organic film of the present invention is an aromatic-containing compound having a molecular weight represented by a molecular formula of 200 to 500 and containing an aromatic ring.

[0070] Examples of the above aromatic ring include aromatic carbon rings such as benzene ring and naphthalene ring, and aromatic heterocyclic rings such as furan ring, pyrrole ring, thiophene ring, phosphole ring, pyrazole ring, oxazole ring, isoxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, and triazine ring.

[0071] From the viewpoints of etching resistance, optical properties, and heat resistance, compounds having an aromatic skeleton are preferably used as the resin for forming an organic film. If the planarizing agent for forming an organic film is an aromatic-containing compound, it has excellent compatibility with the resin for forming an organic film, so film formation defects such as pinholes are less likely to occur during film formation, which is preferable. Further, among aromatic rings, an aromatic carbocyclic ring is preferable, and a benzene ring is more preferable.

[0072] And examples of the planarizing agent for forming an organic film include compounds having two or more benzene rings or containing a structure represented by the following general formula (A) and one benzene ring.

Chemical formula

[0073] More specifically, examples of W include a methylene group, an ethylene group, a propylene group, a butylene group, a trimethylene group, and a tetramethylene group. Among these, an ethylene group is more preferable.

[0074] Furthermore, more preferable embodiments of the planarizing agent for forming an organic film include one or more compounds selected from the following general formulas (I) to (III).

Chemical formula

Chemical formula

[0075] [Chemical formula] (In the formula, R 2 are each independently a hydrogen atom, or an optionally substituted organic group having 1 to 10 carbon atoms. W 4 is a divalent group represented by the following general formula (II-1). W 5 is either a single bond or a divalent group represented by the following general formula (II-2). m 2 is an integer from 3 to 10, and n 3 is an integer from 0 to 5. ) [Chemical formula] (In the formula, * indicates the bonding position, and R 20 , R 21 , R 22 , R 23 are a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. m 20 , m 21 are integers from 0 to 10, and m 20 + m 21 ≧ 1. ) [Chemical formula] (In the formula, * indicates the bonding position. )

[0076] [Chemical formula] (In the formula, R 3 , R 4 is a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms, and may combine to form a cyclic structure. R 5 , R 6 is an organic group having 1 to 10 carbon atoms, and R 5 is a group containing either an aromatic ring or a divalent group represented by the following general formula (III-1). W 6 , W 7 is either a single bond or a divalent group represented by the following general formula (III-2), and at least one is a divalent group represented by any of the following general formula (III-2).) [Chemical formula] (In the formula, * indicates the bonding position, and W 30 is an organic group having 1 to 4 carbon atoms.) [Chemical formula] (In the formula, * indicates the bonding position.)

[0077] In the above general formula (I), R 1 are each independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms. Here, in the present invention, the "organic group" means a group containing at least one carbon, further contains hydrogen, and may also contain nitrogen, oxygen, sulfur, silicon, halogen atoms, etc.

[0078] R 1 may be single or a mixture of multiple types. R 1 More specifically, as R n- , there are a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, n- a butyl group, an s-butyl group, a t-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group,n- A butoxy group, an s-butoxy group, a t-but toxi yl group, iso a butoxy group, a norbornyl group, an adamantyl group, a phenyl group, a toluyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furanyl group, a 2-tetrahydrofuranyl group can be exemplified. Among these, a hydrogen atom is more preferable.

[0079] W 1 is a phenylene group or a divalent group represented by the above general formula (I-1). W 2 and W 3 is either a single bond or a divalent group represented by the above general formula (I-2). m 1 is an integer from 1 to 10, and n 1 is each independently an integer from 0 to 5.

[0080] R 10 and R 11 and R 12 and R 13 more specifically, is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. More specifically, a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, n- a butyl group, an s-butyl group, a t-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, n- a butoxy group, an s-butoxy group, a t-but toxi yl group, iso a butoxy group, a norbornyl group, an adamantyl group, a phenyl group, a toluyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furanyl group, a 2-tetrahydrofuranyl group can be exemplified. Among these, a hydrogen atom and a methyl group are more preferable, and a hydrogen atom is even more preferable.

[0081] W 10 and W 11 are each independently a single bond or a carbonyl group. m 10 and m 11 is an integer from 0 to 10, and m10 +m 11 is ≧ 1.

[0082] R 2 may be single or a mixture of multiple types. R 2 More specifically, as R, a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, n- a butyl group, an s-butyl group, a t-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, n- a butoxy group, an s-butoxy group, a t-but toxi yl group, iso a butoxy group, a norbornyl group, an adamantyl group, a phenyl group, a toluyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furanyl group, a 2-tetrahydrofuranyl group can be exemplified. Among these, a hydrogen atom is more preferable.

[0083] W 4 is a divalent group represented by the above general formula (II-1). W 5 is a single bond or any divalent group represented by the above general formula (II-2). m 2 is an integer from 3 to 10, and n 3 is an integer from 0 to 5.

[0084] R 20 R 21 R 22 R 23 More specifically, as R, a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, n- a butyl group, an s-butyl group, a t-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, n- a butoxy group, an s-butoxy group, a t-but toxi yl group, isoExamples thereof include a butoxy group, a norbornyl group, an adamantyl group, a phenyl group, a toluyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furanyl group, and a 2-tetrahydrofuranyl group. Among these, a hydrogen atom and a methyl group are more preferable, and a hydrogen atom is even more preferable.

[0085] m 20 、m 21 is an integer from 0 to 10, and m 20 +m 21 ≧1.

[0086] R 3 、R 4 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. More specifically, a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, n- a butyl group, an s-butyl group, a t-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, n- a butoxy group, an s-butoxy group, a t-but toxi yl group, iso a butoxy group, a norbornyl group, an adamantyl group, a phenyl group, a toluyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furanyl group, a 2-tetrahydrofuranyl group can be exemplified. Among these, a hydrogen atom is more preferable.

[0087] R 6 is an organic group having 1 to 10 carbon atoms. R 5 is an organic group having 1 to 10 carbon atoms and contains either an aromatic ring or a divalent group represented by the above general formula (III-1). Examples of the organic group having 1 to 10 carbon atoms include the groups mentioned for the above R 3 、R 4 .

[0088] W 6 、W 7is a divalent group that is either a single bond or one represented by the general formula (III-2), and at least one of these is a divalent group represented by any of the general formulas (III-2).

[0089] W 30 is an organic group having 1 to 4 carbon atoms. More specifically, examples thereof include a methylene group, an ethylene group, a propylene group, a butylene group, a trimethylene group, and a tetramethylene group. Among these, an ethylene group is more preferable.

[0090] More specifically, examples of the compound represented by the general formula (I) include, but are not limited to, the following.

Chemical formula

[0091] More specifically, examples of the compound represented by the general formula (II) include, but are not limited to, the following.

Chemical formula

[0092] More specifically, examples of the compound represented by the general formula (III) include, but are not limited to, the following.

Chemical formula

[0093] In addition to the compounds represented by the general formulas (I) to (III), examples of the following aromatic-containing compounds (piperonyl compounds, phthalic acid diesters) can be given, but are not limited thereto.

Chemical formula

[0094] In addition to the performance of planarizing the surface of the substrate, when comprehensively considering etching resistance, optical properties, compatibility with the resin for forming an organic film, film-forming properties, wettability with respect to the substrate to be processed, etc., as the planarizing agent for forming an organic film of the present invention, an aromatic-containing compound having a benzyl group or a benzoyl group is preferable, and in particular, the following aromatic-containing compounds are preferable. (i) (Poly)ethylene glycol dibenzoate (ii) (Poly)ethylene glycol dibenzyl ether (iii) (Poly)propylene glycol dibenzyl ether (iv) (Poly)butylene glycol dibenzyl ether (v) Linear aliphatic dicarboxylic acid dibenzyl (vi) (Poly)ethylene glycol monobenzyl ether (vii) (Poly)phenyl ether (viii) Alkyl benzyl phthalate

[0095] [Chemical formula] Note that n in the above formula is an integer such that the molecular weight is in the range of 200 to 500, and it is applied only in this formula.

[0096] The blending amount of the planarizing agent for forming an organic film is preferably 20 to 300 parts by mass, more preferably 30 to 200 parts by mass, still more preferably 50 to 150 parts by mass, and particularly preferably 80 to 100 parts by mass with respect to 100 parts by mass of the resin for forming an organic film. For the planarizing agent for forming an organic film planarizing agent If the blending amount is 20 parts by mass or more, the blending effect can be sufficiently obtained. The planarizing agent for forming an organic film of the present invention can be used alone or in combination of two or more of the above aromatic-containing compounds.

[0097] As described above, the planarizing agent for forming an organic film of the present invention can provide an organic film-forming composition having high planarization characteristics.

[0098] [Organic film-forming composition] The composition for forming an organic film of the present invention contains a resin for forming an organic film, the planarizing agent for forming an organic film, and a solvent.

[0099] In the composition for forming an organic film of the present invention, the resin for forming an organic film, the planarizing agent for forming an organic film, and the solvent can each be used alone or in combination of two or more.

[0100] [Resin for forming an organic film] The organic film of the present invention for formation The resin for forming an organic film that can be used in the composition is not particularly limited as long as it satisfies the film-forming property and curability of spin coating. However, from the viewpoints of etching resistance, optical properties, heat resistance, etc., those that are compounds containing an aromatic skeleton are more preferable.

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

[0102] Examples of the resin for forming an organic film applied to the present invention include resins containing the following structures described in JP-A-2012-1687 and JP-A-2012-77295.

Chemical formula

[0103]

Chemical formula

[0104] Examples of the resin for forming an organic film applied to the present invention include resins containing the following structures described in JP-A-2004-264710, JP-A-2005-043471, JP-A-2005-250434, JP-A-2007-293294, and JP-A-2008-65303.

Chemical formula

[0105]

Chemical formula

[0106]

Chemical formula

[0107]

Chemical formula

[0108] Specific examples of the resin for forming an organic film applied to the present invention include resins containing the following structures described in JP-A-2004-205685, JP-A-2007-171895, and JP-A-2009-14816.

Chemical formula

[0109] [Chemical formula] (In formula (10), R 1 , R 6 is a hydrogen atom or a methyl group. R 2 , R 3 , R 4 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group, a hydroxy group, an acetoxy Si group or an alkoxycarbonyl group, or an aryl group having 6 to 10 carbon atoms, and R 5 is a condensed polycyclic hydrocarbon group having 13 to 30 carbon atoms, -O-R 7 , -C(=O)-O-R 7 , -O-C(=O)-R 7 , or -C(=O)-NR 8 -R 7 . m is 1 or 2, n is an integer from 0 to 4, and p is an integer from 0 to 6. R 7 is an organic group having 7 to 30 carbon atoms, R 8 is a hydrogen atom, or a hydrocarbon group having 1 to 6 carbon atoms. Z is any one of a methylene group, -O-, -S-, -NH-. a, b, c, d, e are respectively 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. The symbols in the formula are applicable only within this formula.)

[0110] [Chemical formula] (In formula (11), n represents 0 or 1. R 1 represents an optionally substituted methylene group, an optionally substituted alkylene group having 2 to 20 carbon atoms, or an optionally substituted arylene group having 6 to 20 carbon atoms.)2 represents a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms. R 3 ~R 7 represents 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 alkoxycarbonyl group having 2 to 10 carbon atoms, an optionally substituted aryl group having 6 to 14 carbon atoms, or an optionally substituted glycidyl ether group having 2 to 6 carbon atoms. R 9 represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a linear, branched or cyclic alkyl ether group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. Note that the symbols in the formula are applicable only within this formula.)

[0111] For example, the following compounds are exemplified.

Chemical formula

[0112] Examples of the resin for forming an organic film applied to the present invention include resins containing the following structures described in JP-A-2007-199653, JP-A-2008-274250, and JP-A-2010-122656.

Chemical formula

[0113]

Chem.

[0114]

Chem.

[0115]

Chem.

[0116] For example, the following compounds are exemplified.

Chemical formula

[0117]

Chemical formula

[0118]

Chemical formula

[0119]

Chemical formula

[0120] Examples of the resin for forming an organic film applied to the present invention include resins containing the following structures described in JP-A-2012-214720.

Chemical formula

[0121] Examples of the resin for forming an organic film applied to the present invention include resins described in JP-A-2014-29435, International Publication WO2012 / 077640, and International Publication WO2010 / 147155.

Chemical formula

[0122] Moreover, a polymer can be exemplified which includes a unit structure represented by the following formula (18) and a unit structure represented by the following formula (19) described in International Publication WO2012 / 077640, and the ratio of the unit structure represented by formula (18) to the unit structure represented by formula (19) is 3 to 97:97 to 3 in molar ratio. [Chemical formula] (In formula (18), R 1 and R 2 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 those groups which may contain an ether bond, a ketone bond, or an ester bond. R 3 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 those groups which may contain an ether bond, a ketone bond, or an ester bond. R 4 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. R 5 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, an aryl group having 6 to 40 carbon atoms, or a heterocyclic group. R 4 and R 5 may form a ring together. n1 and n2 each represent an integer of 1 to 3. Note that the symbols in the formula are applicable only within this formula.)

[0123]

Chem.

[0124] Examples of the resin for forming an organic film applied to the present invention include polymers containing a unit structure represented by the following formula (20) described in International Publication WO2010 / 147155.

Chem.

[0125] Examples of the resin for forming an organic film applied to the present invention include novolak resins obtained by reacting one or more of phenols such as phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyquinol, phloroglucinol and one or more of aldehyde sources such as formaldehyde, paraformaldehyde, and trioxane using an acidic catalyst, resins containing a repeating unit structure represented by the following formula (21) described in International Publication WO2012 / 176767, and the like. [Chemical formula] (In formula (21), A represents a hydroxy group-substituted phenylene group derived from polyhydroxybenzene, and B represents a monovalent condensed aromatic hydrocarbon ring group in which 2 to 6 benzene rings are condensed. The symbols in the formula are applicable only within this formula.)

[0126] Examples of the resin for forming an organic film applied to the present invention include novolak resins having a fluorene or tetrahydrospirobiindene structure described in JP-A-2005-128509, JP-A-2006-259249, JP-A-2006-259482, JP-A-2006-293298, and JP-A-2007-316282, and resins containing a repeating unit structure represented by the following formula (22-1) or (22-2).

Chemical formula

[0127] Examples of the resin for forming an organic film applied to the present invention include reaction products obtained by the method described in JP-A-2012-145897. More specifically, examples thereof 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 their equivalents.

Chemical formula

Chemical formula

[0128] In addition, examples thereof include polymers obtained by condensing one or more compounds represented by the above general formula (23-1) and / or (23-2) with one or more compounds represented by the above general formula (24-1) and / or (24-2) and / or their equivalents and one or more compounds represented by the following general formula (25) and / or their equivalents. [Chemical] (In formula (25), Y is a hydrogen atom or a monovalent organic group having 30 or fewer carbon atoms which may have a substituent, and formula (25) is different from formula (24-1) and formula (24-2). Note that the symbols in the formula are applicable only within this formula.)

[0129] Examples of the resin for forming an organic film applied to the present invention include resins containing the following structures described in JP-A-2017-119671. [Chemical] (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 symbols in the formula are applicable only within this formula.) [Chemical] (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. Note that the symbols in the formula are applicable only within this formula.) [Chemical] (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 atoms on the benzene ring in the formula may be substituted with a methyl group or a methoxy group. Note that the symbols in the formula are applicable only within this formula.)

[0130] For example, the following compounds are exemplified. [Chemical]

[0131] Examples of the resin for forming an organic film applicable to the present invention include polymers having a repeating unit represented by the following general formula (27-1) described in JP-A-2019-44022

Chemical formula

Chemical formula

Chemical formula

[0132] For example, the following polymers are exemplified.

Chemical formula

[0133]

Chemical formula

[0134] The resin for forming an organic film may be synthesized by a known method or a commercially available product may be used.

[0135] The compounding amount of the resin for forming an organic film is preferably, for example, 0.2 to 50 parts by mass, more preferably 1 to 33.3 parts by mass, based on 100 parts by mass of the composition for forming an organic film.

[0136] [Solvent] The solvent that can be used in the composition for forming an organic film of the present invention is not particularly limited as long as it can dissolve the resin for forming an organic film and the planarizing agent for forming an organic film, and those that can also dissolve the acid generator, crosslinking agent, surfactant, etc. described later are preferable. Specifically, ketones such as 2-heptanone, cyclopentanone, cyclohexanone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 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, diethylene glycol dimethyl ether; 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, γ-butyrolactone, propylene glycol monotert-butyl ether acetate, etc. may be mentioned, and one or more of these can be used in combination, but it is not limited thereto.

[0137] Among them, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, γ-butyrolactone, and mixtures of two or more of these are preferably used.

[0138] The blending amount of the solvent is preferably 100 to 50,000 parts by mass, more preferably 200 to 10,000 parts by mass, per 100 parts by mass of the resin for forming an organic film.

[0139] [Other components] In addition, an acid generator, a crosslinking agent, or the like for further promoting the crosslinking reaction can be added to the composition for forming an organic film of the present invention.

[0140] As the acid generator, there are those that generate an acid by thermal decomposition and those that generate an acid by light irradiation, and any of them can be added. Specifically, examples of the acid generator include those described in paragraphs (0061) to (0085) of JP-A-2007-199653. The blending amount of the acid generator is not particularly limited, but for example, it can be 0.05 to 50 parts by mass per 100 parts by mass of the resin for forming an organic film.

[0141] Specific examples of the crosslinking agent include those described in paragraphs (0055) to (0060) of JP-A-2007-199653. The blending amount of the crosslinking agent is not particularly limited, but for example, it can be 1 to 50 parts by mass per 100 parts by mass of the resin for forming an organic film.

[0142] In addition, a surfactant can be added to the composition for forming an organic film of the present invention in order to improve the coatability in spin coating. Specifically, examples of the surfactant include those described in paragraphs (0142) to (0147) of JP-A-2009-269953. The blending amount of the surfactant is not particularly limited, but for example, it can be 0.001 to 20 parts by mass per 100 parts by mass of the resin for forming an organic film.

[0143] Furthermore, a basic compound for improving storage stability can be added to the composition for forming an organic film of the present invention. The basic compound serves as a quencher for an acid to prevent the acid generated in a trace amount from the acid generator from promoting the crosslinking reaction. Specific examples of such a basic compound include those described in paragraphs (0086) to (0090) of JP-A-2007-199653.

[0144] As described above, the composition for forming an organic film of the present invention becomes a composition for forming an organic film having excellent planarization characteristics. Therefore, the composition for forming an organic film of the present invention is extremely useful as a composition for forming an organic film for a multilayer resist process such as a two-layer resist process, a three-layer resist process using a silicon-containing resist intermediate film or a silicon-containing inorganic hard mask, or a four-layer resist process using a silicon-containing resist intermediate film or a silicon-containing inorganic hard mask and an organic antireflection film or an adhesion film. In addition, since the composition for forming an organic film of the present invention has excellent planarization characteristics, it can also be suitably used as a planarizing material in a semiconductor device manufacturing process other than the multilayer resist process.

[0145] [Method for forming an organic film] The present invention provides a method for forming an organic film that functions as an organic planarizing film used in a manufacturing process of a semiconductor device. The method includes spin-coating the above-described composition for forming an organic film of the present invention on a substrate to be processed, and heat-treating the substrate coated with the composition for forming an organic film at a temperature of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film.

[0146] In this method for forming an organic film, first, the above-described composition for forming an organic film of the present invention is spin-coated on a substrate to be processed. By using the spin-coating method, good embedding characteristics can be obtained. After spin-coating, baking (heat treatment) is performed to promote planarization and crosslinking reaction due to heat flow. Note that since the solvent in the composition can be evaporated by this baking, mixing can be prevented even when a resist upper layer film or a silicon-containing resist intermediate film is formed on the organic film.

[0147] Baking is carried out at a temperature in the range of 100°C or higher and 600°C or lower for 10 to 600 seconds, preferably at a temperature in the range of 200°C or higher and 500°C or lower for 10 to 300 seconds. Considering the influence on device damage and wafer deformation, the upper limit of the heating temperature in the wafer process of lithography is preferably 600°C or lower, more preferably 500°C or lower. By performing heat treatment under such conditions, planarization due to heat flow and crosslinking reaction can be promoted, and an organic film without mixing with the film formed on the upper layer can be formed.

[0148] Also, for example, in the present invention, the above-described composition for forming an organic film of the present invention is spin-coated on a substrate to be processed, and the substrate coated with the composition for forming an organic film is heat-treated (first baking) at a temperature in the range of 100°C or higher and 350°C or lower for 10 to 600 seconds, and further heat-treated (second baking) at a temperature in the range of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film.

[0149] By performing the first baking at a temperature at which the crosslinking reaction of the resin for forming the organic film does not occur, planarization proceeds due to heat flow, and by causing a crosslinking reaction by the second baking, it becomes possible to obtain a cured film having excellent flatness.

[0150] Further, in the method for forming an organic film of the present invention, it is preferable to use a substrate to be processed having a structure or step with a height of 20 nm or more. As described above, since the composition for forming an organic film of the present invention has excellent embedding / planarization characteristics, even if the substrate to be processed has a structure or step (concavo-convex) with a height of 20 nm or more, a flat cured film can be formed. That is, the method for forming an organic film of the present invention is particularly useful when forming a flat organic film on such a substrate to be processed.

[0151] The thickness of the organic film to be formed is appropriately selected, but it is preferably 20 to 20,000 nm, particularly preferably 50 to 15,000 nm.

[0152] In addition, the above-described method for forming an organic film is applicable to both the case of forming an organic film for an organic underlayer film and the case of forming an organic film for a planarization film using the composition for forming an organic film of the present invention.

[0153] [Pattern formation method] [Three-layer resist process using a silicon-containing resist intermediate film] In the present invention, an organic film is formed on a workpiece using the composition for forming an organic film of the present invention described above, a resist intermediate film is formed on the organic film using a resist intermediate film material containing a silicon atom, a resist upper layer film is formed on the resist intermediate film using a resist upper layer film material composed of a photoresist composition, a circuit pattern is formed in the resist upper layer film, the resist intermediate film is etched to transfer the pattern using the resist upper layer film on which the circuit pattern is formed as a mask, the organic film is etched to transfer the pattern using the resist intermediate film on which the pattern is transferred as a mask, and further, a pattern formation method is provided in which the workpiece is etched to transfer the pattern using the organic film on which the pattern is transferred as a mask.

[0154] As the workpiece, it is preferable to use a semiconductor device substrate or a substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxynitride film, and a metal carbonitride film is formed on the semiconductor device substrate. More specifically, although not particularly limited, substrates such as Si, α-Si, p-Si, SiO 2 , SiN, SiON, W, TiN, Al, etc., and those on which the above metal films or the like are formed as a processing layer on the substrate are used.

[0155] As the processing layer, Si, SiO 2 , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si and other various Low-k films and their stopper films are used, and they can usually be formed to a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm. When forming the processing layer, the substrate and the processing layer are made of different materials.

[0156] 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.

[0157] Also, as the workpiece, it is preferable to use a structure having a height of 30 nm or more or a processed substrate having a step.

[0158] When forming an organic film on the workpiece using the composition for forming an organic film of the present invention, the above-described organic film forming method of the present invention may be applied.

[0159] Next, a resist intermediate film (silicon-containing resist intermediate film) is formed on the organic film using a resist intermediate film material containing silicon atoms. As the resist intermediate film material containing silicon atoms, a polysiloxane-based intermediate film material is preferable. By giving the silicon-containing resist intermediate film an antireflection effect, reflection can be suppressed. In particular, for 193 nm exposure, when a material having many aromatic groups and high etching selectivity with the substrate is used as the composition for forming an organic film, the k value becomes high and the substrate reflection becomes high. However, by giving absorption such that an appropriate k value is obtained for the silicon-containing resist intermediate film, it becomes possible to suppress reflection and reduce the substrate reflection to 0.5% or less. As the silicon-containing resist intermediate film having an antireflection effect, anthracene is used for 248 nm and 157 nm exposure, and a polysiloxane having a phenyl group or an absorptive group having a silicon-silicon bond in a pendant structure and crosslinking with an acid or heat is preferably used for 193 nm exposure.

[0160] Next, a resist upper layer film is formed on the resist intermediate film using a resist upper layer film material composed of a photoresist composition. The resist upper layer film material can be either positive or negative, and the same materials as those of commonly used photoresist compositions can be used. After spin-coating the resist upper layer film material, it is preferably pre-baked at 60 to 180 °C for 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, and further, post-exposure baking (PEB) and development are performed to obtain a resist upper layer film pattern. Note that the thickness of the resist upper layer film is not particularly limited, but is preferably 30 to 500 nm, and particularly preferably 50 to 400 nm.

[0161] Next, a circuit pattern (resist upper layer film pattern) is formed on the resist upper layer film. In forming the circuit pattern, it is preferable to form the circuit pattern by lithography using light with a wavelength of 10 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprinting, or a combination thereof.

[0162] Note that as the exposure light, high energy rays with a wavelength of 300 nm or less, specifically, deep ultraviolet rays, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F 2 laser light (157 nm), Kr 2 laser light (146 nm), Ar 2 laser light (126 nm), soft X-rays (EUV) of 3 to 20 nm, electron beam (EB), ion beam, X-rays, etc. can be mentioned.

[0163] Also, in forming the circuit pattern, it is preferable to develop the circuit pattern with alkali development or an organic solvent.

[0164] Next, a pattern is transferred to the resist intermediate film by etching using the resist upper layer film on which the circuit pattern is formed as a mask. The etching of the resist intermediate film performed using the resist upper layer film pattern as a mask is preferably performed using a fluorocarbon-based gas. Thereby, a silicon-containing resist intermediate film pattern is formed.

[0165] Next, using the resist intermediate film onto which the pattern has been transferred as a mask, the pattern is transferred to the organic film by etching. Since the silicon-containing resist intermediate film exhibits etching resistance to oxygen gas or hydrogen gas, the etching of the organic film performed using the silicon-containing resist intermediate film pattern as a mask is preferably performed using an etching gas mainly composed of oxygen gas or hydrogen gas. Thereby, an organic film pattern is formed.

[0166] Next, using the organic film onto which the pattern has been transferred as a mask, the pattern is transferred to the workpiece by etching. The etching of the next workpiece (processed layer) can be performed by a conventional method. For example, if the workpiece is SiO 2 , SiN, or a silica-based low dielectric constant insulating film, etching mainly using a fluorocarbon-based gas is performed. If it is p-Si, Al, or W, etching mainly using a chlorine-based or bromine-based gas is performed. When the substrate processing is performed by etching with a fluorocarbon-based gas, the silicon-containing resist intermediate film pattern is peeled off simultaneously with the substrate processing. On the other hand, when the substrate processing is performed by etching with a chlorine-based or bromine-based gas, in order to peel off the silicon-containing resist intermediate film pattern, it is necessary to separately perform dry etching peeling with a fluorocarbon-based gas after the substrate processing.

[0167] The organic film obtained by using the composition for forming an organic film of the present invention can be made excellent in etching resistance during etching of the workpiece as described above.

[0168] [Four-layer resist process using a silicon-containing resist intermediate film and an organic antireflection film or adhesion film] Further, in the present invention, an organic film is formed on a workpiece using the composition for forming an organic film of the present invention described above. A resist intermediate film is formed on the organic film using a resist intermediate film material containing a silicon atom. An organic antireflection film or adhesion film is formed on the resist intermediate film. The organic antireflection film or adhesion film An upper resist film is formed on the upper layer using a resist upper layer film material composed of a photoresist composition. A circuit pattern is formed on the upper resist film. Using the upper resist film on which the circuit pattern is formed as a mask, the organic antireflection filmor adhesion film A pattern formation method is provided, which transfers a pattern to the resist intermediate film by etching, transfers a pattern to the organic film by etching using the resist intermediate film with the transferred pattern as a mask, and further transfers a pattern to the workpiece by etching using the organic film with the transferred pattern as a mask.

[0169] In addition, this method can be carried out in the same manner as the three-layer resist process using the above-mentioned silicon-containing resist intermediate film, except that an organic anti-reflection film (BARC) or an adhesion film is formed between the resist intermediate film and the resist upper layer film.

[0170] The organic anti-reflection film and the adhesion film can be formed by spin coating using known organic anti-reflection film materials.

[0171] [Three-layer resist process using an inorganic hard mask] In addition, in the present invention, as a pattern formation method by a three-layer resist process using the above-mentioned composition for forming an organic film of the present invention, an organic film is formed on a workpiece using the above-mentioned composition for forming an organic film of the present invention, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the organic film, a resist upper layer film is formed on the inorganic hard mask using a resist upper layer film material composed of a photoresist composition, a circuit pattern is formed on the resist upper layer film, a pattern is transferred to the inorganic hard mask by etching using the resist upper layer film with the formed circuit pattern as a mask, a pattern is transferred to the organic film by etching using the inorganic hard mask with the transferred pattern as a mask, and further a pattern is transferred to the workpiece by etching using the organic film with the transferred pattern as a mask.

[0172] In addition, this method can be carried out in the same manner as the three-layer resist process using the above-mentioned silicon-containing resist intermediate film, except that an inorganic hard mask is formed on the organic film instead of the resist intermediate film.

[0173] Inorganic hard masks selected from silicon oxide films, silicon nitride films, and silicon oxynitride films (SiON films) can be formed by methods such as CVD and ALD. As a method for forming a silicon nitride film, for example, it is described in Japanese Patent Application Laid-Open No. 2002-334869, International Publication No. 2004 / 066377, etc. The film thickness of the inorganic hard mask is preferably 5 to 200 nm, more preferably 10 to 100 nm. As the inorganic hard mask, a SiON film having a high effect as an antireflection film is most preferably used. Since the substrate temperature when forming the SiON film is 300 to 500 °C, the lower layer film needs to withstand a temperature of 300 to 500 °C. The organic film formed using the composition for forming an organic film of the present invention has high heat resistance and can withstand a high temperature of 300 °C to 500 °C. Therefore, a combination of an inorganic hard mask formed by CVD or ALD and an organic film formed by spin coating is possible.

[0174] [Four-Layer Resist Process Using Inorganic Hard Mask and Organic Antireflection Film] Further, in the present invention, as a pattern formation method by a four-layer resist process using the above-described composition for forming an organic film of the present invention, an organic film is formed on a workpiece using the above-described composition for forming an organic film of the present invention, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the organic film, an organic antireflection film or an adhesion film is formed on the inorganic hard mask, a resist upper layer film is formed on the organic antireflection film or the adhesion film using a resist upper layer film material made of a photoresist composition, a circuit pattern is formed on the resist upper layer film, the organic antireflection film or the adhesion film and the inorganic hard mask are etched to transfer the pattern using the resist upper layer film on which the circuit pattern is formed as a mask, the organic film is etched to transfer the pattern using the inorganic hard mask on which the pattern is transferred as a mask, and further, the workpiece is etched to transfer the pattern using the organic film on which the pattern is transferred as a mask. A pattern formation method is provided.

[0175] Note that this method can be carried out in the same manner as the above-described three-layer resist process using the inorganic hard mask, except that an organic anti-reflection coating (BARC) or an adhesion film is formed between the inorganic hard mask and the upper resist film.

[0176] In particular, when a SiON film is used as the inorganic hard mask, it is possible to suppress reflection even in high-NA immersion lithography exceeding 1.0 by the two-layer anti-reflection films of the SiON film and the BARC. Another merit of forming the BARC is that it has the effect of reducing the pull-off of the upper resist film pattern directly on the SiON film.

[0177] Here, an example of the pattern formation method by the three-layer resist process of the present invention is shown in FIGS. 4(A) to (F). In the case of the three-layer resist process, as shown in FIG. 4(A), after forming the organic film 3 on the processed layer 2 formed on the substrate 1 using the composition for forming an organic film of the present invention, a silicon-containing resist intermediate film 4 is formed, and an upper resist film 5 is formed thereon. Next, as shown in FIG. 4(B), the exposed portion 6 of the upper resist film 5 is exposed, and PEB (post-exposure baking) is performed. Next, as shown in FIG. 4(C), development is carried out to form the upper resist film pattern 5a. Next, as shown in FIG. 4(D), using the upper resist film pattern 5a as a mask, the silicon-containing resist intermediate film 4 is dry-etched using a fluorocarbon gas to form the silicon-containing resist intermediate film pattern 4a. Next, as shown in FIG. 4(E), after removing the upper resist film pattern 5a, the organic film 3 is oxygen plasma-etched using the silicon-containing resist intermediate film pattern 4a as a mask to form the organic film pattern 3a. Further, as shown in FIG. 4(F), after removing the silicon-containing resist intermediate film pattern 4a, the processed layer 2 is etched using the organic film pattern 3a as a mask to form the pattern 2a.

[0178] When forming an inorganic hard mask, the silicon-containing resist intermediate film 4 may be changed to an inorganic hard mask. When forming a BARC or an adhesion film, a BARC or an adhesion film may be formed between the silicon-containing resist intermediate film 4 and the resist upper layer film 5. The etching of the BARC may be performed continuously prior to the etching of the silicon-containing resist intermediate film 4, or the etching of only the BARC may be performed and then the etching of the silicon-containing resist intermediate film 4 may be performed after changing the etching apparatus or the like.

[0179] As described above, according to the pattern forming method of the present invention, a fine pattern can be formed on a workpiece with high precision by a multilayer resist process.

Example

[0180] Hereinafter, the present invention will be described more specifically by showing synthesis examples, comparative synthesis examples, examples, and comparative examples, but the present invention is not limited thereto. In addition, the weight loss rate between 30 °C and 350 °C was determined by performing TG (thermogravimetric) measurement using a differential thermal balance under an air approximate atmosphere (oxygen 20 vol%: nitrogen 80 vol%) at a heating rate of 10 °C / min.

[0181] [Preparation of Composition for Forming Organic Film (UDL-1 to 45, Comparative UDL-1 to 17)] The planarizing agents (A1) to (A12) for forming an organic film, comparative additives (a1) to (a8), resins (B1) to (B6) for forming an organic film, and solvents (C-1) to (C-2) used for preparing the composition for forming an organic film are shown below.

[0182] [Planarizing Agent for Forming Organic Film] A1: Compound represented by the following formula (A-1) A2: Compound represented by the following formula (A-2) A3: Compound represented by the following formula (A-3) A4: Compound represented by the following formula (A-4) A5: Compound represented by the following formula (A-5) A6: Compound represented by the following formula (A-6) A7: A compound represented by the following formula (A-7) A8: A compound represented by the following formula (A-8) A9: A compound represented by the following formula (A-9) A10: A compound represented by the following formula (A-10) A11: A compound represented by the following formula (A-11) A12: A compound represented by the following formula (A-12)

[0183] [Comparative additive] a1: A compound represented by the following formula (a-1) a2: A compound represented by the following formula (a-2) a3: A compound represented by the following formula (a-3) a4: A compound represented by the following formula (a-4) a5: A compound represented by the following formula (a-5) a6: A compound represented by the following formula (a-6) a7: A compound represented by the following formula (a-7) a8: A compound represented by the following formula (a-8) Table 1 shows the structural formula, molecular weight (MW), and weight loss rate (from 30°C to 190°C and from 30°C to 350°C) of the above compound.

[0184] [Table 1]

[0185] [Resin for forming organic film] B1: A resin represented by the following formula (B-1) B2: A resin represented by the following formula (B-2) B3: A resin represented by the following formula (B-3) B4: A resin represented by the following formula (B-4) B5: A resin represented by the following formula (B-5) B6: A resin represented by the following formula (B-6)

[0186] [Chemical formula]

[0187] [Solvent] C-1: Propylene Glycol Monomethyl Ether Acetate C-2: Propylene Glycol Monoethyl Ether

[0188] The planarizing agents (A1) to (A12) for forming an organic film, comparative additives (a1) to (a8), and resins (B1) to (B6) for forming an organic film were dissolved in a solvent containing 0.5% by mass of FC-4430 (manufactured by Sumitomo 3M Limited) at the ratios shown in Table 2, and filtered through a 0.1-μm fluororesin filter to prepare organic film materials (organic film-forming compositions: UDL-1 to 45, ratio Comparison U DL-1 to 17), respectively. The numbers in the table are parts by mass.

[0189]

Table 2

[0190] [Solvent Resistance Measurement: Examples 1-1 to 1-45, Comparative Examples 1-1 to 1-17] The organic film-forming compositions (UDL-1 to 45, comparative UDL 1-1 to 1-17) prepared above were applied onto a silicon substrate, baked under the following conditions using a hot plate, then the film thickness was measured. After that, PGMEA solvent was dispensed thereon, left for 30 seconds, spin-dried, baked at 100 °C for 60 seconds to evaporate PGMEA, and the film thickness was measured again. Let the film thickness before dispensing PGMEA solvent be X, and the film thickness after dispensing PGMEA solvent be X 1 Then, the absolute value of the value obtained by (X 1 -X) / X×100 was defined as the film thickness change rate (%). When the film thickness change rate was less than 0.5%, it was considered good; when it was 0.5% or more, it was considered bad. (Baking Conditions) Baked at 180 °C for 60 seconds (first baking), and further baked at 350 °C for 60 seconds (second baking).

[0191] [In-plane Uniformity Measurement: Examples 1-1 to 1-45, Comparative Examples 1-1 to 1-17] The organic film-forming compositions (UDL-1 to 45, comparative UDL(1-1 to 1-17) was applied onto a silicon substrate, fired under the above firing conditions using a hot plate, and then the film thickness was measured. The maximum value X of the film thickness max , the minimum value X of the film thickness min , and the average film thickness X average were defined as (X max - X min ) / X average , and the value obtained was defined as the in-plane uniformity (%). When the in-plane uniformity was less than 2%, it was considered good; when it was 2% or more, it was considered bad.

[0192] [Embedding evaluation: Examples 1-1 to 1-45, Comparative Examples 1-1 to 1-17] As shown in FIG. 5, each of the above-described composition for forming an organic film was applied onto a SiO 2 wafer substrate having a dense hole pattern (hole diameter: 0.16 μm, hole depth: 0.50 μm, distance between the centers of two adjacent holes: 0.32 μm), and fired under the above firing conditions to form an organic film 8. The substrate used was a base substrate (SiO 2 wafer substrate) 7 having a dense hole pattern as shown in FIGS. 5(G) (plan view) and 5(H) (cross-sectional view). The cross-sectional shape of each obtained wafer substrate was observed using a scanning electron microscope (SEM) to confirm whether the holes were filled with an organic film without voids (gaps) inside the holes. When a composition for forming an organic film with poor embedding characteristics was used, voids were generated inside the holes. When a composition for forming an organic film with good embedding characteristics was used, in this evaluation, as shown in FIG. 5(I), the holes were filled with an organic film without voids. When no voids were generated, it was considered good; when voids were generated, it was considered bad.

[0193] [Defect evaluation after coating: Examples 1-1 to 1-45, Comparative Examples 1-1 to 1-17] The composition for forming an organic film (UDL-1 to 45, Comparative UDL-1 to 17) prepared above was applied onto a silicon substrate, fired under the above firing conditions, and then the number of defects was confirmed using an SP5 (defect inspection device) manufactured by KLA-TENCOR. When the number of defects was less than 30, it was considered good; when it was 30 or more, it was considered bad.

[0194]

Table 3

[0195] As shown in Table 3, the organic films (UDL-1 to 45) using the planarizing agent for forming an organic film of the present invention are excellent in solvent resistance, in-plane uniformity, embedding property, and coating after defect number. On the other hand, in Comparative Examples 1-15 to 1-17 using Comparative UDL-15 to 17 containing Comparative Additives a6 to a8 outside the scope of the present invention as the organic film-forming composition, the defect evaluation after coating was poor or a coating film could not be formed. Therefore, the following evaluations were not performed for Comparative UDL-15 to 17. Note that Comparative UDL-15 containing Comparative Additive a6 does not have a temperature range in which its complex viscosity becomes less than 1.0 Pa·s in the temperature range of 175°C or higher.

[0196] [Measurement of complex viscosity: Examples 2-1 to 2-45, Comparative Examples 2-1 to 2-14] The complex viscosity of the above-described composition for forming an organic film (UDL-1 to 45, Comparative UDL-1 to 14) was measured using an Anton Paar MCR rheometer MCR302. When measuring, a measuring jig with an outer diameter of 20 mm was used, and the complex viscosity from 50°C to 300°C was measured at a strain of 1%, a frequency of 1 Hz, and a heating rate of 5°C / min. FIG. 1 is a graph showing the measurement results of the complex viscosity of the pre-composition for forming an organic film (Comparative UDL-1) that does not contain a planarizing agent for forming an organic film. According to the measurement results in FIG. 1, in the range where the heating temperature is 50°C to 74°C, the complex viscosity is less than 1.0 Pa·s, and a relatively low-viscosity state continued. After the heating temperature exceeded 75°C, it was suggested that the complex viscosity exceeded 1.0 Pa·s and increased rapidly, resulting in a decrease in thermal fluidity. FIG. 2 is a graph showing the measurement results of the complex viscosity of the composition for forming an organic film (UDL-1). A relatively low-viscosity state where the complex viscosity is less than 1.0 Pa·s continued from 50°C to 179°C, and the complex viscosity increased rapidly after exceeding 180°C. Since UDL-1 has a configuration in which a planarizing agent A2 for forming an organic film is blended with Comparative UDL-1, by adding the planarizing agent A2 for forming an organic film, in the temperature range where the heating temperature is 175°C or higher, a temperature range of 175°C to 179°C where the complex viscosity is less than 1.0 Pa·s occurred. Table 4 shows the temperature range in which the complex viscosity of the composition for forming an organic film (UDL-1) to (UDL-45), (Comparative UDL-1) to (Comparative UDL-14) measured in this way is less than 1.0 Pa·s, and the temperature range of 175°C or higher where the complex viscosity became less than 1.0 Pa·s by adding an organic film planarizing agent.

[0197] [Table 4]

[0198] As shown in Table 4, the planarizing agent for forming an organic film of the present invention generates a temperature range in which the complex viscosity is less than 1.0 Pa·s in the temperature range of 175°C or higher.

[0199] [Planarization property evaluation: Examples 3-1 to 3-46, Comparative Examples 3-1 to 3-14] Each of the above-described organic film-forming compositions (UDL-1 to 45, Comparative UDL-1 to 14) was applied onto a lower base substrate 9 (SiO 2 wafer substrate) having a large isolated trench pattern (Figure 6(J), trench width 50 μm, trench depth 0.115 μm), baked under the baking conditions described in Table 5, and then the step difference (delta10 in Figure 6(K)) of the organic film 10 between the trench portion and the non-trench portion was observed using an Alpha-Step D-600 (contact profilometer) manufactured by KLA-TENCOR Corporation. The results are shown in Table 5. In this evaluation, it can be said that the smaller the step difference, the better the planarization characteristics. In this evaluation, a trench pattern with a depth of 0.115 μm (115 nm) was planarized by forming an organic film with a normal film thickness of about 0.2 μm (200 nm) using the organic film-forming composition, and special and strict evaluation conditions are set to evaluate the superiority or inferiority of the planarization characteristics.

[0200]

Table 5

[0201] As shown in Table 5, in Examples 3-1 to 3-46 using the organic film-forming composition (UDL-1 to 45) of the present invention, compared with Comparative Examples 3-1 to 3-14 using the comparative organic film-forming composition (Comparative UDL-1 to 14), the step difference between the organic films in the trench portion and the non-trench portion is smaller, indicating excellent planarization characteristics.

[0202] [Pattern Formation Test: Examples 4-1 to 4-46] Each of the above-described organic film-forming compositions (UDL-1 to 45) was applied onto SiO having a trench pattern (trench width 10 μm, trench depth 0.1 μm) 2It was applied onto a wafer substrate and baked under the baking conditions described in Table 8 to form an organic film. On top of that, the following silicon-containing resist intermediate film material (SOG1) was applied and baked at 200 °C for 60 seconds to form a silicon-containing resist intermediate film with a film thickness of 35 nm. On top of that, the following single-layer resist for ArF was applied as the resist upper layer film material and baked at 105 °C for 60 seconds to form a photoresist film with a film thickness of 100 nm. On top of the photoresist film, the following immersion protective film material (TC-1) was applied and baked at 90 °C for 60 seconds to form a protective film with a film thickness of 50 nm.

[0203] As the silicon-containing resist intermediate film material (SOG1), a 2% solution of the following polymer in propylene glycol ethyl ether was prepared.

Chemical formula

[0204] As the resist upper layer film material (single-layer resist for ArF), the polymer (RP1), the acid generator (PAG1), and the basic compound (Amine1) were dissolved in a solvent containing 0.1 mass% of FC-430 (manufactured by Sumitomo 3M Limited) 6 at the ratios shown in the table and filtered through a 0.1-μm fluororesin filter.

Table 6

[0205] The polymer (RP1), the acid generator (PAG1), and the basic compound (Amine1) are shown below.

Chemical formula

[0206] As the immersion protective film material (TC-1), the polymer (PP1) was dissolved in an organic solvent 7 at the ratios shown in the table and filtered through a 0.1-μm fluororesin filter.

Table 7

[0207] The polymer (PP1) is shown below.

Chemical formula

[0208] Next, it was exposed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA1.30, σ0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% halftone phase shift mask), baked at 100 °C for 60 seconds (PEB), developed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) for 30 seconds, and a 55 nm 1:1 positive line-and-space pattern (resist upper layer film pattern) was obtained.

[0209] Next, using the resist upper layer film pattern as a mask, the silicon-containing resist intermediate film was dry-etched (pattern transfer) using the etching apparatus Telius manufactured by Tokyo Electron. Using the obtained silicon-containing resist intermediate film pattern as a mask, the organic film was dry-etched (pattern transfer). Using the obtained organic film pattern as a mask, the SiO 2 wafer substrate (SiO 2 film) was dry-etched (pattern transfer). The etching conditions are as shown below.

[0210] (Transfer conditions of the resist upper layer film pattern to the silicon-containing resist intermediate film) Chamber pressure 10.0 Pa RF power 1,500 W CF 4 Gas flow rate 75 mL / min O 2 Gas flow rate 15 mL / min Time 15 sec

[0211] (Transfer conditions of the silicon-containing resist intermediate film pattern to the organic film) Chamber pressure 2.0 Pa RF power 500 W Ar gas flow rate: 75 mL / min O 2 Gas flow rate: 45 mL / min Time: 120 sec

[0212] (Transfer conditions of the organic film pattern to the SiO 2 wafer substrate) Chamber pressure: 2.0 Pa RF power: 2,200 W C 5 F 12 Gas flow rate: 20 mL / min C 2 F 6 Gas flow rate: 10 mL / min Ar gas flow rate: 300 mL / min O 2 Gas flow rate: 60 mL / min Time: 90 sec

[0213] The cross-section of the obtained pattern was observed with an electron microscope (S-4700) manufactured by Hitachi, Ltd., and the results are shown in Table 8.

[0214]

Table 8

[0215] As shown in Table 8, in Examples 4-1 to 4-46 using the composition for forming an organic film (UDL-1 to 45) of the present invention, the resist upper layer film pattern was finally successfully transferred to the SiO 2 wafer substrate. It was confirmed that the composition for forming an organic film of the present invention is suitably used for microfabrication by the multilayer resist method even on a substrate having a step.

[0216] From the above, the composition for forming an organic film of the present invention containing the planarizing agent for forming an organic film of the present invention has excellent planarizing characteristics, and thus is extremely useful as an organic film material used in a multilayer resist process. Further, it has been clarified that in the pattern forming method of the present invention using this composition, even if the object to be processed is a substrate having steps, a fine pattern can be formed with high precision.

[0217] Note that the present invention is not limited to the above-described embodiment. The above-described embodiment is an example, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

Explanation of Reference Numerals

[0218] 1... Substrate, 2... Layer to be processed, 2a... Pattern formed on the layer to be processed 3... Organic film, 3’... Composition for forming an organic film, 3a... Organic 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... Lower substrate having a dense hole pattern, 8... Organic film 9... Lower substrate having a large isolated trench pattern, 10... Organic film delta10... Difference in film thickness of the organic film between the trench portion and the non-trench portion.

Claims

1. A planarizing agent for forming an organic film, wherein the planarizing agent for forming an organic film is composed of one or more aromatic-containing compounds selected from the following general formulas (I) and (II) and having a molecular weight of 200 to 500 represented by a molecular formula, wherein the planarizing agent for forming an organic film is blended into a composition containing an organic film-forming resin and a solvent having a complex viscosity of 1.0 Pa·s or more in a temperature range of 175°C or higher, whereby the composition has a temperature range in which the complex viscosity is less than 1.0 Pa·s in a temperature range of 175°C or higher. A planarizing agent for forming an organic film, characterized in that. 【Chemical 1】 (In the formula, each R 1 is independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms. W 1 is a phenylene group or a divalent group represented by the following general formula (I-1). W 2 and W 3 are each a single bond or any of the divalent groups represented by the following general formula (I-2). m 1 is an integer of 2 to 10, and n 1 is independently an integer of 0 to 5.) 【Chemical Formula 2】 (In the formula, * indicates the bonding position, and R 10, R 11, R 12, and R 13 are a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. W 10 and W 11 are each independently a single bond or a carbonyl group. m 10 and m 11 are integers of 0 to 10, and m 10 + m 11 ≧ 1.) 【Chemical Formula 3】 (In the formula, * indicates the bonding position.) 【Chemical Formula 4】 (In the formula, each R 2 is independently a hydrogen atom or an optionally substituted organic group having 1 to 10 carbon atoms. W 4 is a divalent group represented by the following general formula (II-1). W 5 is a single bond or any of the divalent groups represented by the following general formula (II-2). m 2 is an integer of 5 to 10, and n 3 is an integer of 0 to 5.) 【Chemical Formula 5】 (In the formula, * indicates the bonding position, and R 20, R 21, R 22, and R 23 are a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. m 20 and m 21 are integers of 0 to 10, and m 20 + m 21 ≧ 1.) 【Chemical Formula 6】 (In the formula, * indicates the bonding position.)

2. The planarizing agent for forming an organic film according to claim 1, wherein the planarizing agent for forming an organic film is an aromatic-containing compound having any of the following benzyl groups or benzoyl groups (i) to (vii). (i) (Poly)ethylene glycol dibenzoate (ii) (Poly)ethylene glycol dibenzyl ether (iii) (Poly)propylene glycol dibenzyl ether (iv) (Poly)butylene glycol dibenzyl ether (v) Linear aliphatic dicarboxylic acid dibenzyl (vi) (Poly)ethylene glycol monobenzyl ether (vii) (Poly)phenyl ether 【Chemical Formula 7】 (In the above formula, n is an integer in the range of 200 to 500 in terms of molecular weight.)

3. An organic film-forming composition, characterized by comprising an organic film-forming resin, the organic film-forming planarizing agent according to Claim 1 or Claim 2, and a solvent.

4. The organic film-forming composition according to Claim 3, wherein the organic film-forming resin has an aromatic skeleton.

5. The organic film-forming composition according to Claim 3 or Claim 4, further characterized in that the skeleton of the organic film-forming resin is any one of benzene, naphthalene, and fluorene.

6. A method for forming an organic film that functions as an organic planarizing film used in a semiconductor device manufacturing process, comprising spin-coating the organic film-forming composition according to any one of Claims 3 to 5 on a substrate to be processed, and heat-treating the substrate coated with the organic film-forming composition at a temperature of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film.

7. A method for forming an organic film that functions as an organic planarizing film used in a semiconductor device manufacturing process, comprising spin-coating an organic film-forming composition containing an organic film-forming resin, an organic film-forming planarizing agent, and a solvent on a substrate to be processed, heat-treating the substrate coated with the organic film-forming composition at a temperature of 100°C or higher and 350°C or lower for 10 to 600 seconds, and further heat-treating at a temperature of 100°C or higher and 600°C or lower for 10 to 600 seconds to form a cured film. The organic film-forming planarizing agent is composed of an aromatic-containing compound having a molecular weight of 200 to 500 represented by a molecular formula, and the organic film-forming planarizing agent is blended into a composition containing an organic film-forming resin and a solvent having a complex viscosity of 1.0 Pa·s or more in a temperature range of 175°C or higher, so that the composition has a temperature range in which the complex viscosity is less than 1.0 Pa·s in a temperature range of 175°C or higher.

8. The method for forming an organic film according to claim 6 or claim 7, wherein a workpiece substrate having a structure or step with a height of 20 nm or more is used as the workpiece substrate.

9. An organic film is formed on a workpiece using the composition for forming an organic film according to any one of claims 3 to 5, a resist intermediate film is formed on the organic film using a resist intermediate film material containing a silicon atom, a resist upper layer film is formed on the resist intermediate film using a resist upper layer film material composed of a photoresist composition, a circuit pattern is formed on the resist upper layer film, the resist intermediate film is etched to transfer the pattern using the resist upper layer film on which the circuit pattern is formed as a mask, the organic film is etched to transfer the pattern using the resist intermediate film on which the pattern is transferred as a mask, and further, the workpiece is etched to transfer the pattern using the organic film on which the pattern is transferred as a mask. A pattern forming method characterized by the above.

10. An organic film is formed on a workpiece using the composition for forming an organic film according to any one of claims 3 to 5, a resist intermediate film is formed on the organic film using a resist intermediate film material containing a silicon atom, an organic antireflection film or an adhesion film is formed on the resist intermediate film, a resist upper layer film is formed on the organic antireflection film or the adhesion film using a resist upper layer film material composed of a photoresist composition, a circuit pattern is formed on the resist upper layer film, the organic antireflection film or the adhesion film and the resist intermediate film are etched to transfer the pattern using the resist upper layer film on which the circuit pattern is formed as a mask, the organic film is etched to transfer the pattern using the resist intermediate film on which the pattern is transferred as a mask, and further, the workpiece is etched to transfer the pattern using the organic film on which the pattern is transferred as a mask. A pattern forming method characterized by the above.

11. An organic film is formed on a workpiece using the composition for forming an organic film according to any one of claims 3 to 5. An inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the organic film. A resist upper layer film is formed on the inorganic hard mask using a resist upper layer film material composed of a photoresist composition. A circuit pattern is formed on the resist upper layer film. The inorganic hard mask is etched to transfer the pattern using the resist upper layer film on which the circuit pattern is formed as a mask. The organic film is etched to transfer the pattern using the inorganic hard mask on which the pattern is transferred as a mask. Further, the workpiece is etched to transfer the pattern using the organic film on which the pattern is transferred as a mask. A pattern forming method characterized by the above.

12. An organic film is formed on a workpiece using the composition for forming an organic film according to any one of claims 3 to 5. An inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the organic film. An organic antireflection film or an adhesion film is formed on the inorganic hard mask. A resist upper layer film is formed on the organic antireflection film or the adhesion film using a resist upper layer film material composed of a photoresist composition. A circuit pattern is formed on the resist upper layer film. The organic antireflection film or the adhesion film and the inorganic hard mask are etched to transfer the pattern using the resist upper layer film on which the circuit pattern is formed as a mask. The organic film is etched to transfer the pattern using the inorganic hard mask on which the pattern is transferred as a mask. Further, the workpiece is etched to transfer the pattern using the organic film on which the pattern is transferred as a mask. A pattern forming method characterized by the above.

13. The pattern forming method according to claim 11 or claim 12, characterized in that the formation of the inorganic hard mask is performed by a CVD method or an ALD method.

14. In the formation of 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 drawing by an electron beam, nanoimprinting, or a combination thereof. The pattern forming method according to any one of claims 9 to 13.

15. The pattern forming method according to any one of claims 9 to 14, wherein in the formation of the circuit pattern, the circuit pattern is developed with an alkali developer or an organic solvent.

16. The pattern forming method according to any one of claims 9 to 15, wherein the workpiece is a semiconductor device substrate or a substrate having a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxynitride film, or a metal oxycarbide film formed thereon.

17. The pattern forming 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.

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