Method for forming a resist underlayer film and method for forming a pattern

Abstract

To provide: a method for forming a resist underlayer film that contains metal and that exhibits both a high filling property and high dry etching resistance; and a patterning method using the same.SOLUTION: A method for forming a resist underlayer film includes the steps of: (i) a coating step of coating a substrate with a composition for forming a resist underlayer film containing a metal compound having a metal-oxygen covalent bond and an organic solvent; (ii) a step of forming a cured film by heat treatment of the coated substrate at a temperature from 100°C to 600°C inclusive for 10 to 7,200 seconds for curing; and (iii) forming a resist underlayer film by irradiating the cured film with plasma. A compound comprising at least one crosslinking group represented by specific general formulas such as general formulas (a-1) to (a-4) in the figure is used as the metal compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for forming a resist underlayer film and a method for forming a pattern. [Background technology]

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern dimensions is progressing rapidly. Lithography technology has achieved the formation of fine patterns in line with this miniaturization by shortening the wavelength of the light source and appropriately selecting the resist composition. At the heart of this is the single-layer positive photoresist composition. This single-layer positive photoresist composition has a framework in the resist resin that is resistant to dry etching with chlorine-based or fluorine-based gas plasma, and also has a switching mechanism that causes the exposed area to dissolve, thereby forming a pattern by dissolving the exposed area, and the remaining resist pattern is used as an etching mask to dry etch the substrate to be processed.

[0003] However, when the thickness of the photoresist film used was kept the same while miniaturization was achieved, i.e., the pattern width was reduced, the resolution performance of the photoresist film decreased. Furthermore, when attempting to develop the photoresist film using a developer, the aspect ratio became too large, resulting in pattern collapse. For this reason, as patterns became smaller, the photoresist film was made thinner.

[0004] On the other hand, the processing of substrates typically involves using a photoresist film with a pattern formed on it as an etching mask and processing the substrate by dry etching. However, in reality, there is no dry etching method that can achieve complete etching selectivity between the photoresist film and the substrate. As a result, the photoresist film is damaged and disintegrates during substrate processing, making it impossible to accurately transfer the resist pattern to the substrate. Therefore, with the miniaturization of patterns, high dry etching resistance has been required for the resist composition. However, at the same time, in order to improve resolution, resins with low light absorption at the exposure wavelength have been required for the resins used in the photoresist composition. Therefore, as the exposure light has become shorter in wavelength, from i-line to KrF and ArF, the resins have also changed to novolac resins, polyhydroxystyrene, and resins with aliphatic polycyclic skeletons. However, in reality, the etching rate under dry etching conditions during substrate processing has become fast, and recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] This necessitates dry etching of substrates using thinner photoresist films with weaker etching resistance, making the securing of materials and processes for this manufacturing stage a matter of urgency.

[0006] One way to solve these problems is the multilayer resist method. In this method, a photoresist film (i.e., a resist upper layer) and a resist lower layer film with different etching selectivity are interposed between the resist upper layer film and the substrate to be processed. After obtaining a pattern on the resist upper layer film, the resist upper layer film pattern is used as a dry etching mask to transfer the pattern to the resist lower layer film by dry etching, and then the resist lower layer film is used as a dry etching mask to transfer the pattern to the substrate to be processed by dry etching.

[0007] One multilayer resist method is the three-layer resist method, which can be performed using the same resist compositions as those used in the single-layer resist method. In this three-layer resist method, for example, an organic film made of novolac resin or the like is deposited on the substrate to be processed as the resist underlayer, a silicon-containing resist interlayer is deposited on top of that as the resist interlayer, and a normal organic photoresist film is formed on top of that as the resist upper layer. When dry etching is performed using a fluorine-based gas plasma, the organic resist upper layer has a good etching selectivity ratio compared to the silicon-containing resist interlayer, so the resist upper layer pattern can be transferred to the silicon-containing resist interlayer by dry etching with a fluorine-based gas plasma. With this method, even if a resist composition that does not have sufficient thickness to form a pattern for direct processing of the substrate or a resist composition that does not have sufficient dry etching resistance for substrate processing is used, the pattern can be transferred to the silicon-containing resist interlayer (resist interlayer), and then by performing pattern transfer by dry etching with an oxygen-based or hydrogen-based gas plasma, a pattern of an organic film (resist underlayer) made of novolac resin or the like with sufficient dry etching resistance for substrate processing can be obtained. Many types of resist underlayer films, such as those described in Patent Document 1, are already known.

[0008] On the other hand, in recent years, the miniaturization of DRAM memory has accelerated, and the need for further improvements in dry etching resistance and resist underlayers with excellent embedding and planarization properties has increased. Examples of coated resist underlayer materials with excellent embedding and planarization properties include those described in Patent Document 2. Furthermore, Patent Document 3 reports that the dry etching resistance of resist underlayer materials can be improved by plasma irradiation, electron beam, and / or ion irradiation. However, when considering applications in the advanced generation, there are concerns about the dry etching resistance of resist underlayer materials, and the applicability limits of conventional coated resist underlayer materials are approaching.

[0009] In response to the above problems, the development of using a material containing a metal element for the resist underlayer film has been studied. In Patent Document 4, it is reported that a material using a Ti compound exhibits excellent dry etching resistance against CHF3 / CF4-based gases and CO2 / N2-based gases.

[0010] On the other hand, when using a metal compound for the resist underlayer film, an issue is the embedding property. Although Patent Document 4 does not mention the embedding property, generally, metal compounds have a large thermal shrinkage during baking and induce a significant deterioration in filling property after high-temperature baking. Therefore, there is a concern that they are insufficient as a resist underlayer film material that requires high planarization characteristics, embedding characteristics, and heat resistance.

[0011] In Patent Documents 5 and 6, it is reported that a metal compound modified with a specific ligand has excellent embedding property. However, the baking temperature for the embedding property evaluation carried out is as low as 150°C, and there is a concern that it is insufficient as a resist underlayer film that requires heat resistance (for example, characteristics against heat treatment that may be applied after forming the resist underlayer film).

Prior Art Documents

Patent Documents

[0012]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0013] This invention has been made in view of the above circumstances, and aims to provide a method for forming a resist underlayer film containing a metal that achieves a high level of both embedding ability and dry etching resistance, and a method for forming a pattern using the same. [Means for solving the problem]

[0014] To solve the above problems, the present invention provides a method for forming a resist underlayer film, (i) A coating step of applying a resist underlayer film formation composition comprising a metal compound having a metal-oxygen covalent bond and an organic solvent to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, The present invention provides a method for forming a resist underlayer film using a metal compound that contains at least one crosslinking group represented by the following general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3). [ka] (In general formulas (a-1) to (a-4), R a (where is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) [ka] (In general formulas (b-1) to (b-4), R b R is a hydrogen atom or a methyl group, and in the same formula they may be the same or different from each other. c (where * represents a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bond.) [ka] (In general formulas (c-1) to (c-3), Y1 is a divalent organic group having 1 to 20 carbon atoms, R is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated divalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and R1 is an organic group whose protecting group is removed by the action of either or both of the following general formula (1) and / or heat, generating one or more hydroxyl or carboxyl groups, and * represents a bond.) [ka] (In general formula (1), R2 is an organic group whose protecting group is removed by the action of acid, heat, or both, and * represents the bond with Y1.)

[0015] This resist underlayer formation method significantly improves the dry etching resistance of metal-containing materials with excellent embedding properties, making it possible to form a resist underlayer containing metal that achieves a high level of both embedding and dry etching resistance, which was difficult to achieve with conventional techniques.

[0016] Furthermore, in the present invention, it is preferable to use N2, NF3, H2, fluorocarbons, noble gases, or a mixture of any of these gases in step (iii).

[0017] By irradiating the resist with plasma using such a gas, it is possible to improve the dry etching resistance without impairing the embedding properties of the resist underlayer film.

[0018] At this time, it is preferable to use a gas containing H2 gas in step (iii) above.

[0019] By irradiating the resist with a plasma using a gas containing H2 gas, the dry etching resistance can be further improved without impairing the embedding properties of the resist underlayer film.

[0020] At this time, it is preferable to use a gas containing helium gas in step (iii) above.

[0021] By irradiating the resist with plasma using a gas containing helium, the dry etching resistance can be further improved without compromising the embedding properties of the resist underlayer film.

[0022] Furthermore, in the present invention, it is preferable to form the cured film in step (ii) above by heat treatment in an atmosphere with an oxygen concentration of 1% by volume or more and 21% by volume or less.

[0023] By performing heat treatment at this oxygen concentration, it becomes possible to improve the thermosetting properties of the resist underlayer film, thereby forming a resist underlayer film with excellent dry etching resistance.

[0024] Furthermore, in the present invention, it is preferable to form the cured film in step (ii) above by heat treatment in an atmosphere with an oxygen concentration of less than 1 volume%.

[0025] By performing heat treatment at this oxygen concentration, it becomes possible to suppress oxidation and thermal decomposition of the resist underlayer film, thereby forming a resist underlayer film with excellent embedding properties.

[0026] Furthermore, in the present invention, it is preferable to form a cured film by heat treatment at a temperature of 100°C to 450°C for 10 to 7,200 seconds in step (ii) above.

[0027] By performing heat treatment at such temperatures, it becomes possible to suppress oxidation and thermal decomposition of the resist underlayer film, thereby forming a resist underlayer film with excellent embedding properties.

[0028] Furthermore, in the present invention, it is preferable that the metal contained in the metal compound be titanium, zirconium, hafnium, or a combination thereof.

[0029] By including the above-mentioned metals, the resistance to dry etching during substrate processing can be further improved.

[0030] Furthermore, in the present invention, it is preferable to use a metal compound that further contains a ligand derived from a silicon compound represented by the following general formula (2). [ka] (In general formula (2), R 3A , R 3B and R 3C This is one of the following organic groups: an organic group having 2 to 30 carbon atoms having a bridging group in any of the structures shown by the general formulas (d-1) to (d-3) below; a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; and an aryl group having 6 to 20 carbon atoms. [ka] (In general formulas (d-1) to (d-3), R3 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.)

[0031] If a resist underlayer film formation method using a metal compound containing the aforementioned silicon compound is used, it is possible to form a resist underlayer film with superior embedding properties.

[0032] Furthermore, the present invention provides a method for forming a pattern on a substrate to be processed, (I-1) A step of forming a resist underlayer film on a substrate to be processed using the resist underlayer film formation method described above, (I-2) A step of forming a silicon-containing resist interlayer on the resist underlayer, (I-3) A step of forming a resist upper layer film on the silicon-containing resist interlayer film using a photoresist material, (I-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (I-5) A step of transferring the pattern to the silicon-containing resist interlayer by dry etching, using the resist upper layer on which the pattern is formed as a mask. (I-6) A step of transferring the pattern to the resist underlayer film by dry etching, using the silicon-containing resist interlayer film on which the pattern has been transferred as a mask, and (I-7) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method having the following characteristics.

[0033] The above pattern formation method makes it possible to form fine patterns on a workpiece with high precision.

[0034] Furthermore, the present invention provides a method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer film on a substrate to be processed using the resist underlayer film formation method described above, (II-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film, (II-3) A step of forming an organic thin film on the inorganic hard mask interlayer, (II-4) A step of forming a resist upper layer film on the organic thin film using a photoresist material, (II-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (II-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and (II-8) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method having the following characteristics.

[0035] The above pattern formation method makes it possible to form fine patterns on a workpiece with high precision.

[0036] Furthermore, the present invention provides a method for forming a pattern on a substrate to be processed, (III-1) A step of forming a resist underlayer film on a substrate to be processed using the resist underlayer film formation method described above, (III-2) A step of forming an organic interlayer on the resist underlayer film, (III-3) A step of forming a combination of an organic thin film and an inorganic hard mask interlayer selected from a silicon-containing resist interlayer, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic interlayer. (III-4) A step of forming a resist upper layer film on the silicon-containing resist interlayer film or the organic thin film using a photoresist material, (III-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (III-6) A step of transferring the pattern to the silicon-containing resist interlayer or the organic thin film and the inorganic hard mask interlayer by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (III-7) A step of transferring the pattern to the organic interfilm by dry etching, using the silicon-containing resist interfilm or inorganic hard mask interfilm on which the pattern has been transferred as a mask. (III-8) A step of transferring the pattern to the resist underlayer film by dry etching using the organic interlayer film on which the pattern has been transferred as a mask, and (III-9) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method having the following characteristics.

[0037] The above pattern formation method makes it possible to form fine patterns on a workpiece with high precision.

[0038] Furthermore, the present invention provides a method for forming a resist underlayer film, (i') A coating step of applying a resist underlayer film formation composition containing metals belonging to the 3rd to 7th periods of Groups 3 to 15 of the periodic table to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, The present invention provides a method for forming a resist underlayer film comprising the above.

[0039] This method for forming a resist underlayer film significantly improves the dry etching resistance of metal-containing materials, and enables the formation of a resist underlayer film that achieves a high level of both embedding and dry etching resistance, which was difficult to achieve with conventional techniques.

[0040] In this case, it is preferable to use a composition for forming the resist underlayer film that contains a metal compound having a metal-oxygen covalent bond or a metal compound having a metal-carbon covalent bond.

[0041] This method for forming a resist underlayer film makes it possible to create a resist underlayer film that achieves a high level of both embedding ability and dry etching resistance, which was difficult to achieve with conventional techniques. [Effects of the Invention]

[0042] As described above, the resist underlayer film formation method and pattern formation method of the present invention are particularly suitable for use in multilayer resist processes, including embedding / planarization of workpiece substrates with steps and irregularities, and are extremely useful in fine patterning for semiconductor device manufacturing. In particular, in fine patterning processes using multilayer resist methods in semiconductor device manufacturing processes, even on workpiece substrates that have areas that are difficult to embed / planarize, such as densely packed areas of high aspect ratio fine pattern structures represented by miniaturized DRAM memory, it is possible to embed without producing defects such as voids or peeling, and to form a resist underlayer film with excellent flatness characteristics. Furthermore, it exhibits superior etching resistance compared to conventional resist underlayer film formation methods, and this effect can be particularly demonstrated by plasma irradiation. Therefore, fine patterns can be formed on the workpiece with even greater precision. [Brief explanation of the drawing]

[0043] [Figure 1] Figure 1 is an explanatory diagram of an example of the pattern formation method of the present invention (3-layer resist process). [Figure 2] Figure 2 is an explanatory diagram of the embedding characteristics evaluation method. [Modes for carrying out the invention]

[0044] As described above, in the fine patterning process using the multilayer resist method, there has been a need for the development of a resist underlayer film formation method that can transfer resist patterns to the workpiece with higher precision, and a pattern formation method using this resist underlayer film formation method.

[0045] Generally, metal oxide compounds exhibit significant thermal shrinkage during baking, and after high-temperature baking, they induce a significant deterioration in filling properties. Therefore, there are concerns that they are insufficient as resist underlayer materials requiring advanced planarization, embedding, and heat resistance properties. Patent document 5 reports a metal-containing material with excellent embedding properties, but because it contains many organic components, it is considered to have insufficient dry etching resistance during substrate processing, which is a strength of metallic materials. There is a trade-off relationship between the embedding properties and dry etching resistance of metallic materials, and a breakthrough was needed. The inventors have developed a method for embedding carbon bonds contained in the metal-containing film after filling in steps. Solution We hypothesized that by promoting separation and recombination with plasma irradiation, we could improve dry etching resistance without degrading embedding properties, and we conducted extensive research. As a result, we found that a resist underlayer formation method that involves plasma irradiation of the metal-containing resist underlayer significantly improves dry etching resistance during substrate processing without impairing embedding properties, and thus completed the present invention.

[0046] In other words, the present invention is a method for forming a resist underlayer film, (i) A coating step of applying a resist underlayer film formation composition comprising a metal compound having a metal-oxygen covalent bond and an organic solvent to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, This method for forming a resist underlayer film uses a metal compound that contains at least one crosslinking group represented by the following general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3). [ka] (In general formulas (a-1) to (a-4), R a (where is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) [ka] (In general formulas (b-1) to (b-4), R b is a hydrogen atom or a methyl group, and in the same formula, they may be the same or different from each other. R c is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bonding part.)

Chemical formula

Chemical formula

[0047] Further, the present invention is a method for forming a resist underlayer film, comprising: (i’) A coating step of coating a substrate with a composition for forming a resist underlayer film containing a metal belonging to the 3rd to 15th groups of the periodic table and the 3rd to 7th periods; (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C or higher and 600°C or lower for 10 seconds to 7,200 seconds to cure it; (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, which is a method for forming a resist underlayer film.

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

[0049] <Method for forming a resist underlayer film> The present invention relates to a method for forming a resist underlayer film, (i') A coating step of applying a resist underlayer film formation composition containing metals belonging to the 3rd to 7th periods of Groups 3 to 15 of the periodic table to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, This is a method for forming a resist underlayer film, comprising the following:

[0050] This method for forming a resist underlayer film allows for the creation of a resist underlayer film with excellent etching resistance during substrate processing without compromising embedding properties.

[0051] In this case, it is preferable to use a composition for forming the resist underlayer film that contains a metal compound having a metal-oxygen covalent bond or a metal compound having a metal-carbon covalent bond.

[0052] With this method of forming a resist underlayer film, the structure is such that ligands are coordinated to metal atoms via oxygen or carbon atoms, which facilitates film modification by plasma irradiation.

[0053] Furthermore, the present invention relates to a method for forming a resist underlayer film, (i) A coating step of applying a resist underlayer film formation composition comprising a metal compound having a metal-oxygen covalent bond and an organic solvent to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, This method for forming a resist underlayer film uses a metal compound that contains at least one crosslinking group represented by the following general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3). [ka] (In general formulas (a-1) to (a-4), R a (where is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) [ka] (In general formulas (b-1) to (b-4), R b R is a hydrogen atom or a methyl group, and in the same formula they may be the same or different from each other. c (where * represents a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bond.) [ka] (In general formulas (c-1) to (c-3), Y1 is a divalent organic group having 1 to 20 carbon atoms, R is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated divalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and R1 is an organic group whose protecting group is removed by the action of either or both of the following general formula (1) and / or heat, generating one or more hydroxyl or carboxyl groups, and * represents a bond.) [ka] (In general formula (1), R2 is an organic group whose protecting group is removed by the action of acid, heat, or both, and * represents the bond with Y1.)

[0054] This method for forming a resist underlayer film allows for the creation of a resist underlayer film with excellent etching resistance during substrate processing without compromising embedding properties.

[0055] The gas atmosphere in step (iii) above is preferably N2, NF3, H2, fluorocarbons, noble gases, or a mixture of any of these gases. Preferred examples include helium, Ar, N2, Ne, NF3, H2, CF4, CHF3, CH2F2, CH3F, C4F6, and C4F8. Two or more of these gases may be used in mixture form.

[0056] From a productivity standpoint, more preferable gas atmospheres include helium, Ar, N2, and H2, and it is even more preferable to use a gas containing helium gas or H2 gas.

[0057] Plasma irradiation can be carried out using known methods. For example, the method described in Japanese Patent Publication No. 5746670 (Patent Document), “Improvement of the wiggling profile of spin-on carbon hard mask by H2plasma treatment” (J.Vac.Sci.Technol.B26(1), Jan / Feb 2008, pp. 67-71, Non-Patent Document). The RF discharge power during plasma irradiation can be selected from 100 to 10,000 W, with 200 to 5,000 W being more preferable.

[0058] Plasma irradiation time can be selected from 10 to 300 seconds. Pressure can be selected as needed.

[0059] The irradiation device is not particularly limited as long as it is capable of plasma irradiation, but for example, Telius SP and Tactras Vigus manufactured by Tokyo Electron Corporation can be used. It is possible to select the device and set the conditions in order to achieve the effects of the present invention.

[0060] In step (ii) above, the bake temperature of the cured film is between 100°C and 600°C, preferably between 100°C and 500°C, and more preferably between 100°C and 450°C. The bake time is in the range of 10 seconds to 7,200 seconds, preferably between 30 seconds and 600 seconds, and particularly preferably between 45 seconds and 240 seconds.

[0061] By appropriately adjusting the bake temperature and time within the above range, it is possible to obtain curing properties such as planarization and embedding characteristics suitable for the application, as well as dry etching resistance and heat resistance. By baking within a temperature range of 100°C to 600°C, the carbon bonds in the cured film can be processed without degrading the embedding properties. Solution This creates a state where the film contains many active sites that undergo separation and recombination, which facilitates film modification by plasma irradiation or electron beam irradiation, thus forming a resist underlayer film with excellent dry etching resistance. Below a bake temperature of 100°C, residual solvent in the film cannot be reduced, leading to deterioration of film thickness uniformity due to plasma irradiation or electron beam irradiation. Above a bake temperature of 600°C, crystallization of the cured film cannot be suppressed. Heating can also be performed in multiple stages (step bake).

[0062] A baking time of less than 10 seconds is undesirable because it may result in uneven curing, while a baking time exceeding 7,200 seconds is undesirable from a productivity standpoint.

[0063] Furthermore, in step (ii) above, it is preferable to form a cured film by heat-treating the substrate coated with the resist underlayer film forming composition in an atmosphere with an oxygen concentration of 1% to 21%.

[0064] Alternatively, in step (ii) above, it is preferable to form a cured film by heat-treating the substrate coated with the resist underlayer film forming composition in an atmosphere with an oxygen concentration of less than 1%.

[0065] By performing heat treatment at the above oxygen concentration, rapid volume shrinkage of the cured film can be suppressed and organic components in the cured film can be gently removed, thereby improving dry etching resistance without impairing embedding properties. Furthermore, if the substrate to be processed is susceptible to air oxidation, substrate damage can be suppressed by forming the cured film by heat treatment in an atmosphere with an oxygen concentration of less than 1%. In such cases, it is preferable to perform the treatment in an atmosphere with an oxygen concentration of less than 1% during heating, particularly preferably 0.1% or less, more preferably 0.01% or less, and even more preferably 0.005% or less.

[0066] During baking, either an oxygen-containing atmosphere such as air (oxygen concentration 1% to 21%) or a non-oxygen-containing atmosphere such as nitrogen can be selected as needed.

[0067] When heating after plasma irradiation, the heating conditions are appropriately selected from the range of 100 to 800°C (preferably 150 to 700°C, more preferably 200 to 600°C) and 10 to 7,200 seconds (preferably 30 to 300 seconds, more preferably 45 to 180 seconds). Although not bound by theory, it is believed that high-temperature heating after plasma irradiation can bond dangling bonds and contribute to increasing the density of the resist underlayer film.

[0068] When heating after plasma irradiation, either an oxygen-containing atmosphere such as air (oxygen concentration 1% to 21%) or a non-oxygen atmosphere such as nitrogen can be selected as needed.

[0069] In the pattern formation method using the resist underlayer formation composition used in the resist underlayer formation method of the present invention, it is preferable to use a workpiece substrate having a structure or step with a height of 30 nm or more. As described above, the resist underlayer formation composition used in the resist underlayer formation method of the present invention has excellent embedding / planarization characteristics, so even if the workpiece substrate has a structure or step (unevenness) with a height of 30 nm or more, a flat resist underlayer can be formed. The height of the structure or step on the workpiece substrate is preferably 30 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. In the method of processing a stepped substrate having a pattern of the above height, by forming the resist underlayer formation composition used in the resist underlayer formation method of the present invention and performing embedding / planarization, it is possible to make the film thickness of the subsequently formed resist interlayer and resist upper layers uniform, which facilitates securing the depth of exposure margin (DOF) during photolithography and is highly preferable.

[0070] <Composition for forming a resist underlayer film> The resist underlayer film formation composition used in the resist underlayer film formation method of the present invention is a resist underlayer film formation composition containing a metal belonging to the 3rd to 7th period of Groups 3 to 15 of the periodic table.

[0071] Metals belonging to the 3rd to 7th periods of the periodic table, Groups 3 to 15, include: Examples of Group 3 metals include scandium, yttrium, lanthanum, and cerium. Examples of Group 4 metals include titanium, zirconium, and hafnium. Examples of Group 5 metals include vanadium, niobium, and tantalum. Examples of metals in Group 6 include chromium, molybdenum, and tungsten. Metals in Group 7 include manganese and rhenium, Metals in Group 8 include iron, ruthenium, and osmium. Metals in Group 9 include cobalt, rhodium, and iridium. Metals in Group 10 include nickel, palladium, and platinum. Metals in Group 11 include copper, silver, and gold. Metals in Group 12 include zinc, cadmium, and mercury. Metals in Group 13 include aluminum, gallium, and indium. Metals in Group 14 include germanium, tin, and lead. Examples of metals in Group 15 include antimony and bismuth.

[0072] Metals from Groups 4-6 and 13-15 are more preferred, with titanium, zirconium, and hafnium being even more preferred.

[0073] With such a resist underlayer formation composition, it is possible to provide a resist underlayer that exhibits extremely excellent dry etching resistance by performing plasma irradiation. The resist underlayer formation method of the present invention can improve dry etching resistance without degrading the embedding properties of the resist underlayer.

[0074] Furthermore, it is preferable to use a composition for forming the resist underlayer film that contains a metal compound having a metal-oxygen covalent bond or a metal compound having a metal-carbon covalent bond.

[0075] With this method of forming a resist underlayer film, the structure is such that ligands are coordinated to metal atoms via oxygen or carbon atoms, which facilitates film modification by plasma irradiation.

[0076] Furthermore, the resist underlayer film formation composition used in the resist underlayer film formation method of the present invention is a resist underlayer film formation composition containing (A) a metal compound and (B) an organic solvent.

[0077] Such a resist underlayer formation composition contains a metal compound that exhibits a high degree of both thermal fluidity and thermosetting properties, thus providing a resist underlayer that shows excellent embedding / planarization characteristics and, when subjected to plasma irradiation, exhibits extremely good dry etching resistance. The resist underlayer formation method of the present invention can improve dry etching resistance without degrading the embedding properties of the resist underlayer.

[0078] [(A) Metal compound] The metal compound contained in the resist underlayer forming composition used in the resist underlayer forming method of the present invention has a metal-oxygen covalent bond and contains at least one crosslinking group represented by the following general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3). [ka] (In general formulas (a-1) to (a-4), R a (where is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) [ka] (In general formulas (b-1) to (b-4), R b R is a hydrogen atom or a methyl group, and in the same formula they may be the same or different from each other. c (where * represents a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bond.) [ka] (In general formulas (c-1) to (c-3), Y1 is a divalent organic group having 1 to 20 carbon atoms, R is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated divalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and R1 is an organic group whose protecting group is removed by the action of either or both of the following general formula (1) and / or heat, generating one or more hydroxyl or carboxyl groups, and * represents a bond.) [ka] (In general formula (1), R2 is an organic group whose protecting group is removed by the action of acid, heat, or both, and * represents the bond with Y1.)

[0079] The metal compound has high etching resistance because it contains a metal-oxygen covalent bond.

[0080] The metal compound contains at least one crosslinking group represented by the general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3), thereby forming a resist underlayer film with excellent embedding properties. Furthermore, since a film with excellent heat resistance can be formed, baking within a temperature range of 100°C to 600°C can improve dry etching resistance without degrading embedding properties.

[0081] The ligands coordinating to the metal compound are not particularly limited as long as one or more ligands having a bridging group represented by the general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3) are coordinated. However, from the viewpoint of stability, carboxylates, acetyl acetates, polyhydric alcohols, etc., are preferred.

[0082] Examples of ligands containing the bridging group shown in the above general formulas (a-1) to (a-4) include, but are not limited to, the following compounds. [ka] (R 1A (This is an organic group selected from substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, and aryl groups having 6 to 20 carbon atoms.)

[0083] [ka]

[0084] [ka] (In the above formula, X1 and X2 represent hydrocarbon groups having 1 to 20 carbon atoms or alkoxy groups having 1 to 20 carbon atoms.)

[0085] [ka] (In the above formula, X1 and X2 represent hydrocarbon groups having 1 to 20 carbon atoms or alkoxy groups having 1 to 20 carbon atoms.)

[0086] [ka] (In the above formula, R 1A X1 represents an organic group selected from substituted or unsubstituted C1-C20 alkyl groups and C6-C20 aryl groups, while X1 and X2 represent C1-C20 hydrocarbon groups or C1-C20 alkoxy groups.

[0087] [ka] (In the above formula, R 1A R represents one of the organic groups selected from substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, and aryl groups having 6 to 20 carbon atoms. a (This represents a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms.)

[0088] [ka]

[0089] [ka] (In the above formula, X1 and X2 represent hydrocarbon groups having 1 to 20 carbon atoms or alkoxy groups having 1 to 20 carbon atoms.)

[0090] [ka] (In the above formula, X1 and X2 represent hydrocarbon groups having 1 to 20 carbon atoms or alkoxy groups having 1 to 20 carbon atoms.)

[0091] [ka] (In the above formula, X1 and X2 represent hydrocarbon groups having 1 to 20 carbon atoms or alkoxy groups having 1 to 20 carbon atoms.)

[0092] [ka] (In the above formula, Y is a divalent organic group having 1 to 10 carbon atoms.)

[0093] Examples of ligands containing the bridging group shown in the above general formulas (b-1) to (b-4) include, but are not limited to, the following compounds.

[0094] [ka] (In the above formula, R c (This can be a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms.)

[0095] [ka] (In the above formula, R cX1 is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms; X1 and X2 represent a hydrocarbon group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms; and Y is a divalent organic group having 1 to 10 carbon atoms.

[0096] Examples of ligands containing the bridging group shown in the above general formulas (c-1) to (c-3) include, but are not limited to, the following compounds. [ka]

[0097] In the above general formulas (c-1) to (c-3), one or more hydroxyl groups or carboxyl groups generated by the elimination of a protecting group due to the action of acid, heat, or both function as a bridging group.

[0098] The metal contained in the above metal compound is preferably titanium, zirconium, hafnium, or a combination thereof.

[0099] By including a metal compound containing the above-mentioned metal in the resist underlayer film formation composition, the dry etching resistance during substrate processing can be further improved.

[0100] It is preferable to use a metal compound that further contains a ligand derived from a silicon compound represented by the following general formula (2). [ka] (In general formula (2), R 3A , R 3B and R 3C This is one of the following organic groups: an organic group having 2 to 30 carbon atoms having a bridging group in any of the structures shown by the general formulas (d-1) to (d-3) below; a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; and an aryl group having 6 to 20 carbon atoms. [ka] (In general formulas (d-1) to (d-3), R3 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.)

[0101] In the above general formula (2), R 3A , R 3B and R 3C The C2-C30 organic group having a bridging group in any of the structures represented by the general formulas (d-1) to (d-3) above, a substituted or unsubstituted C1-C20 alkyl group, and an aryl group having 6 to 20 carbon atoms are selected from these organic groups, with the C2-C30 organic group having a bridging group in any of the structures represented by the general formulas (d-1) to (d-3) above, or an unsubstituted C1-C10 alkyl group being more preferred. Among the unsubstituted C1-C10 alkyl groups, a methyl group or an ethyl group is more preferred.

[0102] In the general formulas (d-1) to (d-3) above, R3 is independently a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, and q is independently 0 or 1.

[0103] By including a ligand derived from the silicon compound represented by the general formula (2) above in the above metal compound, the stability of the metal compound in the resist underlayer film forming composition is improved, and the fluidity of the resist underlayer film forming composition can be improved.

[0104] From the viewpoint of thermosetting properties, it is more preferable that the ligand derived from the silicon compound represented by the above general formula (2) has one of the structures represented by the following general formula (2A). [ka] (In general formula (2A), R 3D and R 3E (where R3 is the same as above, and s is 1 to 10.)

[0105] In the above general formula (2A), R 3D and R 3E From the perspective of raw material availability, it is more preferable that it be a methyl group.

[0106] If, in addition to ligands containing crosslinking groups represented by the general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3) above, the ligands derived from the silicon compound also contain crosslinking groups, the thermosetting properties of the resist underlayer film formation composition can be further improved. When this composition is used for forming a resist underlayer film, it becomes possible to form a resist underlayer film with excellent embedding / planarization properties.

[0107] The above metal compound can be modified with multiple ligands of different structures or ligands derived from silicon compounds, as long as it has one or more ligands containing bridging groups represented by the general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3), and can be appropriately adjusted according to the required properties. Furthermore, the above metal compound may have ligands other than those containing bridging groups represented by the general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3) and ligands derived from silicon compounds. For example, it may contain ligands derived from alkyl groups having 1 to 10 carbon atoms.

[0108] In the above metal compounds, the content of ligands containing the bridging groups represented by the above general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3) is preferably 10 mol% to 100 mol%, and more preferably 20 mol% to 80 mol%, of the total amount of ligands coordinating to the metal atoms. Ligands derived from silicon compounds are preferably 0 mol% to 90 mol%, and more preferably 20 mol% to 80 mol%, of the total amount of ligands coordinating to the metal atoms. Ligands other than those derived from silicon compounds and those containing the crosslinking group represented by the general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3) above, such as ligands derived from alkyl groups having 1 to 10 carbon atoms, are preferably present in an amount of 0 mol% to 50 mol%, and more preferably 0 mol% to 20 mol%, of the total amount of ligands coordinating to the metal atom.

[0109] The following describes the components included in the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention, other than the metal compounds (A) described above.

[0110] <(B) Organic solvents> The (B) organic solvent that can be used in the resist underlayer forming composition used in the resist underlayer forming method of the present invention is not particularly limited as long as it dissolves or disperses the (A) metal compound described above, and, if included, the (C) crosslinking agent, (E) surfactant, (F) acid generator, and other additives described later.

[0111] Specifically, organic solvents described in paragraphs

[0091] to

[0092] of Japanese Patent Publication No. 2007-199653 can be added. More specifically, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and γ-butyrolactone, or a mixture containing one or more of these, are preferably used.

[0112] The amount of organic solvent blended is preferably in the range of 200 to 10,000 parts by mass, more preferably 250 to 5,000 parts by mass, per 100 parts by mass of (A) metal compound.

[0113] The resist underlayer film forming composition may contain one or more of the above-mentioned (A) metal compounds and (B) organic solvents, and may optionally contain (C) a crosslinking agent, (E) a surfactant, and (F) an acid generator. The following describes the components included in the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention, other than the metal compounds (A) described above.

[0114] <(B1) High boiling point solvent> In the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention, the (B) organic solvent may be used as a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher ((B1) high-boiling point solvents).

[0115] (B1) As for the high boiling point solvent, there are no particular restrictions on hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc., as long as it can dissolve or disperse each component of the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention. Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-Hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, n-nonyl acetate, monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol Dibutyl methyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,Examples include 6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate, which may be used individually or in combination.

[0116] (B1) The high-boiling point solvent can be appropriately selected from the above, for example, according to the temperature at which the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention is heat-treated. The boiling point of the high-boiling point solvent is preferably 180°C to 300°C, and more preferably 200°C to 300°C. With such a boiling point, there is no risk of excessive volatilization during baking (heat treatment), so sufficient thermal fluidity can be obtained during film formation, and it is thought that a resist underlayer film with excellent embedding / planarization properties can be formed. Furthermore, with such a boiling point, there is no risk of residual solvent in the film after baking without volatilization, so there is no risk of adverse effects on film properties such as etching resistance.

[0117] Furthermore, when using (B1) a high-boiling point solvent, the amount blended is preferably 1 to 30 parts by mass per 100 parts by mass of an organic solvent with a boiling point of less than 180°C. Such a blending amount is preferable because it provides sufficient thermal fluidity during baking, does not remain in the film, and does not lead to deterioration of film properties such as etching resistance.

[0118] [(C) Crosslinking agent] Furthermore, the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention may further contain a (C) crosslinking agent in order to enhance the curability of the metal compound and further suppress intermixing with the resist upper layer film. The (C) crosslinking agent is not particularly limited, and various known types of crosslinking agents can be widely used. Examples include melamine-based crosslinking agents, acrylate-based crosslinking agents, glycoluryl-based crosslinking agents, benzoguanamine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, epoxy-based crosslinking agents, and phenol-based crosslinking agents (for example, methylol or alkoxymethyl type crosslinking agents of polynuclear phenols). The content of the (C) crosslinking agent is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, per 100 parts by mass of the (A) metal compound.

[0119] Examples of melamine-based crosslinking agents include hexamethoxymethylated melamine, hexasubtoxicmethylated melamine, alkoxy and / or hydroxy-substituted derivatives thereof, and partially self-condensed derivatives thereof. As an example of an acrylate-based crosslinking agent, dipentaerythritol hexaacrylate can be cited. Examples of glycoluryl crosslinking agents include tetramethoxymethylated glycoluryl, tetrabutoxymethylated glycoluryl, their alkoxy and / or hydroxy substituted derivatives, and their partial self-condensates. Examples of benzoguanamine-based crosslinking agents include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, their alkoxy and / or hydroxy-substituted derivatives, and their partial self-condensed derivatives. Examples of urea-based crosslinking agents include dimethoxymethylated dimethoxyethyleneurea, its alkoxy and / or hydroxy-substituted derivatives, and partially self-condensed derivatives thereof. A specific example of a β-hydroxyalkylamide crosslinking agent is N,N,N',N'-tetra(2-hydroxyethyl)adipamide. Examples of isocyanurate-based crosslinking agents include triglycidyl isocyanurate and triallyl isocyanurate. Examples of aziridine-based crosslinking agents include 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate]. Examples of oxazoline-based crosslinking agents include 2,2'-isopropylidenebis(4-benzyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis-4,5-diphenyl-2-oxazoline, 2,2'-methylenebis-4-phenyl-2-oxazoline, 2,2'-methylenebis-4-tertbutyl-2-oxazoline, 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyloxazoline copolymers. Examples of epoxy crosslinking agents include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether.

[0120] Examples of polynuclear phenolic crosslinking agents include the compound represented by the following general formula (XL-1). [ka] (In the general formula (XL-1), Q is a single bond or a q'-valent hydrocarbon group having 1 to 20 carbon atoms. R'3 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. q' is an integer from 1 to 5.)

[0121] Q is a single bond or a q'-valent hydrocarbon group having 1 to 20 carbon atoms. q' is an integer from 1 to 5, more preferably 2 or 3. Examples of Q include methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane, with q' hydrogen atoms removed. R'3 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Examples of alkyl groups having 1 to 20 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, and eicosanyl groups, with hydrogen atoms or methyl groups being preferred.

[0122] As examples of compounds represented by the above general formula (XL-1), the following compounds can be specifically exemplified. Among these, triphenolmethane, triphenolethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and hexamethoxymethylated tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred from the viewpoint of improving the curability and uniformity of the resist underlayer film. R'3 is the same as above. [ka]

[0123] [ka]

[0124] <(E) Surfactants> The resist underlayer film forming composition used in the resist underlayer film forming method of the present invention may contain (E) surfactant to improve the coatability in spin coating. As the (E) surfactant, for example, those described in paragraphs

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953 can be used. When adding the (E) surfactant, the amount to be added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the (A) metal compound.

[0125] <(F) Acid Generator> In the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention, an (F) acid generator can be added to further promote the curing reaction of the (A) metal compound. The (F) acid generator may be one that generates acid by thermal decomposition or one that generates acid by light irradiation, and either type can be added. Specifically, the materials described in paragraphs

[0061] to

[0085] of Japanese Patent Application Publication No. 2007-199653 can be added, but are not limited to these.

[0126] The above (F) acid generating agent can be used individually or in combination of two or more types. When adding the (F) acid generating agent, the amount to be added is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the above (A) metal compound.

[0127] <Other additives> Furthermore, the resist underlayer film forming composition used in the resist underlayer film forming method of the present invention preferably includes, for example, a liquid additive having a polyethylene glycol or polypropylene glycol structure, or a pyrolytic polymer having a mass loss rate of 40% by mass or more between 30°C and 250°C and a weight-average molecular weight of 300 to 200,000, as an additive to impart embedding / planarization properties. This pyrolytic polymer preferably contains repeating units having an acetal structure represented by the following general formulas (DP1) and (DP1a).

[0128] [ka] (In the general formula (DP1), R6 is a hydrogen atom or a monovalent saturated or unsaturated organic group having 1 to 30 carbon atoms, which may be substituted. Y2 is a divalent saturated or unsaturated organic group having 2 to 30 carbon atoms.)

[0129] [ka] (In general formula (DP1a), R 6a Y is an alkyl group having 1 to 4 carbon atoms. a (where n is a saturated or unsaturated divalent hydrocarbon group having 4 to 10 carbon atoms, and may have an ether bond. n represents the average number of repeating units, ranging from 3 to 500.)

[0130] <Pattern formation method using a resist underlayer film formation method> Furthermore, in the present invention, as a pattern formation method by a two-layer resist process using the above resist underlayer film formation method, A resist underlayer film is formed on the substrate to be processed using the above resist underlayer film formation method. A resist upper layer film is formed on the resist lower layer film using a photoresist material. After pattern exposure of the resist upper layer film, it is developed with a developer to form a pattern on the resist upper layer film. Using the resist upper layer film on which the aforementioned pattern is formed as a mask, the pattern is transferred to the resist lower layer film by dry etching. The present invention provides a pattern forming method for forming a pattern on a substrate by processing the substrate using the resist underlayer film on which the pattern is formed as a mask.

[0131] Since the upper resist film of the above two-layer resist process exhibits etching resistance to chlorine-based gases, it is preferable to perform the dry etching of the lower resist film, which is carried out using the upper resist film as a mask, with an etching gas mainly composed of chlorine-based gases in the above two-layer resist process.

[0132] Furthermore, the present invention provides a method for forming a pattern on a workpiece substrate using a three-layer resist process with such a resist underlayer film formation method, (I-1) A step of forming a resist underlayer film on a substrate to be processed using the resist underlayer film formation method described above, (I-2) A step of forming a silicon-containing resist interlayer on the resist underlayer, (I-3) A step of forming a resist upper layer film on the silicon-containing resist interlayer film using a photoresist material, (I-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (I-5) A step of transferring the pattern to the silicon-containing resist interlayer by dry etching, using the resist upper layer on which the pattern is formed as a mask. (I-6) A step of transferring the pattern to the resist underlayer film by dry etching, using the silicon-containing resist interlayer film on which the pattern has been transferred as a mask, and (I-7) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method having the following characteristics.

[0133] A pattern formation method using a three-layer resist process will be explained with reference to Figure 1. In the present invention, as a pattern formation method using a three-layer resist process with such a resist underlayer film formation method, a resist underlayer film 3 is formed on a workpiece layer 2 on a workpiece substrate 1 using the above resist underlayer film formation method, as shown in Figure 1(A), a silicon-containing resist interlayer film 4 is formed on the resist underlayer film using a silicon-containing resist interlayer material, and a resist upper layer film 5 is formed on the silicon-containing resist interlayer film using a photoresist material. The present invention provides a pattern formation method in which, as shown in Figure 1(B), the exposed portion 6 of the resist upper layer film is pattern-exposed, and as shown in Figure 1(C), it is developed with a developer to form a resist upper layer film pattern 5a on the resist upper layer film, as shown in Figure 1(D), the silicon-containing resist interlayer film pattern 4a is transferred to the silicon-containing resist interlayer film by dry etching using the resist upper layer film with the pattern formed on it as a mask, as shown in Figure 1(E), the resist lower layer film pattern 3a is transferred to the resist lower layer film by dry etching using the silicon-containing resist interlayer film with the transferred pattern as a mask, and as shown in Figure 1(F), the workpiece layer on the workpiece is processed using the resist lower layer film with the pattern formed on it as a mask to form a pattern 2a on the workpiece substrate 1.

[0134] Since the silicon-containing resist interlayer in the above three-layer resist process exhibits etching resistance to chlorine-based gases, it is preferable to perform the dry etching of the resist underlayer using the silicon-containing resist interlayer as a mask in the above three-layer resist process using an etching gas mainly composed of chlorine-based gases.

[0135] As the silicon-containing resist interlayer in the above three-layer resist process, a polysiloxane-based interlayer is also preferably used. By giving the silicon-containing resist interlayer an anti-reflective effect, reflection can be suppressed. In particular, for 193nm exposure, if a material containing many aromatic groups as an organic film and having high etching selectivity with the substrate is used, the k value will be high and substrate reflection will be high. However, by giving the silicon-containing resist interlayer an absorption that results in an appropriate k value, it is possible to suppress reflection, and substrate reflection can be reduced to 0.5% or less. As silicon-containing resist interlayers with an anti-reflective effect, anthracene is preferably used for 248nm and 157nm exposure, and polysiloxane is preferably used for 193nm exposure, with phenyl groups or absorbent groups having silicon-silicon bonds pendanted and crosslinked by acid or heat.

[0136] In addition, the present invention provides a pattern formation method using a four-layer resist process employing such a resist underlayer film formation method, A resist underlayer film is formed on the substrate to be processed using the resist underlayer film formation method described above. A silicon-containing resist interlayer is formed on the resist underlayer using a silicon-containing resist interlayer material. An organic anti-reflective film (BARC) or an adhesion film is formed on the silicon-containing resist interlayer. A resist upper layer film is formed on the BARC or the adhesion film using a photoresist material. After pattern exposure of the resist upper layer film, it is developed with a developer to form a pattern on the resist upper layer film. Using the resist upper layer film on which the pattern is formed as a mask, the pattern is transferred to the BARC or the adhesion film and the silicon-containing resist interlayer film by dry etching. Using the silicon-containing resist interlayer film on which the aforementioned pattern has been transferred as a mask, the pattern is transferred to the resist underlayer film by dry etching. The present invention provides a pattern formation method comprising the step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed.

[0137] Alternatively, an inorganic hard mask interlayer may be formed instead of a silicon-containing resist interlayer. In this case, at least the resist underlayer is formed on the workpiece using the resist underlayer formation method of the present invention. An inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the resist underlayer film. A resist upper layer film is formed on the inorganic hard mask interlayer film using a photoresist composition, and a circuit pattern is formed on the resist upper layer film. The inorganic hard mask interlayer is etched using the resist upper layer film on which the pattern is formed as a mask. The inorganic hard mask interlayer film on which the aforementioned pattern is formed is used as a mask to etch the resist underlayer film. Furthermore, by using the resist underlayer film on which the pattern is formed as a mask to etch the workpiece and form a pattern on the workpiece, a semiconductor device circuit pattern can be formed on the substrate.

[0138] As described above, when forming an inorganic hard mask interlayer on a resist underlayer, silicon oxide films, silicon nitride films, and silicon oxynitride films (SiON films) can be formed by CVD or ALD methods. For example, a method for forming a silicon nitride film is described in Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377. The thickness of the inorganic hard mask interlayer is preferably 5 to 200 nm, and more preferably 10 to 100 nm. Furthermore, as the inorganic hard mask interlayer, a SiON film with high anti-reflective properties is most preferably used. Since the substrate temperature when forming the SiON film is 300 to 500°C, the resist underlayer needs to withstand temperatures of 300 to 500°C. The resist underlayer formation composition used in the present invention has high heat resistance and can withstand high temperatures of 300 to 500°C, so it is possible to combine an inorganic hard mask interlayer formed by CVD or ALD with a resist underlayer formed by rotary coating.

[0139] As described above, a photoresist film may be formed as a resist top layer on an inorganic hard mask interlayer, or an organic anti-reflective coating (BARC) or adhesion film may be formed on the inorganic hard mask interlayer by spin coating, and then a photoresist film may be formed on top of that. In particular, when a SiON film is used as the inorganic hard mask interlayer, the two layers of anti-reflective coatings, the SiON film and BARC, make it possible to suppress reflection even in immersion lithography with high NA values ​​exceeding 1.0. Another advantage of forming BARC is that it has the effect of reducing the trailing of the photoresist pattern directly above the SiON film.

[0140] Furthermore, the present invention provides a method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer film on a substrate to be processed using the resist underlayer film formation method described above, (II-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film, (II-3) A step of forming an organic thin film on the inorganic hard mask interlayer, (II-4) A step of forming a resist upper layer film on the organic thin film using a photoresist material, (II-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (II-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and (II-8) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method having the following characteristics.

[0141] In the pattern formation method described above, the resist upper layer film may be either positive or negative type, and the same photoresist composition as commonly used can be used. Furthermore, the photoresist composition may contain metal atoms such as Sn, In, Ga, Ge, Al, Ce, La, Cs, Zr, Hf, Ti, Bi, Sb, and Zn. When forming the resist upper layer film using the above photoresist composition, the method may be spin coating, CVD, or ALD deposition.

[0142] When forming a resist upper layer film by spin coating, pre-baking is performed after coating the photoresist composition, preferably at a temperature of 60 to 180°C for 10 to 300 seconds. Subsequently, exposure is performed according to a conventional method, followed by post-exposure baking (PEB) and development to obtain the resist upper layer film pattern. The thickness of the resist upper layer film is not particularly limited, but 10 to 500 nm, and especially 20 to 400 nm, is preferred.

[0143] When a resist upper layer film is formed by vapor deposition using the CVD or ALD method, the photoresist composition is an EUV-sensitive metal oxide-containing film, the metal being selected from Sn, Zr, Hf, Ti, Bi, Sb, etc., with Sn being preferred due to its excellent EUV photosensitivity. The metal oxide-containing film may be a photosensitive organometallic oxide film such as an organotin oxide (e.g., haloalkylSn, alkoxyalkylSn, or amidealkylSn). Some specific examples of suitable precursors include trimethyltin chloride, dimethyltin dichloride, methyltin trichloride, tris(dimethylamino)methyltin(IV), and (dimethylamino)trimethyltin(IV).

[0144] The metal oxide-containing film may be deposited by PECVD or PEALD using, for example, a Lam Vector® tool, and in the ALD example, the Sn oxide precursor is separated from the O precursor / plasma. The deposition temperature is preferably in the range of 50°C to 600°C. The deposition pressure is preferably between 100 and 6,000 mTorr. The flow rate of the metal oxide-containing film precursor liquid (e.g., organotin oxide precursor) may be 0.01 to 10 cm, and the gas flow rate (CO2, CO, Ar, N2) may be 100 to 10,000 sccm. The plasma power may be 200 to 1,000 W per 300 mm wafer station using a high-frequency plasma (e.g., 13.56 MHz, 27.1 MHz, or higher frequency). The deposition thickness is preferably 100 to 2,000 Å.

[0145] Examples of exposure light include high-energy rays with wavelengths of 300 nm or less, specifically excimer lasers with wavelengths of 248 nm, 193 nm, and 157 nm, soft X-rays, electron beams, and X-rays with wavelengths of 3 to 20 nm.

[0146] As a method for forming the pattern of the resist upper layer film described above, it is preferable to use photolithography with a wavelength of 5 nm to 300 nm, direct writing with an electron beam, nanoimprinting, or a combination thereof to form the pattern.

[0147] Furthermore, it is preferable that the development method in the pattern formation method be alkaline development or development with an organic solvent.

[0148] Next, etching is performed using the obtained resist upper layer pattern as a mask. In the three-layer resist process, etching of the silicon-containing resist interlayer and inorganic hard mask interlayer is performed using a fluorocarbon gas with the resist upper layer pattern as a mask. This forms the silicon-containing resist interlayer pattern and the inorganic hard mask interlayer pattern.

[0149] Next, the resist underlayer is etched using the obtained silicon-containing resist interlayer pattern or inorganic hard mask interlayer pattern as a mask. It is preferable to use an etching gas mainly composed of chlorine-based gas for the etching of the resist underlayer.

[0150] The etching of the next workpiece can also be performed by conventional methods. For example, if the workpiece is made of SiO2, SiN, or silica-based low dielectric constant insulating film, etching is performed primarily using a fluorocarbon gas. When the substrate is etched with a fluorocarbon gas, the silicon-containing resist interlayer pattern in the three-layer resist process is peeled off simultaneously with the substrate processing.

[0151] The resist underlayer film obtained by the resist underlayer film formation method of the present invention has the characteristic of excellent etching resistance when these workpieces are etched.

[0152] The workpiece (workpiece substrate) is not particularly limited and can be any substrate such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, or a substrate on which the workpiece layer has been deposited. Various low-k films and their stopper films can be used as the workpiece layer, typically with a thickness of 50 to 10,000 nm, and especially 100 to 5,000 nm. When depositing the workpiece layer, the substrate and the workpiece layer are made of different materials.

[0153] The pattern formation method using the resist underlayer formation method of the present invention preferably uses a workpiece substrate having a structure or step with a height of 30 nm or more. As described above, the resist underlayer formation composition used in the resist underlayer formation method of the present invention has excellent embedding / planarization characteristics, so even if the workpiece substrate has a structure or step (unevenness) with a height of 30 nm or more, a flat resist underlayer can be formed. The height of the structure or step on the workpiece substrate is preferably 30 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. In the method of processing a stepped substrate having a pattern of the above height, by forming the resist underlayer formation composition used in the resist underlayer formation method of the present invention and performing embedding / planarization, it is possible to make the film thickness of the silicon-containing resist interlayer and resist upper layer that are subsequently formed uniform, which makes it easier to secure the depth of exposure margin (DOF) during photolithography and is highly preferable.

[0154] Furthermore, in the present invention, as a pattern formation method using a four-layer resist process employing such a resist underlayer film formation method, A resist underlayer film is formed on the substrate to be processed using the resist underlayer film formation method described above. An organic interlayer is formed on the resist underlayer using an organic interlayer material. A silicon-containing resist interlayer is formed on the aforementioned organic interlayer using a silicon-containing resist interlayer material. If necessary, an organic anti-reflective coating (BARC) or an adhesion coating is formed on the silicon-containing resist interlayer. A resist upper layer film is formed on the silicon-containing resist interlayer film or on the BARC or the adhesion film using a photoresist material. After pattern exposure of the resist upper layer film, it is developed with a developer to form a pattern on the resist upper layer film. Using the resist upper layer film on which the pattern is formed as a mask, the pattern is transferred to the BARC or the adhesion film and the silicon-containing resist interlayer film by dry etching. Using the silicon-containing resist interlayer on which the aforementioned pattern has been transferred as a mask, the pattern is transferred to the organic interlayer by dry etching. The pattern is transferred to the resist underlayer film using the organic interlayer film on which the pattern has been transferred as a mask. The present invention provides a pattern formation method comprising the step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed.

[0155] Furthermore, the present invention provides a method for forming a pattern on a workpiece substrate using a four-layer resist process with such a resist underlayer film formation method, (III-1) A step of forming a resist underlayer film on a substrate to be processed using the resist underlayer film formation method described above, (III-2) A step of forming an organic interlayer on the resist underlayer film, (III-3) A step of forming a combination of an organic thin film and an inorganic hard mask interlayer selected from a silicon-containing resist interlayer, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic interlayer. (III-4) A step of forming a resist upper layer film on the silicon-containing resist interlayer film or the organic thin film using a photoresist material, (III-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (III-6) A step of transferring the pattern to the silicon-containing resist interlayer or the organic thin film and the inorganic hard mask interlayer by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (III-7) A step of transferring the pattern to the organic interfilm by dry etching, using the silicon-containing resist interfilm or inorganic hard mask interfilm on which the pattern has been transferred as a mask. (III-8) A step of transferring the pattern to the resist underlayer film by dry etching using the organic interlayer film on which the pattern has been transferred as a mask, and (III-9) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. The present invention provides a pattern forming method having the following characteristics.

[0156] As organic interlayer materials that can be used for the above-mentioned organic interlayer, in addition to those already known as underlayers for the 3-layer resist method or the 2-layer resist method using a silicon resist composition, a large number of resins including novolac resins can be used, such as the 4,4'-(9-fluorenylidene)bisphenol novolac resin (molecular weight 11,000) described in Japanese Patent Application Publication No. 2005-128509, as well as those known as underlayer materials for resists in the 2-layer resist method and the 3-layer resist method. Furthermore, if it is desired to increase the heat resistance compared to ordinary novolac, a polycyclic skeleton such as 6,6'-(9-fluorenylidene)-di(2-naphthol) novolac resin can be incorporated, and polyimide resins can also be selected (for example, Japanese Patent Application Publication No. 2004-153125).

[0157] The above-mentioned organic interfilm can be formed on a substrate using a composition solution by a spin coating method or the like, similar to the photoresist composition. After forming the organic interfilm by a spin coating method or the like, it is desirable to bake it to evaporate the organic solvent. The baking temperature is preferably in the range of 80 to 400°C, and the baking time is preferably in the range of 10 to 300 seconds.

[0158] Instead of the organic interlayer described above, it is also possible to apply an organic hard mask formed by CVD or ALD.

[0159] Since the organic interlayer in the above multilayer resist process exhibits etching resistance to chlorine-based gases, it is preferable to perform the dry etching of the resist underlayer using the organic interlayer as a mask in the above multilayer resist process using an etching gas mainly composed of chlorine-based gases. [Examples]

[0160] The present invention will be described more specifically below with reference to synthesis examples, comparative synthesis examples, examples, and comparative examples, but the present invention is not limited thereto.

[0161] [Synthesis Example] In the following synthesis examples, the organic group raw material group G: (G1) to (G20) and the silicon-containing organic group raw material group H: (H1) to (H5) shown below were used. The organic group raw material group G: (G1) to (G20) is shown below. [Chemical Formula]

[0162] The silicon-containing organic group raw material group H: (H1) to (H5) is shown below. [Chemical Formula]

[0163] The following metal compounds were used as the metal raw material M. (M1): Titanium tetraisopropoxide (Sigma-Aldrich Corp, 377996) (M2): Titanium butoxide tetramer (FUJIFILM Wako Pure Chemical Corporation) (M3): Zr(OBu)4: Zirconium(IV) tetrabutoxide (80% by mass 1-butanol solution) (Tokyo Chemical Industry Co., Ltd., Z0016) (M4): Hf(OBu)4: Hafnium(IV) n-butoxide (Sigma-Aldrich Corp, 667943) (M5): Ti(OBu)4: Tetrabutyl orthotitanate (Tokyo Chemical Industry Co., Ltd., B0742) (M6): Titanium(IV) diisopropoxybis(2,4-pentanedionate) (75% by mass isopropyl alcohol solution) (Tokyo Chemical Industry Co., Ltd., B3395)

[0164] [Synthesis Example 1] Synthesis of Compound (A-1) for Forming a Resist Lower Layer Film Under a nitrogen atmosphere, 12.1 g of IPA solution containing 33.4 g of titanium tetraisopropoxide (M1) was stirred, and 24.2 g of IPA solution containing 1.6 g of deionized water was added dropwise over 2 hours at room temperature. 16.6 g of organic raw material group (G1) was added to the resulting solution and stirred at room temperature for 30 minutes. This solution was concentrated under reduced pressure at 30°C, then heated to 60°C, and continued under reduced pressure until no more distillate was observed. Once no distillate was observed, 69.0 g of PGMEA / PGME (mass ratio 70 / 30) solution was added, and the mixture was heated at 40°C under reduced pressure until no more IPA distilled, yielding a PGMEA / PGME solution of the resist underlayer film forming compound (A-1). The concentration of components other than the solvent in the solution was 20% by mass.

[0165] [Synthesis Examples 2-4] Synthesis of Compounds (A-2)-(A-4) for Resist Underlayer Film Formation Compounds for forming the resist underlayer film shown in Table 1 (A-2) to (A-4) were obtained under the same reaction conditions as in Synthesis Example 1, except that the above-mentioned metal raw material M and organic group raw material group G were used in the amounts shown in Table 1. [Table 1]

[0166] [Synthesis Example 5] Synthesis of Compound (A-5) for Forming a Resist Underlayer Film Under a nitrogen atmosphere, 11.8 g of tetrabutyl orthotitanate (M5) was dissolved in 20.6 g of PGMEA / PGME (mass ratio 70 / 30) solution, and the reaction temperature was raised to 50°C while stirring. 6.5 g of silicon-containing organic raw material group (H1) was then added dropwise to the solution. After addition, the reaction temperature was increased to 60°C and stirring was continued for 2 hours. Next, a mixture of 4.8 g of organic raw material group (G5) suspended in 8.6 g of PGMEA / PGME (mass ratio 70 / 30) solution was added to the reaction system, and stirring was continued at a reaction temperature of 60°C for 1 hour. After cooling to room temperature, the resulting reaction solution was filtered through a 0.45 μm PTFE filter to obtain a PGMEA / PGME solution of the resist underlayer film forming compound (A-5). The concentration of components other than the solvent in the solution was 23% by mass.

[0167] [Synthesis Examples 6-20] Synthesis of Compounds (A-6)-(A-20) for Forming Underlayer Films of Resists Compounds for forming the resist underlayer film shown in Table 2 (A-6) to (A-20) were obtained under the same reaction conditions as in Synthesis Example 5, except that the above metal raw material M, above organic group raw material group G, and above silicon-containing organic group raw material group H were used in the amounts shown in Table 2. [Table 2]

[0168] [Synthesis of resin (R-1) for forming a resist underlayer film for comparative examples] Under a nitrogen atmosphere, 160.2 g of 1,5-dihydroxynaphthalene, 56.8 g of formaldehyde, and 300 g of PGME (propylene glycol monomethyl ether) were added and homogenized at an internal temperature of 100°C. Then, a mixture of 8.0 g of p-toluenesulfonic acid monohydrate and 8.0 g of PGME, which had been pre-mixed and homogenized, was slowly added dropwise, and the reaction was carried out at an internal temperature of 80°C for 8 hours. After the reaction was complete, the mixture was cooled to room temperature, 2,000 ml of MIBK was added, and the mixture was washed six times with 500 ml of pure water. The organic layer was dried under reduced pressure. 300 g of THF was added to the residue to make a homogeneous solution, and then crystallized in 2,000 g of hexane. The precipitated crystals were separated by filtration, washed twice with 500 g of hexane, and recovered. The recovered crystals were vacuum-dried at 70°C to obtain a resin (R-1) for forming a resist underlayer film for comparative examples. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined by gel permeation chromatography (GPC) using tetrahydrofuran as the eluent, and the following results were obtained. (R-1): Mw=3,300, Mw / Mn=2.54 [ka]

[0169] [Preparation of the composition for forming the underlayer film of the resist (UDL-1)] Compound (A-1) for forming a resist underlayer film was dissolved in a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) containing 0.5% by mass of surfactant FC-4430 (manufactured by Sumitomo 3M Limited) at the ratios shown in Table 3, and filtered through a 0.02-μm membrane filter to prepare a composition (UDL-1) for forming a resist underlayer film.

[0170] [Preparation of Compositions (UDL-2 to 20) for Forming a Resist Underlayer Film and Comparative Composition (Comparative UDL-1) for Forming a Resist Underlayer Film] Except that the types and contents of each component were as shown in Table 3, the same operations as for UDL-1 were carried out to prepare each composition. In Table 3, “-” indicates that the corresponding component was not used. The following formula (F-1) was used as the acid generator (TAG).

[0171] [Acid Generator] The acid generator (F-1) used in the composition for forming a resist underlayer film is shown below. [Chemical Formula]

[0172] [Table 3]

[0173] [Evaluation of Embedding Characteristics (Examples 1-1 to 1-17, Comparative Example 1-1)] Each of the compositions (UDL-1 to 17 and Comparative UDL-1) prepared above was applied onto a SiO2 wafer substrate having a dense line & space pattern (line width: 60 nm, line depth: 100 nm, distance between the centers of two adjacent lines: 120 nm), and heated at 250°C for 60 seconds using a hot plate to form a cured film with a film thickness of 80 nm (Embedding Evaluation A). In addition, separate from the above substrates, the compositions prepared above (UDL-1 to 17, and Comparative Example UDL-1) were each coated onto an SiO2 wafer substrate having a dense line and space pattern (line width 60 nm, line depth 100 nm, distance between the centers of two adjacent lines 120 nm), heated at 250°C for 60 seconds using a hot plate, and then plasma irradiation was performed under the following conditions to form a resist underlayer film (Embedding Evaluation B).

[0174] The substrate used was a base substrate 7 (SiO2 wafer substrate) having a dense line and space pattern as shown in Figure 2(G) (overhead view) and (H) (cross-sectional view). The cross-sectional shapes of each wafer substrate obtained in embedding evaluations A and B were observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. to confirm whether there were any voids (gaps) inside the resist underlayer film that filled the spaces between lines. The results are shown in Table 4. When a resist underlayer film formation composition with poor embedding characteristics was used, voids were generated inside the resist underlayer film that filled the spaces between lines in this evaluation. When a resist underlayer film formation composition with good embedding characteristics was used, a resist underlayer film 8 without voids was filled inside the resist underlayer film that filled the spaces between lines of the base substrate 7 having a dense line and space pattern as shown in Figure 2(I) in this evaluation.

[0175] [Plasma irradiation conditions 1] Plasma irradiation device: Telius-SP manufactured by Tokyo Electron Corporation Pressure: 100mT Upper RF power: 200W Lower RF power: 2000W H2 gas: 200 sccm Upper HV voltage: -500V Time: 20 seconds

[0176] [Table 4]

[0177] As shown in Table 4, in Examples 1-1 to 1-17 using the resist underlayer film formation method of the present invention, it was possible to fill the dense line and space pattern without generating voids even after plasma treatment (embedding evaluation B), confirming that it has good embedding characteristics.

[0178] [Etching resistance evaluation (Examples 2-1 to 2-20, Comparative Example 2-1)] The resist underlayer film formation compositions (UDL-1 to 20, and Comparative Example UDL-1) were applied to a silicon substrate and heated at 250°C for 60 seconds using a hot plate. death, A cured film with a thickness of 80 nm was formed (film thickness a). Separately from the above evaluation, a substrate coated with the above composition and heated at 250°C for 60 seconds was further subjected to plasma treatment under the following conditions to form a resist underlayer film (film thickness a).

[0179] [Plasma irradiation conditions 2] Plasma irradiation device: Telius-SP manufactured by Tokyo Electron Corporation Pressure: 100mT Upper RF power: 200W Lower RF power: 2000W H2 gas: 200 sccm Upper HV voltage: -500V Time: 20 seconds

[0180] Next, etching was performed using CF4 gas under the following conditions with a ULVAC CE-300I etching system, and the film thickness b was measured. The etching rate (nm / min) was calculated from the film thickness etched per minute (film thickness a - film thickness b) over a specified time using each gas. The results are shown in Table 5.

[0181] Dry etching conditions with CF4 gas Pressure: 1 Pa Antenna RF power: 100W Bias RF Power: 15W CF4 gas flow rate: 15 sccm Time: 30sec

[0182] [Table 5]

[0183] As shown in Table 5, Examples 2-1 to 2-20 using the resist underlayer film formation method of the present invention showed improved etching resistance compared to the condition of heat treatment only. Compared to Examples 2-18 to 2-20 using UDL-18 to UDL-20, which are resist underlayer film formation compositions containing resist underlayer film formation compounds (A-18) to (A-20) that do not contain organic crosslinking groups, Examples 2-1 to 2-17 using UDL-1 to UDL-17, which are resist underlayer film formation compositions containing resist underlayer film formation compounds (A-1) to (A-17) that contain organic crosslinking groups, showed a greater improvement in etching resistance due to plasma treatment. The reason for this is not clear, but it is possible that the organic crosslinking components in the resist underlayer film are cut and re-crosslinked by the plasma treatment, causing densification of the film. Furthermore, Comparative Example 2-1, which used Comparative Example UDL-1, a comparative example composition for forming a resist underlayer film containing a comparative example resin (R-1), was found to have insufficient etching resistance compared to the resist underlayer film formation method of the present invention.

[0184] [Pattern formation method (Examples 3-1 to 3-17, Comparative Example 3-1)] The above resist underlayer formation compositions (UDL-1 to 17, Comparative Example UDL-1) were each applied to an SiO2 wafer substrate, baked in air at 250°C for 60 seconds, and then plasma treated under the following conditions to form a resist underlayer with a thickness of 80 nm. A silicon atom-containing resist interlayer material (SOG-1) was applied on top of this and baked at 220°C for 60 seconds to form a resist interlayer with a thickness of 50 nm. An ArF single-layer resist, which is a resist toplayer material, was applied on top of this and baked at 105°C for 60 seconds to form a photoresist film with a thickness of 100 nm. An immersion protective film material (TC-1) was applied on top of the photoresist film and baked at 90°C for 60 seconds to form a protective film with a thickness of 50 nm.

[0185] [Plasma irradiation conditions 3] Plasma irradiation device: Telius-SP manufactured by Tokyo Electron Corporation Pressure: 100mT Upper RF power: 200W Lower RF power: 2000W H2 gas: 200 sccm Upper HV voltage: -500V Time: 20 seconds

[0186] As a silicon atom-containing resist interlayer material (SOG-1), a polymer represented by ArF silicon-containing interlayer polymer (SiP1) and a thermal crosslinking catalyst (CAT1) were dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 6, and the mixture was filtered through a fluororesin filter with a pore size of 0.1 μm to prepare the silicon atom-containing resist interlayer material (SOG-1).

[0187] [Table 6]

[0188] The structural formulas of the ArF silicon-containing interlayer polymer (SiP1) and thermal crosslinking catalyst (CAT1) used are shown below. [ka]

[0189] The resist upper layer material (single-layer resist for ArF) was prepared by dissolving a polymer (RP1), an acid generator (PAG1), and a basic compound (Amine1) in the proportions shown in Table 7 in a solvent containing 0.1% by mass of the surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.), and filtering the mixture through a 0.1 μm fluororesin filter.

[0190] [Table 7]

[0191] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used in the resist upper layer material (single-layer resist for ArF) are shown below. [ka]

[0192] The immersion protective film material (TC-1) was prepared by dissolving the protective film polymer (PP1) in an organic solvent in the proportions shown in Table 8 and filtering it through a 0.1 μm fluororesin filter.

[0193] [Table 8]

[0194] The protective film polymer (PP1) used in the immersion protective film material (TC-1) is shown below. [ka]

[0195] Next, the sample was exposed using an ArF immersion lithography system (Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s polarized illumination, 6% halftone phase shift mask), baked (PEB) at 100°C for 60 seconds, and developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a 55 nm 1:1 positive-type line-and-space pattern (resist upper layer pattern).

[0196] Next, a hard mask pattern was formed by dry etching, using the resist upper layer pattern as a mask to etch the resist interlayer. The resulting hard mask pattern was then used as a mask to etch the resist lower layer to form the resist lower layer pattern. Finally, the resulting resist lower layer pattern was used as a mask to etch the SiO2 film. The etching conditions are as follows.

[0197] Transfer conditions for the resist upper layer pattern to the resist interlayer. Dry etching conditions with CF4 gas Pressure: 1 Pa Antenna RF power: 100W Bias RF Power: 15W CF4 gas flow rate: 15 sccm Time: 60sec

[0198] Transfer conditions for hard mask patterns to the resist underlayer film. Dry etching conditions with Cl2 gas Pressure: 1 Pa Antenna RF power: 320W Bias RF Power: 30W Cl2 gas flow rate: 25 sccm Time: 45 sec

[0199] Transfer conditions for resist underlayer film patterns onto SiO2 film. Dry etching conditions with CF4 gas Pressure: 1 Pa Antenna RF power: 100W Bias RF Power: 15W CF4 gas flow rate: 15 sccm Time: 60sec

[0200] Table 9 shows the results of observing the pattern cross-section using an electron microscope (S-4700) manufactured by Hitachi, Ltd.

[0201] [Table 9]

[0202] As shown in Table 9, in all cases, the pattern formation method of the present invention (Examples 3-1 to 3-17) successfully transferred the resist upper film pattern to the substrate, confirming its suitability for microfabrication using the multilayer resist method. On the other hand, Comparative Example 3-1, which used Comparative Example UDL-1, which showed insufficient performance in the dry etching resistance evaluation, resulted in distortion of the pattern shape during pattern processing, and ultimately failed to obtain a good pattern.

[0203] Based on the above, the resist underlayer film formation method and pattern formation method of the present invention are particularly suitable for use in multilayer resist processes that include embedding / planarization of workpieces with steps and irregularities, and are extremely useful in fine patterning for semiconductor device manufacturing.

[0204] This specification includes the following embodiments: [1] A method for forming a resist underlayer film, (i) A coating step of applying a resist underlayer film formation composition comprising a metal compound having a metal-oxygen covalent bond and an organic solvent to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, A method for forming a resist underlayer film, characterized in that the aforementioned metal compound contains at least one crosslinking group represented by the following general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3). [ka] (In general formulas (a-1) to (a-4), R a (where is a hydrogen atom or a monovalent organic group with 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) [ka] (In general formulas (b-1) to (b-4), Rb R is a hydrogen atom or a methyl group, and in the same formula they may be the same or different from each other. c (where * represents a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bond.) [ka] (In general formulas (c-1) to (c-3), Y1 is a divalent organic group having 1 to 20 carbon atoms, R is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated divalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and R1 is an organic group whose protecting group is removed by the action of either or both of the following general formula (1) and / or heat, generating one or more hydroxyl or carboxyl groups, and * represents a bond.) [ka] (In general formula (1), R2 is an organic group whose protecting group is removed by the action of acid, heat, or both, and * represents the bond with Y1.) [2]: The resist underlayer film formation method according to [1], characterized in that in step (iii), N2, NF3, H2, fluorocarbon, noble gas, or a mixture of any of these gases is used. [3]: The resist underlayer film formation method according to [2], characterized in that a gas containing H2 gas is used in step (iii). [4]: The resist underlayer film formation method according to [2] or [3] above, characterized in that a gas containing helium gas is used in step (iii). [5]: A method for forming a resist underlayer film according to any one of the above [1] to [4], characterized in that the cured film is formed by heat treatment in an atmosphere with an oxygen concentration of 1 volume% or more and 21 volume% or less in step (ii). [6]: A method for forming a resist underlayer film according to any one of the above [1] to [4], characterized in that the cured film is formed by heat treatment in an atmosphere with an oxygen concentration of less than 1 volume% in step (ii). [7]: A method for forming a resist underlayer film according to any one of the above [1] to [6], wherein in step (ii), a cured film is formed by heat treatment at a temperature of 100°C or higher and 450°C or lower for 10 to 7,200 seconds. [8]: A method for forming a resist underlayer film according to any one of the above [1] to [7], characterized in that the metal contained in the metal compound is titanium, zirconium, hafnium, or a combination thereof. [9]: A method for forming a resist underlayer film according to any one of the above [1] to [8], characterized in that the metal compound further contains a ligand derived from a silicon compound represented by the following general formula (2). [ka] (In general formula (2), R 3A , R 3B and R 3C This is one of the following organic groups: an organic group having 2 to 30 carbon atoms having a bridging group in any of the structures shown by the general formulas (d-1) to (d-3) below; a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms; and an aryl group having 6 to 20 carbon atoms. [ka] (In general formulas (d-1) to (d-3), R3 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.)

[10] A method for forming a pattern on a substrate to be processed, (I-1) A step of forming a resist underlayer on a substrate to be processed by any one of the resist underlayer forming methods described in [1] to [9] above, (I-2) A step of forming a silicon-containing resist interlayer on the resist underlayer, (I-3) A step of forming a resist upper layer film on the silicon-containing resist interlayer film using a photoresist material, (I-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (I-5) A step of transferring the pattern to the silicon-containing resist interlayer by dry etching, using the resist upper layer on which the pattern is formed as a mask. (I-6) A step of transferring the pattern to the resist underlayer film by dry etching, using the silicon-containing resist interlayer film on which the pattern has been transferred as a mask, and (I-7) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

[11] A method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer on a substrate to be processed by any one of the resist underlayer forming methods described in [1] to [9] above, (II-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film, (II-3) A step of forming an organic thin film on the inorganic hard mask interlayer, (II-4) A step of forming a resist upper layer film on the organic thin film using a photoresist material, (II-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (II-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and (II-8) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

[12] A method for forming a pattern on a substrate to be processed, (III-1) A step of forming a resist underlayer on a substrate to be processed by any one of the resist underlayer forming methods described in [1] to [9] above, (III-2) A step of forming an organic interlayer on the resist underlayer film, (III-3) A step of forming a combination of an organic thin film and an inorganic hard mask interlayer selected from a silicon-containing resist interlayer, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic interlayer. (III-4) A step of forming a resist upper layer film on the silicon-containing resist interlayer film or the organic thin film using a photoresist material, (III-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (III-6) A step of transferring the pattern to the silicon-containing resist interlayer or the organic thin film and the inorganic hard mask interlayer by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (III-7) A step of transferring the pattern to the organic interfilm by dry etching, using the silicon-containing resist interfilm or inorganic hard mask interfilm on which the pattern has been transferred as a mask. (III-8) A step of transferring the pattern to the resist underlayer film by dry etching using the organic interlayer film on which the pattern has been transferred as a mask, and (III-9) A step of processing the substrate to be processed using the resist underlayer film on which the pattern has been formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

[13] A method for forming a resist underlayer film, (i') A coating step of applying a resist underlayer film formation composition containing metals belonging to the 3rd to 7th periods of Groups 3 to 15 of the periodic table to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, A method for forming a resist underlayer film, characterized by comprising the above.

[14] : The resist underlayer film formation method according to

[13] , wherein the resist underlayer film formation composition includes a metal compound having a metal-oxygen covalent bond or a metal compound having a metal-carbon covalent bond.

[0205] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention. [Explanation of Symbols]

[0206] 1...Substrate to be processed, 2...Layer to be processed, 2a...Pattern (pattern formed on the processed layer), 3...Resist underlayer film, 3a…Resist underlayer pattern, 4…Silicon-containing resist interlayer, 4a...Silicon-containing resist interlayer pattern, 5...Resist top layer, 5a…Resist upper layer pattern, 6…Exposed area, 7…Underlayment substrate with densely packed lines and spaces, 8…Resist underlayer film.

Claims

1. A method for forming a resist underlayer film, (i) A coating step of applying a resist underlayer film formation composition comprising a metal compound having a metal-oxygen covalent bond and an organic solvent to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) The process comprises the step of irradiating the cured film with plasma to form a resist underlayer film, A method for forming a resist underlayer film, characterized in that the aforementioned metal compound contains at least one crosslinking group represented by the following general formulas (a-1) to (a-4), (b-1) to (b-4), and (c-1) to (c-3). 【Chemistry 1】 (In general formulas (a-1) to (a-4), R ａ (where is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.) 【Chemistry 2】 (In general formulas (b-1) to (b-4), R ｂ R is a hydrogen atom or a methyl group, and in the same formula they may be the same or different from each other. ｃ (where * represents a hydrogen atom, a substituted or unsubstituted saturated or unsaturated monovalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, and * represents a bond.) 【Transformation 3】 (In general formulas (c-1) to (c-3), Y １ R is a divalent organic group having 1 to 20 carbon atoms, R is a hydrogen atom, a substituted or unsubstituted saturated or unsaturated divalent organic group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted arylalkyl group having 7 to 31 carbon atoms, R １ This refers to an organic group represented by the following general formula (1) in which a protecting group is removed by the action of either an acid, heat, or both, generating one or more hydroxyl groups or carboxyl groups, where * represents a bond. 【Chemistry 4】 (In general formula (1), R ２ * is an organic group whose protecting group is removed by the action of acid, heat, or both, and * is Y １ (This represents the connection point.)

2. In the step (iii), N ２ , NF ３ , H ２ , a fluorocarbon, a noble gas, or a mixed gas thereof is used. The method for forming a resist underlayer film according to claim 1, characterized in that.

3. In the above (iii) step, H ２ The method for forming a resist underlayer film according to claim 2, characterized by using a gas containing gas.

4. The method for forming a resist underlayer film according to claim 2, characterized in that a gas containing helium gas is used in the (iii) step.

5. The method for forming a resist underlayer film according to claim 1, characterized in that the cured film is formed by heat treatment in an atmosphere with an oxygen concentration of 1% by volume or more and 21% by volume or less in the (ii) step.

6. The method for forming a resist underlayer film according to claim 1, characterized in that the cured film is formed by heat treatment in an atmosphere with an oxygen concentration of less than 1 volume% in the (ii) step.

7. The method for forming a resist underlayer film according to claim 1, characterized in that in step (ii) above, a cured film is formed by heat treatment at a temperature of 100°C or higher and 450°C or lower for 10 to 7,200 seconds.

8. The method for forming a resist underlayer film according to claim 1, characterized in that the metal contained in the metal compound is titanium, zirconium, hafnium, or a combination thereof.

9. The method for forming a resist underlayer film according to claim 1, characterized in that the aforementioned metal compound further includes a ligand derived from a silicon compound represented by the following general formula (2). 【Transformation 5】 (In general formula (2), R ３Ａ , R ３Ｂ and R ３Ｃ This is one of the following organic groups selected from a C2-C30 organic group having a bridging group in any of the structures shown in the general formulas (d-1) to (d-3) below, a substituted or unsubstituted C1-C20 alkyl group, and a C6-C20 aryl group. 【Transformation 6】 (In general formulas (d-1) to (d-3), R ３ (where is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, q represents 0 or 1, and * represents a bond.)

10. A method for forming a pattern on a substrate to be processed, (I-1) A step of forming a resist underlayer film on a substrate to be processed by a resist underlayer film forming method according to any one of claims 1 to 9. (I-2) A step of forming a silicon-containing resist interlayer on the resist underlayer, (I-3) A step of forming a resist upper layer film on the silicon-containing resist interlayer film using a photoresist material. (I-4) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (I-5) A step of transferring the pattern to the silicon-containing resist interlayer by dry etching, using the resist upper layer on which the pattern is formed as a mask. (I-6) A step of transferring the pattern to the resist underlayer film by dry etching using the silicon-containing resist interlayer film on which the pattern has been transferred as a mask, and (I-7) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

11. A method for forming a pattern on a substrate to be processed, (II-1) A step of forming a resist underlayer film on a substrate to be processed by a resist underlayer film forming method according to any one of claims 1 to 9. (II-2) A step of forming an inorganic hard mask interlayer film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the resist underlayer film, (II-3) A step of forming an organic thin film on the inorganic hard mask interlayer, (II-4) A step of forming a resist upper layer film on the organic thin film using a photoresist material, (II-5) After pattern exposure of the resist upper layer film, develop it with a developer to form a pattern on the resist upper layer film. (II-6) A step of transferring the pattern to the organic thin film and the inorganic hard mask interlayer film by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (II-7) A step of transferring the pattern to the resist underlayer film by dry etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and (II-8) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

12. A method for forming a pattern on a substrate to be processed, (III-1) A step of forming a resist underlayer film on a substrate to be processed by the resist underlayer film forming method described in any one of claims 1 to 9. (III-2) A step of forming an organic interlayer on the resist underlayer, (III-3) A step of forming a combination of an organic thin film and an inorganic hard mask interlayer selected from a silicon-containing resist interlayer, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic interlayer. (III-4) A step of forming a resist upper layer film on the silicon-containing resist interlayer film or the organic thin film using a photoresist material. (III-5) A step of forming a pattern on the resist upper layer film by pattern exposure followed by development with a developer solution. (III-6) A step of transferring the pattern to the silicon-containing resist interlayer or the organic thin film and the inorganic hard mask interlayer by dry etching, using the resist upper layer film on which the pattern is formed as a mask. (III-7) A step of transferring the pattern to the organic interlayer by dry etching, using the silicon-containing resist interlayer or inorganic hard mask interlayer on which the pattern has been transferred as a mask. (III-8) A step of transferring the pattern to the resist underlayer film by dry etching using the organic interlayer film on which the pattern has been transferred as a mask, and (III-9) A step of processing the substrate to be processed using the resist underlayer film on which the pattern is formed as a mask to form a pattern on the substrate to be processed. A pattern forming method characterized by having the following features.

13. A method for forming a resist underlayer film, (i') A coating step of applying a resist underlayer film formation composition containing metals belonging to the 3rd to 7th periods of Groups 3 to 15 of the periodic table to a substrate, (ii) A step of forming a cured film by heat-treating the coated substrate at a temperature of 100°C to 600°C for 10 to 7,200 seconds, (iii) A step of irradiating the cured film with plasma to form a resist underlayer film, A method for forming a resist underlayer film, characterized by comprising the above.

14. The method for forming a resist underlayer film according to claim 13, characterized in that the resist underlayer film formation composition includes a metal compound having a metal-oxygen covalent bond or a metal compound having a metal-carbon covalent bond.

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