Organic film forming material, and pattern forming method and polymer

Abstract

The present invention relates to an organic film forming material, a pattern forming method and a polymer. The object of the present invention is to provide an organic film forming material which does not impair the carbon content of the resin itself and which can exhibit high etching resistance and excellent distortion resistance, and to provide a pattern forming method using the organic film forming material and a polymer suitable for the same. The means for solving the object is an organic film forming material characterized by containing: (A) a polymer having a repeating unit represented by the following general formula (1), and (B) an organic solvent; in the general formula (1), AR1, AR2, AR3 and AR4 are benzene rings or naphthalene rings, W1 is a 4-valent organic group having a carbon number of 6 to 70 and having at least one or more aromatic rings, and W2 is a 2-valent organic group having a carbon number of 1 to 50.

Description

[Technical Field]

[0001] This invention relates to a coating-type organic film forming material suitable for microprocessing in the manufacturing process of semiconductor devices, and a pattern forming method using the organic film forming material suitable for exposure to far-ultraviolet light, KrF excimer laser light (248nm), ArF excimer laser light (193nm), F2 laser light (157nm), Kr2 laser light (146nm), Ar2 laser light (126nm), extreme ultraviolet light (EUV, 13.5nm), electron beam (EB), and X-rays. [Background Technology]

[0002] In recent years, with the increasing integration and speed of semiconductor devices, there is a growing demand for miniaturized patterns. In photolithography, which is currently a common technology, various technologies are being developed to address how to enable the use of light sources to perform fine and high-precision pattern processing.

[0003] Regarding the light source used in photolithography for resist pattern formation, in areas with low integration density, gamma rays (436nm) or i-rays (365nm) from mercury lamps are widely used as light sources for photoexposure. On the other hand, in areas with high integration density and the need for miniaturization, photolithography using shorter wavelengths such as KrF excimer lasers (248nm) and ArF excimer lasers (193nm) has been put into practical use. In the most advanced generation, where further miniaturization is required, extreme ultraviolet (EUV, 13.5nm) photolithography is also close to practical use.

[0004] As resist patterns become increasingly finer, it is well known that in single-layer resist methods, which are typical resist patterning methods, the ratio of pattern height to pattern linewidth (aspect ratio) increases, and the pattern collapses during development due to the surface tension of the developer. Therefore, when forming high aspect ratio patterns on substrates with varying elevations, multilayer resist methods that use films with different dry etching properties to form the pattern are known to be superior. Two-layer resist methods have been developed, combining a photoresist layer based on a silicon-containing photosensitive polymer and a lower layer based on an organic polymer, such as a phenolic varnish polymer, whose main constituent elements are carbon, hydrogen, and oxygen (Patent Document 1, etc.); or three-layer resist methods combining a photoresist layer based on an organic photosensitive polymer used in single-layer resist methods, a lower layer based on a silicon-based polymer or a silicon-based CVD film, and an organic layer based on an organic polymer (Patent Document 2, etc.).

[0005] This three-layer photoresist method first uses a fluorocarbon-based dry etching gas to transfer the pattern of the photoresist layer onto a silicon-containing underlying layer. Using this pattern as a mask, a dry etching process is then performed using an oxygen-based gas to transfer the pattern of an organic film, primarily composed of carbon and hydrogen. This organic film is then used as a mask to form the pattern on the substrate being processed using dry etching. However, in semiconductor device manufacturing processes beyond the 20nm generation, if this organic film pattern is used as a hard mask and dry etching is used to transfer the pattern onto the substrate, distortion or bending of the organic film pattern can be observed.

[0006] For carbon hard masks formed directly on the substrate, amorphous carbon (hereinafter referred to as CVD-C) films prepared by CVD using methane, ethane, acetylene, or other similar gases as raw materials are common. CVD-C films are known to drastically reduce the number of hydrogen atoms in the film, making them very effective for patterns that are twisted or bent as described above. However, it is also known that when the substrate has unevenness, it is difficult to fill such unevenness into a flat surface on the characteristic surface of the CVD process. Therefore, if a substrate with unevenness is filled with a CVD-C film and then patterned with photoresist, the unevenness of the substrate will cause unevenness on the photoresist coating surface, resulting in uneven photoresist film thickness. Consequently, the focus tolerance and pattern shape during photolithography will deteriorate.

[0007] On the other hand, when using spin coating to form an organic film as a carbon hard mask directly formed on the substrate being processed, it is known that the height difference of the substrate with unevenness can be filled into a flat long section. If the substrate is planarized with this organic film material, the thickness variation of the silicon-containing lower layer and the photoresist film formed thereon will be suppressed, the focal latitude of photolithography can be expanded, and a normal pattern can be formed.

[0008] Therefore, there is a need for organic film materials and methods for forming organic films that exhibit high etch resistance during dry etching of substrates and can be formed on substrates using spin coating.

[0009] Previously, in such organic film materials, condensation resins made from carbonyl compounds such as ketones and aldehydes or aromatic alcohols used as condensing agents, particularly phenolic and naphthol-based compounds, were known as materials for forming organic films in the multilayer photoresist method. Examples include the bisphenol fluorene phenolic varnish resin described in Patent Document 2, the bisphenol compound and its phenolic varnish resin described in Patent Document 3, the adamantane phenol compound phenolic varnish resin described in Patent Document 4, and the bisnaphthol compound and its phenolic varnish resin described in Patent Document 5. Although the resins used in such materials are constructed with naphthalene, fluorene, adamantane, etc., which have high carbon density, as the main framework, the degradation of etching resistance caused by oxygen atoms due to phenolic hydroxyl groups cannot be avoided.

[0010] Furthermore, regarding resins used in organic film materials that do not contain heteroatoms such as oxygen in order to avoid compromising etching resistance, for example, the resin with a fluorene structure described in Patent Document 6, however, is used to form a hardened film by using a composition with added crosslinking agents such as hydroxymethyl compounds. Therefore, even if the carbon content of the resin is increased, the presence of crosslinking agents with low carbon content leads to a problem of compromised etching resistance.

[0011] Furthermore, regarding organic film materials used to improve etching resistance, some researchers have explored organic film materials incorporating benzopyran structures, as shown in Patent Document 7. However, there is still room for improvement in various physical properties of organic film materials, such as heat resistance and etching resistance. In addition, the shape of the substrate being processed has become more complex, and various materials are used for the substrate itself, requiring organic film materials with excellent process tolerance.

[0012] [Existing Technical Documents]

[0013] [Patent Literature]

[0014] [Patent Document 1] Japanese Patent Application Publication No. 6-118651

[0015] [Patent Document 2] Japanese Patent Application Publication No. 2005-128509

[0016] [Patent Document 3] Japanese Patent Application Publication No. 2006-293298

[0017] [Patent Document 4] Japanese Patent Application Publication No. 2006-285095

[0018] [Patent Document 5] Japanese Patent Application Publication No. 2010-122656

[0019] [Patent Document 6] WO2013-047106 Publication No.

[0020] [Patent Document 7] WO2017-208796 [Summary of the Invention]

[0021] [The problem that the invention aims to solve]

[0022] The present invention is made in view of the above facts, and aims to provide an organic film forming material that does not impair the carbon content of the resin itself and exhibits high etch resistance and excellent torsion resistance, and to provide a pattern forming method using the organic film forming material and a polymer suitable for such an organic film forming material.

[0023] [Methods for solving the problem]

[0024] To address the aforementioned issues, this invention provides an organic film-forming material comprising:

[0025] (A) A polymer having repeating units represented by the following general formula (1), and

[0026] (B) Organic solvents.

[0027] [Chemistry 1]

[0028]

[0029] In the above general formula (1), AR1, AR2, AR3 and AR4 are benzene rings or naphthalene rings, W1 is a tetravalent organic group with 6 to 70 carbons having at least one aromatic ring, and W2 is a divalent organic group with 1 to 50 carbons.

[0030] The polymer of the present invention represented by general formula (1) utilizes a structure containing a large number of condensed aromatic ring structures with high carbon content to form the main framework, and can further utilize the effect of repeating units containing benzopyran rings to induce cross-linking reaction and form a dense film. Therefore, if an organic film forming material using the polymer of the present invention is used, an organic film with high torsion resistance (bending resistance) and high dry etching resistance can be formed, which is effective when used as an organic film material.

[0031] Moreover, the aforementioned polymer is preferably a polymer having repeating units represented by the following general formula (2) or (3).

[0032] [Chemistry 2]

[0033]

[0034] In the above general formula (2), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above, and AR5 represents a benzene ring or a naphthalene ring.

[0035] [Chemistry 3]

[0036]

[0037] The W2, AR1, AR2, AR3 and AR4 in the above general formula (3) are the same as those mentioned above. W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms. AR6 and AR7 represent benzene rings or naphthalene rings.

[0038] By introducing such a partial structure into the repeating unit, etching resistance and torsion resistance can be further improved.

[0039] Furthermore, the aforementioned polymer is preferably a polymer having repeating units represented by the following general formula (4) or (5).

[0040] [Chemistry 4]

[0041]

[0042] In the above general formula (4), AR5 represents a benzene ring or a naphthalene ring.

[0043] [Chemistry 5]

[0044]

[0045] In the above general formula (5), W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms, and AR6 and AR7 represent benzene rings or naphthalene rings.

[0046] By designing the partial structure in this way, not only can etching resistance and torsion resistance be improved, but also operational performance such as solvent solubility can be enhanced.

[0047] Moreover, the terminal structure of the aforementioned polymer is preferably any one of the following general formulas (6) or (7).

[0048] [Chemistry 6]

[0049]

[0050] In the above general formula (6), AR8 and AR9 represent benzene ring and naphthalene ring, respectively, R1 represents hydrogen atom or monovalent alkyl group with 1 to 10 carbon atoms, and * represents the bonding site with the polymer.

[0051] [Chemistry 7]

[0052]

[0053] In the above general formula (7), AR10 and AR11 are benzene ring and naphthalene ring, R2 is any one of the following formula (8), n represents an integer from 1 to 4, W4 represents an n+2 valence organic group with at least one aromatic ring having a carbon number of 6 to 70, and * represents the bonding site with the polymer.

[0054] [Chemistry 8]

[0055]

[0056] The dashed lines in the above formula represent atomic bonds.

[0057] By introducing such an end structure, it can be hardened by heat or acid to form a dense and torsion-resistant organic membrane.

[0058] Moreover, the weight-average molecular weight of the aforementioned polymer should preferably be between 500 and 5000.

[0059] If the organic film-forming material contains a polymer with such a range of weight-average molecular weights, the solubility in organic solvents will not be compromised and the escape of gases during baking can be suppressed.

[0060] The aforementioned organic solvent (B) is preferably a mixture of one or more organic solvents with a boiling point of less than 180 degrees and one or more organic solvents with a boiling point of more than 180 degrees.

[0061] If the organic solvent is a mixture of the above, the organic film forming material becomes one that simultaneously possesses a high degree of landfill / planarization characteristics by imparting thermal fluidity to the polymer due to the addition of a high-boiling-point solvent.

[0062] The aforementioned organic film forming material preferably contains one or more of the following: (C) acid generating agent, (D) surfactant, (E) crosslinking agent and (F) plasticizer.

[0063] If the organic film forming material contains the above-mentioned additives, it will have better coating properties and landfill / planarization characteristics.

[0064] This invention provides a pattern forming method for forming a pattern on a substrate to be processed. The method is characterized by: forming an organic film on the substrate using the aforementioned organic film forming material; forming a silicon-containing photoresist lower layer film on the organic film using a silicon-containing photoresist lower layer film material; forming a photoresist upper layer film on the silicon-containing photoresist lower layer film using a photoresist composition; forming a circuit pattern on the photoresist upper layer film; using the patterned photoresist upper layer film as a mask and performing pattern transfer on the aforementioned silicon-containing photoresist lower layer film using etching; using the patterned silicon-containing photoresist lower layer film as a mask and performing pattern transfer on the aforementioned organic film using etching; and then using the patterned organic film as a mask and performing etching to form the pattern on the substrate to be processed.

[0065] The patterning method using the above-mentioned three-layer resist process can form fine patterns with high precision on the substrate being processed.

[0066] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed; an organic film is formed on the substrate to be processed using the aforementioned organic film forming material; a silicon-containing photoresist underlayer film material is formed on the organic film to form a silicon-containing photoresist underlayer film; an organic antireflective film (BARC) is formed on the silicon-containing photoresist underlayer film; a photoresist composition is used on the BARC to form a photoresist toplayer film, forming a four-layer film structure; a circuit pattern is formed on the photoresist toplayer film; the patterned photoresist toplayer film is used as a mask and the aforementioned BARC film and the aforementioned silicon-containing photoresist underlayer film are patterned by etching; the patterned silicon-containing photoresist underlayer film is used as a mask and the aforementioned organic film is patterned by etching; and the patterned organic film is used as a mask and the aforementioned substrate to be processed is etched to form a pattern on the substrate to be processed.

[0067] The patterning method using the above-mentioned four-layer resist process can form fine patterns with higher precision on the substrate being processed.

[0068] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed; the method involves forming an organic film on the substrate to be processed using the aforementioned organic film forming material, forming an inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film on the organic film, forming a photoresist top layer film on the inorganic hard mask using a photoresist composition, forming a circuit pattern on the photoresist top layer film, using the patterned photoresist top layer film as a mask and transferring the pattern to the aforementioned inorganic hard mask by etching, using the transferred patterned inorganic hard mask as a mask and transferring the pattern to the aforementioned organic film by etching, and then using the transferred patterned organic film as a mask and etching the aforementioned substrate to form the pattern on the substrate to be processed.

[0069] The patterning method using this 3-layer resist process can form fine patterns with high precision on the substrate being processed.

[0070] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed; the method involves forming an organic film on the substrate to be processed using the aforementioned organic film forming material, forming an inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film on the organic film, forming an organic antireflective film (BARC) on the inorganic hard mask, forming a photoresist top layer film on the BARC using a photoresist composition to form a four-layer film structure, forming a circuit pattern on the photoresist top layer film, using the patterned photoresist top layer film as a mask and transferring the pattern to the aforementioned BARC film and the aforementioned inorganic hard mask by etching, using the transferred patterned inorganic hard mask as a mask and transferring the pattern to the aforementioned organic film by etching, and then using the transferred patterned organic film as a mask and etching the aforementioned substrate to form the pattern on the substrate to be processed.

[0071] The patterning method using this 4-layer resist process can form fine patterns with higher precision on the substrate being processed.

[0072] At this point, the aforementioned inorganic hard mask should be formed using CVD or ALD methods.

[0073] By using CVD or ALD methods to form the aforementioned inorganic hard mask, fine patterns can be formed on the substrate being processed with higher precision.

[0074] The aforementioned method for patterning the upper layer of the resist film is preferably: photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing using an electron beam, nanoimprinting, or a combination of these methods.

[0075] If the above method is used as a method for forming circuit patterns on the upper layer of the above-mentioned resist film, fine patterns can be formed on the substrate being processed with higher precision.

[0076] The development method in the aforementioned pattern formation method should preferably be alkaline development or development using organic solvents.

[0077] If alkaline development or organic solvent development is used as the development method, fine patterns can be formed on the substrate with higher precision.

[0078] The aforementioned substrate to be processed is preferably a semiconductor device substrate, a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film.

[0079] In this invention, for example, the aforementioned substrate can be used with regard to the substrate being processed.

[0080] The aforementioned metals are preferably silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, cobalt, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, manganese, molybdenum, ruthenium, or alloys thereof.

[0081] These can be used as the aforementioned metals. By using the organic film forming material of the present invention to perform patterning, a pattern of the upper photoresist can be formed on the processed substrate with high precision transfer.

[0082] The present invention provides a polymer having repeating units represented by the following general formula (1).

[0083] [Chemistry 9]

[0084]

[0085] In the above general formula (1), AR1, AR2, AR3 and AR4 are benzene rings or naphthalene rings, W1 is a tetravalent organic group with 6 to 70 carbons having at least one aromatic ring, and W2 is a divalent organic group with 1 to 50 carbons.

[0086] If it is a polymer represented by general formula (1), then because the repeating unit contains multiple condensed aromatic ring structures and fused ring structures, it becomes a polymer for forming organic films with excellent heat resistance, torsion resistance and dry etching resistance.

[0087] The aforementioned polymer preferably has repeating units represented by the following general formula (2) or (3).

[0088] [Chemistry 10]

[0089]

[0090] In the above general formula (2), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above, and AR5 represents a benzene ring or a naphthalene ring.

[0091] [Chemistry 11]

[0092]

[0093] The W2, AR1, AR2, AR3 and AR4 in the above general formula (3) are the same as those mentioned above. W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms. AR6 and AR7 represent benzene rings or naphthalene rings.

[0094] The aforementioned polymer preferably has repeating units represented by the following general formula (4) or (5).

[0095] [Chemistry 12]

[0096]

[0097] In the above general formula (4), AR5 represents a benzene ring or a naphthalene ring.

[0098] [Chemistry 13]

[0099]

[0100] In the above general formula (5), W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms, and AR6 and AR7 represent benzene rings or naphthalene rings.

[0101] Because such repeating units contain multiple cardo structures, when used as polymers for organic film forming materials, various physical properties such as etching resistance, heat resistance, landfill characteristics, planarization characteristics, and solvent solubility can be balanced.

[0102] The terminal structure of the aforementioned polymer is preferably any one of the following general formulas (6) or (7).

[0103] [Chemistry 14]

[0104]

[0105] In the above general formula (6), AR8 and AR9 represent benzene ring and naphthalene ring, respectively, R1 represents hydrogen atom or monovalent alkyl group with 1 to 10 carbon atoms, and * represents the bonding site with the polymer.

[0106] [Chemistry 15]

[0107]

[0108] In the above general formula (7), AR10 and AR11 are benzene ring and naphthalene ring, R2 is any one of the following formula (8), n represents an integer from 1 to 4, W4 represents an n+2 valence organic group with at least one aromatic ring having a carbon number of 6 to 70, and * represents the bonding site with the polymer.

[0109] [Chemistry 16]

[0110]

[0111] The dashed lines in the above formula represent atomic bonds.

[0112] Such end structures function as hardening groups and undergo thermal cross-linking due to heat or acid, becoming polymers used in organic film forming materials that can form dense organic films.

[0113] [The effects of the invention]

[0114] As explained above, the polymer of the present invention, by utilizing a structure containing a large number of condensed aromatic rings to form the main framework, is an effective polymer for forming organic films with excellent etching resistance and torsion resistance. Furthermore, the organic film forming material containing this polymer is an effective material for forming organic films with excellent etching resistance, torsion resistance, and also possessing heat resistance, packing / planarization characteristics, and many other properties. Therefore, it is extremely effective as an organic film forming material in multilayer resist processes, such as two-layer resist processes, three-layer resist processes using a silicon-containing resist underlayer film, or four-layer resist processes using a silicon-containing resist underlayer film and an organic antireflective film. Furthermore, in the pattern forming method of the present invention, fine patterns can be formed with high precision on the processed substrate in a multilayer resist process. [Attached Image Description]

[0115] [ Figure 1 (A) to (F) are explanatory figures illustrating an example of the patterning method of the present invention using a three-layer resist process.

[0116] [ Figure 2 [Illustrative diagram of the flattening characteristic evaluation method in the embodiment.]

Detailed Implementation Methods

[0117] We are currently seeking organic film-forming materials that do not compromise the carbon content of the resin itself and exhibit high etch resistance and excellent torsion resistance, patterning methods using such organic film-forming materials, and polymers suitable for such organic film-forming materials.

[0118] The inventors of this application discovered that the polymer of the present invention, by utilizing a large number of structures containing condensed aromatic rings to form the main framework, is an effective polymer for forming organic films with excellent etching resistance and torsion resistance, thus completing the present invention.

[0119] That is, the present invention is an organic film forming material containing:

[0120] (A) A polymer having repeating units represented by the following general formula (1), and

[0121] (B) Organic solvents.

[0122] [Chemistry 17]

[0123]

[0124] In the above general formula (1), AR1, AR2, AR3 and AR4 are benzene rings or naphthalene rings, W1 is a tetravalent organic group with 6 to 70 carbons having at least one aromatic ring, and W2 is a divalent organic group with 1 to 50 carbons.

[0125] The following describes embodiments of the present invention, but the present invention is not limited thereto.

[0126] [(A) Polymers having repeating units represented by general formula (1)]

[0127] The partial structures of the polymers in the above general formula (1) in the fluorene form, consisting of AR1, AR2, AR3, and AR4, can be exemplified as follows. These aromatic rings may also have substituents such as vinyl, ethynyl, ethynylphenyl, allyl, propargyl, aryl, allyloxy, and propargyloxy. Among the following, the fluorene and benzo[a]fluorene structures are more ideal considering the ease of obtaining the raw materials.

[0128] [Chemistry 18]

[0129]

[0130] Dashed lines represent atomic bonds.

[0131] In the above general formula (1), W1 is a tetravalent organic group with 6 to 70 carbon atoms having at least one aromatic ring, and specific examples include the structures shown below.

[0132] [Chemistry 19]

[0133]

[0134] [Chemistry 20]

[0135]

[0136] [Chemistry 21]

[0137]

[0138] Dashed lines represent atomic bonds.

[0139] The tetravalent organic group represented by W1 should ideally have an atomic bond on the aromatic ring, with the atomic bond located adjacent to each other on one side of the aromatic ring. In this case, it forms two sets of benzopyran-type heterocyclic structures with the substituent at the 9-position of fluorene. By adopting such a structure, hardening properties are improved, as are heat resistance and etching resistance.

[0140] In the above general formula (1), W2 is a divalent organic group with 1 to 50 carbon atoms, and specific examples can be shown in the following structures.

[0141] [Chemistry 22]

[0142]

[0143] Dashed lines represent atomic bonds.

[0144] Furthermore, the polymer of the present invention preferably has repeating units represented by the following general formula (2) or (3).

[0145] [Chemistry 23]

[0146]

[0147] In the above general formula (2), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above, and AR5 represents a benzene ring or a naphthalene ring.

[0148] [Chemistry 24]

[0149]

[0150] The W2, AR1, AR2, AR3 and AR4 in the above general formula (3) are the same as those mentioned above. W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms. AR6 and AR7 represent benzene rings or naphthalene rings.

[0151] AR5 in the above general formula (2) represents a benzene ring or a naphthalene ring, and the following are ideal examples. Among them, the naphthalene ring is more ideal from the perspective of etch resistance.

[0152] [Chemistry 25]

[0153]

[0154] Ideal examples of the tetravalent organic groups composed of AR6, AR7, and W3 in the above general formula (3) are as follows, among which those having a naphthalene ring and a fluorene structure are particularly preferred, and those having both a naphthalene ring and a fluorene ring structure are especially preferred.

[0155] [Chemistry 26]

[0156]

[0157] Furthermore, the polymers of the present invention preferably have repeating units represented by the following general formula (4) or (5).

[0158] [Chemistry 27]

[0159]

[0160] In the above general formula (4), AR5 represents a benzene ring or a naphthalene ring.

[0161] [Chemistry 28]

[0162]

[0163] In the above general formula (5), W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms, and AR6 and AR7 represent benzene rings or naphthalene rings.

[0164] Thus, the divalent organic group represented by W2 is preferably a benzene ring, and the structure composed of AR1, AR2, AR3 and AR4 is fluorene, which is particularly good considering the ease of obtaining raw materials.

[0165] Furthermore, the end structure of the polymer of the present invention is preferably any of the following general formulas (6) or (7).

[0166] [Chemistry 29]

[0167]

[0168] In the above general formula (6), AR8 and AR9 represent benzene ring and naphthalene ring, respectively, R1 represents hydrogen atom or monovalent alkyl group with 1 to 10 carbon atoms, and * represents the bonding site with the polymer.

[0169] [Chemistry 30]

[0170]

[0171] In the above general formula (7), AR10 and AR11 are benzene ring and naphthalene ring, R2 is any one of the following formula (8), n represents an integer from 1 to 4, W4 represents an n+2 valence organic group with at least one aromatic ring having a carbon number of 6 to 70, and * represents the bonding site with the polymer.

[0172] [Chemistry 31]

[0173]

[0174] The dashed lines in the above formula represent atomic bonds.

[0175] The above general formula (6) can be exemplified as follows. Among them, considering the ease of obtaining raw materials, the structure composed of AR8 and AR9 is fluorene and R1 is hydrogen atom, which is particularly good.

[0176] [Chemistry 32]

[0177]

[0178] In the above formula, * indicates the bonding site of the polymer.

[0179] The structures of AR8, AR9, and R1 can be adjusted to meet desired performance requirements. For example, by adjusting the alkyl chain length of R1, the polymer's solvent solubility, thermal fluidity, and curability can be controlled. Furthermore, by introducing naphthalene rings into AR8 and AR9 to improve heat resistance and etch resistance, or by setting AR8 and AR9 as a combination of benzene and naphthalene rings, the polymer's cohesiveness can be reduced and its solvent solubility improved.

[0180] The above general formula (7) can be exemplified as follows. Among them, considering the ease of obtaining raw materials, the structure composed of AR10 and AR11 is preferably fluorene and W4 is a benzene ring or a naphthalene ring.

[0181] [Chemistry 33]

[0182]

[0183] [Chemistry 34]

[0184]

[0185] In the above formula, * indicates the bonding site of the polymer.

[0186] The structures of AR10, AR11, and W4 can be adjusted to meet requirements for etching resistance, heat resistance, solvent solubility, and thermal fluidity. The structure of R2, which functions as a thermosetting group as indicated in equation (8), can also be appropriately selected based on the baking temperature. For example, when AR10 and AR11 are benzene rings, they have fluorene structures, and the raw materials are readily available. The same applies when W4 is a benzene ring or a naphthalene ring. Furthermore, by introducing a large amount of condensed aromatic ring structures containing fluorene structures into W4, improvements in heat resistance and etching resistance can be expected. Additionally, by increasing the substitution amount of R2, the baking temperature can be lowered.

[0187] Furthermore, the Mw (weight-average molecular weight) of the polymer described above is preferably 500 to 5000, and more preferably 600 to 4000. Additionally, the molecular weight can be obtained in the form of the weight-average molecular weight (Mw) converted from polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran as the mobile phase.

[0188] Such a molecular weight ensures solubility in organic solvents and suppresses sublimation during baking. Furthermore, because the polymer used in the organic film-forming material has good thermal fluidity, when incorporated into the composition, it can not only effectively fill the microstructure already formed on the substrate, but also form an organic film that makes the entire substrate flat.

[0189] [Polymer Manufacturing Methods]

[0190] In one example of the method for manufacturing a polymer having repeating units represented by general formula (1) of the present invention, the polymer can be synthesized by repeatedly using a diol compound with W1 as a partial structure shown below and fluorene alcohols composed of AR1, AR2, AR3, AR4 and W2 as monomers, accompanied by dehydration cyclization reactions. In order to form a benzopyran structure by utilizing condensation, the hydroxyl group of the diol represents a phenolic hydroxyl group, and the diol compound specifically represents phenyl glycols such as catechol and resorcinol; or naphthalene glycols such as 1,5-dihydroxynaphthalene and 2,6-dihydroxynaphthalene; bisphenols such as bisphenol A and dihydroxyphenylfluorene; and bisnaphthols such as dihydroxynaphthylfluorene. W1, AR1, AR2, AR3, AR4 and W2 in the following formula are the same as those described above.

[0191] [Chemistry 35]

[0192]

[0193] The aforementioned polymers can typically be obtained in organic solvents in the presence of an acid catalyst at room temperature or, if necessary, under cooling or heating. Regarding the acid catalyst used, inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropoly acids can be used; organic acids such as oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid can be used; and Lewis acids such as aluminum trichloride, aluminum ethoxide, aluminum isopropoxide, boron trifluoride, boron trichloride, boron tribromide, tin tetrachloride, tin tetrabromide, dibutyltin dichloride, dimethoxydibutyltin, dibutyltin oxide, titanium tetrachloride, titanium tetrabromide, methoxytitanium (IV), ethoxytitanium (IV), isopropoxytitanium (IV), and titanium oxide (IV) can be used.

[0194] There are no particular restrictions on the organic solvents used. Examples include alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as dichloromethane, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; and nonprotic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These solvents can be used alone or in combination of two or more.

[0195] Regarding reaction methods, there are methods that feed the glycol compound, fluorene alcohol, and acid catalyst in a single step; methods that disperse or dissolve the glycol compound or fluorene alcohol before adding the catalyst in a single step or in stages, or methods that dilute with a solvent and add dropwise; and methods that disperse or dissolve the catalyst before adding the fluorene alcohol or glycol compound in a single step or in stages, or methods that dilute with a solvent and add dropwise. After the reaction is complete, to remove the catalyst used in the reaction, it can be diluted in an organic solvent, separated, and the target substance can be recovered.

[0196] Regarding the organic solvent used, there are no particular restrictions if it can dissolve the target substance and separate into two layers when mixed with water. Examples include hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, and ethylcyclopentyl methyl ether; chlorinated solvents such as dichloromethane, chloroform, dichloroethane, and trichloroethylene; and mixtures thereof. The cleaning water used can be deionized water or ultrapure water. One or more cleaning cycles are sufficient; even more than 10 cycles may not achieve the desired cleaning effect, so approximately 1 to 5 cycles are recommended.

[0197] To remove acidic components from the system during separation and washing, alkaline aqueous solutions can also be used. Specific examples of alkalis include: alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, ammonia, and organic ammonium compounds.

[0198] In addition, acidic aqueous solutions can be used to remove metallic impurities or alkaline components from the system during separation and washing. Specific examples of acids include: inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropolymeric acids; and organic acids such as oxalic acid, fumaric acid, maleic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0199] The separation cleaning using alkaline and acidic aqueous solutions described above can be performed using only one or a combination of both. Ideally, separation cleaning should be performed in the order of alkaline and acidic aqueous solutions to remove metallic impurities.

[0200] After the separation and cleaning process using alkaline and acidic aqueous solutions, a subsequent cleaning with neutral water can be performed. One or more cleaning cycles are sufficient, ideally approximately 1 to 5 times. Deionized water or ultrapure water, as described above, can be used as the neutral water. While one or more cleaning cycles are generally sufficient, fewer cycles may result in the inability to remove alkaline or acidic components. Even 10 or more cleaning cycles may not guarantee the desired cleaning effect; therefore, approximately 1 to 5 cycles are recommended.

[0201] Furthermore, the reaction products after the liquid-liquid separation operation can be concentrated and dried by reducing the pressure or normal pressure, or subjected to crystallization, and recovered in powder form. However, to improve the operability when preparing organic film-forming materials, a solution of appropriate concentration can also be prepared beforehand. The concentration should preferably be 0.1–50% by mass, with 0.5–30% by weight being more preferable. Such a concentration prevents the viscosity from increasing too much, thus avoiding compromised operability, and is also economical because the amount of solvent is not excessive.

[0202] Regarding the solvent used, there are no particular restrictions if it is a solvent that can dissolve the polymer. Specific examples include: ketones such as cyclohexanone and methyl-2-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate. These can be used alone or in combination of two or more.

[0203] The polymer of the present invention having the terminal structure represented by general formula (6) can be obtained, for example, by reacting the above-mentioned diol compound with fluorene alcohol in an excess ratio, and then capping the end with an alcohol represented by water or R1-OH, as described below. AR1, AR2, AR3, AR4, AR8, AR9, W1, W2 and R1 in the following formula are the same as those described above.

[0204] [Chemistry 36]

[0205]

[0206] The polymer of the present invention having the terminal structure represented by general formula (7) can be obtained, for example, by reacting the above-mentioned diol compound with fluorene alcohol in an excess ratio, and then capping it with an alcohol having W4 as a partial structure, as described below. AR1, AR2, AR3, AR4, AR10, AR11, W1, W2, W4, R2, and n in the following formula are the same as those described above.

[0207] [Chemistry 37]

[0208]

[0209] The reaction and recovery methods of the above-mentioned polymers can be carried out using the methods described in the section on the method for synthesizing polymers having repeating units represented by general formula (1) in the manufacturing method of the above-mentioned polymers.

[0210] Furthermore, when R2 in the terminal structural group represented by general formula (7) of the polymer used in the organic film forming material of the present invention is propargyl ether, it is possible to exemplify the following: in the first stage, the feed ratio of the above-mentioned diol compound and fluorene alcohol is set to an excess of the diol compound to react and synthesize a polymer with residual alcohol at the end, and then the residual alcohol is propargyl etherified as the second stage. If the reaction can introduce propargyl ether group, there are no particular limitations, and examples include the following substitution reaction using a halide or toluene sulfonate or methanesulfonate with propargyl group and a base catalyst. X in the following formula represents halogen, toluene sulfonyl group or methanesulfonyl group, and AR1, AR2, AR3, AR4, AR10, AR11, W1, W2, W4 in the following formula are the same as those described above.

[0211] [Chemistry 38]

[0212] (Phase 1)

[0213]

[0214] [Chemistry 39]

[0215] (Phase 2)

[0216]

[0217] In the above general formula, W4 and W1 are the same.

[0218] The base catalysts used in substitution reactions can include inorganic base compounds such as sodium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, and potassium phosphate; and organic amine compounds such as triethylamine, pyridine, and N-methylmorpholine. They can be used alone or in combination of two or more.

[0219] There are no particular restrictions on the solvents used at this time if they are not reactive to the above reactions. For example, ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; aromatic solvents such as benzene, toluene, and xylene; acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, and water can be used alone or in combination.

[0220] Regarding the reaction method and the polymer recovery method, the recovery can be carried out using the method described in the above-mentioned polymer manufacturing method for synthesizing polymers having repeating units represented by general formula (1).

[0221] The preparation of polymers used in organic film-forming materials obtained by this method allows for the use of various halides, toluenesulfonates, and methanesulfonates, either alone or in combination, to meet specific performance requirements. For example, side-chain structures contributing to improved planarization properties and rigid aromatic ring structures contributing to etch resistance and heat resistance can be combined in any proportion. Therefore, organic film-forming materials using these polymers can achieve a high degree of combination of landfill / planarization properties and etch resistance.

[0222] As described above, the polymer used in the organic film forming material of the present invention is an organic film forming material that can exhibit high etch resistance and excellent torsion resistance.

[0223] <Organic Film Forming Materials>

[0224] Furthermore, the present invention provides a material for forming organic films, which is an organic film forming material containing (A) the polymer for forming organic films described above and (B) an organic solvent. Additionally, in the organic film forming material of the present invention, multiple polymers for forming organic films can be used alone or in combination.

[0225] [(B) Organic solvents]

[0226] Regarding the organic solvent used in the organic film-forming material of the present invention, there are no particular limitations as long as it can dissolve the aforementioned polymer (base polymer) and, when containing the acid-generating agent, crosslinking agent, other additives, etc., described later. Specifically, solvents with a boiling point not reaching 180°C, such as those described in paragraphs

[0091] to

[0092] of Japanese Patent Application Publication No. 2007-199653, can be used. Among them, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and mixtures of two or more thereof are ideally used. The amount of organic solvent incorporated relative to 100 parts of the aforementioned polymer in (A) is preferably 200 to 10,000 parts, and more preferably 300 to 5,000 parts.

[0227] If it is such an organic film forming material, it can be coated by spin coating. Furthermore, since it contains the polymer of the organic film forming material of the present invention as described above, it becomes an organic film forming material with good dry etching resistance, as well as heat resistance and a high degree of landfill / planarization characteristics.

[0228] Furthermore, in the organic film-forming material of the present invention, regarding the organic solvent, a high-boiling-point solvent (a mixture of a solvent with a boiling point of less than 180°C and a solvent with a boiling point of 180°C or higher) may be added to the solvent with a boiling point of less than 180°C. Regarding the high-boiling-point organic solvent, if it is a polymer that can dissolve the organic film-forming material, there are no particular limitations on hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc. Specific examples include: 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecylol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol. Alcohols, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, n-nonyl acetate, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol diethyl ether, triethylene glycol diethyl ether, di ... Ethylene glycol monomethyl ether, triethylene glycol n-butyl ether, triethylene glycol butyl methyl ether, triethylene glycol diacetate, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol n-propyl ether, dipropylene glycol n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol n-propyl ether, tripropylene glycol 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, triacetyl ester, Propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butanediol diacetate, 1,6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, dibutyl adipate, etc., can be used alone or in combination.

[0229] The boiling point of the aforementioned high-boiling-point solvent can be appropriately selected in conjunction with the heat treatment temperature of the organic film-forming material. The boiling point of the added high-boiling-point solvent should preferably be between 180℃ and 300℃, with 200℃ to 300℃ being more desirable. With such a boiling point, there is no concern about excessively rapid evaporation during baking (heat treatment) due to a low boiling point, thus ensuring sufficient thermal fluidity. Furthermore, with such a boiling point, the boiling point will not be too high, and there will be no residue remaining in the film after baking without evaporation, thus eliminating concerns about adverse effects on film properties such as etching resistance.

[0230] Furthermore, when using the aforementioned high-boiling-point solvent, the amount of high-boiling-point solvent should preferably be set to 1 to 30 parts by mass relative to 100 parts by mass of solvent with a boiling point not reaching 180°C. If such an amount of solvent is used, there is no concern that the amount of solvent used is too small and cannot impart sufficient thermal fluidity during baking, or that the amount of solvent used is too large and remains in the film, thereby causing deterioration of film properties such as etching resistance.

[0231] If such an organic film forming material is used, then by imparting thermal fluidity to the organic film forming material due to the addition of a high-boiling-point solvent, it becomes an organic film forming composition with both high landfill / planarization characteristics.

[0232] [(C) Acid generating agent]

[0233] In the organic film-forming material of the present invention, an acid-generating agent (C) may be added to further promote the curing reaction. The acid-generating agent may be one that generates acid through thermal decomposition or one that generates acid through light exposure; either one may be added. Specifically, the material described in paragraphs

[0061] to

[0085] of Japanese Patent Application Publication No. 2007-199653 may be added, but it is not limited thereto.

[0234] The acid generating agent described above can be used alone or in combination of two or more. The amount of acid generating agent added relative to 100 parts of the polymer mentioned in (A) is preferably 0.05 to 50 parts, and more preferably 0.1 to 10 parts.

[0235] [(D) Surfactant]

[0236] In the organic film-forming material of the present invention, a surfactant (D) may be added to improve the coatability during spin coating. For example, the surfactants described in

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953 may be used. The amount of surfactant added is preferably 0.01 to 10 parts, and more preferably 0.05 to 5 parts, relative to 100 parts of the aforementioned polymer (A).

[0237] [(E) Crosslinking agent]

[0238] Furthermore, in the organic film-forming material of the present invention, a crosslinking agent (E) may be added to improve curability and further suppress mixing with the upper film. There are no particular limitations on the crosslinking agent, and various known systems of crosslinking agents can be widely used. Examples include: melamine-based crosslinking agents, glycourea-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, and epoxy-based crosslinking agents.

[0239] Examples of melamine-based crosslinking agents include hexamethoxymethylated melamine, hexabutoxymethylated melamine, their alkoxy and / or hydroxyl substituents, and their partial self-condensation products. Examples of glycourea-based crosslinking agents include tetramethoxymethylated glycourea, tetrabutoxymethylated glycourea, their alkoxy and / or hydroxyl substituents, and their partial self-condensation products. Examples of benzoguanidine-based crosslinking agents include tetramethoxymethylated benzoguanidine, tetrabutoxymethylated benzoguanidine, their alkoxy and / or hydroxyl substituents, and their partial self-condensation products. Examples of urea-based crosslinking agents include dimethoxymethylated dimethoxyethylidene urea, its alkoxy and / or hydroxyl substituents, and their partial self-condensation products. Examples of β-hydroxyalkylamide-based crosslinking agents include N,N,N',N'-tetra(2-hydroxyethyl)hexamethylenediamide. Examples of isocyanurate-based crosslinking agents include tricyclooxypropyl isocyanurate and triallyl isocyanurate. Examples of aziridine-based crosslinking agents include 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bishydroxymethylbutanol-tris[3-(1-aziridine)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-tert-butyl-2-oxazoline, 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyloxazoline copolymers. Specific examples of epoxy-based crosslinking agents include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanediethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and neopentyl terephthalol tetraglycidyl ether. The amount of crosslinking agent added relative to 100 parts of the aforementioned polymer in (A) is preferably 1 to 100 parts, and more preferably 5 to 50 parts.

[0240] [(F) Plasticizer]

[0241] Furthermore, in the organic film forming material of the present invention, a plasticizer (F) may be added to further improve the planarization / landfill characteristics. There are no particular limitations on the plasticizer, and a wide range of known plasticizer systems can be used. Examples include: low molecular weight compounds such as phthalates, adipates, phosphates, trimellitic esters, and citrates; and polymers such as polyether-based, polyester-based, and polyacetal-based polymers as described in Japanese Patent Application Laid-Open No. 2013-253227. The amount of plasticizer added is preferably 1 to 100 parts, and more preferably 5 to 30 parts, relative to 100 parts of the aforementioned polymer (A).

[0242] Furthermore, in the organic film-forming material of the present invention, for additives used to impart landfill / planarization properties in the same way as plasticizers, liquid additives having polyethylene glycol or polypropylene glycol structures, or thermally degradable polymers with a weight loss rate of 40% or more from 30°C to 250°C and a weight-average molecular weight of 300 to 200,000, are ideally used. The thermally degradable polymer is preferably one containing repeating units having an acetal structure represented by the following general formulas (DP1) and (DP1a).

[0243] [Chemistry 40]

[0244]

[0245] In the formula, R6 is a hydrogen atom or a monovalent organic group with 1 to 30 carbon atoms that may be substituted. Y1 is a divalent organic group with 2 to 30 carbon atoms that may be saturated or unsaturated.

[0246] [Chemistry 41]

[0247]

[0248] In the formula, R 6a It is an alkyl group having 1 to 4 carbon atoms. a It consists of a saturated or unsaturated divalent hydrocarbon group with 4 to 10 carbon atoms, and may also have an ether bond. n represents the average number of repeating units, which is 3 to 500.

[0249] [(G) Other ingredients]

[0250] In the organic film-forming material of the present invention, other compounds or polymers may be further incorporated. The compound or polymer incorporated will play a role in mixing with the organic film-forming material of the present invention and improving the film-forming properties of spin coating or the filling characteristics of substrates with elevation differences.

[0251] Such materials can be listed as follows: phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-triphenylmethylphenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol. 2-Methoxyphenol, 3-Methoxyphenol, 2-Propylphenol, 3-Propylphenol, 4-Propylphenol, 2-Isopropylphenol, 3-Isopropylphenol, 4-Isopropylphenol, 2-Methoxy-5-Methylphenol, 2-T-butyl-5-Methylphenol, Gallnutol, Thymol, Isothymol, 4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-Dimethyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-Diallyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-Difluoro-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-Diphenyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-Dimethoxy -4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,3,2',3'-tetrahydro-(1,1')-spiroindene-6,6'-diol, 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spiroindene-6,6'-diol, 3,3,3',3',4,4'-hexamethyl-2,3 2',3'-Tetrahydro-(1,1')-spirobindin-6,6'-diol, 2,3,2',3'-Tetrahydro-(1,1')-spirobindin-5,5'-diol, 5,5'-Dimethyl-3,3,3',3'-Tetramethyl-2,3,2',3'-Tetrahydro-(1,1')-spirobindin-6,6'-diol, 1-Naphthol, Phenolic varnish resins of 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol and 1,5-dihydroxynaphthol, 1,7-dihydroxynaphthol, 2,6-dihydroxynaphthol and other dihydroxynaphthols, methyl 3-hydroxynaphthyl-2-carboxylate, indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthene, biphenyl, bisphenol, triphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norcamphene, 5-vinylnorcamphene-2-ene, α-pinene, β-pinene, limonene and other phenolic resins, polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinylanthracene, polyvinylcarbazole, polyindene, polyacenaphthene, polynorcamphene, polycyclodecene, polytetracyclododecene, polynortricycloene, poly(meth)acrylates and their copolymers.Furthermore, it may also be blended with naphthol dicyclopentadiene copolymer as disclosed in Japanese Patent Application Publication No. 2004-205685, bisphenol fluorene phenolic varnish resin as disclosed in Japanese Patent Application Publication No. 2005-128509, acenaphthene copolymer as disclosed in Japanese Patent Application Publication No. 2005-250434, fullerene with phenol group as disclosed in Japanese Patent Application Publication No. 2006-227391, bisphenol compound and its phenolic varnish resin as disclosed in Japanese Patent Application Publication No. 2006-293298, phenolic varnish resin of adamantane phenol compound as disclosed in Japanese Patent Application Publication No. 2006-285095, bisnaphthol compound and its phenolic varnish resin as disclosed in Japanese Patent Application Publication No. 2010-122656, and fullerene resin compound as disclosed in Japanese Patent Application Publication No. 2008-158002, etc.

[0252] The amount of the compound or polymer used for blending is preferably 0 to 1,000 parts by weight, and more preferably 0 to 500 parts by weight, relative to 100 parts by weight of the organic film forming material of the present invention.

[0253] Furthermore, the organic film forming material of the present invention can be used alone or in combination of two or more. The above-mentioned organic film forming material can be used in the applications of organic film materials or planarization materials for semiconductor device manufacturing.

[0254] Furthermore, the organic film forming material of the present invention is extremely effective as an organic film material for multilayer resist processes, such as a two-layer resist process, a three-layer resist process using a silicon-containing lower layer film, and a four-layer resist process using a silicon-containing inorganic hard mask lower layer film and an organic antireflective film.

[0255] (Methods for forming organic films)

[0256] The present invention provides a method for forming an organic film that functions as a multilayer resist film used in photolithography or as a planarization film for semiconductor manufacturing using the above-mentioned organic film forming material.

[0257] The organic film forming method using the organic film forming material of the present invention involves coating the aforementioned organic film forming material onto a substrate to be processed using a spin coating method or the like. By using a spin coating method or the like, good embedding characteristics can be obtained. After spin coating, baking (heat treatment) is performed to evaporate the solvent and prevent mixing with the upper or lower resist film, and to promote the crosslinking reaction. Baking is preferably performed in the range of 100°C to 600°C for 10 to 600 seconds, and more preferably in the range of 200°C to 500°C for 10 to 300 seconds. Considering the impact on device damage and wafer deformation, the upper limit of the heating temperature for the photolithography wafer process is preferably set to 600°C or lower, and more preferably 500°C or lower.

[0258] Furthermore, the organic film forming method using the organic film forming material of the present invention can also form an organic film by coating the organic film forming material of the present invention onto a substrate using a spin coating method as described above, and then calcining the organic film forming material in an environment with an oxygen concentration of 0.1% or more and 21% or less to harden it.

[0259] By calcining the organic film-forming material of the present invention in such an oxygen environment, a sufficiently hardened film can be obtained. The baking environment is not affected by air; however, pre-sealing with inert gases such as N2, Ar, or He to reduce oxygen is preferable as it prevents oxidation of the organic film. To prevent oxidation, the oxygen concentration must be controlled, preferably below 1000 ppm, and more preferably below 100 ppm. Preventing oxidation of the organic film during baking is ideal because it avoids increased absorption or decreased etching resistance.

[0260] The organic film forming method using the organic film forming material of the present invention can obtain a flat hardened film regardless of the unevenness of the substrate being processed due to its excellent filling / planarization characteristics. Therefore, it is extremely effective when forming a flat hardened film on a structure with a height of 30 nm or more or on a substrate with a height difference.

[0261] In addition, the thickness of the organic film, such as the organic film or the planarization film for manufacturing semiconductor devices, is appropriately selected, preferably set to 30 to 20,000 nm, and preferably 50 to 15,000 nm.

[0262] (Pattern Formation Method)

[0263] This invention provides a pattern forming method for forming a pattern on a substrate using a three-layer resist process with an organic film forming material. The method involves forming an organic film on the substrate using the organic film forming material of this invention, forming a silicon-containing lower resist film on the organic film, forming an upper resist film on the silicon-containing lower resist film using a photoresist composition, and creating a multilayer resist film. After exposing the patterned circuit area of ​​the upper resist film, the resist is developed using a developer to form a resist pattern on the upper resist film. This resist pattern is then used as an etching mask to transfer the pattern onto the silicon-containing lower resist film. The silicon-containing lower resist film pattern is then used as an etching mask to transfer the pattern onto the organic film using etching. Finally, the organic film pattern is used as an etching mask to transfer the pattern onto the substrate.

[0264] Since the silicon-containing photoresist underlayer film in the above-mentioned three-layer photoresist process exhibits etching resistance to oxygen or hydrogen, it is advisable to use an etching gas mainly composed of oxygen or hydrogen to perform dry etching of the organic film using the silicon-containing photoresist underlayer film as a mask in the above-mentioned three-layer photoresist process.

[0265] Regarding the silicon-containing photoresist underlayer film in the aforementioned three-layer photoresist process, a polysiloxane-based underlayer film can also be ideally used. By giving the silicon-containing photoresist underlayer film an anti-reflective effect, reflection can be suppressed. Especially for 193nm exposure, if an organic film uses a material containing a large number of aromatic groups and with high etching selectivity to the substrate, the k-value will become high and the substrate reflection will become high. However, by giving the silicon-containing photoresist underlayer film an absorption value that is appropriate to a certain k-value, reflection can be suppressed, and the substrate reflection can be controlled to below 0.5%. Regarding silicon-containing photoresist underlayer films with anti-reflective effects, for 248nm and 157nm exposure, polysiloxanes cross-linked with acid or heat and draped anthracene can be ideally used, while for 193nm exposure, polysiloxanes cross-linked with acid or heat and draped phenyl groups or light-absorbing groups with silicon-silicon bonds can be ideally used.

[0266] Furthermore, a four-layer resist process using an organic antireflective film is also ideal. In this process, an organic film is formed by using the organic film forming material of the present invention on at least the substrate being processed; a silicon-containing resist lower layer film is formed on the organic film using a silicon-containing resist lower layer film material; an organic antireflective film is formed on the silicon-containing resist lower layer film; and a resist upper layer film film of a photoresist composition is formed on the organic antireflective film to form a resist upper layer film, thus forming a multilayer resist film. The pattern of the above-mentioned resist upper layer film is then electrically... After the area is exposed, a resist pattern is formed on the upper resist film by developing with a developer. The obtained resist pattern is used as an etching mask and the pattern is transferred to the organic anti-reflective film and the silicon-containing resist lower film by etching. The obtained silicon-containing resist lower film pattern is used as an etching mask and the pattern is transferred to the organic film by etching. The obtained organic film pattern is then used as an etching mask and the pattern is transferred to the substrate being processed by etching. A semiconductor device circuit pattern can be formed on the substrate.

[0267] Alternatively, the silicon-containing photoresist lower layer film can be replaced by forming an inorganic hard mask. In this case, an organic film is formed by using the organic film forming material of the present invention on at least the substrate to be processed. An inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film is formed on the organic film. An upper photoresist film composed of a photoresist composition is formed on the inorganic hard mask. After exposing the patterned circuit area of ​​the upper photoresist film, a photoresist pattern is formed on the upper photoresist film by developing with a developer. The obtained photoresist pattern is used as an etching mask and the pattern is transferred to the inorganic hard mask by etching. The obtained inorganic hard mask pattern is used as an etching mask and the pattern is transferred to the organic film by etching. The obtained organic film pattern is used as an etching mask and the pattern is transferred to the substrate to be processed by etching. A semiconductor device circuit pattern can be formed on the substrate.

[0268] When forming an inorganic hard mask on an organic film as described above, silicon oxide films, silicon nitride films, and silicon oxide nitride films (SiON films) can be formed using methods such as CVD and ALD. For example, methods for forming silicon nitride films are described in Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377. The thickness of the inorganic hard mask is preferably 5–200 nm, and more preferably 10–100 nm. Furthermore, for inorganic hard masks, SiON films, which have high anti-reflective properties, are most ideally used. Since the substrate temperature during the formation of SiON films reaches 300–500°C, the organic film must withstand temperatures of 300–500°C. The organic film forming material used in this invention has high heat resistance and can withstand high temperatures of 300°C–500°C, thus enabling the combination of inorganic hard masks formed by CVD or ALD methods and organic films formed by spin coating.

[0269] Furthermore, a four-layer resist process using an organic antireflective film is also ideal. In this process, an organic film is formed by using the organic film forming material of the present invention on at least the substrate to be processed. An inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film is formed on the organic film. An organic antireflective film is formed on the inorganic hard mask. A photoresist upper layer film material of a photoresist composition is used on the organic antireflective film to form a photoresist upper layer film and to form a multilayer resist film. After exposing the patterned circuit area of ​​the photoresist upper layer film, a photoresist pattern is formed on the photoresist upper layer film by developing with a developer. The obtained photoresist pattern is used as an etching mask and the pattern is transferred to the organic antireflective film and the inorganic hard mask by etching. The obtained inorganic hard mask pattern is used as an etching mask and the pattern is transferred to the organic film by etching. The obtained organic film pattern is used as an etching mask and the pattern is transferred to the substrate to be processed by etching. A semiconductor device circuit pattern can be formed on the substrate.

[0270] As described above, a photoresist film can be formed on top of an inorganic hard mask as the upper layer of the photoresist film. Alternatively, an organic antireflective film (BARC) can be formed on top of an inorganic hard mask by spin coating, and then a photoresist film can be formed on top of it. Especially when using a SiON film as an inorganic hard mask, the two layers of antireflective film, SiON film and BARC, can suppress reflection even in immersion exposure with a high photoresist intensity (NA) exceeding 1.0. Another advantage of forming BARC is that it reduces the trailing of the photoresist pattern on the SiON film.

[0271] In the above three-layer photoresist process, the top layer of photoresist can be either positive or negative, and can be the same as commonly used photoresist compositions. After spin-coating the photoresist composition, pre-baking is performed, preferably at 60–180°C for 10–300 seconds. Subsequently, exposure is performed according to standard methods, followed by post-exposure baking (PEB) and development to obtain the photoresist pattern. Furthermore, there are no particular limitations on the thickness of the top layer of photoresist, but it is preferably 30–500 nm, with 50–400 nm being particularly desirable.

[0272] Furthermore, the exposure light is a high-energy ray with a wavelength below 300nm, specifically including excimer lasers of 248nm, 193nm, and 157nm, soft X-rays of 3-20nm, electron beams, X-rays, etc.

[0273] Regarding the above-mentioned method for patterning the upper layer of the resist film, it is preferable to use photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing using an electron beam, nanoimprinting, or a combination of these methods to form the pattern.

[0274] Furthermore, the development method in the aforementioned pattern forming method should preferably be a development method using alkali or organic solvents.

[0275] Then, the obtained resist pattern is used as a mask for etching. In the three-layer resist process, the etching of the silicon-containing resist underlayer and the inorganic hard mask is performed using a fluorocarbon-based gas and the upper resist pattern as a mask. This forms the silicon-containing resist underlayer pattern and the inorganic hard mask pattern.

[0276] Then, the obtained silicon-containing photoresist lower layer film pattern and inorganic hard mask pattern are used as masks, and the organic film is etched.

[0277] Subsequent etching of the substrate can also be performed using conventional methods. For example, if the substrate is a low-dielectric-constant insulating film based on SiO2, SiN, or silicon dioxide, etching with fluorocarbon (FLON) based gas is performed; if it is p-Si, Al, or W, etching with chlorine or bromine based gas is performed. When etching the substrate with fluorocarbon (FLON) based gas, the silicon-containing resist underlayer pattern in the three-layer resist process will peel off simultaneously with the substrate processing. When etching the substrate with chlorine or bromine based gas, the peeling of the silicon-containing resist underlayer pattern requires a separate dry etching peeling with fluorocarbon (FLON) based gas after substrate processing.

[0278] Organic films obtained using the organic film forming material of the present invention have excellent etch resistance when these processed substrates are etched.

[0279] Furthermore, there are no particular restrictions on the substrate to be processed; substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, or substrates with the processed layer formed on such substrates, can be used. The processed layer can be various Low-k films and their barrier films, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, typically forming thicknesses of 50–10,000 nm, and particularly 100–5,000 nm. Additionally, the substrate and the processed layer can be made of different materials when forming the processed layer.

[0280] The substrate to be processed is preferably a semiconductor device substrate or a semiconductor device substrate on which any one of a metal film, metal carbide film, metal oxide film, metal nitride film, metal oxide carbide film, and metal oxide nitride film is formed. More specifically, substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, or substrates on which the above-mentioned metal films are formed, can be used as the processed layer, but are not limited thereto.

[0281] The processed layer can be made of various Low-k films and their barrier films, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, typically forming thicknesses of 50–10,000 nm, and particularly 100–5,000 nm. Furthermore, the substrate and the processed layer can be made of different materials during film formation.

[0282] In addition, the metal constituting the substrate being processed is preferably silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, ruthenium, or alloys thereof.

[0283] Furthermore, the substrate to be processed should preferably be a structure with a height of 30 nm or more, or a substrate with a height difference.

[0284] For an example of a 3-layer resist process, using Figure 1 Specifically, as illustrated below, in the case of a 3-layer resist process, such as... Figure 1 As shown in (A), after forming an organic film 3 on a processed layer 2 stacked on a substrate 1 using the organic film forming material of the present invention, a silicon-containing photoresist lower layer 4 is formed, and a photoresist upper layer 5 is formed thereon.

[0285] Then, as Figure 1 As shown in (B), the portion 6 of the resist upper film 5 is exposed, and PEB and development are performed to form the resist pattern 5a. Figure 1 (C)). Using the obtained resist pattern 5a as a mask, the silicon-containing resist underlayer film 4 is etched using CF-based gas to form the silicon-containing resist underlayer film pattern 4a. Figure 1 (D)). After removing the resist pattern 5a, the resulting silicon-containing resist lower layer film pattern 4a is used as a mask to perform plasma etching on the organic film 3, forming the organic film pattern 3a. Figure 1 (E)). After removing the silicon-containing photoresist lower layer pattern 4a, the organic film pattern 3a is used as a mask to etch the processed layer 2, forming pattern 2a. Figure 1 (F)).

[0286] When using an inorganic hard mask, the silicon-containing photoresist lower layer film 4 is an inorganic hard mask. When applying BARC, a BARC layer is placed between the silicon-containing photoresist lower layer film 4 and the photoresist upper layer film 5. Sometimes, the etching of BARC is carried out continuously before the etching of the silicon-containing photoresist lower layer film 4, or the etching of the silicon-containing photoresist lower layer film 4 can be carried out by changing the etching equipment after only the etching of BARC.

[0287] Thus, if it is the pattern forming method of the present invention, fine patterns can be formed on the substrate being processed with high precision during the multilayer resist process.

[0288] [Example]

[0289] The present invention will be described in more detail below with examples of synthesis, embodiments, and comparative examples, but the present invention is not limited thereto. In addition, in terms of molecular weight and dispersibility, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polystyrene converted by gel permeation chromatography (GPC) with tetrahydrofuran as the mobile phase are determined, and the dispersibility (Mw / Mn) is obtained.

[0290] [Synthesis Example: Synthesis of Polymers for Organic Film Forming Materials]

[0291] The synthesis of the polymers (A1) to (A11) for organic membrane forming materials and the compounds (R1) and (R2) for comparative examples uses the diol compounds (B1) to (B6), fluorene alcohols (C1) to (C4), and water or (D1) to (D3) as end capping agents.

[0292] Diol compounds:

[0293] [Chemistry 42]

[0294]

[0295] Fluorene alcohols:

[0296] [Chemistry 43]

[0297]

[0298] End capping agent:

[0299] [Chemistry 44]

[0300]

[0301] (Synthesis example 1)

[0302] Synthesis of polymer (A1)

[0303] [Chemistry 45]

[0304]

[0305] Under nitrogen atmosphere, 5.7 g of diol compound (B1), 30.0 g of fluorene alcohol (C1), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 15.4 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 2.3 g of pure water was added, and the reaction was carried out for another 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 200 ml of MIBK (methyl isobutyl ketone) was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A1).

[0306] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0307] (A1): Mw=2700, Mw / Mn=1.58

[0308] (Synthesis example 2)

[0309] Synthesis of polymer (A2)

[0310] [Chemistry 46]

[0311]

[0312] Under nitrogen atmosphere, 8.6 g of diol compound (B5), 25.0 g of fluorene alcohol (C1), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 12.9 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 9.6 g of end-capping agent (D1) was added, and the reaction was further carried out for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A2).

[0313] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0314] (A2): Mw=3400, Mw / Mn=1.78

[0315] (Synthesis example 3)

[0316] Synthesis of polymer (A3)

[0317] [Chemistry 47]

[0318]

[0319] Under nitrogen atmosphere, 5.4 g of diol compound (B1), 30.0 g of fluorene alcohol (C2), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 14.8 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 2.2 g of pure water was added, and the reaction was carried out for another 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 200 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A3).

[0320] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0321] (A3): Mw=3100, Mw / Mn=1.59

[0322] (Synthesis Example 4)

[0323] Synthesis of polymer (A4)

[0324] [Chemistry 48]

[0325]

[0326] Under nitrogen atmosphere, 7.9 g of diol compound (B2), 30.0 g of fluorene alcohol (C2), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 14.8 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 9.1 g of end-capping agent (D2) was added, and the reaction was further carried out for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A4).

[0327] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0328] (A4): Mw=3200, Mw / Mn=1.51

[0329] (Synthesis Example 5)

[0330] Synthesis of polymer (A5)

[0331] [Chemistry 49]

[0332]

[0333] Under nitrogen atmosphere, 12.0 g of diol compound (B6), 20.0 g of fluorene alcohol (C2), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 9.9 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 8.6 g of end-capping agent (D1) was added, and the reaction was further carried out for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A5).

[0334] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0335] (A5): Mw=3800, Mw / Mn=1.84

[0336] (Synthesis Example 6)

[0337] Synthesis of polymer (A6)

[0338] [Transformation 50]

[0339]

[0340] Under nitrogen atmosphere, 7.9 g of diol compound (B3), 30.0 g of fluorene alcohol (C3), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 14.8 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 2.2 g of pure water was added, and the reaction was carried out for another 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 200 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A6).

[0341] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0342] (A6): Mw=2900, Mw / Mn=1.59

[0343] (Synthesis Example 7)

[0344] Synthesis of polymer (A7)

[0345] [Chemistry 51]

[0346]

[0347] Under nitrogen atmosphere, 7.9 g of diol compound (B4), 30.0 g of fluorene alcohol (C3), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 14.8 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 4.4 g of end-capping agent (D3) was added, and the reaction was further carried out for 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A7).

[0348] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0349] (A7): Mw=3200, Mw / Mn=1.67

[0350] (Synthesis Example 8)

[0351] Synthesis of polymer (A8)

[0352] [Chemistry 52]

[0353]

[0354] Under nitrogen atmosphere, 9.4 g of diol compound (B5), 25.0 g of fluorene alcohol (C3), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 12.3 g of methanesulfonic acid was slowly added, and the reaction was carried out at an internal temperature of 50 °C for 6 hours. Then, 6.1 g of end-capping agent (D1) was added, and the reaction was carried out for another 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A8).

[0355] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0356] (A8): Mw=3000, Mw / Mn=1.71

[0357] (Synthesis Example 9)

[0358] Synthesis of polymer (A9)

[0359] [Chemistry 53]

[0360]

[0361] Under nitrogen atmosphere, 6.6 g of diol compound (B3), 30.0 g of fluorene alcohol (C4), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 12.3 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 3.6 g of end-capping agent (D3) was added, and the reaction was carried out for another 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A9).

[0362] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0363] (A9): Mw=3500, Mw / Mn=1.74

[0364] (Synthesis Example 10)

[0365] Synthesis of polymer (A10)

[0366] [Chemistry 54]

[0367]

[0368] Under nitrogen atmosphere, 6.6 g of diol compound (B4), 30.0 g of fluorene alcohol (C4), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50 °C. 12.3 g of methanesulfonic acid was slowly added, and the reaction was carried out at 50 °C for 6 hours. Then, 1.8 g of pure water was added, and the reaction was carried out for another 3 hours. After the reaction was completed, the mixture was cooled to room temperature, and 200 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain (A10).

[0369] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0370] (A10): Mw=2900, Mw / Mn=1.53

[0371] (Synthesis Example 11)

[0372] Synthesis of polymer (A11)

[0373] [Chemistry 55]

[0374]

[0375] Under nitrogen atmosphere, 21.9 g of diol compound (B6), 20.0 g of fluorene alcohol (C4), and 100 g of 1,2-dichloroethane were added, and a homogeneous dispersion was prepared at an internal temperature of 50°C. 8.2 g of methanesulfonic acid was slowly added, and the reaction was carried out at an internal temperature of 50°C for 9 hours. After the reaction, the mixture was cooled to room temperature, and 300 ml of MIBK was added. The mixture was washed six times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of DMF was added to the residue to prepare a homogeneous solution. 8.1 g of potassium carbonate was added to the resulting solution, and a homogeneous dispersion was prepared at an internal temperature of 50°C under nitrogen atmosphere. 5.2 g of propargyl bromide was slowly added, and the reaction was carried out at an internal temperature of 50°C for 8 hours. 300 ml of methyl isobutyl ketone and 200 g of pure water were added to the reaction solution to dissolve the precipitated salt, and the separated aqueous layer was removed. The organic layer was washed six times with 100g of 3% nitric acid aqueous solution and 100g of pure water, and then dried under reduced pressure. 150g of THF was added to the residue to prepare a homogeneous solution, which was then crystallized with 300g of methanol. The precipitated crystals were separated by filtration and washed twice with 200g of methanol for recovery. The recovered crystals were then vacuum dried at 70°C to obtain compound (A11).

[0376] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0377] (A11): Mw=3900, Mw / Mn=2.03

[0378] (Synthesis Example 12)

[0379] Synthesis of the comparative example compound (R1)

[0380] [Chemistry 56]

[0381]

[0382] Under nitrogen atmosphere, 10.0 g of diol compound (B6), 13.8 g of 9-ethynyl-9-fluorenol, 14.1 g of trimethyl orthoformate, and 250 g of 1,2-dichloroethane were prepared into a homogeneous solution at 80 °C. Then, 3.4 g of pyridinium p-toluenesulfonate was added, and the reaction was carried out at 80 °C for 12 hours. After cooling to room temperature, 300 ml of MIBK was added, and the organic layer was washed five times with 100 g of pure water. The organic layer was then dried under reduced pressure. 50 g of THF was added to the residue to prepare a homogeneous solution, and then 200 g of methanol was used to induce crystallization. The precipitated crystals were separated by filtration and dried under reduced pressure to obtain compound (R1).

[0383] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0384] (R1): Mw=900, Mw / Mn=1.04

[0385] (Synthesis Example 13)

[0386] Synthesis of the comparative example compound (R2)

[0387] [Chemistry 57]

[0388]

[0389] Under nitrogen atmosphere, 80 g of 2,7-diacetylacetoxynaphthalene, 22 g of 37% formaldehyde solution, and 250 g of 1,2-dichloroethane were mixed at 70°C to form a homogeneous solution. Then, 5 g of methanesulfonic acid was slowly added, and the reaction was carried out at 80°C for 12 hours. After cooling to room temperature, 500 ml of MIBK was added, and the organic layer was washed five times with 200 g of pure water. The organic layer was then dried under reduced pressure. 300 g of THF was added to the residue to form a homogeneous solution, and then 2000 g of hexane was used to redefine the polymer. The precipitated polymer was separated by filtration and dried under reduced pressure to obtain compound (R2).

[0390] When using GPC to determine the weight-average molecular weight (Mw) and dispersion (Mw / Mn), the results are as follows.

[0391] (R2): Mw=2900, Mw / Mn=1.57

[0392] The results of Mw and Mw / Mn for the polymers (A1) to (A11) used in the examples and the compounds (R1) and (R2) used in the comparative examples are shown in Tables 1 to 3.

[0393] [Table 1]

[0394]

[0395] [Table 2]

[0396]

[0397] [Table 3]

[0398]

[0399] [Preparation of organic film forming materials (UDL-1~17, comparative UDL-1~2)]

[0400] Organic film-forming materials (UDL-1 to 17, comparative UDL-1 to 2) were prepared by using the above polymers (A1) to (A11) and (R1), (R2), acid generating agent (AG), (S1) 1,6-diacetoxyhexane (boiling point 260°C) and (S2) tripropylene glycol monomethyl ether (boiling point 242°C) as high-boiling solvents, and by dissolving them in propylene glycol monomethyl ether acetate (PGMEA) containing 0.1% by mass of PF-6320 (manufactured by OMNOVA) in the proportions shown in Table 4, and then filtering them through a 0.1 μm fluoropolymer filter.

[0401] [Table 4]

[0402]

[0403] The structural formula of the acid-generating agent (AG) used is shown below.

[0404] [Chem.58]

[0405]

[0406] [Example 1 Solvent Resistance Test (Examples 1-1 to 1-17, Comparative Examples 1-1 to 1-2)]

[0407] The UDL-1 to 17 and comparative UDL-1 to 2 prepared above were coated onto a silicon substrate and baked at 350°C for 60 seconds in atmospheric conditions. The film thickness was then measured. PGMEA solvent was applied to the substrate and left for 30 seconds. The substrate was then rotary dried and baked at 100°C for 60 seconds to evaporate the PGMEA. The film thickness before and after PGMEA treatment was measured. The residual film yield was obtained using the film thickness after deposition and the film thickness after PGMEA treatment. The results are shown in Table 5.

[0408] [Table 5]

[0409]

[0410] As shown in Table 5, the organic films using the polymers of the present invention (Examples 1-1 to 1-17) exhibited a residual film rate of over 99.5% after PGMEA treatment, demonstrating sufficient solvent resistance due to the crosslinking reaction induced by heat treatment. In contrast, the crosslinking sites in Comparative Example 1-1 were monomolecular compounds, thus only having crosslinking sites at both ends. Therefore, compared to other examples, the film loss in the solvent resistance test was slightly greater.

[0411] [Example 2: Evaluation of Heat Resistance Properties (Examples 2-1 to 2-17, Comparative Examples 2-1 to 2-2)]

[0412] The aforementioned organic film-forming materials (UDL-1 to 17, and comparative UDL-1 to 2) were coated onto a silicon substrate and calcined at 350°C for 60 seconds in atmospheric conditions to form a 200 nm coated film. The film thickness A was measured. The substrate was then further calcined at 450°C for 10 minutes under a nitrogen flow with oxygen concentration controlled below 0.2%, and the film thickness B was measured. The results are shown in Table 6.

[0413] [Table 6]

[0414]

[0415] As shown in Table 6, the organic film-forming materials of the present invention (Examples 2-1 to 2-17) showed a film thickness reduction of less than 5% after calcination at 450°C. The organic film-forming materials of the present invention maintained the film thickness before high-temperature baking even after calcination at 450°C. In particular, as seen in Examples 2-3 to 2-17, by introducing aromatic rings instead of alkyl chains as linking groups, the residual film yield remained above 99%, and heat resistance was improved. On the other hand, in Comparative Example 2-1, the results of Example 1 showed that insufficient crosslinking density resulted in poor heat resistance. In Comparative Example 2-2, although the film curability was sufficient as shown in the results of Example 1, it is believed that the thermal decomposition of the methylene sites constituting the polymer led to a deterioration in heat resistance.

[0416] [Example 3: Hardness Measurement (Examples 3-1 to 3-17, Comparative Examples 3-1 to 3-2)]

[0417] The UDL-1 to 17 and comparative UDL-1 to 2 prepared above were coated onto a silicon substrate and baked at 350°C for 60 seconds in atmospheric conditions to form a coating film with a thickness of 200 nm. These films were subjected to nanoindentation tests using a TOYO Corporation NANOINDENTER SA2 device to determine the hardness of the coating films. The results are shown in Table 7.

[0418] [Table 7]

[0419] Organic film forming materials Hardness (GPa) Example 3-1 UDL-1 0.61 Example 3-2 UDL-2 0.60 Example 3-3 UDL-3 0.66 Examples 3-4 UDL-4 0.68 Examples 3-5 UDL-5 0.65 Examples 3-6 UDL-6 0.66 Examples 3-7 UDL-7 0.72 Examples 3-8 UDL-8 0.70 Examples 3-9 UDL-9 0.74 Examples 3-10 UDL-10 0.74 Example 3-11 UDL-11 0.65 Example 3-12 UDL-12 0.65 Example 3-13 UDL-13 0.66 Example 3-14 UDL-14 0.66 Example 3-15 UDL-15 0.71 Example 3-16 UDL-16 0.74 Example 3-17 UDL-17 0.66 Comparative Example 3-1 Comparison with UDL-1 0.54 Comparative Example 3-2 Comparison of UDL-2 0.63

[0420] As shown in Table 7, Examples 3-1 to 3-17 can form films with a hardness of 0.6 or higher, confirming that a denser and stronger film can be formed compared to Comparative Example 3-1. This is a result shown by the results of Example 1. Furthermore, in Comparative Example 3-2, since the hardening properties are sufficient as shown by the results of Example 1, it has a hardness of 0.6 or higher.

[0421] [Example 4: Etching Test (Examples 4-1 to 4-17, Comparative Examples 4-1 to 4-2)]

[0422] [Etching Experiment Using CF4 / CHF3 Gas System]

[0423] The UDL-1 to 17 and comparative UDL-1 to 2 prepared above were coated onto a silicon substrate and baked at 350°C for 60 seconds in atmospheric conditions to form an organic film with a thickness of 200 nm. An etching test using a CF4 / CHF3 gas system was then performed under the following conditions. A TE-8500 dry etching apparatus manufactured by Tokyo Powertech Co., Ltd. was used to determine the difference in polymer film thickness before and after etching, and the etching rate (nm / min) was calculated. The results are shown in Table 8.

[0424] The etching conditions are as follows.

[0425]

[0426] [Etching Experiment Using O2-Based Gases]

[0427] Similar to the above, UDL-1 to 17 and comparative UDL-1 to 2 were coated on a silicon substrate and baked at 350°C for 60 seconds in air to form an organic film with a thickness of 200 nm. An etching test using an O2-based gas was then performed under the following conditions. The difference in polymer film thickness before and after etching was determined using a TE-8500 dry etching apparatus manufactured by Tokyo Powertech Co., Ltd., and the etching rate (nm / min) was calculated. The results for both the CF4 / CHF3-based gas and the CF4 / CHF3-based gas are combined and presented in Table 8.

[0428] The etching conditions are as follows.

[0429]

[0430]

[0431] In the etching tests of CF4 / CHF3 and O2 gases, the lower the etching rate, the better the etching resistance of the film.

[0432] [Table 8]

[0433]

[0434] As shown in Table 8, compared with Comparative Examples 4-1 to 4-17, Examples 4-1 to 4-2 exhibited lower etching rates in any etching test in either CF4 / CHF3 or O2 gas, resulting in films with excellent etching resistance.

[0435] [Example 5: Pattern Etching Test (Examples 5-1 to 5-17, Comparative Examples 5-1 to 5-2)]

[0436] The UDL-1 to UDL-17 and comparative UDL-1 to UDL-2 prepared above were coated onto a 300 mm diameter silicon wafer substrate on which a 200 nm thick SiO2 film was formed. An organic film was formed by baking at 350 °C for 60 seconds in atmospheric conditions, resulting in a film thickness of 200 nm. A silicon-containing photoresist lower layer material (SOG-1) was coated onto this layer and baked at 220 °C for 60 seconds to form a 35 nm thick silicon-containing photoresist lower layer film. An upper photoresist material (SL photoresist for ArF) was then coated onto this layer and baked at 105 °C for 60 seconds to form a 100 nm thick upper photoresist film. An immersion protective film (TC-1) was coated onto the upper photoresist film and baked at 90 °C for 60 seconds to form a 50 nm thick protective film.

[0437] Regarding the top layer film material of the resist (SL resist for ArF), it is prepared by dissolving the polymer (RP1), acid generator (PAG1), and basic compound (Amine1) in the proportions shown in Table 9 in a solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M Co., Ltd.), and then filtering it through a 0.1 μm fluoropolymer filter.

[0438] [Table 9]

[0439]

[0440] The structural formulas of the polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used are shown below.

[0441] [Chemistry 59]

[0442]

[0443] As for the impregnation protective film material (TC-1), it is prepared by dissolving the protective film polymer (PP1) in an organic solvent at the proportions in Table 10, and then filtering it through a 0.1 μm fluororesin filter.

[0444] [Table 10]

[0445]

[0446] The structural formula of the polymer (PP1) used is shown below.

[0447] [Transformation 60]

[0448]

[0449] Regarding the silicon-containing photoresist underlayer material (SOG-1), it is prepared by dissolving a polymer represented by ArF silicon-containing intermediate film polymer (SiP1) and a crosslinking catalyst (CAT1) in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M) in the proportions shown in Table 11, and then filtering it through a fluoropolymer filter with a pore size of 0.1 μm.

[0450] [Table 11]

[0451]

[0452] The structural formulas of the ArF silicon-containing intermediate membrane polymer (SiP1) and crosslinking catalyst (CAT1) used are shown below.

[0453] [Chemistry 61]

[0454]

[0455] Then, using an ArF immersion exposure apparatus (Nikon, NSR-S610C, NA1.30, σ0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% half-step phase shift mask), exposure was performed while changing the exposure amount. The image was baked at 100°C (PEB) for 60 seconds, and then developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds. Positive line and space patterns with resist linewidths ranging from 50 nm to 30 nm were obtained with a pitch of 100 nm.

[0456] Then, using the Telius etching apparatus created by Tokyo Powertech, the processing of silicon-containing photoresist underlayer films with photoresist patterns formed by dry etching as masks, the processing of organic films with silicon-containing photoresist underlayer films as masks, and the processing of SiO2 films with organic films as masks were carried out.

[0457] The etching conditions are as follows.

[0458] Transfer conditions of resist pattern onto SOG film.

[0459]

[0460] Transfer conditions of SOG film pattern onto organic film.

[0461]

[0462] Transfer conditions for organic film patterns onto SiO2 film.

[0463]

[0464] The cross-sections of the patterns were observed and the shapes were compared using an electron microscope (S-4700) manufactured by Hitachi, Ltd., and the results are summarized in Table 12.

[0465] [Table 12]

[0466]

[0467] As shown in Table 12, the results confirm that, in any case, the resist upper film pattern is well transferred to the substrate, as described in the organic film forming materials of the present invention (Examples 5-1 to 5-17). The organic film forming materials of the present invention can ideally be used as materials for organic films made using the multilayer resist method. Furthermore, the pattern size after substrate transfer varies with the resist linewidth created by exposure. In Comparative Example 5-1, pattern distortion occurred at a linewidth of approximately 40 nm, while in Examples 5-1 to 5-17 using the polymer of the present invention, the pattern size did not exhibit distortion up to 35 nm, indicating high torsion resistance. As is known from the polymer of the present invention, high torsion resistance can be obtained by using an organic film that can form a dense, high-strength film with a hardness exceeding 0.60 GPa.

[0468] [Example 6: Evaluation of Flattening Characteristics (Examples 6-1 to 6-12, Comparative Example 6-1)]

[0469] Organic film-forming materials (UDL-3, 5, 6, 7, 9, 11–17, and comparative UDL-2) were respectively coated onto SiO2 substrates with large isolated trench patterns (trench width 10 μm, trench depth 0.10 μm). Figure 2 On (8), after calcining at 350°C for 60 seconds in the atmosphere, the organic film in the grooved and non-grooved regions was observed using a Park Systems NX10 atomic force microscope (AFM). Figure 2 The height difference in 7) Figure 2 (delta in the figure). The results are shown in Table 13. In this evaluation, the smaller the height difference, the better the planarization characteristics. In addition, this evaluation planarized the groove pattern with a depth of 0.10 μm using an organic film forming material with a film thickness of about 0.2 μm. In order to evaluate the quality of the planarization characteristics, relatively stringent evaluation conditions were adopted.

[0470] [Table 13]

[0471]

[0472] As shown in Table 13, the organic film forming material of the present invention exhibits a smaller height difference between the grooved and non-grooved portions of the organic film compared to Comparative Example 6-1, resulting in superior planarization characteristics. This is as described in Example 2, because the polymer of the present invention has excellent heat resistance, thus suppressing film shrinkage caused by baking. Furthermore, comparing Examples 6-7 to 6-12, which contain high-boiling-point solvents, with Examples 6-1 to 6-6, which do not contain high-boiling-point solvents, it is evident that the addition of high-boiling-point solvents improves planarity.

[0473] As described above, the organic film forming material of the present invention has excellent heat resistance, high etching resistance, and torsion resistance during etching, making it extremely effective as a multilayer resist for ultra-fine and high-precision pattern processing, and especially as an organic film for 3-layer resist processes.

[0474] [Explanation of Labels in the Attached Image]

[0475] 1:Substrate

[0476] 2: Processed layer

[0477] 2a: Pattern formed on the substrate

[0478] 3: Organic membrane

[0479] 3a: Organic film pattern

[0480] 4: Silicon-containing photoresist underlayer film

[0481] 4a: Pattern of silicon-containing photoresist underlayer film

[0482] 5: Top layer of resist film

[0483] 5a: Resist pattern

[0484] 6: Parts used

[0485] 7: Organic membrane

[0486] 8:SiO2 substrate

[0487] delta: elevation difference

Claims

1. An organic film-forming material, characterized by containing: (A) A polymer having repeating units represented by the following general formula (1), and (B) Organic solvents; In the general formula (1), AR1, AR2, AR3 and AR4 are benzene rings or naphthalene rings, W1 is a tetravalent organic group with 6 to 70 carbon atoms having at least one aromatic ring, and the tetravalent organic group represented by W1 has an atomic bond on the aromatic ring, and the atomic bonds are adjacent to each other on one side of the aromatic ring, and W2 is a divalent organic group with 1 to 50 carbon atoms.

2. The organic film forming material according to claim 1, wherein, The polymer is a polymer having repeating units represented by the following general formula (2) or (3); In this general formula (2), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above, and AR5 represents a benzene ring or a naphthalene ring; In this general formula (3), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above. W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms. AR6 and AR7 represent benzene rings or naphthalene rings.

3. The organic film forming material according to claim 1 or 2, wherein, The polymer is a polymer having repeating units represented by the following general formula (4) or (5); In this general formula (4), AR5 represents a benzene ring or a naphthalene ring; In the general formula (5), W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms, and AR6 and AR7 represent benzene rings or naphthalene rings.

4. The organic film forming material according to claim 1 or 2, wherein, The end structure of the polymer is any one of the following general formulas (6) or (7); In this general formula (6), AR8 and AR9 represent benzene ring and naphthalene ring, respectively; R1 represents hydrogen atom or monovalent alkyl group with 1 to 10 carbon atoms; and * represents the bonding site with the polymer. In the general formula (7), AR10 and AR11 are benzene ring and naphthalene ring, R2 is any one of the following formula (8), n represents an integer from 1 to 4, W4 represents an n+2 valence organic group with at least one aromatic ring having a carbon number of 6 to 70, and * represents the bonding site with the polymer. The dashed lines in this formula represent atomic bonds.

5. The organic film forming material according to claim 1 or 2, wherein, The weight-average molecular weight of this polymer is 500–5000.

6. The organic film forming material according to claim 1 or 2, wherein, The organic solvent (B) is a mixture of one or more organic solvents with a boiling point of less than 180°C and one or more organic solvents with a boiling point of 180°C or higher.

7. The organic film forming material according to claim 1 or 2, wherein, The organic film forming material also contains one or more of the following: (C) an acid generator, (D) a surfactant, (E) a crosslinking agent, and (F) a plasticizer.

8. A pattern forming method, characterized in that: An organic film is formed on a substrate according to any one of claims 1 to 7 using an organic film forming material. A silicon-containing photoresist lower layer film is formed on the organic film using a silicon-containing photoresist lower layer film material. A photoresist upper layer film is formed on the silicon-containing photoresist lower layer film using a photoresist composition. A circuit pattern is formed on the photoresist upper layer film. The patterned photoresist upper layer film is used as a mask and the pattern is transferred to the silicon-containing photoresist lower layer film by etching. The patterned silicon-containing photoresist lower layer film is used as a mask and the pattern is transferred to the organic film by etching. The pattern is then formed on the substrate according to the organic film by etching, using the patterned organic film as a mask.

9. A pattern forming method, characterized in that: An organic film is formed on a substrate according to any one of claims 1 to 7 using an organic film forming material. A silicon-containing photoresist underlayer film is formed on the organic film using a silicon-containing photoresist underlayer film material. An organic antireflective film is formed on the silicon-containing photoresist underlayer film. A photoresist composition is formed on the organic antireflective film to form a photoresist toplayer film, resulting in a four-layer film structure. A circuit pattern is formed on the photoresist toplayer film. The patterned photoresist toplayer film is used as a mask, and the organic antireflective film and the silicon-containing photoresist underlayer film are patterned by etching. The patterned silicon-containing photoresist underlayer film is used as a mask, and the organic film is patterned by etching. The patterned organic film is then used as a mask, and the substrate is etched to form a pattern on the substrate.

10. A pattern forming method, characterized in that: An organic film is formed on a substrate according to any one of claims 1 to 7 using an organic film forming material. An inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film is formed on the organic film. A photoresist composition is used on the inorganic hard mask to form a photoresist top layer film. A circuit pattern is formed on the photoresist top layer film. The patterned photoresist top layer film is used as a mask and the pattern is transferred to the inorganic hard mask by etching. The patterned inorganic hard mask is used as a mask and the pattern is transferred to the organic film by etching. The patterned organic film is then used as a mask and the substrate is etched to form the pattern on the substrate.

11. A pattern forming method, characterized in that: An organic film is formed on a substrate according to any one of claims 1 to 7 using an organic film forming material. An inorganic hard mask selected from silicon oxide film, silicon nitride film, and silicon oxide nitride film is formed on the organic film. An organic antireflective film is formed on the inorganic hard mask. A photoresist composition is used on the organic antireflective film to form a photoresist top layer film, forming a four-layer film structure. A circuit pattern is formed on the photoresist top layer film. The patterned photoresist top layer film is used as a mask, and the pattern is transferred to the organic antireflective film and the inorganic hard mask by etching. The patterned inorganic hard mask is used as a mask, and the pattern is transferred to the organic film by etching. The patterned organic film is then used as a mask, and the substrate is etched to form the pattern on the substrate.

12. The pattern forming method according to claim 10 or 11, wherein, The inorganic hard mask is formed using CVD or ALD methods.

13. The pattern forming method according to any one of claims 8 to 11, wherein, The patterning method for the upper layer of the resist film is as follows: photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing using an electron beam, nanoimprinting, or a combination of these methods.

14. The pattern forming method according to any one of claims 8 to 11, wherein, The development method in this pattern formation method is alkaline development or development using organic solvents.

15. The pattern forming method according to any one of claims 8 to 11, wherein, The substrate being processed can be a semiconductor device substrate, a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film.

16. The pattern forming method according to claim 15, wherein, The metal is silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, cobalt, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, manganese, molybdenum, ruthenium, or alloys thereof.

17. A polymer, characterized by: A repeating unit represented by the following general formula (1); In the general formula (1), AR1, AR2, AR3 and AR4 are benzene rings or naphthalene rings, W1 is a tetravalent organic group with 6 to 70 carbon atoms having at least one aromatic ring, and the tetravalent organic group represented by W1 has an atomic bond on the aromatic ring, and the atomic bonds are adjacent to each other on one side of the aromatic ring, and W2 is a divalent organic group with 1 to 50 carbon atoms.

18. The polymer according to claim 17, wherein, The polymer has repeating units represented by the following general formula (2) or (3); In this general formula (2), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above, and AR5 represents a benzene ring or a naphthalene ring; In this general formula (3), W2, AR1, AR2, AR3 and AR4 are the same as those mentioned above. W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms. AR6 and AR7 represent benzene rings or naphthalene rings.

19. The polymer according to claim 17 or 18, wherein, The polymer has repeating units represented by the following general formula (4) or (5); In this general formula (4), AR5 represents a benzene ring or a naphthalene ring; In the general formula (5), W3 is a single bond or a divalent organic group with 1 to 58 carbon atoms, and AR6 and AR7 represent benzene rings or naphthalene rings.

20. The polymer according to claim 17 or 18, wherein, The end structure of the polymer is any one of the following general formulas (6) or (7); In this general formula (6), AR8 and AR9 represent benzene ring and naphthalene ring, respectively; R1 represents hydrogen atom or monovalent alkyl group with 1 to 10 carbon atoms; and * represents the bonding site with the polymer. In the general formula (7), AR10 and AR11 are benzene ring and naphthalene ring, R2 is any one of the following formula (8), n represents an integer from 1 to 4, W4 represents an n+2 valence organic group with at least one aromatic ring having a carbon number of 6 to 70, and * represents the bonding site with the polymer. The dashed lines in this formula represent atomic bonds.

Images