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JP-7856405-B2 - Compositions for forming organic films, methods for forming patterns, and compounds and polymers for forming organic films.

JP7856405B2JP 7856405 B2JP7856405 B2JP 7856405B2JP-7856405-B2

Inventors

  • 郡 大佑
  • 小林 直貴

Assignees

  • 信越化学工業株式会社

Dates

Publication Date
20260511
Application Date
20211117

Claims (20)

  1. A composition for forming an organic film, comprising an organic film-forming material and an organic solvent, The organic film-forming material is a compound represented by the following general formula (1) and/or (2), and the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the compound, measured by gel permeation chromatography, is 1.00 ≤ Mw/Mn ≤ 1.10, characterized in that the organic film-forming material is a compound represented by the following general formula (1) and/or (2), and the ratio is 1.00 ≤ Mw/Mn ≤ 1.10. (In the above general formula (1), R1 is an allyl group or a propargyl group, R2 is a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched, or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, and R3 is a C1-C4 alkyl group, a C2-C4 alkynyl group, or a C2-C4 alkenyl group. m represents 0 or 1, n represents an integer of 1 or 2, l represents 0 or 1, when l=0 it means that the aromatic rings at both ends of the "-(O)l-" group are not substituted with "-(O)l-" groups, when l=1 it means that a cyclic ether structure is formed between the aromatic rings. k represents an integer from 0 to 2.) (In the above general formula (2), R 4 is an allyl group or a propargyl group, and R 5 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 6 represents a hydrogen atom, a C1-C4 alkyl group, a C2-C4 alkynyl group, or a C2-C4 alkenyl group. i represents 0 or 1, q represents an integer from 0 to 2, h and j independently represent integers from 0 to 2, satisfying the relationship 1 ≤ h + j ≤ 4, r represents 0 or 1, where r = 0 means the aromatic rings at both ends of the "-(O)r-" group are not substituted with "-(O)r-" groups, and r = 1 means the aromatic rings form a cyclic ether structure. W is one of the divalent groups represented by the following formula (3). (The dashed lines represent connecting points.)
  2. A composition for forming an organic film, comprising an organic film-forming material and an organic solvent, The organic film-forming material is a polymer having repeating units represented by the following general formula (4) and/or (5), An organic film-forming composition characterized in that the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the polymer, as determined by gel permeation chromatography, is greater than 1.10. (In the above general formula (4) , R1 is an allyl group or a propargyl group, and R2 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 3 represents an alkyl group with 1 to 4 carbon atoms, an alkynyl group with 2 to 4 carbon atoms, or an alkenyl group with 2 to 4 carbon atoms. m represents 0 or 1, n represents an integer of 1 or 2, and l represents 0 or 1. When l = 0, it means that the aromatic rings at both ends of the "-(O)l-" group are not substituted with "-(O)l-" groups. When l = 1, it means that the aromatic rings form a cyclic ether structure. k represents an integer from 0 to 2. L is a divalent organic group with 1 to 40 carbon atoms, and is one of the following (L1) formulas. (In the above general formula (5), R4 is an allyl group or a propargyl group, and R5 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 6 represents a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, an alkynyl group with 2 to 4 carbon atoms, or an alkenyl group with 2 to 4 carbon atoms. i represents 0 or 1, q represents an integer from 0 to 2, h and j independently represent integers from 0 to 2, satisfying the relationship 1 ≤ h + j ≤ 4, r represents 0 or 1, and when r = 0, it means that the aromatic rings at both ends of the "-(O)r-" group are not substituted with "-(O)r-" groups. When r = 1, it means that a cyclic ether structure is formed between the aromatic rings. W is one of the divalent groups represented by the following formula (3). L is a divalent organic group with 1 to 40 carbon atoms, and is one of the following formulas (L1). (The dashed lines represent connecting points.) (The dashed lines represent connecting points.)
  3. The organic film-forming composition according to claim 2, characterized in that L is a divalent organic group which is one of the following formulas (L2). (The dashed lines represent connecting points.)
  4. The organic film-forming composition according to claim 2 or 3, characterized in that the weight-average molecular weight of the polymer, measured by gel permeation chromatography in terms of polystyrene, is 1,000 to 5,000.
  5. A composition for forming an organic film, comprising an organic film-forming material and an organic solvent, The organic film-forming material contains one or more compounds selected from the following general formulas (1) and/or (2) and polymers having repeating units represented by the following general formulas (4) and/or (5). The ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the compound, measured by gel permeation chromatography, is 1.00 ≤ Mw/Mn ≤ 1.10. An organic film-forming composition characterized in that the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the polymer, as determined by gel permeation chromatography, is greater than 1.10. (In the above general formula (1), R1 is an allyl group or a propargyl group, R2 is a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched, or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, and R3 is a C1-C4 alkyl group, a C2-C4 alkynyl group, or a C2-C4 alkenyl group. m represents 0 or 1, n represents an integer of 1 or 2, l represents 0 or 1, when l=0 it means that the aromatic rings at both ends of the "-(O)l-" group are not substituted with "-(O)l-" groups, when l=1 it means that a cyclic ether structure is formed between the aromatic rings. k represents an integer from 0 to 2.) (In the above general formula (2), R 4 is an allyl group or a propargyl group, and R 5 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 6 represents a hydrogen atom, a C1-C4 alkyl group, a C2-C4 alkynyl group, or a C2-C4 alkenyl group. i represents 0 or 1, q represents an integer from 0 to 2, h and j independently represent integers from 0 to 2, satisfying the relationship 1 ≤ h + j ≤ 4, r represents 0 or 1, where r = 0 means the aromatic rings at both ends of the "-(O)r-" group are not substituted with "-(O)r-" groups, and r = 1 means the aromatic rings form a cyclic ether structure. W is one of the divalent groups represented by the following formula (3). (The dashed lines represent connecting points.) (In the general formula (4) above, R1 , R2 , R3 , m, n, l, and k are the same as described above. L is a divalent organic group having 1 to 40 carbon atoms, and is one of the formulas (L1) below.) (In the above general formula (5), R4 , R5 , R6 , W, L, h, i, j, q, and r are the same as described above. ) (The dashed lines represent connecting points.)
  6. The organic film-forming composition according to any one of claims 1 to 5, characterized in that the organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.
  7. Furthermore, the organic film-forming composition according to any one of claims 1 to 6 is characterized in that it contains one or more surfactants and plasticizers.
  8. A pattern formation method characterized by: forming an organic film on a workpiece using an organic film forming composition according to any one of claims 1 to 7; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming a resist upper layer on the silicon-containing resist interlayer using a photoresist composition; forming a circuit pattern on the resist upper layer; transferring the pattern to the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern has been formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further forming a pattern on the workpiece by etching using the organic film on which the pattern has been transferred as a mask.
  9. A pattern formation method characterized by: forming an organic film on a workpiece using an organic film-forming composition according to any one of claims 1 to 7; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming an organic anti-reflective film (BARC) on the silicon-containing resist interlayer; forming a resist upper layer on the BARC using a photoresist composition to form a four-layer structure; forming a circuit pattern on the resist upper layer; transferring the pattern to the BARC film and the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern has been formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further etching the workpiece using the organic film on which the pattern has been transferred as a mask to form a pattern on the workpiece.
  10. A pattern formation method characterized by forming an organic film on a workpiece using an organic film-forming composition according to any one of claims 1 to 7; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming a resist upper layer film on the inorganic hard mask using a photoresist composition to form a circuit pattern on the resist upper layer film; etching the inorganic hard mask using the resist upper layer film on which the pattern is formed as a mask; etching the organic film using the inorganic hard mask on which the pattern is formed as a mask; and further etching the workpiece using the organic film on which the pattern is formed as a mask to form a pattern on the workpiece.
  11. A pattern forming method characterized by: forming an organic film on a workpiece using an organic film forming composition according to any one of claims 1 to 7; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming an organic anti-reflective film (BARC) on the inorganic hard mask; forming a resist upper layer film on the BARC using a photoresist composition to form a four-layer film structure; forming a circuit pattern on the resist upper layer film; etching the BARC film and the inorganic hard mask using the resist upper layer film on which the pattern is formed as a mask; etching the organic film using the inorganic hard mask on which the pattern is formed as a mask; and further etching the workpiece using the organic film on which the pattern is formed as a mask to form a pattern on the workpiece.
  12. The pattern forming method according to claim 10 or 11, characterized in that the inorganic hard mask is formed by CVD or ALD.
  13. The pattern formation method according to any one of claims 8 to 12, characterized in that the pattern formation of the resist upper layer film is performed by photolithography with a wavelength of 10 nm to 300 nm, direct writing with an electron beam, nanoimprinting, or a combination thereof.
  14. The pattern formation method according to any one of claims 8 to 13, characterized in that exposure and development are performed to form a circuit pattern on the resist upper layer film, and the development is alkaline development or development with an organic solvent.
  15. The pattern forming method according to any one of claims 8 to 14, characterized in that the workpiece is 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, characterized in that 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 an alloy thereof.
  17. A compound represented by the following general formula (1), characterized in that the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the compound, measured by gel permeation chromatography on a polystyrene basis, is 1.00 ≤ Mw/Mn ≤ 1.10. (In the formula, R1 is an allyl group or a propargyl group; R2 is a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched, or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group; R3 is a C1-C4 alkyl group, a C2-C4 alkynyl group, or a C2-C4 alkenyl group. m represents 0 or 1, n represents an integer of 1 or 2, l represents 0 or 1, when l=0 it means that the aromatic rings at both ends of the "-(O)l-" group are not substituted with "-(O)l-"groups; when l=1 it means that the aromatic rings form a cyclic ether structure. k represents an integer from 0 to 2.)
  18. A compound represented by the following general formula (2), characterized in that the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the compound, measured by gel permeation chromatography on a polystyrene basis, is 1.00 ≤ Mw/Mn ≤ 1.10. (In the formula, R 4 is an allyl group or a propargyl group, and R 5 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 6 represents a hydrogen atom, a C1-C4 alkyl group, a C2-C4 alkynyl group, or a C2-C4 alkenyl group. i represents 0 or 1, q represents an integer from 0 to 2, h and j independently represent integers from 0 to 2, satisfying the relationship 1 ≤ h + j ≤ 4, r represents 0 or 1, where r = 0 means the aromatic rings at both ends of the "-(O)r-" group are not substituted with "-(O)r-" groups, and r = 1 means the aromatic rings form a cyclic ether structure. W is one of the divalent groups represented by the following formula (3). (The dashed lines represent connecting points.)
  19. A polymer having repeating units represented by the following general formula (4), characterized in that the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the polymer, measured by gel permeation chromatography on a polystyrene basis, is greater than 1.10. (In the formula, R1 is an allyl group or a propargyl group, and R2 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 3 represents an alkyl group with 1 to 4 carbon atoms, an alkynyl group with 2 to 4 carbon atoms, or an alkenyl group with 2 to 4 carbon atoms. m represents 0 or 1, n represents an integer of 1 or 2, and l represents 0 or 1. When l = 0, it means that the aromatic rings at both ends of the "-(O)l-" group are not substituted with "-(O)l-" groups. When l = 1, it means that the aromatic rings form a cyclic ether structure. k represents an integer from 0 to 2. L is a divalent organic group with 1 to 40 carbon atoms, and is one of the following (L1) formulas. (The dashed lines represent connecting points.)
  20. A polymer having repeating units represented by the following general formula (5), characterized in that the ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the polymer, measured by gel permeation chromatography in terms of polystyrene, is greater than 1.10. (In the formula, R 4 is an allyl group or a propargyl group, and R 5 represents a nitro group, a halogen atom, a hydroxyl group, a C1-C4 alkyloxy group, a C2-C4 alkynyloxy group, a C2-C4 alkenyloxy group, a C1-C6 linear, branched or cyclic alkyl group, a trifluoromethyl group, or a trifluoromethyloxy group, R 6 represents a hydrogen atom, an alkyl group with 1 to 4 carbon atoms, an alkynyl group with 2 to 4 carbon atoms, or an alkenyl group with 2 to 4 carbon atoms. i represents 0 or 1, q represents an integer from 0 to 2, h and j independently represent integers from 0 to 2, satisfying the relationship 1 ≤ h + j ≤ 4, r represents 0 or 1, and when r = 0, it means that the aromatic rings at both ends of the "-(O)r-" group are not substituted with "-(O)r-" groups. When r = 1, it means that a cyclic ether structure is formed between the aromatic rings. W is one of the divalent groups represented by the following formula (3). L is a divalent organic group with 1 to 40 carbon atoms, and is one of the following formulas (L1). (The dashed lines represent connecting points.) (The dashed lines represent connecting points.)

Description

This invention relates to an organic film-forming composition used in fine patterning by a multilayer resist method in semiconductor device manufacturing processes, a pattern-forming method using the composition, and compounds and polymers used in the organic film-forming composition. With the increasing integration and speed of LSIs, the miniaturization of pattern dimensions is progressing rapidly. Lithography technology has achieved the formation of fine patterns in line with this miniaturization by shortening the wavelength of light sources and appropriately selecting resist compositions. At the heart of this is the single-layer positive-type photoresist composition. This single-layer positive-type photoresist composition incorporates a framework within the resist resin that provides etching resistance to dry etching with chlorine-based or fluorine-based gas plasma, and also includes a switching mechanism that causes the exposed areas to dissolve. This dissolves the exposed areas to form a pattern, and the remaining resist pattern is used as an etching mask to dry etch the workpiece (substrate). However, when the thickness of the photoresist film used was kept the same while miniaturization was achieved, i.e., the pattern width was reduced, the resolution performance of the photoresist film decreased. Furthermore, when attempting to develop the photoresist film using a developer, the aspect ratio became too large, resulting in pattern collapse. Therefore, as patterns became smaller, the photoresist film thickness was reduced. On the other hand, the processing of substrates typically involves using a photoresist film with a pattern formed on it as an etching mask and processing the substrate by dry etching. However, in reality, there is no dry etching method that can achieve complete etching selectivity between the photoresist film and the substrate. Therefore, during substrate processing, the resist film is damaged and disintegrates, making it impossible to accurately transfer the resist pattern to the substrate. Consequently, with the miniaturization of patterns, higher dry etching resistance has been required for resist compositions. However, to improve resolution, resins with low light absorption at the exposure wavelength have been required for the resins used in photoresist compositions. Therefore, as exposure light has become shorter in wavelength (i-line, KrF, ArF), resins have also changed to novolac resins, polyhydroxystyrene, and resins with aliphatic polycyclic skeletons. However, in reality, the etching rate under dry etching conditions during substrate processing has become faster, and recent photoresist compositions with high resolution tend to have weaker etching resistance. Therefore, it becomes necessary to dry etch the substrate using a thinner photoresist film with weaker etching resistance, making the securing of materials and processes for this processing step crucial. One method to solve these problems is the multilayer resist method. This method involves interposing a photoresist film (i.e., a resist upper layer) and an intermediate film with different etching selectivity between the resist upper layer and the substrate to be processed. After obtaining a pattern on the resist upper layer, the resist upper layer pattern is used as a dry etching mask to transfer the pattern to the intermediate film by dry etching. Finally, the intermediate film is used as a dry etching mask to transfer the pattern to the substrate by dry etching. One multilayer resist method is the three-layer resist method, which can be performed using the same resist compositions as those used in the single-layer resist method. In this three-layer resist method, for example, an organic film made of novolac resin is deposited on the substrate to be processed, a silicon-containing film is deposited on top of it as a resist interlayer, and a normal organic photoresist film is formed on top of that as the resist upper layer. When dry etching is performed using a fluorine-based gas plasma, the organic resist upper layer has a good etching selectivity ratio compared to the silicon-containing resist interlayer, so the resist upper layer pattern can be transferred to the silicon-containing resist interlayer by dry etching with a fluorine-based gas plasma. With this method, even if a resist composition that does not have sufficient thickness to form a pattern for direct processing of the substrate or a resist composition that does not have sufficient dry etching resistance for substrate processing is used, the pattern can be transferred to the silicon-containing film (resist interlayer), and then by performing pattern transfer by dry etching with an oxygen-based or hydrogen-based gas plasma, a pattern of an organic film (resist lower layer) made of novolac resin or the like with sufficient dry etching resistance for substrate processing can be obtained. Many organic films like those described above are already known, such a