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US-12625428-B2 - Stepped substrate coating composition including compound having photocrosslinking group due to unsaturated bond between carbon atoms

US12625428B2US 12625428 B2US12625428 B2US 12625428B2US-12625428-B2

Abstract

A stepped substrate coating composition includes: a compound (E) containing partial structures (I) and (II) and a solvent (F). The partial structure (II) contains a hydroxy group generated by an epoxy group and a proton-generating compound reaction; the partial structure (I) is at least one partial structure selected from partial structures of Formula (1-1) to Formula (1-5) or a partial structure combining a partial structure of Formula (1-6) and Formula (1-7) or Formula (1-8); and the partial structure (II) is a partial structure of Formula (2-1) or Formula (2-2). The photocurable stepped substrate coating composition wherein in the compound (E), the epoxy group and the hydroxy group are contained in a molar ratio of 0≤(Epoxy group)/(Hydroxy group)≤0.5 and the partial structure (II) is contained in a molar ratio of 0.01≤(Partial structure (II))/(Partial structure (I)+Partial structure (II))≤0.8.

Inventors

  • Takafumi Endo
  • Keisuke Hashimoto
  • Hirokazu Nishimaki
  • Mamoru Tamura
  • Rikimaru Sakamoto
  • Hikaru TOKUNAGA

Assignees

  • NISSAN CHEMICAL CORPORATION

Dates

Publication Date
20260512
Application Date
20170307
Priority Date
20160310

Claims (20)

  1. 1 . A photocurable stepped substrate coating composition comprising a compound (E) and a solvent (F), wherein the compound (E) is selected from the group consisting of: and when compound (E) has formula (E-17), the proportion of the unit structure (E-17-1) and the unit structure (E-17-2) is in a molar ratio of 60:40, wherein the coating composition does not contain an acid catalyst.
  2. 2 . The photocurable stepped substrate coating composition according to claim 1 , wherein the stepped substrate coating composition is a resist underlayer film-forming composition used in a lithography process for producing a semiconductor device.
  3. 3 . A method for producing a coated substrate, the method comprising: (i) applying the photocurable stepped substrate coating composition as claimed in claim 1 to a substrate having a step, and (ii) performing exposure of the applied composition to light, wherein Bias (coating step) between the open area and the pattern areas is 1 nm to 50 nm.
  4. 4 . The method for producing a coated substrate according to claim 3 , further comprising (ia) heating the applied composition at 70° C. to 400° C. for 10 seconds to 5 minutes after the step (i) of applying the photocurable stepped substrate coating composition.
  5. 5 . The method for producing a coated substrate according to claim 3 , wherein the exposure wavelength in the step (ii) is 150 nm to 248 nm.
  6. 6 . The method for producing a coated substrate according to claim 3 , wherein the exposure amount in the step (ii) is 10 mJ/cm 2 to 3,000 mJ/cm 2 .
  7. 7 . The method for producing a coated substrate according to claim 3 , wherein the substrate has an open area (non-pattern area) and pattern areas of DENCE (dense) and ISO (coarse) and an aspect ratio of the pattern is 0.1 to 10.
  8. 8 . A method for producing a semiconductor device, the method comprising: forming an underlayer film using the stepped substrate coating composition as claimed in claim 1 on a substrate having a step; forming a resist film thereon; forming a resist pattern by irradiation with light or electron beams and development; etching the underlayer film using the formed resist pattern; and processing the semiconductor substrate using the patterned underlayer film.
  9. 9 . The method for producing a semiconductor device according to claim 8 , wherein the substrate having a step is a substrate having an open area (non-pattern area) and pattern areas of DENCE (dense) and ISO (coarse) and having an aspect ratio of the pattern of 0.1 to 10.
  10. 10 . The method for producing a semiconductor device according to claim 8 , wherein the step of forming an underlayer film using the stepped substrate coating composition comprises (i) applying the photocurable stepped substrate coating composition to a substrate having a step, and (ii) performing exposure of the applied composition to light.
  11. 11 . The method for producing a semiconductor device according to claim 10 , further comprising (ia) heating the applied composition at 70° C. to 400° C. for 10 seconds to 5 minutes after the step (i) of applying the photocurable stepped substrate coating composition.
  12. 12 . The method for producing a semiconductor device according to claim 10 , wherein the exposure wavelength in the step (ii) is 150 nm to 248 nm.
  13. 13 . The method for producing a semiconductor device according to claim 10 , wherein the exposure amount in the step (ii) is 10 mJ/cm 2 to 3,000 mJ/cm 2 .
  14. 14 . The method for producing a semiconductor device according to claim 8 , wherein the underlayer film obtained from the stepped substrate coating composition has a coating step of 1 nm to 50 nm.
  15. 15 . A method for producing a semiconductor device, the method comprising: forming an underlayer film using the photocurable stepped substrate coating composition as claimed in claim 1 on a substrate having a step; forming a hard mask thereon; further forming a resist film thereon; forming a resist pattern by irradiation of light or electron beams and development; etching the hard mask using the formed resist pattern; etching the underlayer film using the patterned hard mask; and processing a semiconductor substrate using the patterned underlayer film.
  16. 16 . The method for producing a semiconductor device according to claim 15 , wherein the substrate having a step is a substrate having an open area (non-pattern area) and pattern areas of DENCE (dense) and ISO (coarse) and having an aspect ratio of the pattern of 0.1 to 10.
  17. 17 . The method for producing a semiconductor device according to claim 15 , wherein the step of forming an underlayer film using the stepped substrate coating composition comprises (i) applying the photocurable stepped substrate coating composition to a substrate having a step, and (ii) performing exposure of the applied composition to light.
  18. 18 . The method for producing a semiconductor device according to claim 17 , further comprising (ia) heating the applied composition at 70° C. to 400° C. for 10 seconds to 5 minutes after the step (i) of applying the photocurable stepped substrate coating composition.
  19. 19 . The method for producing a semiconductor device according to claim 17 , wherein the exposure wavelength in the step (ii) is 150 nm to 248 nm.
  20. 20 . The method for producing a semiconductor device according to claim 17 , wherein the exposure amount in the step (ii) is 10 mJ/cm 2 to 3,000 mJ/cm 2 .

Description

TECHNICAL FIELD The present invention relates to a stepped substrate coating composition for forming a planarization film on a substrate having a step by photocrosslinking and a method for producing a planarized layered substrate using the stepped substrate coating composition. BACKGROUND ART In recent years, semiconductor integrated circuit devices have been processed in accordance with fine design rules. In order to form a finer resist pattern by a photolithography technique, the exposure wavelength is required to be shortened. The depth of focus, however, decreases with the shortening of the exposure wavelength. Therefore, the planarization property of the coated film formed on the substrate is required to be improved. In other words, in order to produce a semiconductor device having a fine design rule, a planarization technique on a substrate has become important. Heretofore, as methods for forming a planarization film, for example, a method for forming a resist underlayer film formed under a resist film by photocuring has been described. A resist underlayer film-forming composition including a polymer having epoxy groups or oxetane groups in side chains and a photo cationic polymerization initiator or a resist underlayer film-forming composition including a polymer having a radical polymerizable ethylenic unsaturated bond and a photoradical polymerization initiator has been described (refer to Patent Document 1). A resist underlayer film-forming composition including a silicon compound having a cationically polymerizable reactive group such as an epoxy group and a vinyl group, a photo cationic polymerization initiator, and a photoradical polymerization initiator has been described (refer to Patent Document 2). A method for producing a semiconductor device using a resist underlayer film including a polymer having crosslinkable functional groups (for example, hydroxy groups) in side chains, a crosslinking agent, and a photoacid generator has been described (refer to Patent Document 3). A resist underlayer film that is not a photocrosslinking-based resist underlayer film but has an unsaturated bond in its main chain or side chain has been described (refer to Patent Documents 4 and 5). PRIOR ART DOCUMENTS Patent Documents Patent Document 1: WO 2006/115044 PamphletPatent Document 2: WO 2007/066597 PamphletPatent Document 3: WO 2008/047638 PamphletPatent Document 4: WO 2009/008446 PamphletPatent Document 5: Japanese Translation of PCT Application No. 2004-533637 SUMMARY OF THE INVENTION Problem to be Solved by the Invention In a conventional resist underlayer film-forming composition including a polymer having a thermally crosslinkable functional group such as a hydroxy group, a crosslinking agent, and an acid catalyst (acid generator), in the case of a conventional photocrosslinking material, a viscosity increases as crosslinking reaction proceeds at the time of heating the composition so that the composition is filled into the pattern formed on the substrate (for example, a hole or a trench structure), resulting in causing a problem of poor filling into the pattern. In addition, heat shrinkage due to degasification occurs and thus a problem of impairing flatness arises. In the case of the resist underlayer film-forming composition including a polymer having a cationically polymerizable reactive group such as an epoxy group and a vinyl group and an acid generator, light irradiation and heating are carried out. At this time, heat shrinkage due to the degasification also occurs and thus a problem of flatness arises. Therefore, an object of the present invention is to provide a stepped substrate coating composition that has a high filling property into a pattern and is for forming a coated film being capable of forming a coating film that does not cause degasification or heat shrinkage and having a planarization property. Means for Solving the Problem The present invention includes, as a first aspect, a photocurable stepped substrate coating composition comprising: a compound (E) containing a partial structure (I) and a partial structure (II) and a solvent (F), in which the partial structure (II) contains a hydroxy group generated by a reaction of an epoxy group and a proton-generating compound; the partial structure (I) is at least one partial structure selected from the group consisting of partial structures of Formula (1-1) to Formula (1-5) or a partial structure combining a partial structure of Formula (1-6) and a partial structure of Formula (1-7) or Formula (1-8); and the partial structure (II) is a partial structure of Formula (2-1) or Formula (2-2), (wherein R1, R1a, R3, R5, R5a, and R6a each are a C1-10 saturated hydrocarbon group, a C6-40 aromatic hydrocarbon group, an oxygen atom, a carbonyl group, a sulfur atom, a nitrogen atom, an amide group, an amino group, or a combination thereof; R2, R2a, R4, and R6 each are a hydrogen atom, a C1-10 saturated hydrocarbon group, a C2-10 unsaturated hydrocarbon