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EP-4738008-A1 - CURABLE COMPOSITION AND METHODS FOR FORMING FILM AND MANUFACTURING ARTICLE

EP4738008A1EP 4738008 A1EP4738008 A1EP 4738008A1EP-4738008-A1

Abstract

A curable composition includes a polymerizable compound (a), a photopolymerization initiator (b), and a solvent (d). The curable composition has a viscosity of 1.3 mPa·s to 60 mPa·s at 23°C and 1 atm. The amount of the solvent (d) ranges from more than 5% to 95% by volume relative to the entire curable composition. The boiling point of the solvent (d) is less than 250°C. The curable composition in a state excluding the solvent (d) has a viscosity of 8 mPa·s to 30 mPa·s at 23°C and 1 atm.

Inventors

  • ITO, Yuto
  • ITO, TOSHIKI
  • KAWATA, ISAO
  • IMAMURA, HIDEKI
  • NAKATA, EIICHI

Assignees

  • Canon Kabushiki Kaisha

Dates

Publication Date
20260506
Application Date
20251030

Claims (14)

  1. A curable composition comprising: a polymerizable compound (a); a photopolymerization initiator (b), and a solvent (d) having a boiling point of less than 250°C in an amount ranging from more than 5% to 95% by volume relative to the entire curable composition, wherein the curable composition has a viscosity of 1.3 mPa·s to 60 mPa·s at 23°C and 1 atm, and the viscosity of a composition formed by excluding the solvent (d) from the curable composition is 8 mPa·s to 30 mPa·s at 23°C and 1 atm.
  2. A curable composition comprising: a polymerizable compound (a); a photopolymerization initiator (b); a surfactant (c) having a viscosity of 500 mPa·s or less at 23°C and 1 atm; and a solvent (d) having a boiling point of less than 250°C in an amount ranging from more than 5% to 95% by volume relative to the entire curable composition, wherein the curable composition has a viscosity of 1.3 mPa·s to 60 mPa·s at 23°C and 1 atm.
  3. The curable composition according to claim 1 or 2, wherein the polymerizable compound (a) includes one or more polymerizable compounds, and each of the one or more polymerizable compounds has a boiling point of 250°C or more at 1 atm.
  4. The curable composition according to claim 1 or 2, wherein the polymerizable compound (a) includes a monofunctional polymerizable compound and a polyfunctional polymerizable compound, and wherein the polyfunctional polymerizable compound accounts for 20% or more by mass of the polymerizable compound (a).
  5. The curable composition according to claim 1 or 2, wherein the polymerizable compound (a) includes one or more polymerizable compounds, and each of the one or more polymerizable compounds has a molecular weight of 200 or more.
  6. The curable composition according to any one of claims 1 to 5, wherein the curable composition exhibits a glass transition temperature of 70°C or more after being cured.
  7. The curable composition according to any one of claims 1 to 5, wherein the polymerizable compound (a) includes one or more polymerizable compounds, and each of the one or more polymerizable compounds has a vapor pressure of 0.001 mmHg or less at 80°C and 1 atom.
  8. The curable composition according to any one of claims 1 to 5, wherein the polymerizable compound (a) includes a compound (a-1) having an aromatic structure, an aromatic heterocyclic structure, or an alicyclic structure.
  9. The curable composition according to any one of claims 1 to 5, wherein the polymerizable compound (a) includes one or more polymerizable compounds and the polymerizable compound (a) has an Ohnishi parameter abbreviated to OP of 1.80 to 4.00, the Ohnishi parameter being the molar fraction weighted average of the N/(Nc - No) value of each molecule of the one or more polymerizable compounds, wherein N represents the total number of atoms in a molecule, Nc is the number of carbon atoms in the molecule, and No is the number of oxygen atoms in the molecule.
  10. A film formation method for forming a film of a curable composition on a substrate (101) using a mold, the method comprising: applying a plurality of droplets (102) of the curable composition according to any one of claims 1 to 16 discretely onto the substrate (101); bringing the plurality of droplets (102) on the substrate (101) into contact with a mold (106) to form a liquid film (104) between the substrate (101) and the mold (104) after the application of the droplets (102); curing the liquid film (104) into a cured film (108) after the contact of the droplets with the mold; and releasing the cured film (108) from the mold (106) after the curing.
  11. The film formation method according to claim 10, further comprising waiting until the droplets of the curable composition merge on the substrate to form a substantially continuous liquid film between the application and the contact and until the solvent in the liquid film volatilizes.
  12. The film formation method according to claim 11, wherein the waiting lasts until the solvent in the liquid film volatilizes to 10% by volume or less relative to the entire liquid film.
  13. The film formation method according to claim 11, wherein the substrate is heated at a temperature of 30°C to 200°C for 10 s to 600 s in the waiting step.
  14. A method for manufacturing an article, comprising: forming a film of a curable composition on a substrate using the film formation method according to claim 10; processing the substrate with the film formed in the formation of a film; and fabricating an article using the substrate processed in the processing of the substrate.

Description

TECHNICAL FIELD The present disclosure relates to a curable composition and methods for forming a film and producing an article. BACKGROUND In the field of semiconductor devices, microelectromechanical systems (MEMS), and similar technologies, miniaturization is increasingly demanded, and imprinting techniques (optical imprinting techniques) are attracting attention as microfabrication techniques. In imprinting techniques, a curable composition is fed (applied) onto a substrate and cured in a state where a mold having a fine relief pattern in the contact surface is in contact with the composition. Thus, the relief pattern of the mold is transferred to the cured film of the curable composition, thereby forming a pattern on the substrate. Imprinting techniques enable the formation of fine patterns (structures) with sizes of several nanometers on substrates. An example of pattern formation using an imprinting technique will be described. First, a liquid curable composition is discretely dropped (applied) in a pattern formation region on a substrate. The droplets of the curable composition in the pattern formation region spread over the surface of the substrate. This phenomenon is called pre-spreading. Next, the curable composition on the substrate is brought into contact with (pressed on) the contact face of a mold. Consequently, the droplets of the curable composition spread throughout the gap between the substrate and the mold due to capillary action. This phenomenon is called spreading. In addition, the curable composition fills the recesses of the mold pattern due to capillary action. This phenomenon is called filling. The duration required to complete such spreading and filling is called filling time. After completion of filling, the curable composition is irradiated with light to be cured. The cured composition on the substrate is then separated from the mold. Thus, a cured pattern of the curable composition is formed by transferring the pattern of the mold to the curable composition on the substrate through these steps. At this point, the cured pattern of the curable composition formed on the substrate has a residual film. The residual film is a cured film remaining between the recesses of the cured film of the curable composition (protrusions of the mold pattern) and the substrate. Also, photolithography for manufacturing semiconductor devices requires the substrate to be planarized. For example, in extreme ultraviolet lithography (EUV), which is a technique of photolithography that has been attracting attention in recent years, the relief pattern in the surface of the substrate to which the curable composition is fed must be restricted to several tens of nanometers or smaller because the focal depth at which the projected image is formed decreases as miniaturization progresses. Imprinting techniques also require planarization to the same extent as EUV to improve the degree of filling and line width accuracy of the curable composition. In a planarization technique (Japanese Patent Laid-Open No. 2019-140394), a flat surface is formed by dropping a curable composition discretely onto a substrate provided with a relief structure in an amount corresponding to the relief structure and subsequently curing the composition while being in contact with a mold having a flat surface. In pattern formation methods and planarization techniques using imprinting, the curable composition on the substrate is brought into contact with a mold in a state where the droplets of the curable composition do not touch each other. This process inevitably causes air bubbles to be trapped between the mold, the substrate, and the composition. Consequently, it takes a long time for the air bubbles to diffuse across the mold and substrate to disappear, which is one of the factors that reduce productivity (throughput). Accordingly, a technique has been developed to merge the droplets of the curable composition on the substrate before bringing the curable composition into contact with the mold (see Japanese Patent Laid-Open No. 2022-188736). The technique disclosed in Japanese Patent Laid-Open No. 2022-188736, requires that the curable composition fills the contact area (pattern formation region), reaching the ends (edges), between the mold and the substrate by bringing the mold into contact with (pressing the mold against) the liquid film of the curable composition formed through spreading the droplets. This phenomenon is called edge filling. The speed at which edge filling proceeds is called edge filling speed. In pattern formation methods and planarization techniques using imprinting, in which droplets of the curable composition on the substrate are brought into contact with a mold, it takes time to fill a desired area (pattern formation region), reaching the ends (edges). This is one of the factors that reduce productivity (throughput). SUMMARY Accordingly, the present disclosure provides a novel technique for curable compositions. T