Method for forming fine concavo-convex patterns, method for producing optical diffraction structure, and method for copying optical diffraction structure

A method for forming fine concavo-convex patterns, the method comprising:

• providing a relief formation material comprising a substrate for the relief formation material composed of plastic film, a photothermal conversion layer 0.1 to 5 μm thick on the substrate for the relief formation material, and a relief formation layer composed of an ionizing radiation-curable resin having thermoplasticity on the photothermal conversion layer;
• forming a relief pattern sheet by coating a second ionizing radiation-curable resin composition onto a substrate, contacting the second ionizing radiation-curable resin with a diffraction lattice pattern resin master-hologram having fine concavo-convex patterns, partially curing the ionizing radiation-curable resin composition by temporarily exposing the substrate and diffraction lattice pattern resin master-hologram laminate to ionizing radiation thereby imparting the fine concavo-convex patterns from the diffraction lattice pattern resin master-hologram to the second ionizing radiation-curable resin, separating the diffraction lattice pattern resin master-hologram from the second ionizing radiation-curable resin, exposing the fine concavo-convex patterns of the substrate to further ionizing radiation to completely cure the fine concavo-convex patterns in the second ionizing radiation-curable resin;
• contacting the relief formation material and the relief pattern sheet with each other in such a manner that the relief formation layer is brought into contact with the fine concavo-convex patterns of the substrate, the fine concavo-convex patterns of the master hologram corresponding to the fine concavo-convex patterns formed on the relief formation layer;
• irradiating the photothermal conversion layer with an energy beam from the relief pattern sheet side to make the photothermal conversion layer generate heat;
• and
• separating the relief pattern sheet and the relief formation layer and exposing the relief formation layer to curing ionizing radiation.