Fabrication of metal three-dimensional periodic nanostructures by diffraction phenomenon

Recently, there has been considerable interest in mass production technology of metal three-dimensional periodic nanostructures. For mass production, photolithography using diffraction phenomenon is well suited expect the disadvantage that it is difficult to fabricate the metal structures. Therefore, this paper reports for the first time a fabrication of the metal three-dimensional periodic nanostructures, by the diffraction-based lithography using metal ion-containing photoresists. In this report, Ag was used as a metal material to fabricate the structures. An examination of Ag+ concentration shows that for Ag+ equal to 0.28% or less, Ag nanoparticles are not formed on the photoresist. Under these conditions, it is found that the optimum exposure for fabricating the structures is 400 mJ/cm2.