2D periodic structures patterned on 3D surfaces by interference lithography for SERS

Abstract This contribution brings novel concept of Ag islands formation in 2D periodic arrangement with square symmetry on special 3D surfaces – gallium phosphide (GaP) nanocones, for surface-enhanced Raman spectroscopy application. 2D periodic structure in square symmetry with period of app. 470 nm is patterned in photoresist layer by interference lithography using double exposure of a two-beam interference optical field. Two different techniques for photoresist deposition on 3D surface are compared: spin-coating and photoresist deposition from water level. After Ag sputtering and lift-off, GaP nanocones are decorated with Ag islands in 2D periodical arrangement. Detectable enhancement in Raman signal for Rhodamine 6G adsorbed on prepared samples is demonstrated.