Fabrication of metal nanorod arrays using anodic porous alumina mask with elliptical apertures prepared by lattice conversion process

Highly ordered Au nanorod arrays were fabricated using anodic porous alumina with elliptical nanoholes as an evaporation mask and applied as a substrate for measurements of surface-enhanced Raman scattering (SERS) spectra. Shape of nanoholes in anodic porous alumina obtained by self-ordering anodization process is usually circular. In the present study, elliptical nanoholes ordered in rectangular lattice were successfully fabricated by lattice conversion process using naturally ordered anodic porous alumina. The Au nanorod arrays were fabricated by thermal evaporation using the obtained anodic porous alumina. The SERS activity of the Au nanorods were higher than that of a circular Au nanodots.