We report on the fabrication process of SiO 2 templates with periodic sub-100 nm patterns by electron-beam (e-beam) lithography followed by reactive ion etching. One-dimensional and two-dimensional periodic patterns were defined in 350 nm polymethylmethacrylate resist by e-beam lithography, and then transferred into 100 nm SiO 2 layers which were coated on GaAs or GaN/sapphire substrate. Patterns including line arrays and square/hexagonal hole arrays were obtained in the SiO 2 layers with sizes ranging from 100 nm to 52 nm in width or diameter. A pattern size deviation of less than 4% in a hole array of 100 µm by 100 µm was achieved. The patterned SiO 2 layers can serve as templates for the growth of periodic III-V semiconductor nanostructures. In this work, periodic InGaN nanowires and nanodots with high optical quality have been fabricated successfully by using the SiO 2 templates on GaN/sapphire.