1. A substrate is coated with a polymer film called resist layer.
2. A beam of UV light passes through the mask and react with the resist.
3. The exposed parts of the resist are dissolved during the developing stage -revealing the replica of the mask pattern.
4. The substrate is then placed in an acidic solution which etches silica has been removed, the resist is dissolve in a different solution.
5. Further etches remove silicon from the exposed areas-creating nanostructures