Effect of Cryogenic Substrate Temperature on the Growth of Ag and Cu Nanostructured Optical Metamaterials

We demonstrate an improved technique to grow glancing angle nanostructured thin films of silver and copper using electron-beam evaporation. Silver has particular interest for optical metamaterial activity, but unlike most other metals, the surface mobility of these atoms makes it difficult to grow distinct nanocolumns. By cryogenically cooling the substrate, we demonstrate that these metals can show marked improvement in their nanocolumn structure.