Design, fabrication, and characterization of subwavelength periodic structures for semiconductor antireflection coating in the visible domain

Abstract

Subwavelength structured (SWS) surfaces etched directly into different substrates provide performance equivalent to an ideal anti-reflection thin film. We report on SWS surfaces etched into silicon which present anti-reflection properties for visible light. The fabrication of the SWS component is based on a double holographic exposure of photoresist and reactive ion etching processes. At normal incidence, the reflectivity for the HeNe line is 0.02. This reflectivity measurement includes a 1 percent diffusion by the surface. Measurements of the reflectivity over the whole visible spectrum and over a wide field of view are provided.