Fabrication of periodic nanohole multilayer structure on silicon surface toward photonic crystal

We have studied a porous structure on silicon surfaces that is introduced by electron irradiation. The structure consists of nanometer-sized holes arranged on silicon surfaces. Investigatinghe size and the distribution of surface nanoholes in a temperature range from about 4K to about 600K, we have estimated the porosity on a surface with nanoholes. We have fabricated a periodic dielectric multilayer structure on a silicon surface by introducing nanoholes periodically in one direction: alternating layers with different dielectric constants (the dielectric contrast of about 1.08), spaced by a distance of 100nm. We can form periodic dielectric layers at arbitrary locations on surfaces by scanning an electron beam, changing the periodicity and the dielectric constant by varying irradiation condition.