Journal of Vacuum Science & Technology B, Vol.21, No.6, 2496-2499, 2003
Fabrication of subwavelength surface structures combining self-assembled masking layer with plasma etching techniques
A lithography-free: method for producing periodic and nonperiodic surface structures is presented. It combines self-assembly of masking particles with well established plasma etching techniques known from microelectromechanical system technology. The method is generally applicable to bulk as well as layered materials. In our experiments, layers of glass spheres of different diameter were assembled on the sample surface forming a mask against plasma etching. Silicon surface structures with periodicity of 500 nm and feature dimensions of 20 nm were produced in this way. Thermal oxidation of the so structured silicon substrate offers the capability to vary the fill factor of the periodic structure owing to volume expansion during oxidation but also to define silicon dioxide surface structures by selective plasma etching. Similar structures can be simply obtained structuring silicon dioxide layers on silicon. The method offers a simple route, e.g., for photonic crystal fabrication. (C) 2003 American Vacuum Society.