Simple fabrication of pillar silicon nanostructures by a contact block copolymer technique

In this study, silicon nanopillar structures were fabricated by a contact block copolymer (BCP) technique, which is a potential technique for the fabrication of self-aligned silicon nanoscale structures. For the contact BCP technique, a nanometer-scale BCP hole pattern was formed on the silicon surface and the silicon, masked with BCP, was exposed to a nitrogen ion beam for surface nitriding. Using the nitride surface as the etch mask, after the removal of the BCP silicon nanopillar structures could be successfully fabricated using a low-energy chlorine-based ion beam. By eliminating the additional steps of hard mask deposition and etching, this technique provided a simplified method of forming a silicon nanostructure. Especially, due to the extremely low thickness of the nitride mask layer, precise transfer of the mask dimension to the silicon was possible. The use of a low-energy ion beam could not only minimize the damage to the nanopillar silicon surface but could also increase the etch selectivity.