Nanopatterning of Si/SiGe Two-dimensional Hole Gases by PFOTS-aided AFM Lithography of Carrier Supply Layer

Abstract

AbstractThe nanopatterning of Si/SiGe layers by PFOTS (perfluorooctyl trichlorosilane) -aided AFM (atomic force microscopy) lithography is demonstrated. We use self-assembled PFOTS monolayers as a resist for AFM exposure and then transfer patterns in to underlying SiGe layers by a two-step selective wet etching. Linewidths well under 100nm can be achieved with improved uniformity and repeatability compared to AFM lithography without PFOTS. This lithography technique was used to pattern the carrier supply layer in Si/SiGe 2-D hole gases to localize holes for epitaxially passivated quantum dot applications.