Novel Nanofabrication Process for InAs/AlGaSb Heterostructures Utilizing Atomic Force Microscope Oxidation

We demonstrate a novel nanofabrication process for InAs which is shown to be readily applicable to the fabrication of InAs-based nanostructure devices that employ quantum dot or wire structures. The fabrication process is achieved by direct local oxidation using an atomic force microscope (AFM). This is based on the oxidation of an InAs layer instead of oxidizing a GaSb surface layer which we recently demonstrated for the fabrication of InAs/AlGaSb nanostructures. Oxidation characteristics were studied and fabrication capabilities for commonly used chemical solutions were examined for the development of a simple nanofabrication process. We found that the oxidized InAs becomes insoluble to the acetic-acid-based etchant enabling a selective formation of InAs islands with a desired shape that are drawn by AFM oxidation. We comparatively describe the oxidation characteristics for both InAs and GaSb and discuss the feasibility of the new AFM oxidation process for InAs as a nanofabrication process.