Self-organized nanodot pattern fabrication using the reverse sputtering method

We demonstrate the synthesis of high density periodic 2D nanodot patterns using reverse sputtering in magnetron sputtering equipment on a single crystal Si substrate and sputter-deposited Si-thin film. In this etching process, a minute amount of Ta is supplied by DC sputtering or splashing from the substrate holder surface. STEM, EDX, TEM and XPS analyses confirmed preferentially localized Ta-silicide in the nanodots. The nanodot pattern formation is attributed to the repeated adsorption and desorption of Ta and Si molecules forming Ta-silicide, and its segregation with self-organization. We also discuss power and time dependence of the nanodot pattern sizes and hole structure formation as a side-effect. This simple process is conducted at room temperature and makes use of an extremely simple setup. Our result promises a significant improvement in the productivity of quantum dot devices and has the potential to trigger their worldwide spread.