Beschreibung:
Lateral patterning is a crucial technological step for the fabrication of complex nanostructures. It can be achieved either by etching or by a local deposition process. Most of the dry etching techniques for nanometer dimensions such as reactive ion etching (RIE) or focused ion beam (FIB) etching suffer from unintentional degradation such as crystal damage and contamination. In order to overcome these problems and to create well-defined and reproducible nanostructures we propose a self-organizing deposition process. It is based on local silicon molecular beam epitaxy (MBE) via ultrahigh-vacuum (UHV)-compatible shadow masks. By using this technique, well-defined tips and lines in the nanometer range have been fabricated. The shape of these mesa structures is basically determined by the physical growth mechanism. The sidewalls are well-defined crystallographic planes. This technique offers a convenient tool for the study of one- and zero-dimensional electronic systems.