Fabrication of quantum wires by in-situ ion etching and MBE overgrowth

Link:
Autor/in:
Erscheinungsjahr:
2001
Medientyp:
Text
Beschreibung:
  • We fabricate GaAs quantum wires (QW) that are completely embedded in epitaxial material. Here we report about an in-vacuo fabrication process, in which an ex-situ pre-patterned GaAlAs/GaAs heterostructure is in-situ etched and subsequently transferred under ultra high vacuum conditions into the growth chamber for epitaxial overgrowth. The in-situ etching step involves a chemical assisted ion beam etching with subsequent chemical gas etching. The aim of our investigations is to optimize the in-vacuo process for the reduction of interface states between the etched and overgrown material. We have studied structural properties of such processed samples with cross-sectional scanning-electron microscopy and transmission-electron microscopy. The optical and electronic properties of overgrown QW are investigated with magneto-transport measurements and far-infrared transmission spectroscopy. Overgrown QW show in comparison to conventional QW without overgrowth clearly increased carrier densities and a reduced depletion zone at the QW side-walls. These results indicate the successful reduction of surface states and establish the potential of the suggested in-situ technique for the fabrication of quantum structures.
Lizenz:
  • info:eu-repo/semantics/restrictedAccess
Quellsystem:
Forschungsinformationssystem der UHH

Interne Metadaten
Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/9dfef516-e197-4549-8901-2bc47d679e3d