Templated self-assembly of SiGe quantum dots [Elektronische Ressource] / vorgelegt von Christian Dais

Templated Self-Assembly of SiGe Quantum Dots Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der RWTH Aachen University zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von Diplom Physiker Christian Dais aus Ludwigsburg, Deutschland Berichter: Prof. Dr. D. Grützmacher Prof. Dr. G. Güntherodt Tag der mündlichen Prüfung: 19. August 2009 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar. Abstract This PhD thesis reports on the fabrication and characterization of exact aligned SiGe quantum dot structures. In general, SiGe quantum dots which nucleate via the Stranski-Krastanov growth mode exhibit broad size dispersion and nucleate randomly on the surface. However, to tap the full potential of SiGe quantum dots it is necessary to control the positioning and size of the dots on a nanometer length, e.g. for electronically addressing of individual dots. This can be realized by so-called templated self-assembly, which combines top-down lithography with bottom-up self-assembly. In this process the lithographically defined pits serve as pre-defined nucleation points for the epitaxially grown quantum dots. In this thesis, extreme ultra-violet interference lithography at a wavelength of λ = 13.4 nm is employed for pre-patterning of the Si substrates.