Growth of Ge dots on templated Si substrates with diffusion-altered holes

¹  Forschungszentrum Jülich, Institute of Bio- and Nanosystems 1 - Leo Brandt Strasse, 52428 Jülich, Germany, EU
²  JARA - Fundamentals of Future Information Technologies

Corresponding author: g.rinke@fz-juelich.de

Received: 27 November 2008
Accepted: 9 February 2009

Abstract

We have studied the impact of the hole shape on the growth of Ge dots. Si substrates that have been templated by means of electron beam lithography and reactive ion etching have been used to grow Si buffer layers at different substrate temperatures by molecular-beam epitaxy. Atomic-force-microscopy studies show that for high substrate temperatures, the prepatterned holes are smeared out. A model has been employed to quantitatively analyze the smearing out of the holes. The study further shows that the shape of the holes has a substantial impact on the morphology of the subsequently grown Ge dots, i.e. Ge dots grown in smeared out holes show a tendency towards an inhomogeneous size distribution and the formation of multiple dots in one hole.