Lateral alignment of SiC dots on Si

Abstract

An alignment of self-assembled SiC dots grown by molecular beam epitaxy on Si substrates is demonstrated. Atomic force microscopy was applied showing the possibility to control the lateral ordering in linear chains and in dense dot arrays. The large lattice mismatch between Si and SiC of 20% stimulates a three-dimensional nucleation on the substrate. The formation of well ordered monoatomic, and biatomic steps as well as step bands on (100) and (111) Si was used, offering the advantage to not need additional processing steps to define the alignment. However, during the SiC nucleation on Si the substrate participates in the reaction to SiC by lateral Si diffusion resulting in an unstable surface during the growth. Thus, the reproducible control of the nucleation sites independent on the movement of the steps during the growth is a critical issue to achieve the lateral alignment. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)