Linear alignment of GaN quantum dots on AlN grown on vicinal SiC substrates

We demonstrate linear alignment of self-assembled GaN quantum dots (QDs) grown by molecular beam epitaxy on AlN using vicinal SiC-substrates. Under specific surface preparation, such substrates can present well-ordered steps. We also show that stepped AlN layers can be grown on such SiC substrates, the height and width of AlN step depending on growth parameters. Such steps induce a heterogeneous nucleation of QDs and promote an alignment along their edges. We demonstrate, by atomic force microscopy, the possibility of controlling the island spatial distribution. and point out a lateral ordering of the dots. (C) 2003 American Institute of Physics.