Formation of macroscopic steps during selective area metalorganic chemical vapor deposition on GaAs (001) vicinal substrates

Abstract

We have investigated the influence of substrate misorientation on facet formation in selective area metalorganic chemical vapor deposition (MOCVD) on GaAs (001) vicinal substrates. Macroscopic steps several hundred angstroms high were generated on the epitaxial layer over triangular voids where the voids were formed using the conditions of the reverse-mesa-shaped facets. AFM observations of the steps revealed that the exact (001) crystallographic surface developed on the side for which the (001) surface is exposed since the surface energy of a low index plane was lower than that of a misoriented high index plane. The wide terrace width of 1100 Angstrom was also observed, which was evidence for the step flow mode growth. Periodic steps were generated over the periodic stripe masks and their potential application to quantum wire fabrication was discussed briefly.