Step ordering during OMCVD growth on non-planar substrates

We used atomic force microscopy (AFM) in air to investigate the structure of atomically smooth terraces separated by monoatomic steps which are formed during organometallic chemical vapor deposition (OMCVD) on non-planar substrates. We found that grooves along the [01(1) over bar]-direction can orient the steps on the (100) ridge between them in the [011]-direction. This orientation effect is sustained for a distance of about 500 nm from each groove. The distance between the oriented steps is determined by the initial misorientation angles of the substrate, and their width is nearly constant. We explain these step orientation phenomena as coming from the interplay between {311}A and (100) growth on the non-planar substrate. The step orientation control could be useful for preparation of improved nanostructures, such as quantum wells, quantum wires and fractional monolayer superlattices.