Preparation of large step-free mesas on Si(111) by molecular beam epitaxy

Development of surface morphology in Si molecular beam epitaxy on mesa‐structured Si(111) at temperatures around the (7x7) –“1x1” surface phase transition was studied using atomic force microscopy. Significant changes in surface morphology were found for a small increase in temperature near the surface phase transition accompanied by a strong increase in step‐free area dimension. This will be discussed with regard to the simultaneous appearance of the two surface phases under certain condition and their specific influence on the growth behaviour. Small triangular islands and voids appeared after growth at 1080 K indicating surface instability of larger step‐free areas. Growth at 1120 K with a rate of 1 nm/min results in the formation of atomically step‐free surface over 10x10 µm2 mesas without any irregularities. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)