Scanning tunneling microscopy study of the growth and self-organization of Ge nanostructures on vicinal Si(111) surfaces

摘要

The initial stages of Ge growth on Si(111) vicinal surfaces tilted in the [(1) over bar(1) over bar2] and [11 (2) over bar] directions were studied in situ in the temperature range 350-500 degrees C using scanning tunneling microscopy. It was shown that, at low Ge deposition rates of 10(-2) to 10(-3) BL/min, ordered Ge nanowires can form on surfaces tilted in the [(1) over bar(1) over bar2] direction under conditions of step-layered growth. The height of a nanosized Ge wire is one or three interplanar distances and is determined by the initial height of a silicon step. It was established that, during epitaxial ;growth, steps with a [11 (2) over bar] front are replaced by steps with a [(1) over bar(1) over bar2] front. As a result, the step edge is serrated and the formation of smooth nanosized Ge wires uniform in width is hampered on the serrated Si(111) surfaces tilted in the [11 (2) over bar] direction.