Wavelength selection in unstable homoepitaxial step flow growth

The growth of Cu on a vicinal Cu surface is investigated using variable tem perature scanning tunneling microscopy. A meandering instability caused by the step edge barrier for diffusion leads to a lateral patterning of the su rface with a temperature-dependent, distinctive wavelength. This length sca le is set by nucleation of one-dimensional islands at step edges. In the te mperature range covered by our experiment (230 to 400 K) a specific slope o f the growth features within the plane of the surface is selected. This may point to a pronounced spatial anisotropy of the step edge barrier.