Scaling characteristics of bunching and no bunching regions of semiconductor mounds


TÜZEMEN A. T.

JOURNAL OF CRYSTAL GROWTH, cilt.546, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

The equilibrations of initial surfaces bounded by envelope functions of the form h (0) - x(alpha) and consist of concentric circular monoatomic steps in two dimensions are studied in diffusion limited (DL) regime. Repulsive and attractive step interactions of the form w(-2) and w(-1), respectively, where w is the step separation are considered. For certain parameter values of repulsive and attractive interactions an initial surface either equilibrates to a flat surface or step bunching occurs on the surface. The bunching -no bunching regions of initial surfaces in a parameter space are investigated and scaling characteristics of bunching/no bunching regions are obtained numerically. The bunching and no bunching regions scales as (x(0)/x(0)')(gamma) (N/N)(delta) for a general surface where x(0) is the initial range of the surface and N is the initial number of steps on the surface. For all forms of initial surface (alpha = 1/2, 1, 2), we find that gamma similar to 1/2 and delta similar to 1/6 and these results for scaling can be generalized which takes into account both the size and the slope (and curvature) of the initial surface as provided in the text. Our findings can directly be tested experimentally.