Abstract
We carry out phase field simulations to study properties of the comblike step patterns induced by an adatom source. When an adatom source advances right in front of a step, step wandering is caused by the asymmetry of the surface diffusion field and small protrusions are formed. If the velocity of the source is smaller than a critical value , the protrusions follow the adatom source with coarsening of the step pattern, and a regular comblike pattern with finger-like protrusions is formed. With a sufficiently small , the gap of the supersaturation is large at the adatom source. Since the period of protrusions, , decreases with increasing , the coarsening of step pattern is irrelevant for the protrusions to catch up with the adatom source. Near , the gap of the supersaturation at the adatom source is small. Taking account of the increase in with increasing , the coarsening of the step pattern is essential for the protrusions to follow the adatom source.
2 More- Received 20 October 2016
DOI:https://doi.org/10.1103/PhysRevE.95.032803
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