Ordering of Ge islands on hill-patterned Si (001) templates

Abstract

We studied the nucleation and ordering mechanism of Ge islands on hill-patterned Si (001) templates. Like in the case of pit-patterned substrates, the initial Ge wetting layer decorates the inclined surfaces of the hill pattern with corrugations consisting entirely of {105} faceted prisms and {001} terraces. Upon further Ge deposition, islands nucleate as pairs in the V-shaped troughs between neighboring hills, and subsequently merge into a single island near the center of each trough. Finite element calculations show that island nucleation and the subsequent movement toward the center of the trough are governed by elastic energy minimization.