Interplay of growing facets during self-assembled growth of GaAs on patterned substrates

摘要

The self-assembled growth of GaAs on mesa stripes with a sidewall angle of ～65° formed on pre-patterned GaAs(001) substrates has been studied by secondary electron microscopy (SEM) and atomic force microscopy (AFM). Specific emphasis is placed on the morphological evolution and interplay of different growing facets with increasing GaAs deposition. Three facets form during the initial stages of growth (<0.25 μm), however significant changes are apparent before closure of the ridge structure occurs after ～1 μm deposition. Growth leads to a stable structure with {310}, {110} and {320} facets. The {110} facet is formed preferentially during the initial stages of growth, with the {310} facet becoming more favourable at greater deposition quantities. This interplay of different facets highlights the complexity of growing high quality structures on patterned substrates.