Spontaneous change of growth orientation of In0.5Ga0.5P/GaAs superlattices in molecular beam epitaxy

Abstract

The spontaneous change of growth orientation during the molecular beam epitaxy of In0.5Ga0.5P/GaAs superlattices is investigated as a function of the growth temperature by cross‐sectional transmission electron microscopy. It is observed that there exists a critical temperature above which a change in growth orientation from 〈100〉 to 〈311〉 occurs and is characterized by the evolution of V‐shaped grooves with {311} facets. Further increase in the temperature enhances the evolution of the {311} facets. It is found that the formation of the V‐shaped grooves is along the [011] direction and that the most critical stage for the change in orientation is the interruption after the growth of the GaAs layer with P2 flux. Based on these observations the atomic arrangement on a stable (311) surface resulting from the spontaneous change of the growth orientation is discussed.