Nanostructure Formation In Inas/inp(001) Heteroepitaxy: Importance Of Surface Reconstruction

摘要

Scanning tunneling microscopy has been used to study the deposition by molecular-beam epitaxy of thin InAs films on InP(001) substrates and compared with InAs growth on GaAs(001) under nominally identical conditions. In contrast to InAs/GaAs, InAs growth on InP does not proceed via a Stranski-Krastanov type mechanism, with a well-defined two-dimensional-three-dimensional growth mode transition, but instead a gradual and continuous surface roughening process occurs even from the earliest stages of deposition. Average height and surface roughness measurements indicate the absence of lateral surface correlations generated between adjacent elongated wires formed at higher deposition coverages. The origin of this growth behavior is attributed to the pregrowth formation of a self-templating arsenic-stabilized InP(001)-(2 × 4) surface, which is prepatterned on the atomic scale for the growth of highly anisotropic nanostructures.