Growth mechanism of highly uniform InAs/GaAs quantum dot with periodic arsine interruption by metalorganic chemical vapor deposition

Abstract

The mechanism for suppressing the formation of abnormally large islands during the conventional quantum dot (QD) growth was investigated. In comparison of the periodic arsine interruption method to the conventional method, InAs QDs grown on GaAs substrate by metal organic chemical vapor deposition has a higher density and aspect ratio without large islands. The formation of large islands was related to the inhomogeneity in the nucleation and growth process of QDs. The surface modification from As-stabilized to In-stabilized surfaces during arsine interruption modulated the surface energy and resulted in more homogeneous and simultaneous nucleation of QDs. The arsine interruption time was found to be a critical parameter for the homogeneous QD growth without abnormally large islands. (C) 2011 American Institute of Physics.