Effect of Growth Interruption in Migration Enhanced Epitaxy on InAs/GaAs Quantum Dots

Abstract

In this study, we investigated the effect of growth interruption time (t(GI)) during migration enhanced epitaxy (MEE) growth of self-assembled InAs/GaAs quantum dots (QDs) to control the density of the QDs without any substrate rotation stop during QD formation. By manipulating the growth factor (t(Gt)), the control of CID density in the range of 3.4 x 10(9)-3.5 x 10(10) dots/cm(2), as well as the QD shape, was demonstrated. We concluded that three phenomena occur during growth interruption: 1) In re-evaporation, 2) In segregation, and 3) the redistribution of InAs QDs. From photoluminescence (PL), it is found that the emission wavelength of samples increased from 967.7 to 1151.7 nm as t(GI) increased due to redistribution. In addition, we confirmed PL peak emissions from QDs, quasi-three-dimensional (Q3D) clusters, and wetting layer. As a result, the manipulation of t(GI) in the MEE method can control the density, uniformity, size, and wavelength of QDs. (C) 2009 The Japan Society of Applied Physics