Synchrotron X-ray diffraclion has been applied Lo he in siLu monftoring of Lhe molecular beam cpilaxial growth of self-assembled InAs/GaAs(001) quantum dots (QDs). As well as the strain distribution inside QDs, the lateral and vertical size of QDs was determined as a function of growth time. In combination with post-growth atomic force microscopy, the evolution of the total volume of QDs was evaluated. It was found that the QD volume increases at a similar rate over the temperature range of 450-480 degrees C. A significant mass transport from the wetting layer and the substrate was confirmed. (C) 2013 Elsevier B.V. All rights reserved.