Effect of lattice mismatch on surface morphology of InAs quantum dots on (100) In1-xAlxAs/InP

We present the results of the formation of the InAs quantum dots (QDs) on the (100) In1-xAlxAs(InAlAs)/InP substrate by using relaxed InAlAs buffer layers with different compositions. Variations of surface morphology of InAs QDs as a function of InAs-InAlAs lattice mismatch have been evaluated by atomic force microscopy. When the lattice mismatch increases from 2.4% to 4.2%, the size of QDs decreases, and the density of QDs increases. Each of these dependences can be fitted to a power function of the misfit unless the Al diffusion, roughness of the buffer layer, and/or the ripening of small dots modify the size and density. (C) 2001 American Institute of Physics.