Area-controlled growth of InAs quantum dots and improvement of density and size distribution

Abstract

We propose and demonstrate a scheme (area-controlled growth) for controlling where self-assembled InAs quantum dots form, using a SiO2 mask and selective area metalorganic chemical vapor deposition growth. Using this technique, quantum dots can be formed in only selected areas of a growth plane. However, in the regions where dots are formed there is variation of dot density and size along the mask stripe direction because of the diffusion of species in the vapor phase. We achieve more uniform distributions of dot density and size by changing the mask pattern. Using this growth technique, it is possible to fabricate integrated optical devices containing an external reflector together with quantum dots serving as the active layer of a semiconductor laser.