Facet preferential growth of self-assembled InAs dots on patterned GaAs substrates

We have investigated the self-assembled InAs dot growth on patterned (100), (111)B, and (311)A GaAs substrates in order to obtain facet preferential characteristics among various facets for the purpose of better position control of the dots for possible applications to the electronic and photonic devices. The self-assembled InAs dots were found to grow selectively in the bottom of the tetrahedral etch-pits or on certain ridges or valleys or slopes of grooved surfaces in a regular fashion. Some common preference relationships among different original orientation of the substrate were consistent with each other. The physical origin of the preference is explained by the combination of difference in number of bonds on different surfaces and the accommodation of strains by surface misfit dislocations.