Spatial ordering of self-organized InGaAs AIGaAs quantum disks on GaAs (311)B substrates

We report the control of self-organization of InxGa1-xAs/AlGaAs quantum dis ks on GaAs (311)B surfaces using a novel technique based upon lithography-d efined SiN dot arrays. A strained InGaAs island array selectively grown usi ng the SiN dots provides periodic strain field. When the pitch of lateral o rdering corresponds with the period of the strain field, self-organized qua ntum disks stacked on the InGaAs islands are precisely arranged just as the buried SiN dot array. The spacing of the array element is 250-300 nm (x = 0.3) and around 150 nm (x = 0.4). Vertical alignment by strain is achieved at a very thick (95 nm) separating layer. Characterization using atomic for ce microscopy reveals the size-fluctuation of disk is dramatically improved with spatial ordering.