Dependence of buffer layer on the distribution of InAs quantum dots

Self-assembled quantum dots (SAQD) utilizing a Stranski-Krastanow growth mode are attractive because they are easily formed defect-free compared to other fabrication methods, but it is difficult to control the size and the position of QDs. Recently, preferential alignment of the QDs along the multiatomic steps, which were formed on a 2/spl deg/-off(100) GaAs substrate was reported. This method is attractive because it is a kind of in-situ process without using physical constraints such as dielectric masks and patterns. The size of QDs on 2/spl deg/-off(100) GaAs substrate is normally less than the terrace widths. The terrace width of 2/spl deg/-off(100) GaAs substrate is transformed by bunching effect mainly due to Ga diffusion during the growth. In particular, the terrace widths increase as increasing the growth thickness of GaAs buffer layer. In this work, we have investigated the dependence of GaAs buffer layer on the distribution of InAs QDs grown on 2/spl deg/-off(100) GaAs substrate.