Medium energy ion scattering analysis of InAs-GaAs(001) MBE-grown quantum dots

Bell, G.*; Quinn, P.*; Noakes, T.*; Bailey, P.*; Takahashi, Masamitsu

Medium energy ion scattering (MEIS) has been used for some years as a powerful probe of semiconductor layer structures. In particular, MEIS energy spectra can be converted to depth profiles of different atomic species in a structure with vertical resolution approaching single atomic layer thickness. However, the application of MEIS to discrete nanostructures (zero- or one-dimensional objects, rather than two-dimensional layer structures) has been very limited. We have recently analyzied InAs-GaAs quantum dot (QD) structures grown by MBE using MEIS and derived the vertical In composition profile in them. In the present work, we extended these experiments to InAs-GaAs QDs grown under different conditions at the in situ MBE facility at SPring-8, Japan. We discuss the variation of In composition profiles obtained by different MBE growth conditions.