We have investigated by atomic force microscopy and scanning tunneling microscopy subsequent stages of the heteroepitaxy of InAs on GaAs(001) from the initial formation of the strained two-dimensional wetting layer up to the development of three-dimensional quantum dots. We provide evidence of structural features that play a crucial role in the two- to three-dimensional transition and discuss their contribution to the final morphology of the self-assembled nanoparticles. A model is suggested for the strained phase at the critical thickness consisting of an intermixed InxGa1-xAs surface layer of composition x = 0.82 and InAs "floating" on top. Such "floating" phase participate to the large mass transport along the surface during the two- to three-dimensional transition that accounts quantitatively for the total volume of dots.
Tracing the two- to three-dimensional transition in the InAs/GaAs(001) heteroepitaxial growth / Patella, F.; Nufris, S.; Arciprete, F.; Fanfoni, M.; Placidi, E.; Sgarlata, A.; Balzarotti, A.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 67:20(2003). [10.1103/PhysRevB.67.205308]
Tracing the two- to three-dimensional transition in the InAs/GaAs(001) heteroepitaxial growth
Placidi E.;
2003
Abstract
We have investigated by atomic force microscopy and scanning tunneling microscopy subsequent stages of the heteroepitaxy of InAs on GaAs(001) from the initial formation of the strained two-dimensional wetting layer up to the development of three-dimensional quantum dots. We provide evidence of structural features that play a crucial role in the two- to three-dimensional transition and discuss their contribution to the final morphology of the self-assembled nanoparticles. A model is suggested for the strained phase at the critical thickness consisting of an intermixed InxGa1-xAs surface layer of composition x = 0.82 and InAs "floating" on top. Such "floating" phase participate to the large mass transport along the surface during the two- to three-dimensional transition that accounts quantitatively for the total volume of dots.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
