Surface morphology evolution during the overgrowth of large InAs–GaAs quantum dots

The effects of GaAs overgrowth on the structural properties of large low-growth-rate InAs quantum dots (LGR-QDs) grown on GaAs(001) are examined using in situ scanning tunneling microscopy. Strongly anisotropic surface diffusion produces a characteristic valley-ridge structure above the LGR-QDs and the surface is not planarized even after a cap thickness >400 A. The evolution of surface morphology proceeds very differently to the case of smaller conventional growth rate QDs capped under the same conditions, due to the different initial strain states of the QDs.

[1]  L. Lazzarini,et al.  SELF-AGGREGATED INAS QUANTUM DOTS IN GAAS , 1998 .

[2]  Anupam Madhukar,et al.  Punctuated island growth: An approach to examination and control of quantum dot density, size, and shape evolution , 1999 .

[3]  David J. Srolovitz,et al.  ON THE STABILITY OF SURFACES OF STRESSED SOLIDS , 1989 .

[4]  B. A. Joyce,et al.  Surface alloying at InAsGaAs interfaces grown on (001) surfaces by molecular beam epitaxy , 1997 .

[5]  Axel Lorke,et al.  Intermixing and shape changes during the formation of InAs self-assembled quantum dots , 1997 .

[6]  David T. D. Childs,et al.  Effect of growth rate on the size, composition, and optical properties of InAs/GaAs quantum dots grown by molecular-beam epitaxy , 2000 .

[7]  M. Lagally,et al.  Self-organization in growth of quantum dot superlattices. , 1996, Physical review letters.

[8]  G. Salamo,et al.  Morphology of InAs self-organized islands on AlAs surfaces , 1999 .

[9]  T. Jones,et al.  Shape and surface morphology changes during the initial stages of encapsulation of InAs/GaAs quantum dots , 2001 .

[10]  A. R. Kovsh,et al.  InAs/InGaAs quantum dot structures on GaAs substrates emitting at 1.3 μm , 1999 .

[11]  V. LaBella,et al.  Monte Carlo derived diffusion parameters for Ga on the GaAs(001)- (2×4) surface: A molecular beam epitaxy–scanning tunneling microscopy study , 2000 .

[12]  T. Metzger,et al.  Determination of strain fields and composition of self-organized quantum dots using x-ray diffraction , 2001 .

[13]  Anupam Madhukar,et al.  InAs island‐induced‐strain driven adatom migration during GaAs overlayer growth , 1994 .

[14]  Zhichuan Niu,et al.  Methods to tune the electronic states of self-organized InAs/GaAs quantum dots , 2000 .

[15]  David T. D. Childs,et al.  SCANNING TRANSMISSION-ELECTRON MICROSCOPY STUDY OF INAS/GAAS QUANTUM DOTS , 1998 .

[16]  D. Ritchie,et al.  Modification of InAs quantum dot structure by the growth of the capping layer , 1998 .

[17]  D. W. Pashley,et al.  Quantitative compositional analysis of InAs/GaAs quantum dots by scanning transmission electron microscopy , 2001 .

[18]  Jerry Tersoff,et al.  Stresses and first-order dislocation energetics in equilibrium Stranski-Krastanow islands , 2001 .

[19]  Gerhard Abstreiter,et al.  Influence of growth conditions on the photoluminescence of self-assembled InAs/GaAs quantum dots , 1999 .