Dresden 2003 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 31: Quantenpunkte und -dr
ähte: Herstellung und Charakterisierung

HL 31.2: Vortrag

Mittwoch, 26. März 2003, 14:45–15:00, BEY/154

Shape, size, and number density of InAs quantum dots grown on the GaAs(113)B surface at different temperatures — •Mingchun Xu, Takayuki Suzuki, Yevgeniy Temko, and Karl Jacobi — Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin

InAs quantum dots (QDs) were grown on the GaAs(113)B surface by molecular beam epitaxy at temperatures between 435 - 490 ^∘C. Their shape, size distribution, and number density were investigated by in-situ scanning tunneling microscopy [1,2]. The shape of the QDs is given for the most part by {110}, (111)B and vicinal (001) bounding facets and does not change significantly with growth temperature. The size and the height of the QDs increase monotonously from 25 to 54 nm and from 3.5 to 9.8 nm, respectively, whereas the number density decreases, as temperature increases. This is explained in assuming a decrease of the number density of critical growth nuclei with temperature. The size distribution is bimodal: besides the coherent QDs, some larger and probably incoherent islands are observed that are extended along [332]. Post-annealing increases the diameter and the height by about 30% and decreases the number density, but does not change the shape significantly.

[1] T. Suzuki, Y. Temko, and K. Jacobi, Appl. Phys. Lett. 80, 4744 (2002).

[2] T. Suzuki, Y. Temko, and K. Jacobi, Phys. Rev. B, in press.