“STM/AFM study of Ge quantum dots grown on Si(111)”

Author

Sgarlata, A. ; Rosei, F. ; Fanfoni, M. ; Motta, N. ; Balzarotti, A.

Author_Institution

Dipartimento di Fisica, Rome Univ., Italy

fYear

2000

fDate

2000

Firstpage

228

Lastpage

231

Abstract

We study by scanning tunneling microscopy (STM) and atomic force microscopy (AFM) in situ the evolution of Ge islands grown by physical vapor deposition (PVD) on 7×7 Si(111) reconstructed surfaces. On the 5×5 reconstructed wetting layer, large 3D islands form whose average lateral dimension is about 200-500 nm. The statistical distribution of the island shapes has been analyzed, showing that three types of shapes coexist under certain conditions: strained, relaxed and ripened (atoll-like) islands. By scanning probe microscopy (SPM) it was possible to measure the contact angles of the island facets and to observe the depletion of the substrate around the ripened islands. All these features are attributed to the misfit strain. These findings successfully compare with a recent theoretical model

Keywords

atomic force microscopy; contact angle; elemental semiconductors; germanium; island structure; scanning tunnelling microscopy; semiconductor quantum dots; silicon; surface reconstruction; wetting; 200 to 500 nm; 5×5 reconstructed wetting layer; 7×7 Si(111) reconstructed surfaces; AFM; Ge islands; Ge quantum dots; STM; Si; Si(111); Si-Ge; atomic force microscopy; contact angles; island facets; island shapes; large 3D islands; lateral dimension; misfit strain; physical vapor deposition; relaxed islands; ripened atoll-like islands; scanning probe microscopy; scanning tunneling microscopy; statistical distribution; strained islands; Atherosclerosis; Atomic force microscopy; Atomic layer deposition; Chemical vapor deposition; Quantum dots; Scanning probe microscopy; Shape; Statistical distributions; Surface reconstruction; Tunneling;

fLanguage

English

Publisher

ieee

Conference_Titel

Semiconducting and Insulating Materials Conference, 2000. SIMC-XI. International

Conference_Location

Canberra, ACT

Print_ISBN

0-7803-5814-7

Type

conf

DOI

10.1109/SIM.2000.939232

Filename

939232