METALORGANIC CHEMICAL-VAPOR-DEPOSITION OF GASB QUANTUM DOTS ON GERMANIUM

Metaloganic chemical vapour deposition (MOCVD) was used to study the g rowth of GaSb islands on (100)Ge. For the first time formation GaSb is lands on Ce with dimensions of 250 nm wide by 100 nm high were observe d using atomic force microscopy. The average density of these islands across the surface was 4 x 10(8) cm(-2) for 30 s or 60 monolayers of d eposition. For longer growth times, these islands coalesced as three-d imensional growth became dominant. The existence of GaSb islands for 6 0 monolayers of growth suggests that nucleation of islands in the GaSb /Ge system is slower compared to previously reported island growth in the GaSb/GaAs system. The size of the GaSb islands observed here is co mpatible with the onset of size quantisation. (C) 1998 Elsevier Scienc e S.A. All rights reserved.