Alloying mechanisms for epitaxial nanocrystals.
The different mechanisms involved in the alloying of epitaxial nanocrystals are reported in this Letter. Intermixing during growth, surface diffusion, and intraisland diffusion were investigated by varying the growth conditions and annealing environments during chemical vapor deposition. The relative importance of each mechanism was evaluated in determining a particular composition profile for dome-shaped Ge:Si (001) islands. For samples grown at a faster rate, intermixing during growth was reduced. Si surface diffusion dominates during H2 annealing, whereas Ge surface diffusion and intraisland diffusion prevail during annealing in a PH3 environment.
Leite
M S
MS
Laboratório Nacional de Luz Síncrotron, Caixa Postal 6192, CEP 13083-970, Campinas, SP, Brazil.
Medeiros-Ribeiro
G
G
Kamins
T I
TI
Williams
R Stanley
RS