Paul N, Filimonov S, Cherepanov V, Cakmak M, Voigtländer B. Identification of Ge/Si intermixing processes at the Bi/Ge/Si(111) surface.
PHYSICAL REVIEW LETTERS 2007;
98:166104. [PMID:
17501435 DOI:
10.1103/physrevlett.98.166104]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Indexed: 05/15/2023]
Abstract
The chemical contrast between Si and Ge obtained by scanning tunneling microscopy on Bi-covered Si(111) surfaces is used as a tool to identify two vertical Ge/Si intermixing processes. During annealing of an initially pure Ge monolayer on Si, the intermixing is confined to the first two layers approaching a 50% Ge concentration in each layer. During epitaxial growth, a growth front induced intermixing process acting at step edges is observed. Because of the open atomic structure at the step edges, relative to the terraces, a lower activation barrier for intermixing at the step edge, compared to the terrace, is observed.
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