Irradiation-induced Ge multilayer growth from GeH4 on Si(111)

Citation
J. Braun et al., Irradiation-induced Ge multilayer growth from GeH4 on Si(111), SURF SCI, 454, 2000, pp. 811-817
Citations number
16
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
SURFACE SCIENCE
ISSN journal
00396028 → ACNP
Volume
454
Year of publication
2000
Pages
811 - 817
Database
ISI
SICI code
0039-6028(20000520)454:<811:IGMGFG>2.0.ZU;2-1
Abstract
Scanning tunneling microscopy and X-ray photoelectron spectroscopy measurem ents after Ge chemical vapor deposition on Si(111)-(7 x 7) show that no mor e than 2.5 bilayers of Ge can be deposited upon GeH4 exposure at 730 K [p(G eH4) = 7 x 10(-5) mbar], and that the surface remains atomically flat with a high quality(5 x 5) reconstruction. If, however, the Si substrate is expo sed to Al K alpha radiation prior to GeH4 exposure, Ge growth does not stop and three-dimensional islands form on top of the initial Ge wetting layers . Photoluminescence measurements show that defects are created in the Si su bstrate during X-ray irradiation, which may account for the different growt h behavior of Ge on irradiated and non-irradiated Si surfaces. (C) 2000 Els evier Science B.V. All rights reserved.