Surface segregation and growth-mode transitions during the initial stages of Si growth on Ge(001)2[times]1 by cyclic gas-source molecular beam epitaxy from Si[sub 2]H[sub 6]

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.355890· OSTI ID:5445881

Tsu, R; Xiao, H Z; Kim, Y; Hasan, M; Birnbaum, H K; Greene, J E ^[1]; Lin, D; Chiang, T ^[2]

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1. Department of Materials Science, the Coordinated Science Laboratory and the Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)
2. Department of Physics and the Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

Surface morphological and compositional evolution during the initial stages of Si growth on Ge(001)2[times]1 by cyclic gas-source molecular beam epitaxy from Si[sub 2]H[sub 6] has been investigated using [ital in] [ital situ] reflection high-energy electron diffraction (RHEED), Auger electron spectroscopy, electron-energy-loss spectroscopy, and scanning tunneling microscopy, combined with post-deposition high-resolution cross-sectional transmission electron microscopy. The layers were deposited using repetitive cycles consisting of saturation Si[sub 2]H[sub 6] dosing at room temperature, followed by annealing for 1 min at 550 [degree]C. Film growth was observed to proceed via a mixed Stranski--Krastanov mode. Single-step-height two-dimensional growth was obtained for nominal Si deposition thicknesses [ital t][sub Si] up to [congruent]1.5 monolayers (ML). However, the upper layer remained essentially pure Ge which segregated to the surface through site exchange with deposited Si as H was desorbed. At higher [ital t][sub Si], the Ge coverage decreased slowly, the surface roughened, and two-dimensional multilayer island growth was observed for [ital t][sub Si] up to [congruent]7.5 ML, where bulk reflections in RHEED patterns provided evidence for the evolution of three-dimensional island formula.

• DOE Contract Number: FG02-91ER45439
• OSTI ID: 5445881
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 75:1; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
COHERENT SCATTERING
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
EPITAXY
GERMANIUM
GROWTH
METALS
MICROSCOPY
MOLECULAR BEAM EPITAXY
SCATTERING
SEGREGATION
SEMIMETALS
SILICON
SPECTROSCOPY