Enhanced Ge/Si(001) island areal density and self-organization due to P predeposition

Journal Article · Sun May 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3587226· OSTI ID:21560229

Cho, B; Bareno, J; Petrov, I; Greene, J E ^[1]

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1. Materials Science Department and the Frederick-Seitz Materials Research Laboratory, University of Illinois, 104 South Goodwin Ave., Urbana, Illinois 61801 (United States)

The predeposition of P, with coverages {theta}{sub P} ranging from 0 to 1 ML, on Si(001) significantly increases both the areal density and spatial self-organization of Ge islands grown by gas-source molecular beam epitaxy from hydride precursors. The Ge island density {rho}{sub Ge} initially increases with {theta}{sub P}, reaching a maximum of 1.4 x 10{sup 10} cm{sup -2} at {theta}{sub P} = 0.7 ML, a factor of four times higher than on bare Si(001) under the same deposition conditions, before decreasing at higher P coverages. The increase in {rho}{sub Ge}({theta}{sub P}) is due to a corresponding decrease in Ge adatom mean free paths resulting from passivation of surface dangling bonds by adsorbed pentavalent P atoms which, in addition, leads to surface roughening and, therefore, higher Ge coverages at constant Ge{sub 2}H{sub 6} dose. As {theta}{sub P} (and hence, {rho}{sub Ge}) increases, so does the degree of Ge island ordering along <100> directions due to the anisotropic strain field surrounding individual islands. Similar results are obtained for Ge island growth on P-doped Si(001) layers where strong P surface segregation provides partial monolayer coverage prior to Ge deposition.

• OSTI ID: 21560229
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 9; Other Information: DOI: 10.1063/1.3587226; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADSORPTION
ANISOTROPY
ATOMS
DENSITY
DEPOSITION
DOPED MATERIALS
GERMANIUM
GERMANIUM HYDRIDES
LAYERS
MEAN FREE PATH
MOLECULAR BEAM EPITAXY
MOLECULAR STRUCTURE
PASSIVATION
PHOSPHORUS
SEGREGATION
SEMICONDUCTOR MATERIALS
SILICON
STRAINS
SURFACES
CRYSTAL GROWTH METHODS
ELEMENTS
EPITAXY
GERMANIUM COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
MATERIALS
METALS
NONMETALS
PHYSICAL PROPERTIES
SEMIMETALS
SORPTION