Ion beam sputter deposited Si_0.8Ge_0.2 epilayers: Lattice defects and surface topology

TY - JOUR

T1 - Ion beam sputter deposited Si0.8Ge0.2 epilayers

T2 - Lattice defects and surface topology

AU - Demuth, V.

AU - Dorsch, W.

AU - Strunk, H. P.

AU - Lyakas, M.

AU - Eizenberg, M.

AU - Mosleh, N.

AU - Meyer, F.

AU - Schwebel, C.

PY - 1996

Y1 - 1996

N2 - We study growth topology and defect structure of heteroepitaxial Si0.8Ge0.2 layers grown by ion beam sputter deposition (20 keV Xe+) on (001)-Si substrates (growth rate: 1.4 Å/ s) And use transmission electron microscopy and atomic force microscopy. The sputtered surfaces are, at all growth temperatures, rather smooth (mean surface roughness < 18 Å). There is a slight tendency for improved quality at higher growth temperatures, which we attribute to the larger diffusion length of adatoms at the Si0.8Ge0.2 layer surface. The lattice defects observed in the Si0.8Ge0.2 layer can be classified into a) misfit induced defects (dislocations) and b) defects due to the bombardment of the growing film with high energetic Si and Ge atoms (defects parallel to {113} and {001} lattice planes). The origin of {113} defects is discussed in terms of point defect generation and agglomeration due to a supersaturation of point defects. At high growth temperatures (700 °C) the enhanced diffusion of point defects to the layer surface and the Si substrate reduces the supersaturation. Thus, nucleation of {113} and {001} defects is suppressed.

AB - We study growth topology and defect structure of heteroepitaxial Si0.8Ge0.2 layers grown by ion beam sputter deposition (20 keV Xe+) on (001)-Si substrates (growth rate: 1.4 Å/ s) And use transmission electron microscopy and atomic force microscopy. The sputtered surfaces are, at all growth temperatures, rather smooth (mean surface roughness < 18 Å). There is a slight tendency for improved quality at higher growth temperatures, which we attribute to the larger diffusion length of adatoms at the Si0.8Ge0.2 layer surface. The lattice defects observed in the Si0.8Ge0.2 layer can be classified into a) misfit induced defects (dislocations) and b) defects due to the bombardment of the growing film with high energetic Si and Ge atoms (defects parallel to {113} and {001} lattice planes). The origin of {113} defects is discussed in terms of point defect generation and agglomeration due to a supersaturation of point defects. At high growth temperatures (700 °C) the enhanced diffusion of point defects to the layer surface and the Si substrate reduces the supersaturation. Thus, nucleation of {113} and {001} defects is suppressed.

UR - http://www.scopus.com/inward/record.url?scp=17544380036&partnerID=8YFLogxK

M3 - 文章

AN - SCOPUS:17544380036

SN - 1012-0394

VL - 47-48

SP - 431

EP - 436

JO - Solid State Phenomena

JF - Solid State Phenomena

ER -