TY - JOUR

T1 - Sn – Induced decomposition of SiGeSn alloys grown on Si by molecular-beam epitaxy

AU - Talochkin, A. B.

AU - Timofeev, V. A.

AU - Gutakovskii, A. K.

AU - Mashanov, V. I.

PY - 2017/11/15

Y1 - 2017/11/15

N2 - Structural features of Si1 − x − yGexSny alloy layers grown on Si by molecular-beam epitaxy are studied. These layers with the thickness of 2.0 nm, the nominal Ge composition of x0 ≈ 0.3, and the Sn-content of y ≈ 2–6 at.% have been grown at low temperatures (100–150 °C). We have used high-resolution transmission electron microscopy to analyze atomic structure of grown layers and Raman spectroscopy to evaluate the real Ge-content x from the observed optical phonon frequencies. It is found that the x value coincides with the nominal one at low Sn-content (2–3 at.%), and when it is increased (y ≥ 5 at.%), the decomposition of alloys into two fractions occurs. One of them is enriched by Ge with x up to 0.6 and the other fraction is Si-enriched. It is shown that the observed decomposition is Sn-induced and related to increase in Ge adatoms mobility in the growth process. This mechanism is similar to that theoretically predicted by Venezuela and Tersoff (Phys. Rev. 58, 10871 (1998)) for the case of high growth temperature.

AB - Structural features of Si1 − x − yGexSny alloy layers grown on Si by molecular-beam epitaxy are studied. These layers with the thickness of 2.0 nm, the nominal Ge composition of x0 ≈ 0.3, and the Sn-content of y ≈ 2–6 at.% have been grown at low temperatures (100–150 °C). We have used high-resolution transmission electron microscopy to analyze atomic structure of grown layers and Raman spectroscopy to evaluate the real Ge-content x from the observed optical phonon frequencies. It is found that the x value coincides with the nominal one at low Sn-content (2–3 at.%), and when it is increased (y ≥ 5 at.%), the decomposition of alloys into two fractions occurs. One of them is enriched by Ge with x up to 0.6 and the other fraction is Si-enriched. It is shown that the observed decomposition is Sn-induced and related to increase in Ge adatoms mobility in the growth process. This mechanism is similar to that theoretically predicted by Venezuela and Tersoff (Phys. Rev. 58, 10871 (1998)) for the case of high growth temperature.

KW - A1. Nanostructures

KW - A1. Solid solutions

KW - A3. Molecular beam epitaxy

KW - B1. Germanium silicon alloys

KW - B2. Semiconducting silicon compounds

KW - Germanium silicon alloys

KW - SEMICONDUCTORS

KW - SILICON

KW - Nanostructures

KW - SI(100)

KW - BAND-GAP

KW - STRAIN-SHIFT COEFFICIENTS

KW - RAMAN-SCATTERING

KW - Semiconducting silicon compounds

KW - GERMANIUM

KW - Solid solutions

KW - Molecular beam epitaxy

KW - SIXSNYGE1-X-Y

UR - http://www.scopus.com/inward/record.url?scp=85029479254&partnerID=8YFLogxK

U2 - 10.1016/j.jcrysgro.2017.09.005

DO - 10.1016/j.jcrysgro.2017.09.005

M3 - Article

AN - SCOPUS:85029479254

VL - 478

SP - 205

EP - 211

JO - Journal of Crystal Growth

JF - Journal of Crystal Growth

SN - 0022-0248

ER -