Thermal conductivity of Si{endash}Ge superlattices

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.118755· OSTI ID:508920

Lee, S; Cahill, D G ^[1]; Venkatasubramanian, R ^[2]

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1. Department of Materials Science and Engineering
2. Center for Semiconductor Research, Research Triangle Institute, Research Triangle Park, Durham, North Carolina 27709-2195 (United States)

The thermal conductivity of Si{endash}Ge superlattices with superlattice periods 30{lt}L{lt}300 {Angstrom}, and a Si{sub 0.85}Ge{sub 0.15} thin film alloy is measured using the 3{omega} method. The alloy film shows a conductivity comparable to bulk SiGe alloys while the superlattice samples have a thermal conductivity that is smaller than the alloy. For 30{lt}L{lt}70 {Angstrom}, the thermal conductivity decreases with decreasing L; these data provide a lower limit to the interface thermal conductance G of epitaxial Si{endash}Ge interfaces: G{gt}2{times}10{sup 9}Wm{sup {minus}2}K{sup {minus}1} at 200 K. Superlattices with relatively longer periods, L{gt}130 {Angstrom}, have smaller thermal conductivities than the short-period samples. This unexpected result is attributed to a strong disruption of the lattice vibrations by extended defects produced during lattice-mismatched growth. {copyright} {ital 1997 American Institute of Physics.}

• Research Organization: University of Illinois
• DOE Contract Number: FG02-91ER45439
• OSTI ID: 508920
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 22 Vol. 70; ISSN 0003-6951; ISSN APPLAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL DEFECTS
GERMANIUM
GERMANIUM SILICIDES
LATTICE VIBRATIONS
SEMICONDUCTOR MATERIALS
SILICON
SUPERLATTICES
THERMAL CONDUCTIVITY
THICKNESS