TY - JOUR
T1 - Laser-vibrometric ultrasonic characterization of resonant modes and quality factors of Ge membranes
AU - Trushkevych, Oksana
AU - Shah, Vishal A.
AU - Myronov, Maksym
AU - Halpin, John E.
AU - Rhead, Stephen D.
AU - Prest, Martin J.
AU - Leadley, David R.
AU - Edwards, Rachel S.
N1 - © 2014 National Institute for Materials Science
The author was not affiliated to SAMS at the time of publication
PY - 2014/4/7
Y1 - 2014/4/7
N2 - The vibrations of a single-crystal germanium (Ge) membrane are studied in air and vacuum using laser vibrometry, in order to determine mechanical properties such as Q-factors, tensile stress, anisotropy, and robustness to shock. Resonance modes up to 3:2 are identified, giving a residual stress measurement of 0.22 GPa, consistent with the value obtained from x-ray relaxation studies. The membrane is found to be isotropic, with Q-factors ranging from around 40 at atmospheric pressure to over 3200 at 5 × 10 -4 mbar, significantly lower than those found in polycrystalline Ge micromechanical devices. The robustness to shock is explained through the high resonance mode frequencies and the dissipation mechanism into the substrate, which is a direct consequence of having a high quality film with low residual tensile stress, giving the potential for such films to be used in optoelectronic devices.
AB - The vibrations of a single-crystal germanium (Ge) membrane are studied in air and vacuum using laser vibrometry, in order to determine mechanical properties such as Q-factors, tensile stress, anisotropy, and robustness to shock. Resonance modes up to 3:2 are identified, giving a residual stress measurement of 0.22 GPa, consistent with the value obtained from x-ray relaxation studies. The membrane is found to be isotropic, with Q-factors ranging from around 40 at atmospheric pressure to over 3200 at 5 × 10 -4 mbar, significantly lower than those found in polycrystalline Ge micromechanical devices. The robustness to shock is explained through the high resonance mode frequencies and the dissipation mechanism into the substrate, which is a direct consequence of having a high quality film with low residual tensile stress, giving the potential for such films to be used in optoelectronic devices.
KW - elastic properties
KW - laser interferometry
KW - quality factor
KW - single crystal Ge membrane
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U2 - 10.1088/1468-6996/15/2/025004
DO - 10.1088/1468-6996/15/2/025004
M3 - Article
AN - SCOPUS:84898680916
SN - 1468-6996
VL - 15
JO - Science and Technology of Advanced Materials
JF - Science and Technology of Advanced Materials
IS - 2
M1 - 025004
ER -