Regensburg 2022 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 9: Thin Film Properties: Structure, Morphology and Composition (XRD, TEM, XPS, SIMS, RBS, AFM, ...) 3

DS 9.2: Vortrag

Dienstag, 6. September 2022, 09:45–10:00, H14

Structural and elastic properties of Sc_xAl_1−xN — •Saskia Mihalic¹, Armin Dadgar², Niclas M. Feil¹, Christopher Lüttich², André Strittmatter², and Oliver Ambacher¹ — ¹Department of Sustainable Systems Engineering, University of Freiburg, Germany — ²Department of Semiconductor Epitaxy, Otto von Guericke University Magdeburg, Germany

The hexagonal compound alloy scandium aluminum nitride (Sc_xAl_1−xN) shows an enhancement of the piezoelectric module d₃₃(x) by more than 300 % compared to aluminum nitride (AlN). Therefore, Sc_xAl_1−xN is a highly promising material for the implementation of acoustic resonators for mobile communication systems, although usually a larger stiffness of the material is required. The direction-dependent elastic behavior of hexagonal Sc_xAl_1−xN crystals is represented by the reciprocal Young’s modulus S*₁₁(x) and aids in identifying the best trade-off between piezoelectric and elastic properties of anisotropic Sc_xAl_1−xN for microacoustic applications. To confirm the calculations with experimental results, thin films of Sc_xAl_1−xN(0001) and ScN(111) on Si-substrates were grown by reactive magnetron sputter epitaxy. The structural properties of thin films have been investigated by high-resolution X-Ray diffractometry (HRXRD) and high-resolution transmission electron microscopy (HRTEM). Furthermore, we will present a detailed comparison of theoretical and experimental results of the piezoelectric and stiffness coefficients achieved by the analysis of Sc_xAl_1−xN-based SAW resonators.