PiTrans - AlScN – development of novel piezoelectric materials

Si wafer with AlScN-based surface acoustic wave resonator structures fabricated at Fraunhofer IAF.
© Fraunhofer IAF
Si wafer with AlScN-based surface acoustic wave resonator structures fabricated at Fraunhofer IAF.

Our needs for different ways to communicate and to share large amounts of information are constantly growing. A modern smartphone contains 20 – 50 RF frequency components, and this number will increase to >100 in the near future. In order to accommodate higher frequencies and to build more efficient and smaller devices, the main goal of Pitrans project is to develop novel piezoelectric materials, such as AlScN, for high frequency RF filter applications in telecommunication industry.


PiTrans − Development of novel piezoelectric materials



2015 − 2020


Fraunhofer Attract excellence stipend program


  • Development of AlScN layers for the next generation high-frequency filters
  • High quality sputtered AlScN with up to 40% Sc
  • Piezoelectric material and electroacoustic device characterization



A. Ding; N. Kurz; R. Driad; Y. Lu; R. Lozar; T. Christoph; L. Kirste; O. Ambacher and A. Žukauskaitė, Experimental determination of Al1-xScxN thin film thermo-electro-acoustic properties up to 140°C by using SAW resonators, IEEE International Ultrasonics Symposium 2019, 6-9 Oct. 2019, DOI: 10.1109/ULTSYM.2019.8926095


N. Feil; N. Kurz; D. Urban; A. Altayara; B. Christian; A. Ding; A. Žukauskaitė and O. Ambacher, Finite Element Analysis of SAW Propagation Characteristics in c-plane (0001) and a-plane (11-20) AlScN Thin Films; IEEE International Ultrasonics Symposium 2019, 6-9 Oct. 2019, DOI: 10.1109/ULTSYM.2019.8925570


N. Kurz; A. Ding; D. F. Urban; Y. Lu; L. Kirste; N. M. Feil; A. Žukauskaitė and O. Ambacher, Experimental determination of the electro-acoustic properties of thin film AlScN using surface acoustic wave resonators; Journal of Applied Physics 126, 075106 (2019); https://doi.org/10.1063/1.5094611


M. Baeumler; Y. Lu; N. Kurz; L. Kirste; M. Prescher; T. Christoph; J.  Wagner; A. Žukauskaitė and O. Ambacher, Optical constants and band gap of wurtzite Al1−xScxN/Al2O3 prepared by magnetron sputter epitaxy for scandium concentrations up to x = 0.41; Journal of Applied Physics ; Nr. 126; Art.: 045715 (07/2019); doi.org/10.1063/1.510104.


A. Ding; M. Reusch; Y. Lu; N. Kurz; R. Lozar; T. Christoph; R. Driad; O. Ambacher; and A. Žukauskaitė, Investigation of Temperature Characteristics and Substrate Influence on AlScN-Based SAW Resonators; 2018 IEEE International Ultrasonics Symposium (IUS) (IEEE, 10/2018); pp. 1–9.; doi.org/10.1109/ULTSYM.2018.8579751.


Y. Lu; M. Reusch; N. Kurz; A. Ding; T. Christoph; M. Prescher; L. Kirste; O. Ambacher; A. Žukauskaitė, Elastic modulus and coefficient of thermal expansion of piezoelectric Al1−xScxN (up to x = 0.41) thin films; APL Materials; Nr. 6, Art.: 076105 (07/2018); doi.org/10.1063/1.5040190.


N. Kurz; Y. Lu; L. Kirste; M. Reusch; A. Žukauskaitė; V. Lebedev; and O. Ambacher, Temperature Dependence of the Pyroelectric Coefficient of AlScN Thin Films; Phys. Status Solidi A; Online First, Art. 1700831 (03/2018); p. 7, doi.org/10.1002/pssa.201700831.

Y. Lu; M. Reusch; N. Kurz; A. Ding; T. Christoph; L. Kirste; V. Lebedev; A. Žukauskaitė, Surface morphology and microstructure of pulsed DC magnetron sputtered piezoelectric AlN and AlScN thin films; Phys. Status Solidi; A. 215 ; Nr. 9, Art. 1700559 (11/2017); p. 6, doi.org/10.1002/pssa.201700559.


M. Reusch; S. Cherneva; Y. Lu; A. Žukauskaitė; L. Kirste; K. Holc; M. Datcheva; D. Stoychev; V. Lebedev; and O. Ambacher, Microstructure and mechanical properties of stress-tailored piezoelectric AlN thin films for electro-acoustic devices; Appl. Surf. Sci.; A. 407 (06/2017); p. 307–314, doi.org/10.1016/j.apsusc.2017.02.147.

Piezoelectric Material

Another project at Fraunhofer IAF that uses piezoelectric materials is mAgnes