Sputter Deposited Magnetostrictive Layers for SAW Magnetic Field Sensors

Sensors

Dirk Meyners¹  Lars Thormählen¹  Viktor Schell¹  Dennis Seidler¹  Jeffrey McCord¹  Frans Munnik² 

[1] Institute for Materials Science, Kiel University, Kaiserstraße 2, 24143 Kiel, Germany;Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden, Germany;

关键词: magnetron sputter deposition;    FeCoSiB;    ERDA;    XRD;    film stress;    magnetic field sensor;   

DOI  :  10.3390/s21248386

来源: DOAJ

【 摘 要 】

For the best possible limit of detection of any thin film-based magnetic field sensor, the functional magnetic film properties are an essential parameter. For sensors based on magnetostrictive layers, the chemical composition, morphology and intrinsic stresses of the layer have to be controlled during film deposition to further control magnetic influences such as crystallographic effects, pinning effects and stress anisotropies. For the application in magnetic surface acoustic wave sensors, the magnetostrictive layers are deposited on rotated piezoelectric single crystal substrates. The thermomechanical properties of quartz can lead to undesirable layer stresses and associated magnetic anisotropies if the temperature increases during deposition. With this in mind, we compare amorphous, magnetostrictive FeCoSiB films prepared by RF and DC magnetron sputter deposition. The chemical, structural and magnetic properties determined by elastic recoil detection, X-ray diffraction, and magneto-optical magnetometry and magnetic domain analysis are correlated with the resulting surface acoustic wave sensor properties such as phase noise level and limit of detection. To confirm the material properties, SAW sensors with magnetostrictive layers deposited with RF and DC deposition have been prepared and characterized, showing comparable detection limits below 200 pT/Hz^1/2 at 10 Hz. The main benefit of the DC deposition is achieving higher deposition rates while maintaining similar low substrate temperatures.

【 授权许可】

Unknown