Annealing effects on the microstructure and magnetic properties of Y3Fe5O12 films deposited on Si/SiO2 substrates by RF magnetron sputtering

Crack-free Yttrium iron garnet (Y3Fe5O12, YIG) thin films were successfully deposited on Si/SiO2 substrates by RF magnetron sputtering, through controlling the annealing temperature and cooling rate during post-annealing process. The annealing condition dependences of crystallinity, microstructures and magnetic properties of YIG films were investigated. With the increase of the annealing temperature, the saturation magnetization of YIG films increases and the coercive field decreases, while the ferromagnetic resonance (FMR) linewidth becomes wider. The films annealed at 750 °C with cooling rate of 1 °C/min are crack-free and present excellent comprehensive performances, the corresponding coercive field is 32 Oe and the FMR linewidth is 57 Oe at 9.4 GHz. These results indicate that high-quality crack-free YIG films with excellent magnetic properties can be achieved on Si/SiO2 substrates by controlling the annealing process, which makes it more convenient to fabricate low-loss microwave integrated devices.