Microstructure of microwave dielectricthin films by RF magnetron sputtering

The article describes the microstructure and morphological properties of microwave dielectric ceramic thin films. These thin films were successfully prepared on SiO2 (1 1 0) single-crystal substrates by radio frequency magnetron-sputtering system. The microstructure and morphology of the thin films were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy. The results show that the main phase is Ba0.5Sr0.5Nb2O6,which has a tetragonal perovskite structure, a long strip pattern, and uniform crystal-grain size of about 2–3 μm in length when annealed under 1150 °C for 30 min in an O2 atmosphere. These thin films are of excellent crystallization quality, with a polycrystalline and dense structure.