Deposition and characterization of reactive magnetron sputtered aluminum nitride thin films for film bulk acoustic wave resonator

This work studies the relationship between the deposition process parameters and the properties of sputtered c-axis-oriented aluminum nitride (AlN) thin films. AlN films were deposited on a Pt electrode by reactive magnetron sputtering under various deposition conditions. The films were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). A polycrystalline AlN film with highly c-axis-preferred orientation was achieved. The XRD rocking curve was 2.7°. The FESEM photographs also show that the AlN film has a dense hexagonal surface texture with uniform grain size and a highly ordered column structure.