| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piezoelectric thin film resonator with a greater electromechanical coupling factor, excellent in both resonance-antiresonance acoustic quality factor (Q value) and a frequency temperature characteristic and considerably high performance in comparison with that of prior arts from the standpoint of characteristics such as a bandwidth and an insertion loss while keeping the feature of an AlN thin film with a fast elastic wave propagation speed. <P>SOLUTION: A piezoelectric thin film resonator 10 includes: at least a substrate 11 made of a semiconductor or an insulator with a vibration space; a lower electrode 15, an aluminum nitride thin film, and an upper electrode 17 sequentially arranged at positions facing the vibration space of the substrate. The aluminum nitride thin film is a thin film with c axis orientation wherein a locking curve half width at (0002) diffraction peak is ≤2.0 degrees, at least either of the lower and upper electrodes is a metallic thin film with a thickness of 150nm to 450nm including a layer whose principal component is ruthenium, and a locking curve half width at (0002) diffraction peak of ruthenium is ≤3.0 degrees. <P>COPYRIGHT: (C)2007,JPO&INPIT |
