| 摘要 |
PURPOSE:To obtain a surface acoustic wave resonator having a good resonance characteristic by forming a piezoelectric thin film on a semiconductor substrate and forming a glass material layer on this thin film and forming surface wave reflecting groove rows on both sides of input/output electrodes provided on the piezoelectric thin film. CONSTITUTION:The surface wave generated by electrodes 4 and 5 is propagated to both sides of electrodes and are efficiently reflected on groove rows 6 whose period is integer-number of times as long as a half wavelength of the surface wave. A standing wave of the surface wave is generated between groove rows 6 and 6 and is detected by electrodes 4 and 6. With respect to the constitution of a two-port resonator, an AlN piezoelectric thin film layer 2 is formed on an Si substrate 1 with 0.5mum thickness, and a phosphor silicate glass layer 3 is formed on this layer 2 with about 2.5mum thickness. IDTs as electrodes 4 and 6 consist of Al, and the wavelength of the surface wave is 32mum and its propagation direction is the Si direction. The depth of reflecting grooves 6 is set to about 5000Angstrom .
|
