| abstract |
Provided are a thin-film bulk acoustic wave oscillator capable of obtaining an original oscillation with high frequency purity in a high frequency range from several hundred MHz to around 10 GHz, less spurious, high reliability, and easy to use. To do. In addition, a voltage variable oscillator having a wide variable frequency range and a method for manufacturing the same are provided. A circuit element portion in which a transistor or a capacitance circuit element is formed on a substrate using a microfabrication technique, and an upper layer of the circuit element portion for acoustically separating the substrate and the circuit element portion. An acoustic mirror layer formed by alternately stacking thin films made of a high acoustic impedance material and thin films made of a low acoustic impedance material, and a piezoelectric film formed using a thin film forming technique directly on the acoustic mirror layer It consists of a thin film bulk acoustic wave resonator that is sandwiched between an upper electrode layer and a lower electrode layer, and is acoustically separated from the substrate side. The circuit element and the thin film bulk acoustic wave resonator are microfabricated. Wire connection using technology. [Selection] Figure 1 |