| 摘要 |
PROBLEM TO BE SOLVED: To provide the broad band surface acoustic wave device having provision for a high frequency that incorporates an IC with a desired resonance frequency without the need for very fine processing of interdigital electrodes through the use of an inexpensive single crystal Si substrate. SOLUTION: The device is formed with a piezoelectric thin film via a buffer layer on a single crystal Si substrate, interdigital electrodes (1a, 1b, 2a, 2b) made of a conductive film are formed on the piezoelectric thin film. The piezoelectric thin film is made of a lead titanate thin film that is manufactured by the sol gel method and whose thickness is 0.03-5μm, the buffer layer is a thin film made of strontium barium titanate, strontium titanate or barium titanate and whose thickness is 0.01-0.2μm manufactured by the sol gel method as required, and the piezoelectric thin film subject to polarization processing by applying an electric field among the interdigital electrodes 1a, 1b, 2a, 2b is used.
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