PURPOSE: To obtain a surface acoustic wave element that can be used in a higher frequency range by laminating a boron nitride layer and piezoelectric body to enhance the propagation rate of the surface acoustic wave.
CONSTITUTION: A surface acoutic wave element 10 forms boron nitride layer 2 on a substrate 1 for preparing a molybdenum film. Since boron nitride can be ground more easily than grinding diamond, the surface of a boron nitride film 2 is ground using a diamond electrodeposite wheel. Successively, using the resistance heating method, aluminum is vacuum evaporated 500 thick on the boron nitride film 2, followed by using the photolithographic method to form interdigital electrodes 3a and 3b. Next, under the condition of applying a sputter power of 100W at a substrate temperature of 380°C, the magnet sputtering method for sputtering ZnO polycrystalline substance in a mixed Argon Oxide gas with a ratio of 1:1 is used to deposit a ZnO piezoelectric film 4 over interdigital electrodes 3a and 3b. The surface acoustic wave element 10 having an electrode width of 2μm thus obtained can be operated at a high frequency of about 1GHz.
NAKAHATA HIDEAKI
SHIKADA SHINICHI
FUJIMORI NAOHARU
