Abstract: A surface acoustic wave device which can operate at a higher frequency range is produced by irradiation with a focused ion beam to produce a narrower electrode width and narrower spacing width between neighboring electrodes in contact with a piezoelectric body, without degrading the reliability of the device. The surface acoustic wave device includes a piezoelectric body 3 and interdigital electrodes 2a and 2b in close contact with the piezoelectric body 3 and formed by using the focused ion beam. In order to increase the frequency of the device, the piezoelectric body 3 may be formed on a substrate 1, for example of diamond.

Abstract: A surface acoustic wave device is so manufactured that it's reliability is increased and so that it is surface-mountable with no requirement for packaging. The surface acoustic wave device (20) has a pair of opposite interdigital electrodes (2a, 2b) and a piezoelectric member (4) in close contact with the interdigital electrodes (2a, 2b). A portion located between the pair of interdigital electrodes (2a, 2b) propagates surface acoustic waves. This device (20) is characterized by an air bridge (13) covering the portion of the piezoelectric member (4) for propagating surface acoustic waves and the pair of interdigital electrodes (2a, 2b). The air bridge (13), may be provided with an insulating film (14) which is not in contact with the piezoelectric member (4).

Abstract: A surface acoustic wave device having a diamond layer, a piezoelectric layer and a comb-like electrode, in which the piezoelectric layer and the comb-like electrode are formed on a surface of the diamond layer, which surface has been contacted to a substrate used in the formation of the diamond layer by a vapor phase growth method, which device has high stability and can be produced economically.

Abstract: A surface acoustic wave element has a diamond layer, a piezoelectric thin film formed on the diamond layer, and a pair of electrodes for generating a surface acoustic wave having a specific wavelength and extracting the surface acoustic wave, wherein at least one electrode is a copper electrode epitaxially grown on the surface of the diamond layer. To manufacture this surface acoustic wave element, after the diamond layer is formed on a substrate by epitaxial growth, the copper electrodes each having the predetermined shape are formed on the surface of the diamond layer by epitaxial growth. In the surface acoustic wave element having the above structure, since the copper electrodes formed on the diamond layer consist of high-quality singlecrystal copper, resistances to electromigration and stress migrations can be increased.

Abstract: A surface acoustic wave device having a diamond layer, a piezoelectric layer and a comb-like electrode, in which the piezoelectric layer and the comb-like electrode are formed on a surface of the diamond layer, which surface has been contacted to a substrate used in the formation of the diamond layer by a vapor phase growth method, which device has high stability and can be produced economically.

Abstract: A method of manufacturing a surface acoustic wave device which has a smaller insertion loss and which operates at higher frequency than a conventional surface acoustic wave device is provided. The surface acoustic wave device includes a substrate, a diamond layer formed on the substrate, a piezoelectric layer formed on the diamond layer, and electrodes formed on any of the substrate, the diamond layer and the piezoelectric layer. The piezoelectric layer is formed by the laser ablation method. The insertion loss of this acoustic wave device is small even in a high frequency range of several hundreds MHz to GHz. Therefore, the device can be used as a frequency filter, a resonator, a delay line, a convolver, a correlator and the like.

Abstract: Disclosed herein is a surface acoustic wave device employing diamond, which has an operation frequency in a range of several hundred MHz to several GHz, a high propagation velocity and a large electromechanical coefficient. This surface acoustic wave comprises a substrate, a diamond layer which is formed on the substrate, a ZnO layer which is formed on the diamond layer, and interdigital electrodes which are formed on the ZnO layer, and utilizes a second order mode of a surface acoustic wave which is excited in a structure satisfying (2.pi..H/.lambda.)=0.9 to 2.3 where H represents the thickness of the ZnO layer and .lambda. represents the wavelength of the surface acoustic wave. This surface acoustic wave device can be used in an extremely high frequency range, whereby the same is applicable to a resonator, a delay line, a signal processing device, a convolver, a correlator or the like in addition to a filter.

Abstract: Disclosed herein is a surface acoustic wave device whose characteristics can be stably maintained against temperature changes. The surface acoustic wave device has an insulating diamond layer (2), which is provided thereon with a part (3) defined by a pair of interdigital electrodes (7, 7') and a piezoelectric layer (8), and a thermistor (4) made of semi-conductive diamond. The thermistor (4) quickly detects the temperature of the device.