Abstract: The present invention directed to a SAW device comprising a diamond layer a ZnO layer and an SiO.sub.2 layer, which can be operated at the frequency of 2 GHz or higher, with superior durability and less energy loss. The SAW device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention comprises: (i) a diamond layer, (ii) a ZnO layer formed on the diamond layer, the ZnO layer having a thickness t.sub.z, (iii) an interdigital transducer (IDT) formed over the ZnO layer, and (iv) a SiO.sub.2 layer formed over the interdigital transducer onto the ZnO layer, the SiO.sub.2 layer having a thickness of t.sub.s ; wherein parameters kh.sub.z =(2.pi./.lambda.)t.sub.z and kh.sub.s =(2.pi./.lambda.)t.sub.s are given within a region A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-A in a two-dimensional Cartesian coordinate graph having abscissa axis of kh.sub.z and ordinate axis of kh.sub.

Abstract: A first surface acoustic wave device for 2nd mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention is a SAW device of "type A" device shown in FIG. 6A, wherein a parameter kh3=2.pi.(t.sub.A /.lambda.) is: 0.033.ltoreq.kh3.ltoreq.0.099, and wherein a parameter kh1=2.pi.(t.sub.z /.lambda.) and a parameter kh2=2.pi.(t.sub.s /.lambda.) are given within a region ABCDEFGHIJKLA in a two-dimensional Cartesin coordinate graph of FIG. 1.

Abstract: The present invention directed to a SAW device comprising a diamond layer thinner ZnO layer, which can be operated at higher frequency, with superior characteristics including less energy loss. The first SAW device according to the present invention comprises a layer constitution shown in FIG. 23, wherein, for 0th mode surface acoustic wave having a wavelength .lambda., a parameter kh3 =(2.pi./.lambda.)t3 satisfies: 0.0470.ltoreq.kh3.ltoreq.0.0625, and wherein a parameter kh1 =(2.pi./.lambda.)t1 and a parameter kh2=(2.pi./.lambda.)t2 are given within a region A-B-C-D-E-F-A in a two-dimensional Cartesian coordinate graph having ordinate axis of the kh1 and abscissa axis of kh2, the outer edge of the region A-B-C-D-E-F-A being given by a closed chain in the Cartesian coordinate, consisting of points A, B, C, D, E, and F, and lines A-B, B-C, C-D, D-E, E-F and F-A, as shown in a two-dimensional Cartesian coordinate graph of FIG. 3.

Abstract: A diamond base material for surface acoustic wave device, which includes: a low-resistivity base material, and a high-resistivity diamond layer having a thickness of 5-50 .mu.m disposed on the low-resistivity base material.

Abstract: A substrate having a superconducting thin film of compound oxide thereon. An intermediate layer consists of at least one layer of copper-containing oxide is interposed between the substrate and the superconducting thin film.

Abstract: The present invention directed to a SAW device comprising a diamond layer and an LiTaO.sub.3 layer, which can be operated at the frequency of 3 GHz or higher, with superior durability and less energy loss. The SAW device for 1st mode surface acoustic wave of a wavelength .lambda. (.mu.m) according to the present invention comprises: a diamond layer, an interdigital transducer formed onto the diamond layer, and a polycrystalline C-axis-oriented LiTaO.sub.3 layer formed over the interdigital transducer; wherein the SAW device satisfies a relationship of 0.4.ltoreq.kh.sub.1 .ltoreq.1.2, where a parameter kh.sub.1 is defined as kh.sub.1 =2.pi.(t.sub.1 /.lambda.), and t.sub.1 (.mu.m) is the thickness of the LiTaO.sub.3 layer.

Abstract: An orientational material including: diamond, and a ZnO film disposed on a surface of (111) orientational diamond provided by the diamond. Such an orientational material may suitably be used as a component for fabricating a surface acoustic wave device utilizing diamond.

Abstract: A SAW device which includes at least, diamond, an LiNbO.sub.3 layer disposed on the diamond, and an IDT provided so as to contact the LiNbO.sub.3 layer; and utilizes SAW of an "n-th" mode (n=0, 1 or 2) having a wavelength of .lambda..sub.n (.mu.m), wherein a parameter of kh.sub.1 =2.pi.(t.sub.1 /.lambda..sub.n) is in a specific range provided that the thickness of the LiNbO.sub.3 layer is denoted by t.sub.1 (.mu.m).

Abstract: A microwave component includes a superconducting signal conductor formed on a first dielectric substrate, and a superconducting ground conductor formed on a second dielectric substrate. The first dielectric substrate is stacked on the superconducting ground conductor of the second dielectric substrate. Each of the superconducting signal conductor and the superconducting ground conductor is formed of an oxide superconductor thin film of which crystals are orientated in such a manner that the c-planes of the crystals are parallel to the direction in which an electro-magnetic field generated by microwave launched to the microwave component changes.

Abstract: There is disclosed a superconducting microwave component including a first substrate of a dielectric material with a conductor line of an oxide superconductor formed in a required pattern on the surface, a second substrate of a dielectric with a grounding conductor of an oxide superconductor formed on the surface, and a third substrate of a dielectric which is laid on the first and the second substrates, with the third substrate sandwiched between the first and the second substrates.

Abstract: A diamond substrate having a smooth surface, including a polycrystalline diamond film having a surface with a pit, and an insulating material other than diamond, which occupies the pit.

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. Since the copper electrodes formed on the diamond layer consist of high-quality single crystal copper, resistances to electromigration and stress migrations can be increased. As a result, there is provided an excellent surface acoustic wave element free from electrical defects caused by degradation and failure of the copper electrodes or free from degradation of the electrical characteristics.

Abstract: There is disclosed a superconducting microwave component including a first substrate having a conductor line formed of an oxide superconductor on the surface thereof, a second substrate having a grounding conductor formed of an oxide superconductor on the surface thereof, and a package of a conducting material housing the first and the second substrates so that they are substantially parallel with each other. At least one portion of the grounding conductor is in contact with the inside of the package, through surface contact.

Abstract: A surface acoustic wave element includes a hard layer containing a composition component essentially consisting of at least one of diamond and a diamond-like carbon film, a piezoelectric layer formed on the hard layer, a silicon dioxide (SiO.sub.2) layer formed on the piezoelectric layer, and electrodes combined with the piezoelectric layer to perform electro-mechanical conversion. The surface acoustic wave element has a larger electro-mechanical coupling coefficient and a higher surface acoustic wave propagation velocity than does a conventional surface acoustic wave element having no silicon dioxide layer, thereby obtaining a surface acoustic wave element that can operate in a high-frequency range. In particular, the electro-mechanical coupling coefficient is increased. The SiO.sub.2 layer is an electric insulator and rarely reacts with moisture or acids. The SiO.sub.

Abstract: A surface acoustic wave device includes a hard layer comprising diamond or a diamond-like carbon film, and a piezoelectric layer formed on the hard layer. It further includes a paired interdigital transducer and grounding electrode, which perform an electro-mechanical conversion, with the piezoelectric layer arranged therebetween. Then, the feature of the present invention is to form the grounding electrode of a conductive oxide. It is preferred that the conductive oxide is formed by doping an impurity into a piezoelectric material of ZnO. Therefore, the adhesion between the piezoelectric layer and the hard layer, and the grounding electrodes is increased, so that the device yield is enhanced, and a high electromechanical coupling coefficient can be achieved in a high frequency range.

Abstract: A microwave resonator includes a superconducting signal conductor formed on a first dielectric substrate, and a superconducting ground conductor formed on a second dielectric substrate. The first dielectric substrate is stacked on the superconducting ground conductor of the second dielectric substrate. A temperature adjustable heater is mounted near to the second dielectric substrate, so that the resonating frequency .function..sub.o of the microwave resonator can be easily adjusted by controlling the temperature of the superconducting conductors by the adjustable heater.

Abstract: A microwave resonator includes a superconducting signal conductor formed on a first dielectric substrate, and a superconducting ground conductor formed on a second dielectric substrate. The first dielectric substrate is stacked on the superconducting ground conductor of the second dielectric substrate. A rod is adjustably provided to be able to penetrate into an electromagnetic field created by a microwave propagation through the superconducting signal conductor, so that the resonating frequency .function..sub.0 of the microwave resonator can be easily adjusted by controlling the position of a tip end of the rod.

Abstract: A superconducting thin film of a compound oxide represented by YBa.sub.2 Cu.sub.3 O.sub.y in which "y" is a number of 6<y<8 and deposited on a substrate, characterized in that a buffer layer of a compound oxide represented by Y.sub.2 BaCuO.sub.x in which "x" is a number of 4<x<6 is interposed between the superconducting thin film and the substrate.

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 process for preparing a thin film of oxide superconductor on a single crystal substrate of semiconductor by RF sputtering. At first, an under-layer of an oxide having a thickness of 50 to 200 .ANG. is deposited on the single crystal substrate of semiconductor at a substrate temperature of lower than 500.degree. C., and secondly an upper-layer of superconducting oxide material is deposited on said under-layer at a substrate temperature of higher than 600.degree. C.