Abstract: The present invention relates to a high-output diamond semiconductor element, including a Schottky electrode as a cathode, a diamond P? drift layer, a diamond p+ ohmic layer, an ohmic electrode as an anode, and an insulating film layer disposed to surround a circumference of the Schottky electrode. It also relates to a high-output diamond semiconductor element, including a Schottky electrode as a cathode, a diamond P? drift layer, a diamond p+ ohmic layer, an ohmic electrode as an anode, a dielectric layer disposed on a part of a junction surface of the Schottky electrode and the diamond p? drift layer, and a field plate containing a conductor, the field plate being disposed on an external surface of the dielectric layer to surround a circumference of the Schottky electrode.

Abstract: A logical operation element and logical operation circuit are provided that are capable of high speed and a high degree of integration. A logical operation circuit has a construction wherein, in a logical operation element, the anodes of first and second field emission type microfabricated electron emitters are put at the same potential and two or more signal voltages are input to gate electrodes corresponding to these emitters. A NOR element so arranged that when a high potential input signal is input to either of the two lines, electron emission occurs from the emitters and the potential of said anodes is lowered, and a NAND element wherein the cathodes of the first and second field emission type microfabricated electron emitters are connected in series, two signal voltages are applied to the gate electrodes corresponding to the first and second emitter and the anode potential of the second emitter is lowered when the two input signals are high potential are employed.

Abstract: A cold-cathode electron source is formed that successfully achieves a high frequency and a high output. Embodiments include a cold-cathode electron source comprising emitters having a tip portion tapered at an aspect ratio R of not less than 4, thereby decreasing capacitance between the emitters and a gate electrode by a degree of declination from the gate electrode, such that the cold-cathode electron source is able to operate at a high frequency. Embodiments also include a cold-cathode electron source formed of a diamond with a high melting point and a high thermal conductivity, such that the emitters operate at a high current density and at a high output.

Abstract: An electron emitting device 2 comprises an electron emitting portion 6 made of diamond. At an electron emission current value of 10 ?A or more, a deviation of the electron emission current value over one hour is within ±20% in the electron emitting device 2. The number of occurrence of step-like noise changing the electron emission current value stepwise is once or less per 10 minutes.

Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.

Abstract: A method for production includes a step for forming concave molds on a surface of a substrate and a step for growing a diamond heteroepitaxially on the substrate in an atmosphere containing a doping material. The crystal structure of the slope of the concave molds of the substrate can have the cubic system crystal orientation (111), and the doping material is phosphorous. Further, the substrate is Si, and the slope of the molds can be the Si(111) face. The diamond electron emission device contains projection parts on the surface thereof, where a slope of the projection parts 1 contains a diamond (111) face, and flat parts 2, which are not the projection parts, contain face orientations other than (100) face or (110) face and grain boundaries.

Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.

Abstract: An electron emission device which is smaller, able to operate at lower voltage and more efficient than the conventional device is provided. The device contains a light emitting device to irradiate light to a cathode wherein at least an electron emission face of the cathode is made of diamond. By composing the device in such a way, the voltage to draw out electrons can be lowered with a wide margin compared to the conventional device, and thus a small device which can be operated with low voltage may be obtained. The light emitting device can be formed as one unit with the cathode and it can also be that the light emitting device and the electrode are made of diamond. Furthermore, the electron emission face of the cathode is preferably an n- or p-type diamond semiconductor.

Abstract: A method for production includes a step for forming concaved molds on a surface of a substrate and a step for growing a diamond heteroepitaxially on the substrate in an atmosphere containing a doping material. The crystal structure of the slope of the concaved molds of the substrate can have the cubic system crystal orientation (111), and the doping material is phosphorous. Further, the substrate is Si, and the slope of the molds can be the Si (111) face. The diamond electron emission device contains projection parts on the surface thereof, where a slope of the projection parts 1 contains a diamond (111) face, and flat parts 2, which are not the projection parts, contain face orientations other than (100) face or (110) face and grain boundaries.

Abstract: A logical operation element and logical operation circuit are provided that are capable of high speed and a high degree of integration. A logical operation circuit has a construction wherein, in a logical operation element, the anodes of first and second field emission type microfabricated electron emitters are put at the same potential and two or more signal voltages are input to gate electrodes corresponding to these emitters. A NOR element so arranged that when a high potential input signal is input to either of the two lines, electron emission occurs from the emitters and the potential of said anodes is lowered, and a NAND element wherein the cathodes of the first and second field emission type microfabricated electron emitters are connected in series, two signal voltages are applied to the gate electrodes corresponding to the first and second emitter and the anode potential of the second emitter is lowered when the two input signals are high potential are employed.

Abstract: An object of the present invention is to provide a cold-cathode electron source successfully achieving a high frequency and a high output, a microwave tube using it, and a production method thereof. In a cold-cathode electron source according to the present invention, emitters have a tip portion tapered at an aspect ratio R of not less than 4, and thus the capacitance between the emitters and a gate electrode is decreased by a degree of declination from the gate electrode. For this reason, the cold-cathode electron source is able to support an operation at a high frequency. A cathode material of the cold-cathode electron source is none of the conventional cathode materials such as tungsten and silicon, but is a diamond with a high melting point and a high thermal conductivity. For this reason, the emitters are unlikely to melt even at a high current density of an electric current flowing in the emitters, and thus the cold-cathode electron source is able to support an operation at a high output.

Abstract: The present invention relates to an electron emitting device having a structure for efficiently emitting electrons. The electron emitting device has a substrate comprised of an n-type diamond, and a pointed projection provided on the substrate. The projection comprises a base provided on the substrate side, and an electron emission portion provided on the base and emitting electrons from the tip thereof. The base is comprised of an n-type diamond. The electron emission portion is comprised of a p-type diamond. The length from the tip of the projection (electron emission portion) to the interface between the base and the electron emission portion is preferably 100 nm or less.

Abstract: Further improvements in circuit-element performance of surface-acoustic wave devices are anticipated by being able to produce a diamond substrate on which is formed a Li(NbxTa1−x)O3 (wherein 0≦x≦1) thin film whose c-axis orientation is favorable and whose piezoelectric characteristics are satisfactory. A diamond substrate on which a highly c-axis oriented, piezoelectrically satisfactory Li(NbxTa1−x)O3 (wherein 0≦x≦1) thin film is formed can be obtained by using a laser ablation technique to form a Li(NbxTa1−x)O3 (wherein 0≦x≦1) thin film onto a (110)-oriented gas-phase synthesized polycrystalline diamond substrate, that is superficially mirror-surface processed. By utilizing a diamond substrate on which a piezoelectric-substance thin film is formed, surface-acoustic wave devices having high propagation speeds can be offered.

Abstract: Provided are a substrate for a surface-acoustic-wave device and a surface-acoustic-wave device, in which an intermediate layer for controlling crystal characteristics of a piezoelectric layer does not easily separate from a diamond layer. A surface-acoustic-wave device substrate 20 and a surface-acoustic-wave device 10, according to the present invention, comprises a diamond layer 22, an intermediate layer 24 disposed on the diamond layer 22, and a piezoelectric layer 26 disposed on the intermediate layer 24, the piezoelectric layer 26 being made of LiNbO3 or LiTaO3, the intermediate layer 24 being made of AlN.

Abstract: Further improvements in circuit-element performance of surface-acoustic wave devices are anticipated by being able to produce a diamond substrate on which is formed a Li(NbxTa1−x)O3 (wherein 0≦x≦1) thin film whose c-axis orientation is favorable and whose piezoelectric characteristics are satisfactory. A diamond substrate on which a highly c-axis oriented, piezoelectrically satisfactory Li(NbxTa1−x)O3 (wherein 0≦x≦1) thin film is formed can be obtained by using a laser ablation technique to form a Li(NbxTa1−x)O3 (wherein 0≦x≦1) thin film onto a (110)-oriented gas-phase synthesized polycrystalline diamond substrate, that is superficially mirror-surface processed and superficially covered with an amorphous layer. By utilizing a diamond substrate on which a piezoelectric-substance thin film is formed, surface-acoustic wave devices having high propagation speeds can be offered.

Abstract: Provided are a substrate for a surface-acoustic-wave device and a surface-acoustic-wave device, in which an intermediate layer for controlling crystal characteristics of a piezoelectric layer does not easily separate from a diamond layer.