Abstract: A method of forming a single crystal diamond film in which a single crystal diamond film of large area can be formed at low cost, thereby making it possible to realize a large improvement in the properties of the diamond and also making possible the practical use of diamond in a wide range of applications thereof, said method comprising the steps of: first vapor-depositing a platinum film 2 on a first substrate 1, pressing a second substrate 3 onto the platinum film 2, and carrying out annealing in a vacuum. Next the platinum film 2 and the first substrate 1 are mechanically separated from each other, and the join surface 2a of the platinum film that had once been joined to the first substrate 1 is subjected to a surface scratching treatment, after which diamond is formed by gas-phase synthesis on this join face 2a. A single crystal diamond film is obtained in this way. In the case that the vapor-deposited platinum film has a thickness of no less than 20 .mu.

Abstract: The present invention relates to a heat dissipating substrate with a highly-oriented diamond film of a low crystal inclination and a low density grain boundaries and having a significantly high thermal conductivity. At least 90% of the surface area of the highly-oriented diamond film is covered with either (100) or (111) crystal planes, and the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of the Euler angles, which represent the orientations of the crystals, between adjacent (100) or (111) crystal planes, simultaneously satisfies the following relationship: .vertline..DELTA..alpha..vertline..ltoreq.5.degree., .vertline..DELTA..beta..vertline..ltoreq.5.degree., and .vertline..DELTA..gamma..vertline..ltoreq.5.degree.. In addition, this highly-oriented diamond film can be grown on a non-diamond substrates, and therefore the diamond film with a large surface area can be obtained. Thus, the present invention provides the heat dissipating substrate with an excellent thermal conductivity at low cost.

Abstract: The highly-oriented diamond film is a diamond film formed by chemical vapor deposition, with at least 95% of its area consisting of either (100) or (111) crystal planes, and the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of the Euler angles {.alpha., .beta., .gamma.} between the adjacent crystals satisfying (.vertline..DELTA..alpha..vertline..ltoreq.1.degree., .vertline..DELTA..beta..vertline..ltoreq.1.degree. and .vertline..DELTA..gamma..vertline..ltoreq.1.degree.) simultaneously. Thus obtained highly-oriented diamond film has few grain boundaries and high carrier mobility. And the area of the diamond film can be large.

Abstract: A diamond film field effect transistor, excellent in characteristics and a method of manufacturing the transistor, in which a contact resistance between electrodes and respective source and drain region is small. The transistor has a channel layer of a p-layer made of semiconducting diamond, an i-layer made of high resistance diamond as a gate insulating layer, which is formed on the channel layer, a gate electrode film formed on the i-layer and a source region and a drain region formed on the surface of the i-layer in self-alignment to the gate electrode film by ion implantation using the gate electrode film, side walls and a protective film as masks.

Abstract: A pair of electrodes 3 are first formed on a substrate. Subsequently, an undoped diamond film is selectively deposited between the above electrodes. A B-doped diamond film is then selectively formed on both the insulating diamond film and part of each electrode. The substrate may be contained in a container provided with an opening portion from which only the B-doped diamond film is exposed.

Abstract: A magnetic sensor element using highly-oriented diamond film comprises a magnetic detecting part, at least a pair of main current electrodes for flowing a main current and generating the Hall electromotive force at the magnetic detecting part, and detection electrodes for detecting said Hall electromotive force. Said magnetic detecting part is formed of a highly-oriented diamond film grown by chemical vapor deposition, at least 90% of which consists of either (100) or (111) crystal planes. Between the adjacent crystal planes, the differences {.DELTA..alpha., .DELTA..beta., .DELTA..gamma.} of the Euler angles {.alpha., .beta., .gamma.} which represent the orientation of the crystal planes, satisfy the following relations simultaneously: .vertline..DELTA..alpha..vertline..ltoreq.10.degree., .vertline..DELTA..beta..vertline..ltoreq.10.degree. and .vertline..DELTA..gamma..vertline..ltoreq.10 .degree..

Abstract: A surface acoustic wave device uses a highly oriented diamond film with a planar surface, increasing the propagating velocity of a surface acoustic wave, and fabricating many devices on a large area without polishing processes. The surface acoustic wave device includes the highly oriented diamond films, a piezoelectric film and electrodes which are formed on the diamond film. In the highly oriented diamond film, 80% or more of the surface area of the diamond film is composed of the (100) faces or (111) faces of diamond; and the difference {.DELTA..alpha.,.DELTA..beta.,.DELTA..gamma.} between the Euler angles {.alpha.,.beta.,.gamma.} expressing the crystal orientations of the adjacent (100) or (111) faces of the diamond film simultaneously satisfies the relations of .vertline..DELTA..alpha..vertline..ltoreq.10.degree., .vertline..DELTA..beta..vertline..ltoreq.10.degree., and .vertline..DELTA..gamma..vertline..ltoreq.10.degree..

Abstract: A semiconducting diamond electroluminescence element comprises an electrically conductive substrate, a semiconducting diamond layer formed on the substrate, an insulating diamond layer formed on the semiconducting diamond layer, a front electrode formed on the insulating diamond layer, and a back electrode formed on the conductive substrate in ohmic contact with the same. The color of light to be emitted by the semiconducting diamond electroluminescence element can readily be determined by changing the impurity content in the semiconducting diamond layer. The luminescence intensity of the semiconducting diamond electroluminescence element can readily be changed by changing the voltage applied across the front and back electrodes without entailing dielectric breakdown.

Abstract: A method for forming diamond films by vapor phase synthesis comprising a process of forming the diamond films on a substrate by direct current discharge plasma, in an atmosphere of a reaction gas including a gas containing at least carbon and hydrogen, or in an atmosphere of a mixed gas containing at least a carbon-containing gas and a hydrogen gas, at a gas pressure between 0.1 and 5 Torr and a substrate temperature between 300.degree. and 1000.degree. C.

Abstract: Disclosed is a method for forming a diamond film on a substrate by vapor-phase synthesis using a reaction gas which contains B.sub.2 H.sub.6 and O.sub.2 with a gas concentration ratio (volume %) of ([B.sub.2 H.sub.6 ]/[O.sub.2 ]).gtoreq.1.times.10.sup.-4 in addition to a hydrocarbon gas in hydrogen. By this invention, it is possible to form p-type semiconducting diamond films having an excellent crystallinity and desired electric characteristics.

Abstract: A diamond Schottky diode including an electrically conductive substrate, a multi-layer structure of a semiconducting diamond layer and an insulating diamond layer, and a metal electrode. This diode has a greater potential barrier under a reversed bias and hence exhibits better rectifying characteristics with a smaller reverse current.

Abstract: A is a heat-resisting ohmic electrode on diamond film, including: a p-type semiconducting diamond film; a boron-doped diamond layer provided on the semiconducting diamond film; and an electrode element made of p-type Si selectively formed on the boron-doped diamond layer; wherein the boron concentration in the boron-doped diamond layer is from 1.0.times.10.sup.19 to 1.8.times.10.sup.23 cm.sup.-3, and at least one impurity selected from the group consisting of B, Al and Ga is doped in the electrode element with a concentration from 1.0.times.10.sup.20 to 5.0.times.10.sup.22 cm.sup.-3. The ohmic electrode on diamond film is applicable for electronic devices operative at high temperature.

Abstract: Thin diamond films can be selectively deposited imagewise on a substrate by gas phase synthesis. The substrate may be either a silicon substrate or a basal thin diamond film formed beforehand on a substrate by gas phase synthesis. Where a silicon substrate is used, its surface is first abraded to give a surface roughness suitable for gas phase synthesis of diamond. When a basal thin diamond film is used, a coating material capable of withstanding a temperature higher than a substrate temperature required for gas phase synthesis of diamond and having a high etching selectivity to diamond is needed to cover areas other than where the thin diamond film is to be newly formed. When a lift-off method is used, a thin masking film having a melting point higher than a temperature to be employed for gas phase synthesis of diamond can also be used in place of the coating material described above.

Abstract: A diamond heterojunction diode having an improved rectifying characteristics with a small reverse current and a large forward current. Three layers are formed on a low-resistance p-type silicon substrate by the microwave plasma CVD in the order of a B-doped p type semiconducting diamond layer, an insulating undoped diamond layer (thinner than 1 .mu.m), and an n-type semiconducting silicon layer. Ohmic electrodes are formed on the front side of a n-type semiconducting silicon layer and the back side of a substrate. Under a forward bias, the electric field is applied to the intermediate insulating layer to accelerate the transport of holes and electrons. Under a reversed bias, the energy band has a notch as well as a potential barrier due to the intermediate layer thus preventing holes from transporting from the n-type semiconducting diamond layer to the p-type semiconducting diamond layer, resulting in the improved rectifying characteristics.

Abstract: A method and apparatus for contructing diamond semiconductor structures made of polycrystalline diamond thin films is disclosed. The use of a polycrystalline diamond deposition on a substrate material provides an advantage that any substrate material may be used and the ability to use polycrystalline diamond as a material is brought about through the use of an undoped diamond layer acting as an insulating layer which is formed on a boron-doped layer. Because of the structure, ion implantation can be employed to reduce the ohmic contact resistance. The ion implantation also provides that the entire structure can be made using a deep implant to form a channel layer which allows the insulating gate structure to be formed as an integral part of the device. The buried channel can be doped through the use of several implantation steps through the insulating undoped layer.

Abstract: Described is an etching method of a diamond film which comprises providing a diamond film in an atmosphere of a gas containing at least oxygen and/or hydrogen and subjecting the diamond film to an irradiation of an electron beam generated by direct current discharge through a pattern of a mask. In this condition, when the diamond film is contacted with the plasma produced by the electron beam in the atmosphere, the unmasked areas are irradiated by the electron beam, and converted to graphite. The graphite is more readily etched by the plasma, so that the diamond film can be etched at a high rate. The etching through a mask ensures a fine etched pattern of the diamond film. In addition, a diamond film with a large area can be etched by this method.

Abstract: Disclosed herein is a MIS type diamond field-effect transistor comprising a diamond semiconductor layer provided as an active layer by chemical vapor deposition (CVD), and a diamond insulator layer provided on the diamond semiconductor layer also by CVD, a gate electrode being formed on the diamond insulator layer, wherein a diamond insulator undercoat is provided on a non-diamond substrate by CVD, and the diamond semiconductor layer and the diamond insulator layer are sequentially provided on the diamond insulator undercoat. The MIS type diamond field-effect transistor with this structure ensures that in the manufacture thereof, a diamond insulator undercoat of large area can be formed on a non-diamond substrate of CVD, whereby a large number of elemental devices can be fabricated simultaneously.

Abstract: A schottky diode manufacturing process employing diamond film comprises forming a B-doped p-type polycrystalline diamond film on a low-resistance p-type Si substrate by CVD using a source gas consisting of CH.sub.4, H.sub.2 and B.sub.2 H.sub.6, forming an ohmic contact on the back of the p-type Si substrate, and forming a metal electrode of Al, Pt Au, Ti or W on the B-doped p-type polycrystalline diamond film. The B/C concentration ratio of the source gas is greater than 0.01 ppm and less than 20 ppm.

Abstract: A diamond thin film thermistor having a substrate, an electrically insulating diamond layer formed on the substrate by vapor-phase synthesis, a semiconducting diamond layer as a temperature-sensing part on the electrically insulating diamond layer by vapor-phase synthesis, and metal thin film electrodes attached to the semiconducting diamond layer. A plurality of such diamond thin film thermistors can simultaneously be formed on a single substrate, and the substrate is cut with a dicing saw to provide individual diamond thin film thermistor chips of the same quality.

Abstract: A plasma reactor for diamond synthesis includes a microwave generator, a waveguide connected to the microwave generator, an antenna disposed within the waveguide to direct the microwaves propagated along the waveguide toward the interior of a reaction chamber, a microwave window provided above the upper wall of the waveguide, a reaction chamber defined by (a) a cylindrical bottom member hermetically joined to the microwave window and the waveguide, (b) a reaction gas inlet port and a gas outlet port in the side wall thereof, and (c) a substrate holder disposed within the reaction chamber in facing opposition to the microwave window so as to be moved toward and away from the microwave window to adjust the distance between the microwave window and the substrate holder to generate a desired microwave resonance mode.