Abstract: A method for producing a single crystals by preferential epitaxial growth of {100} face, comprising the steps of (1) growing the crystal on a single crystal {100} substrate; (2) forming on the side of the grown crystal a surface parallel to a {100} face different from the {100}face in the growth direction, and (3) growing the crystal on the formed {100} surface; and the steps (2) and (3) being performed once or more than once. A method for producing a single-crystal diamond using a metallic holder for the single-crystal diamond having a crystal holding portion which is raised above an outer peripheral portion of the holder, is part from the outer peripheral portion of the holder, and has a recessed shape. The methods enable the production of a large single-crystal diamond in a comparatively short time at low cost.

Abstract: The present invention provides a method for producing a single crystals by preferential epitaxial growth of {100} face, the method comprising the steps of (1) growing the crystal on a single crystal {100} substrate; (2) forming on the side of the grown crystal a surface parallel to a {100} face different from the {100} face in the growth direction, and (3) growing the crystal on the formed {100} surface; and the steps (2) and (3) being performed once or more than once. The present invention further provides a method for producing a single-crystal diamond wherein used is a metallic holder for the single-crystal diamond having a crystal holding portion which is raised above an outer peripheral portion of the holder, is apart from the outer peripheral portion of the holder, and has a recessed shape.

Abstract: The heater module (30) for heating an optical waveguide device (2) is provided with a ceramics heater (40) having a heating circuit (42) adapted to generate heat when energized and an AlN ceramics layer (44) stacked on the heating circuit.

Abstract: This polishing apparatus permits for polishing of hard-material coated complex films that traditionally have been difficult to polish due to the hardness of the films, the fragility of the substrate, and the inherent distortion of the film. The polishing apparatus includes a rotary turn-table, a holder for a wafer having the film, a shaft connected to the center of the holder for transmitting rotation and pressure to the holder and permitting the holder to incline, an arm rotatably supporting the holder, a cylinder for applying pressure to the center of the shaft, a driving device for rotating the shaft, and at least one auxiliary shaft. The auxiliary shaft pushes peripheral points along a diameter of the holder in order to impart a swaying motion on the holder.

Abstract: A conductive polycrystalline diamond film having specific resistance of at least 1×10−4 &OHgr;cm and less than 1×103 &OHgr;cm, whose film thickness is in the range of at least 0.1 &mgr;m and not more than 500 &mgr;m, is film-formed by vapor-phase synthesis on a surface employed for pressure bonding, a surface opposite to this surface or at least two side surfaces intersecting with these surfaces on a substrate of a bonding tool tip that is applicable for bonding and packaging a semiconductor chip.

Abstract: A method of producing and polishing a hard-material-coated wafer. A hard-material film is disposed on a substrate to form the wafer and provide the wafer with a convex shape. A surface of the substrate is fixed on a holder of a polishing machine having a whetstone turn-table. The holder is rotated about its axis, and the whetstone turn-table is revolved about its shaft. The convex film surface of the hard-material film is polished on the whetstone turn-table while the inclination angle of the holder relative to the turn-table is changed. In this way, the convex film surface is polished either from its center to its periphery or from its periphery to its center.

Abstract: Diamond having a large coefficient of thermal conductivity is prepared by a CVD method in which a reaction gas is decomposed and reacted under such condition that a concentration of carbon atoms in relation to hydrogen gas (A %), a concentration of nitrogen gas in relation to the whole reaction gas (B ppm) and a concentration of oxygen atoms in relation to the hydrogen gas (C %) satisfy the equation:.alpha.=B.times.(A-1.2C) (I)provided that a is not larger than 13, or B is not larger than 20.

Abstract: A diamond wafer including a substrate and a (100) oriented polycrystalline diamond film grown on the substrate for making surface acoustic wave devices, semiconductor devices or abrasion-resistant discs. The (100) oriented film is produced by changing a hydrocarbon ratio in a material gas halfway from a higher value to a lower value. The wafer is monotonously distorted with a distortion height H satisfying 2 .mu.m.ltoreq..vertline.H.vertline..ltoreq.150 .mu.m. The film is polished to a roughness of less than Rmax50 nm and Ra20 nm.

Abstract: A single crystal quartz thin film having a thickness of 5 nm to 50 .mu.m can be prepared by forming the thin film on a single crystal substrate by a sol-gel process and peeling the thin film from the substrate. The present invention can provide the single crystal quartz thin film at a low price without a large and complex apparatus.

Abstract: No wide bulk diamond wafer exists at present. A wide diamond-coated wafer is proposed instead of the bulk diamond wafer. Diamond is heteroepitaxially deposited on a convex-distorted non-diamond single crystal substrate by a vapor phase deposition method. In an early step, a negative bias is applied to the substrate. In the case of a Si substrate, an intermediate layer of .beta.-SiC is first deposited on the Si substrate by supplying a low carbon concentration material gas. Then the carbon concentration is raised for making a diamond film. The convex-distorted wafer is stuck to a holder having a shaft which is capable of inclining to the holder. The wafer is pushed to a turn-table of a polishing machine. The convex diamond wafer can fully be polished by inclining the holder to the shaft. A wide distorted mirror wafer of diamond is produced. Fine wire patterns can be made on the diamond mirror wafer by the photolithography.

Abstract: An object of the invention is to provide a high quality synthetic diamond having a high bonding strength between a substrate surface and synthetic diamond or between synthetic diamond films. The object can be attained by a process for the synthesis of diamond comprising pre-heating mixed gases of a hydrocarbon and hydrogen by a heating body and feeding the heated mixed gases to a substrate surface heated to deposit diamond thereon, characterized by allowing the distance between the heating body and substrate surface to be apart from each other as far as possible in the carburizing step of the heating body and allowing the distance between the heating body and substrate surface to be nearer in the step of synthesizing diamond than in the former case.

Abstract: A semiconductor substrate comprising a single crystal substrate base such a silicon and a superconducting thin film layer deposited on said substrate base and composed of compound oxide such as Ln.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-.delta.. (Ln is lanthanide).

Abstract: An oxide thin film having a quartz crystal structure formed on a substrate, the oxide thin film being composed of a single layer or a plurality of layers having a thickness of 5 nm to 50 .mu.m per layer, each of the layer comprising silicon dioxide, germanium dioxide, or a mixture thereof.

Abstract: An X-ray generation apparatus has an anticathode which includes a high thermal conductive substrate and a target for generating X-rays by irradiation with electrons. The target penetrates the high heat conductive substrate. Improved cooling efficiency and durability of the anticathode is obtained as well as miniaturization and simplification of the X-ray generation apparatus is achieved.

Abstract: A diamond wafer including a substrate and a (111) oriented polycrystalline diamond film grown on the substrate for making surface acoustic wave devices, semiconductor devices or abrasion-resistant discs. The (111) oriented film is produced by supplying a lower carbon concentration gas and a higher carbon concentration gas alternately. The lower carbon concentration means 0% to 1% of the atomic ratio C/H. The higher carbon concentration means 1% to 8% of the atomic ratio C/H. More than 40% of layered defects are either parallel with or slanting at an angle less than 5 degrees to the surface. The wafer is monotonously distorted with a distortion height H satisfying 2 .mu.m.ltoreq..vertline.H.vertline..ltoreq.150 .mu.m. The film is polished to a roughness of less than Rmax50 nm and Ra20 nm.

Abstract: High quality diamond excellent in crystalline property as well as transparency, can be synthesized at a high growth speed by a process which comprises using, as a raw material gas, a mixed gas of hydrogen gas A, an inert gas B, a carbon atom-containing gas C and an oxygen atom-containing inorganic gas D in such a proportion as satisfying the following relationship by mole ratio:0.001.ltoreq.B/(A+B+C+D).ltoreq.0.950.001.ltoreq.C/(A+B+C+D).ltoreq.0.10.0005.ltoreq.D/C.ltoreq.10except where a same gas is chosen from the carbon atom-containing gas C and the oxygen atom-containing inorganic gas D, feeding the mixed gas into a reactor in which plasma is then formed by applying a DC or AC electric field at a pressure of 10 to 760 torr and thereby depositing and forming diamond on a substrate arranged in the reactor.

Abstract: A hard material-coated wafer that having a distortable substrate and a hard material film deposited thereon by a CVD method is provided. The substrate is substantially flat while in a free-standing state. However, deposition of the hard material film having a Vickers hardness of more than Hv3000 on the substrate causes the substrate to distort into a generally convex-shape. Specifically, the wafer is distorted to the film side with a distortion height H of -150 .mu.m to -2 .mu.m. The resulting wafer can have a total thickness that ranges from 0.1 mm to 2.1 mm; and a diameter that is bigger than 25 mm. Moreover, more than 50% of the film can be polished to a roughness less than Rmax 50 nm and Ra 20 nm.

Abstract: A diamond heat sink having a very high thermal property, to be used for radiation of semiconductor devices or compressors, includes a plate-shaped diamond substrate and fins for increasing the thermal property. The fins are combined with the substrate and are of a material having a heat conductivity of at least 1 (W/cm.multidot.K), for example, diamond. Such heat sink is produced by a simple process including arranging a base material and fins for growing diamond in such a manner that the surface of the base material and the upper ends of the fins are substantially the same height by the use of a suitable supporting member or by working the base material itself and growing diamond thereon by a gaseous phase synthesis method.

Abstract: A window material, which has a high thermal conductivity material layer having a thermal conductivity of at least 10 W/cm.multidot.K and which has a cooling medium flow path on or in the high thermal conductivity material layer, has a high heat-dissipating property and a high transmittance.

Abstract: A substrate, which has a high thermal conductivity material layer having a thermal conductivity of at least 10 W/cm.multidot.K and which has a cooling medium flow path on or in the high thermal conductivity material layer, has a high heat-dissipating property.