Abstract: This bonded body (10) comprising a mosaic diamond wafer and a semiconductor of a different type is a bonded body in which a mosaic diamond wafer (1) having a coalescence boundary (B1) between a plurality of single-crystal diamond substrates (1A and 1B) and a semiconductor of a different type (2) are bonded together, in which a maximum level difference on a bonding surface (1aa) of the mosaic diamond wafer (1) with the semiconductor of a different type (2) is 10 nm or less.

Abstract: A microwave plasma treatment device includes a resonator including a container; a single microwave oscillation source that outputs a reference microwave; a waveguide that connects the microwave oscillation source and the resonator to each other; and a phase control mechanism that generates a modified microwave having a phase different from a phase of the reference microwave by controlling the phase of the reference microwave. The resonator includes one or more first-type introducing portions for introducing the reference microwave into the resonator and one or more second-type introducing portions for introducing the modified microwave into the resonator, and the microwave plasma treatment device is configured such that at least one of a position, a size, and a shape of a plasma ball generated in the container is changed by superimposing the modified microwave on the reference microwave in the resonator.

Abstract: A stack including at least a semiconductor drift layer stacked on a single-crystal diamond substrate having a coalescence boundary, wherein the coalescence boundary of the single-crystal diamond substrate is a region that exhibits, in a Raman spectrum at a laser excitation wavelength of 785 nm, a full width at half maximum of a peak near 1332 cm?1 due to diamond that is observed to be broader than a full width at half maximum of the peak exhibited by a region different from the coalescence boundary, the coalescence boundary has a width of 200 ?m or more, and the semiconductor drift layer is stacked on at least the coalescence boundary.

Abstract: Provided is a single crystal diamond having a lowered dislocation density. The single crystal diamond (10) is provided with single crystal diamond layers (2, 3). One single crystal diamond layer (2) is formed on a diamond substrate (1) and contains point defects. The other single crystal diamond layer (3) is grown on the single crystal diamond layer (2). The single crystal diamond layers (2, 3) have a lower dislocation density than the diamond substrate.

Abstract: Provided is a single crystal diamond having a lowered dislocation density. The single crystal diamond (10) is provided with single crystal diamond layers (2, 3). One single crystal diamond layer (2) is formed on a diamond substrate (1) and contains point defects. The other single crystal diamond layer (3) is grown on the single crystal diamond layer (2). The single crystal diamond layers (2, 3) have a lower dislocation density than the diamond substrate.

Abstract: There is provided a novel stack that includes a single-crystal diamond substrate having a coalescence boundary, yet effectively uses the coalescence boundary. A stack comprising at least a semiconductor drift layer stacked on a single-crystal diamond substrate having a coalescence boundary, wherein the coalescence boundary of the single-crystal diamond substrate is a region that exhibits, in a Raman spectrum at a laser excitation wavelength of 785 nm, a full width at half maximum of a peak near 1332 cm?1 due to diamond that is observed to be broader than a full width at half maximum of the peak exhibited by a region different from the coalescence boundary, the coalescence boundary has a width of 200 ?m or more, and the semiconductor drift layer is stacked on at least the coalescence boundary.

Abstract: The present invention provides a method for separating a surface layer of a diamond, which comprises implanting ions into a diamond to form a non-diamond layer near a surface of the diamond; and etching the non-diamond layer in the diamond by applying an alternating-current voltage across electrodes in an electrolytic solution; and a method for separating a grown layer of a diamond, which further comprises the step of growing a diamond by a vapor-phase synthesis method, after forming a non-diamond layer according to the above-described method. The invention is applicable to various single-crystal and polycrystal diamonds. More specifically, even with a large single-crystal diamond, a portion of the single-crystal diamond can be efficiently separated in a reusable form in a relatively short period of time.

Abstract: The present invention provides a method for producing a large substrate of single-crystal diamond, including the steps of preparing a plurality of single-crystal diamond layers separated form an identical parent substrate, placing the single-crystal diamond layers in a mosaic pattern on a flat support, and growing a single-crystal diamond by a vapor-phase synthesis method on faces of the single-crystal diamond layers where they have been separated from the parent substrate. According to the method of the invention, a mosaic single-crystal diamond having a large area and good quality can be produced relatively easily.

Abstract: The present invention discloses a method for producing a mosaic diamond comprising implanting ions in the vicinity of the surfaces of a plurality of single-crystal diamond substrates arranged in the form of a mosaic, or in the vicinity of the surfaces of mosaic single-crystal diamond substrates whose back surfaces are bonded by a single-crystal diamond layer, so as to form non-diamond layers; growing a single-crystal diamond layer by a vapor-phase synthesis method; and separating the single-crystal diamond layer above the non-diamond layers by etching the non-diamond layers. The method of the present invention prevents the destruction of single-crystal diamond substrates by using a process that is simpler than conventional methods, thus allowing a large quantity of mosaic diamond to be produced in a stable and efficient manner.

Abstract: The present invention provides a method for separating a surface layer of a diamond, which comprises implanting ions into a diamond to form a non-diamond layer near a surface of the diamond; and etching the non-diamond layer in the diamond by applying an alternating-current voltage across electrodes in an electrolytic solution; and a method for separating a grown layer of a diamond, which further comprises the step of growing a diamond by a vapor-phase synthesis method, after forming a non-diamond layer according to the above-described method. The invention is applicable to various single-crystal and polycrystal diamonds. More specifically, even with a large single-crystal diamond, a portion of the single-crystal diamond can be efficiently separated in a reusable form in a relatively short period of time.

Abstract: The present invention provides a method for producing a large substrate of single-crystal diamond, including the steps of preparing a plurality of single-crystal diamond layers separated form an identical parent substrate, placing the single-crystal diamond layers in a mosaic pattern on a flat support, and growing a single-crystal diamond by a vapor-phase synthesis method on faces of the single-crystal diamond layers where they have been separated from the parent substrate. According to the method of the invention, a mosaic single-crystal diamond having a large area and good quality can be produced relatively easily.

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 process for removing surface damage of a single-crystal diamond, which comprises implanting ions into a single-crystal diamond to form a non-diamond layer near a surface of the diamond, graphitizing the non-diamond layer, and removing a surface layer by etching. According to the invention, the surface damage can be removed or reduced without increasing the surface roughness of a single crystal diamond.

Abstract: The invention provides a process for producing a single-crystal substrate with an off-angle, which comprises using, as a substrate, a material capable of epitaxial growth by a vapor-phase synthesis method, whose surface has an off-angle with respect to a crystal plane capable of epitaxial growth; implanting ions into the substrate having a surface with an off-angle to form a layer with a deteriorated crystal structure near the surface of the substrate; growing a crystal on the surface with an off-angle of the substrate by a vapor-phase synthesis method; and separating a grown crystal layer from the substrate. In accordance with the process of the invention, when producing off-substrates usable in vapor-phase synthesis of single crystals, the manufacturing costs can be reduced, and substrates with an identical off-angle can be produced easily and in large quantities.

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: A method for the extraction of an ion current from a space of a high degree of vacuum into a space of a low degree of vacuum comprises interposing between the space of the high degree of vacuum and the space of the low degree of vacuum an ion current thin film formed of a member having a uniform crystal orientation and causing the ion current to pass from the space of the high degree of vacuum through the thin film into the space of the low degree of vacuum.