A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 m.

A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 m.

Embodiments described herein provide processes for forming and removing epitaxial films and materials from growth wafers by epitaxial lift off (ELO) processes. In some embodiments, the growth wafer has edge surfaces with an off-axis orientation which is utilized during the ELO process. The off-axis orientation of the edge surface provides an additional variable for controlling the etch rate during the ELO process and therefore the etch front may be modulated to prevent the formation of high stress points which reduces or prevents stressing and cracking the epitaxial film stack. In one embodiment, the growth wafer is rectangular and has an edge surface with an off-axis orientation rotated by an angle greater than 0 and up to 90 relative to an edge orientation of <110> at 0.

Materials, devices, methods of use and fabrication thereof are disclosed. The materials are particularly well suited for application in superconducting devices and quantum computing, due to ability to avoid undesirable effects from inherent noise and decoherence. The materials are formed from select isotopes having zero nuclear spin into a single crystal-phase film or layer of thickness depending on the desired application of the resulting device. The film/layer may be suspended or disposed on a substrate. The isotopes may be enriched from naturally-occurring sources of isotopically mixed elemental material(s). The single crystal is preferably devoid of structural defects such as grain boundaries, inclusions, impurities and lattice vacancies. Device configurations may be formed from the layer according to a predetermined pattern using lithographic and/or milling techniques. An optional protective layer may be deposited on some or all of the device to avoid formation of oxides and/or patinas on surfaces of the device.

An evaluation method of a SiC epitaxial wafer includes: a first observation step of preparing a SiC epitaxial wafer having a high-concentration epitaxial layer having an impurity concentration of 110.sup.18 cm.sup.3 or more, irradiating a surface of the high-concentration epitaxial layer having an impurity concentration of 110.sup.18 cm.sup.3 or more with excitation light, and observing a surface irradiated with the excitation light via a band-pass filter having a wavelength band of 430 nm or less.

In order to prevent an increase in width of a part of an accommodation bag from when polycrystalline silicon packed is lifted and until when the polycrystalline silicon is placed into a predetermined position and thus to accurately place the accommodation bag into a predetermined space, an accommodation case (10) includes a side surface body (11) forming an insertion space (12) into which an accommodation bag (B1) accommodating polycrystalline silicon (S1) is to be inserted; lift portions 13 for lifting the side surface body (11); and a tray (15) configured to support the accommodation bag (B1), the tray (15) being configured to be detached from a bottom portion (11a) of the side surface body (11), so that an opening (OP) is formed at the bottom portion of the side surface body (11), the opening (OP) being configured to form a placement path (30) for the accommodation bag (B1).

To provide a lithium niobate (LN) substrate which allows treatment conditions regarding a temperature, a time, and the like to be easily managed and in which an in-plane distribution of a volume resistance value is very small, and a method of producing the same. A method of producing an LN substrate by using an LN single crystal grown by the Czochralski process, in which an LN single crystal having a Fe concentration of 50 mass ppm or more and 1000 mass ppm or less in the single crystal and processed into a form of a substrate is buried in an Al powder or a mixed powder of Al and Al.sub.2O.sub.3, and heat-treated at a temperature of 350 C. or more and less than 450 C., to produce a lithium niobate single crystal substrate having a volume resistivity controlled to be within a range of more than 110.sup.10 .Math.cm to 210.sup.12 .Math.cm or less.

A method for producing a wafer from a hexagonal single crystal ingot includes: planarizing an upper surface of the hexagonal single crystal ingot; applying a laser beam of such a wavelength as to be transmitted through the ingot, with a focal point positioned in an inside of a region not to be formed with devices of a wafer to be produced from the upper surface of the ingot which has been planarized, to form a production history; and applying a laser beam of such a wavelength as to be transmitted through the hexagonal single crystal ingot with a focal point of the laser beam positioned at a depth corresponding to a thickness of the wafer to be produced from the upper surface of the hexagonal single crystal ingot which has been planarized, to form an exfoliation layer.

A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 m.

A silicon carbide single crystal substrate includes a first main surface and an orientation flat. The orientation flat extends in a <11-20> direction. The first main surface includes an end region extending by at most 5 mm from an outer periphery of the first main surface. In a direction perpendicular to the first main surface, an amount of warpage of the end region continuous to the orientation flat is not greater than 3 m.