A method for removing a portion of a crystalline material (e.g., SiC) substrate includes joining a surface of the substrate to a rigid carrier (e.g., >800 μm thick), with a subsurface laser damage region provided within the substrate at a depth relative to the surface. Adhesive material having a glass transition temperature above 25° C. may bond the substrate to the carrier. The crystalline material is fractured along the subsurface laser damage region to produce a bonded assembly including the carrier and a portion of the crystalline material. Fracturing of the crystalline material may be promoted by (i) application of a mechanical force proximate to at least one carrier edge to impart a bending moment in the carrier; (ii) cooling the carrier when the carrier has a greater coefficient of thermal expansion than the crystalline material; and/or (iii) applying ultrasonic energy to the crystalline material.

High quality ammonothermal group III metal nitride crystals having a pattern of locally-approximately-linear arrays of threading dislocations, methods of manufacturing high quality ammonothermal group III metal nitride crystals, and methods of using such crystals are disclosed. The crystals are useful for seed bulk crystal growth and as substrates for light emitting diodes, laser diodes, transistors, photodetectors, solar cells, and for photoelectrochemical water splitting for hydrogen generation devices.

Magnetoelectric heterostructures, and related articles, systems, and methods, are generally described.

An engineered substrate comprising: a seed layer made of a first semiconductor material for growth of a solar cell; a first bonding layer on the seed layer; a support substrate made of a second semiconductor material; a second bonding layer on a first side of the support substrate; a bonding interface between the first and second bonding layers; the first and second bonding layers each made of metallic material; wherein doping concentration and thickness of the engineered substrate, in particular, of the seed layer, the support substrate, and both the first and second bonding layers, are selected such that the absorption of the seed layer is less than 20%, preferably less than 10%, as well as total area-normalized series resistance of the engineered substrate is less than 10 mOhm.Math.cm.sup.2, preferably less than 5 mOhm.Math.cm.sup.2.

A silicon carbide ingot is cut using a wire. The silicon carbide ingot has a polytype of 4H—SiC. The silicon carbide ingot includes a top surface, a bottom surface opposite to the top surface, and a side surface between the top surface and the bottom surface. A direction from the bottom surface toward the top surface is a direction parallel to a [0001] direction or a direction inclined by less than or equal to 8° relative to the [0001] direction. In the cutting of the silicon carbide ingot, the silicon carbide ingot is cut from the side surface at a (000-1) plane side along a straight line parallel to a direction within ±5° relative to a direction that bisects an angle formed by a [1-100] direction and a [11-20] direction when viewed in the direction from the bottom surface toward the top surface.

A method for processing a wide band gap semiconductor wafer is proposed. The method includes depositing a non-monocrystalline support layer at a back side of a wide band gap semiconductor wafer, depositing an epitaxial layer at a front side of the wide band gap semiconductor wafer, and splitting the wide band gap semiconductor wafer along a splitting region to obtain a device wafer including at least a part of the epitaxial layer, and a remaining wafer including the non-monocrystalline support layer.

Systems and methods for generating one or more single crystal monolayers from two-dimensional van der Waals crystals are disclosed herein. Example methods include providing a bulk material including a plurality of van der Waals crystal layers, and exfoliating one or more single crystal monolayers of van der Waals crystal from the bulk material by applying a flexible and flat metal tape to a surface of the bulk material. In certain embodiments, the one or more single crystal monolayers can be assembled into an artificial lattice. The present disclosure also provides techniques for manufacturing flexible and flat metal tape for generating one or more single crystal monolayers from two-dimensional van der Waals crystals. The present disclosure also provides compositions for creating a macroscopic artificial lattice. In certain embodiments, the composition can include two or more macroscopic single crystal monolayers adapted from a bulk van der Waals crystal, where the single crystal monolayers are configured for assembly into an artificial lattice based on one or more properties.

A method of manufacturing a hexagonal Group-III nitride semiconductor plate crystal using a crystal cutting wire. where the hexagonal semiconductor crystal has one principal face on one side and another principal face on an opposite side, and the hexagonal semiconductor crystal is cut by causing the crystal cutting wire to move so as to (i) divide the one principal face and the another principal face and (ii) satisfy conditions of Expressions (A) and (B):

25°<α≤90°  Expression (A); and

β=90°±5°  Expression (B) where α represents an angle formed by a c axis of the hexagonal Group-III nitride semiconductor crystal and a normal line of a crystal face cut out by the wire, and β represents an angle formed by a reference axis, which is obtained by perpendicularly projecting the c axis of the hexagonal Group-III nitride semiconductor crystal to the crystal face cut out by the wire, and a cutting direction.

A method of manufacturing a hexagonal Group-III nitride semiconductor plate crystal using a crystal cutting wire. where the hexagonal semiconductor crystal has one principal face on one side and another principal face on an opposite side, and the hexagonal semiconductor crystal is cut by causing the crystal cutting wire to move so as to (i) divide the one principal face and the another principal face and (ii) satisfy conditions of Expressions (A) and (B):

25°<α≤90°  Expression (A); and

β=90°±5°  Expression (B) where α represents an angle formed by a c axis of the hexagonal Group-III nitride semiconductor crystal and a normal line of a crystal face cut out by the wire, and β represents an angle formed by a reference axis, which is obtained by perpendicularly projecting the c axis of the hexagonal Group-III nitride semiconductor crystal to the crystal face cut out by the wire, and a cutting direction.

[Object] It is an object of the present invention to provide a lithium tantalate single crystal substrate which undergoes only small warpage, is free from cracks and scratches, has better temperature non-dependence characteristics and a larger electromechanical coupling coefficient than a conventional Y-cut LiTaO.sub.3 substrate. [Means to solve the Problems] The lithium tantalate single crystal substrate of the present invention is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36° Y-49° Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.