US Patent 7464702 Method of producing III-nitride substrate

An ingot 3 of a hexagonal III-nitride crystal is cut using a wire array 21 composed of a wire 22. On this occasion, the ingot 3 is cut in such a manner that the ingot 3 is sliced with supply of an abrasive fluid while feeding at least one of the ingot 3 and wire 22 in a direction perpendicular to an extending direction B of the wire 22. During cutting the ingot 3, the extending direction B of the wire 22 is inclined at 3° or more to the {1-100} plane of the ingot 3.