FREE-STANDING GALLIUM NITRIDE SUBSTRATE, LIGHT EMITTING ELEMENT, METHOD FOR PRODUCING FREE-STANDING GALLIUM NITRIDE SUBSTRATE, AND METHOD FOR MANUFACTURING LIGHT EMITTING ELEMENT

摘要

Provided is a free-standing gallium nitride substrate which is formed of a plate that is configured from a plurality of gallium nitride-based single crystal grains having a single crystal structure generally in the normal direction. This free-standing gallium nitride substrate can be produced by a method which comprises: a step for preparing an oriented polycrystalline sintered body; a step for forming a seed crystal layer formed of gallium nitride on the oriented polycrystalline sintered body so that the seed crystal layer has a crystal orientation generally following the crystal orientation of the oriented polycrystalline sintered body; a step for forming a layer, which is configured from a gallium nitride-based crystal and has a thickness of 20μm or more, on the seed crystal layer so that the layer has a crystal orientation generally following the crystal orientation of the seed crystal layer; and a step for obtaining a free-standing gallium nitride substrate by removing the oriented polycrystalline sintered body. The present invention can provide a low-cost free-standing gallium nitride substrate that is suitable for area increase and is useful as an alternative material for a gallium nitride single crystal substrate.