| 摘要 |
The purposes of the present invention are: to provide an alumina substrate material that allows crystals of greater quality to be produced in a case where aluminum nitride (AlN) crystals or the like are produced on an alumina substrate; to provide an alumina substrate having an AlN layer for which warping has been reduced; and to provide a substrate material that, if used as a seed substrate and if excessive stress due to unavoidable lattice mismatch is applied, promotes spontaneous peeling to produce a self-supporting substrate. By an AlN layer being formed on the surface of an alumina substrate and a rare-earth-containing layer and/or region being formed within the AlN layer or at the interface between the AlN layer and the alumina substrate, stress on the AlN layer can be alleviated and warping thereof can be reduced. Moreover, if AlN crystals are grown using such a substrate, the grown crystals can be made self-supporting by spontaneous peeling. |
