| 摘要 |
When sapphire is epitaxially grown on a seed substrate of Si at a growth temperature of about 350° C. by an ionized cluster beam vapor deposition and epitaxy method, a gamma phase Al2O3 layer is formed. When the gamma phase Al2O3 layer is exposed to a high temperature of not lower than 1000° C., the gamma phase Al2O3 layer then changes to an alpha phase Al2O3 layer by phase transition. A known or optional semiconductor light-emitting element can be formed on the alpha phase sapphire. When the seed substrate of Si is then selectively removed by etching, a semiconductor light-emitting element having a light-extracting surface of the sapphire processed into a desired shape can be obtained. As a result, external quantum efficiency of the semiconductor light-emitting element can be improved as well as light-condensing characteristic and directivity of light output from the semiconductor light-emitting element can be improved.
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