| 摘要 |
PURPOSE:To suppress the increase of the electric resistance caused by the discontinuity of a band by alternately stacking first semiconductors and second semiconductors different in band gap, and interposing middle layers, which have band gaps intermediate between the first semiconductors and the second semiconductors, between them and stacking these. CONSTITUTION:For a reflector 14, the first semiconductor 32 consisting of a p-AlAs semiconductor, a middle layer 34 consisting of a p-AlyGa1-yAs semiconductor, the second semiconductor 36 consisting of a p-AlyGa1-yAs semiconductor, and a middle substance 38 consisting of a p-AlyGa1-yAs semiconductor are stacked in order repeatedly. These are epitaxially grown continuously by changing the rate of the material gas introduced into a MOCVD device. The mixed crystal ratios of the middle layers 34 and 38 are determined to be values smaller than 1 and larger than the Al mixed ratio of the second semiconductor 36. The band gaps of the middle layers 34 and 38 are smaller than first semiconductor 32 and larger than the second semiconductor 36 consisting of p-AlxGa1-xAs. |
