| 摘要 |
PURPOSE:To obtain a small dislocation density even when a GaAs layer, an AlGaAs layer are epitaxially grown on an N-type Si substrate, small defect density of recombination center and high quality by providing a superlattice layer made of AlGaAs, GaAs regulated to specific amounts in AlAs composition. CONSTITUTION:A light emitting diode is formed of an N-type Si substrate 1, an N-type GaAs layer 2, an AlGaAs and GaAs superlattice layer 3, an N-type AlGaAs layer 4, a P-type AlGaAs layer 5, a P-type GaAs layer 6, a p-type electrode 7, and an N-type electrode 8. In this case, dislocation density reducing effect is abruptly increased from the vicinity of exceeding 0.3 in the AlAs composition in the layer 3, and alleviated from the vicinity of exceeding 0.7. On the other hand, a defect density of recombination center tends to, reversely, increase. Accordingly, the AlAs composition in the layer 3 is optimum to be regulated between 0.4 and 0.5. Thus, the GaAs or AlGaAs layer of high quality is obtained. |
