| 摘要 |
PURPOSE:To alleviate the difference in lattice constants between a substrate and an operating layer and to prevent the desorption of an element from the substrate, by forming a very thin compound semiconductor layer between the compound semiconductor substrate and a compound semiconductor operating layer. CONSTITUTION:A GaAs layer 2 as a very thin compound semiconductor layer, whose dissociation temperature is higher than that of a substrate 1, is grown on a semi-insulating InP substrate 1 as a compound semiconductor substrate by three atomic planes. Thereafter the layer 2 undergoes elastic deformation, and the lattice constant of the layer 2 in the planar direction is brought close to the lattice constant of the substrate 1. Then an In0.75Ga0.25As operating layer is formed as a compound-semiconductor operating layer on the layer 2. Thus the difference in lattice constants between the substrate 1 and the layer 3 is alleviated. The dissociation of elements from the substrate 1 can be prevented by the layer 2. The substrate temperature is increased in the forming step of the layer 3 and remaining impurity gas can be decreased. As a result, the excellent electric characteristics can be implemented.
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