| 摘要 |
PURPOSE:To make an equivalent lattice constant nearly equal to that of a clad layer when a quantum well structure is considered as one layer, to make a critical film thickness thick, to increase the degree of designing freedom of the quantum well structure containing a strain and to obtain a high-performance semiconductor optical element by a method wherein an active layer of the quantum well structure is constituted of layers having a large lattice constant and layers having a small lattice constant with reference to clad layers. CONSTITUTION:An n-InP clad layer 2 is grown on an n-InP substrate 1 by an MOCVD method; after that, 11 layers of In0.35Ga0.65As barrier layers 3 and 10 layers of In0.7Ga0.3 As well layers 4 are grown alternately to form an active layer 5 of a multiple quantum well structure. In addition, a P-InP clad layer 6 is grown on the active layer 5 to form a laser structure. The lattice constant of the layers 4 is by about 1% larger than that of the layer 2 and the layer 6. Inversely, the lattice constant of the layers 3 is by about 1% smaller than that of the layer 2 and the layer 6. When thin-film crystals of the layers having the large lattice constant and the layers having the small lattice constant with reference to the upper and lower clad layers are grown alternately in this manner, it is possible to obtain a semiconductor laser structure, of quantum well type, in which no dislocation occurs and which contains a strain. |
