| 摘要 |
PURPOSE:To form semiconductor layers different in lattice constant from a semiconductor substrate on the substrate further to minimize the defects in the semiconductor layers by inserting an SLS(distorted superlattice) between the semiconductor layers and the semiconductor substrate. CONSTITUTION:The lattice constant B of as in the substrate 11 changes to ae in an SLS 12 for changing the lattice constant B to be kept unchanged until a semiconductor layer 15. Within the SLS 12 for changing the lattice constant B, the lattice constant B is to be gradually changed from as in the substrate 11 to ae in the semiconductor layer 15 so that the propagation of resultant stress and defects in the surface direction may be minimized consequently the distortion can be actually relieved by introduced the dislocation to some extent. Therefore, the semiconductor substrate 11 in the specific lattice constant and semiconductor layers in the different lattice constant can be formed and the semiconductor layers are subjected to minimum crystalline defects due to restrained propagation of dislocation. Furthermore, the change in the lattice constant B and the prevention of dislocation propagation can be designed independently to facilitate the optimization of the designs. |
