| 摘要 |
PURPOSE:To obtain a semiconductor structure where the strain quantity and a thin film of a strain layer are controlled independently by a method wherein a matching layer provided between a substrate and at least two strain layers different in lattice constant has a band gap energy equal to that of the strain layer and makes lattice match with the substrate. CONSTITUTION:Strain layers 1 of a critical film thickness or less and a matching layer 2 which makes lattice match with a substrate are provided alternately to constitute a strain well layer 4'. In this way, the strain layer is divided by the matching layer to increase the strain quantity added in the strain well layer. An alternate way is to make the strain layer of a quarternary crystal, the matching layer of a binary or ternary crystal, or both of a quarternary crystal, resulting in a change in its mixed crystal ratio. Thus, the band gap energy in the strain well layer is made equal to that of the strain layer 1 at the matching layer 2 to change only the strain quantity. This process can provide a semiconductor structure where the stain quantity and the film thickness of a strain layer are controlled independently. |
