| 摘要 |
PURPOSE:To provide a multiple strain quantum well structure which ensures a large number of quantum wells per constant layer thickness, less crystal dislocation and excellent optical characteristic. CONSTITUTION:In a multiquantum well structure alternately forming a semiconductor quantum well layer 4 and semiconductor barrier layers 5 to 7 having a larger band gap than that of the semiconductor quantum well layer 4 on a InP substrate 1, a period of the multiquantum well structure comprises a quantum well layer 4 consisting of a semiconductor layer having a lattice constant a1 different from that of the InP substrate 1 and a first barrier layer 5 consisting of a semiconductor layer having a lattice constant a0 same as that of the semiconductor substrate 1. Moreover, such period of structure is of a multilayer film which may be obtained by sequentially laminating a second barrier layer 6 consisting of a semiconductor layer having the lattice constant a2 and a third barrier layer 7 consisting of a semiconductor layer having a lattice constant a0 under the condition of a1<a0<=a2 or a1>a0>=a2. |
