| 摘要 |
PROBLEM TO BE SOLVED: To prevent the breakage of a multiple quantum well structure caused by the unstableness of barrier layers by successively alternately laminating InGaAs well layers having compressive-strains and the barrier layers having compressive strains and composed of InGaAsP or InGaAs upon another on an InP substrate. SOLUTION: A compressive-strain quantum well structure 2 composed of well layers 3 and barrier layers 4 is constructed on a substrate 1 composed of a single semiconductor crystal. The well layers 3 and barrier layers 4 are alternately laminated upon another and carriers are enclosed in the well layers 3. Compressive strains εW and εb are respectively applied to the well layers 3 and barrier layers 4. The well layers 3 are made of InGaAs and the compressive strains applied to the layers 3 and the thicknesses of the layers 3 are respectively adjusted to, for example, 1.6% and 120Å. The barrier layers 4 are made of InGaAs and the thicknesses of the layers 4 are adjusted to, for example, 200Å. In addition, the number of the well layers 3 is adjusted to, for example, two. Therefore, the breakage of the multiple quantum well structure caused by the unstableness of the barrier layers can be prevented by reducing the strain discrepancy between the well layers and barrier layers. |
