ABSTRACT
InGaAs/(Al)GaAs multiple quantum-well (QW) structures with various barrier thicknesses have been grown by metalorganic chemical vapor deposition. Characterization was performed by means of x-ray diffraction measurements as well as microscopic photoluminescence mapping measurements. The characterization results show that the degradation in crystalline quality of the strained QW structure is more suppressed by increasing the barrier thickness. It is pointed out that these results cannot be explained by equilibrium theory concerning the critical thickness in strained layers. It has also been demonstrated that the reliability of InGaAs/AlGaAs double QW lasers is improved by increasing the barrier thickness.
