STRUCTURAL STABILITY OF ULTRATHIN INAS/GAAS QUANTUM-WELLS GROWN BY MIGRATION ENHANCED EPITAXY

In order to study the strained-structure of InAs films on GaAs substrates, photoluminescence (PL) properties have been examined for ultrathin InAs/GaAs single quantum well (SQW) structures grown by migration enhanced epitaxy. Observed PL spectra from SQWs are discussed in conjunction with in-situ monitored growth conditions of the heterostructure by using reflection high energy electron diffraction. Rapid thermal annealing on the grown samples has been performed to understand the stability of strained heterostructure. By the PL analysis on the annealing effect, the critical thickness for the stably strained heterostructure is determined to be 2-3 MLs and nearly 1 ML for samples grown at 520 and 420-degrees-C, respectively.