Strain analysis and quantum well intermixing of a laterally modulated multiquantum well system produced by focused ion beam implantation

摘要

We report on the strain analysis of a vertically stacked GaAs/G(0.97)In(0.03) As/[GaAs/Al0.2Ga0.8As](9)/GaAs [001] multiquantum well structure which was laterally patterned by a focused Ga+ ion beam implantation of 5 x 10(13) cm(-2) ions. We studied the strain distribution in the samples before and after a rapid thermal annealing for 60 s at 650 and 800 degreesC by means of x-ray grazing incidence diffraction. In the as-implanted sample we found a nearly constant strain distribution of about 4 x 10(-3) up to a maximum information depth of approximately 500 nm. Annealing at 650 degreesC led to a reduced strain within the sample. After annealing at 800 degreesC the strain disappeared almost completely but a significant increase of the multilayer interface width could be observed, indicating an intermixing of Ga and Al atoms across the interfaces. [References: 13]