Reciprocal-Space Analysis of Compositional Modulation in Short-Period Superlattices Using Position-Sensitive X-Ray Detection

Epitaxial growth of AlAs-InAs short-period superlattices on (0 0 1) InP can lead to heterostructures exhibiting strong, quasi-periodic, lateral modulation of the alloy composition; transverse satellites arise in reciprocal space as a signature of the compositional modulation. Using an x-ray diffractometer equipped with a position-sensitive x-ray detector, we demonstrate reciprocal-space mapping of these satellites as an efficient, non-destructive means for detecting and characterizing the occurrence of compositional modulation. Systematic variations in the compositional modulation due to the structural design and the growth conditions of the short-period superlattice are characterized by routine mapping of the lateral satellites.