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 modula tion of the alloy composition; transverse satellites arise in reciprocal sp ace as a signature of the compositional modulation. Using an x-ray diffract ometer equipped with a position-sensitive x-ray detector, we demonstrate re ciprocal-space mapping of these satellites as an efficient, non-destructive means for detecting and characterizing the occurrence of compositional mod ulation. Systematic variations in the compositional modulation due to the s tructural design and the growth conditions of the short-period superlattice are characterized by routine mapping of the lateral satellites.