Interatomic distance and local order in InAs-AlSb semiconductor superlattices

We report the first measurement of local structure in the thin layers of a semiconductor superlattice using the extended x-ray absorption fine structure. The measured values of interatomic distance and Debye-Waller factor in InAs offer a direct confirmation of the structure as intended in the growth process, and set an upper limit of the lattice strain to less than 1.5%. The data also indicate an anisotropy of the electron mean-free path in the thin layers and structural disorder at distances beyond the nearest neighbors.