Structural characterization of an (InAs) 8(AlAs) 2 superlattice on GaAs(001) with a four-circle X-ray diffractometer

• Published in: Thin solid films Vol. 189; no. 2; pp. 329 - 338
• Main Authors: Fayos, Jose, Mendez, Mercedes Perez
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.08.1990; Elsevier Science
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Epitaxy; Solid solid interface; Growth interface; Interdiffusion; Experimental study; X ray diffraction; Thin film; Gallium Arsenides; Structure factor; Aluminium Arsenides; Molecular beam condensation; Growth mechanism; Models; Indium Arsenides; Space group; Superlattice; Laue method
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/0040-6090(90)90462-M

An (InAs) 8(AlAs) 2 superlattice (SL) 0.3 μm thick grown on a GaAs(001) substrate by alternate layer molecular beam epitaxy, has been structurally characterized with a conventional four-circle X-ray diffractometer. Alternative structural models for any (InAl) n 1 (AlAs) n 2 SL are established. The SL Laue group mmm was selected on the basis of the 2468 reflections measured in the half Ewald sphere of the sample. The structural model best matching the observed 200 SL independent reflections can be described by the space group Pmm2, where a considerable improvement in the fit is reached by introducing some InAsAlAs diffusion through the interface, modulating the interplanar spacings, which is here indistinguishable from interface roughness.