Analysis of growth parameters and strain in GaInSb/InAs superlattices

InAs/InGaSb strained-layer superlattices have been deposited for long wavelength infrared (IR) detectors. The superlattice structure consists of alternating periods of InAs and InGaSb deposited upon GaSb or GaAs substrates. The lattice mismatch between the two layers is accommodated by strain which modifies the electronic and optical properties of the material. These properties can be controlled by varying the layer thickness, composition, and heterointerface properties. Molecular beam epitaxy was used to deposit the InAs/InGaSb superlattice and reflection high energy electron diffraction (RHEED) patterns were observed during growth. It was found that RHEED oscillations and x-ray diffraction patterns were heavily influenced by the incident As2 flux used during the InAs layers. Precise control of the As flux with a valve cracker resulted in RHEED intensity oscillations continuing throughout the superlattice and excellent x-ray diffraction patterns. Fast Fourier transform IR spectroscopy of the superlattices indicate absorption around 13 micrometers .© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.