AN EVALUATION OF LIQUID-PHASE EPITAXIAL INGAAS INAS HETEROSTRUCTURES FOR INFRARED DEVICES USING SYNCHROTRON X-RAY TOPOGRAPHY/

Synchrotron x-ray topography was used to evaluate dislocation generati on for liquid phase heteroepitaxy of strained layer In0.97Ga0.03As on n-type InAs substrates. Severe misfit dislocation generation is observ ed for epilayer thicknesses of 4 mu m and many of these form threading dislocations which are observed at the surface. However, for thicker epilayer growth (up to 70 mu m in this study), this misfit dislocation generation appears to be confined to a region close to the heterointe rface, with few threading dislocations approaching the surface. These data correlates well with photoluminescence and optical microscopy mea surements.