Comparison of MBE grown InSb on CU substrates using different sacrificial layers

InSb epitaxial layers with approximately 15% lattice mismatched to GaAs were grown on a conventional GaAs substrate and compliant universal (CU) substrates using various sacrificial layers. Transmission electron microscopy studies showed dislocation free InSb films grown on the CU substrate using the AlGaAs sacrificial layer, whereas the InSb films on the normal GaAs substrate and the CU substrate with the InGaP sacrificial layer exhibited dislocation densities as high as 10/sup 11/ cm/sup -2/. Reciprocal space maps of the (004) peak for the dislocation free InSb layer revealed a large mosaic spread of -0.25/spl deg/. Using atomic force microscopy on the dislocation free InSb layer, the mosaic spread was found to be generated by a periodic surface undulation with a three micron period and 700 /spl Aring/ amplitude.