Characterization of InGaAs/InP heteroepitaxial layers grown by vapor phase epitaxy.

The background carrier concentration of undoped VPE-grown In (1-x)Ga(x)As/InP has been found to correlate to the x-ray linewidth. Lattice mismatches were measured using an x-ray double crystal diffractometer, and due to the general occurrence of tetragonal distortion it was necessary to measure both the lattice mismatch perpendicular to the (100) plane, and that parallel to it, to completely characterize the mismatch. X- ray linewidths were found to correlate to the parallel mismatch and to group into three branches which were found to correspond to the presence of specific features on x-ray topographs. Both wafers grown on-(100) and wafers grown on 6C off-(100) wafers. From our data we established the existence or absence of misfit dislocations, and these results were used to establish coherency limits for VPE In(1-x)Ga(x)As/InP.