Misfit dislocation-free In1−<i>x</i>Ga<i>x</i>As1−<i>y</i>P<i>y</i>/InP heterostructure wafers grown by liquid phase epitaxy

Abstract

The conditions to grow misfit dislocation-free In1−xGaxAs1−yPy/InP (0⩽x⩽0.47, 0⩽y⩽1.0) heterostructure wafers were first determined systematically by observing etch pits and x-ray topographs. Etch pits were produced on InP substrates on which an In1−xGaxAs1−yPy layer was grown, and they were observed to find whether misfit dislocations generated or not. Threshold regions for initiation of misfit dislocations into the wafers were determined as a function of both lattice misfit and layer thickness. The misfit dislocation-free regions determined by the etch pit observation of InP was found to be equivalent to the regions where misfit dislocations form in neither InP nor In1−xGaxAs1−yPy . The misfit dislocation-free regions of the quaternary wafers are larger than the region of the ternary In1−xGaxAs/InP wafers by more than three times.