Misfit dislocation-free In1−xGaxAs1−yPy/InP heterostructure wafers grown by liquid phase epitaxy

Abstract

The conditions to grow misfit dislocation‐free In_1−xGa_xAs_1−yP_y/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 In_1−xGa_xAs_1−yP_y 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 In_1−xGa_xAs_1−yP_y . The misfit dislocation‐free regions of the quaternary wafers are larger than the region of the ternary In_1−xGa_xAs/InP wafers by more than three times.