Melt removal and planar growth of In1−xGaxP1−zAsz heterojunctions

Evidence is provided showing that incomplete melt removal, or wipe-off, at the conclusion of liquid phase epitaxial (LPE) In1−xGaxP1−zAsz growth results in strained pitted dark layers because of the loss in composition match between the melt and substrate. Similarly, a small amount of drag-over of one quaternary melt under a different composition melt is sufficient to cause attack of the underlying substrate (or LPE layer) and to cause local changes in the second melt destroying the composition match with the substrate. Single-layer and multilayer In1−xGaxP1−zAsz structures are shown in which incomplete melt removal causes the growth of pitted ragged nonuniform layers side by side with uniform planar layers.