Orientation-dependent metalorganic vapor phase epitaxy regrowth on GaInAsP/InP laser structures

GaInAsP/InP lasers made by low-pressure metalorganic vapor phase epitaxy regrowth on patterned surfaces exhibit yield and performance dependent on laser stripe orientation. Structures with stripes parallel to the (011) and (011) directions are investigated by secondary-ion mass spectroscopy (SIMS). Three-dimensional SIMS profiles taken with high horizontal resolution using the checkerboard matrix gate technique yield unexpected results for structures with stripes parallel to the (011) direction: phosphorus is found in the nominal GaInAs layer, its distribution is strongly inhomogeneous. Zn diffused into the GaInAs layer exhibits also pronounced spatial variations. Unwanted P outdiffusion and anomalous Zn diffusion are attributed to reduced crystalline perfection of the InP above (01) oriented laser stripes.