INP ON PATTERNED SI(001) - DEFECT REDUCTION BY APPLICATION OF THE NECKING MECHANISM

InP is grown by low-pressure metalorganic chemical vapor deposition on exactly (001)-oriented, patterned Si substrates. The Si structure consists of narrow stripes of different widths down to 0.6 mum oriented along [110], bound by V-grooves with {111} sidewalls. Transmission electron microscopy (TEM) of [110]-oriented cross sections shows that InP nucleation occurs on (001) as well as on {111} planes which results in a faceted growth. Thereby, the epilayer shape is remarkably different from what one would expect from the substrate structure. By choosing proper geometries, antiphase domain free InP can be grown. Moreover, with increasing thickness of the growing layer the density of stacking faults and microtwins is drastically reduced due to their propagation towards the side planes of the InP stripes. This process is comparable with the necking procedure in the Czochralski growth technique used to obtain single-crystalline material free from defects. The defect reductions results in a smoother surface morphology and an increase of quantum efficiency by more than 50% as compared to planar film material.