GROWTH-PROCESS AND MECHANISM OF NANOMETER-SCALE GAAS DOT-STRUCTURES USING MOCVD SELECTIVE GROWTH

Nanometer-scale GaAs dot-structures were fabricated by the selective epitaxial growth on SiO2-masked GaAs (100) substrates with low pressure metalorganic chemical vapor deposition. The growth process and the mechanism were investigated using the growth rate distribution and a surface potential model. It was revealed that the growth rates of the crystal planes change in dependence on the existence of other planes with faster growth rates, and that the in-plane migration is an important factor in the growth process. Based on these characteristics and the study on AlGaAs dot-structure growth, GaAs dot-structures three-dimensionally surrounded by Al0.4Ga0.6As were fabricated. The clear photoluminescence peak from the dots with high quantum efficiency shows the usefulness of the fabrication technique for quantum dots.