InGaAs island shapes and adatom migration behavior on (100), (110), (111), and (311) GaAs surfaces

The evolution of InGaAs island formation on (100), (110), (111), and (311) GaAs substrates was studied by atomic force microscopy. In addition to determining the growth mode, shape, average size and distribution of InGaAs islands on each orientation, measurement of the saturation island densities enabled an estimation of effective group III adatom surface diffusion lengths. Small lens-shaped islands in addition to larger faceted islands were formed on (100) and (311) surfaces, while trapezoidal and triangular islands were obtained on (110) and (111)B orientations, respectively. Adatom diffusion lengths on these surfaces were found to range from 0.06 μm on (311)B to 3 μm on (111)B.