Initial growth behaviour of indium phosphide on molybdenum substrates

We describe the initial stages of indium phosphide growth on preferentially etched molybdenum using an In-PCl₃-H₂ reaction system. It is shown that the island size of a few microns increases while the island density decreases with growth temperature. The saturation island density is found to be 10⁴–10⁸ cm^-2 and increases exponentially with the reciprocal of the growth temperature. The difference between the island saturation phenomenon that we observed and that described by the present nucleation theories may involve a smaller supersaturation in the vapour phase and the molecular diffusion of associated species on the molybdenum surface.