InAs self-assembled quantum dots (SAQDs) were grown on InP at various temperatures and V/III ratios by metalorganic chemical vapor deposition. The density, size distribution, and shape of the InAs SAQDs changed significantly with temperature and V/III ratio. Careful analysis of the total volume of the dots grown at various conditions showed that the volume far exceeded the amount of deposition supplied from the gas-phase sources. The amount of excess InAs and the aspect ratio (height/lateral size) of the SAQD increased with temperature and V/III ratio, strongly suggesting that the As/P exchange reaction at the surface played an important role in the kinetics of SAQD formation. Insertion of a lattice-matched InGaAs buffer layer suppressed the excess InAs formation, and lowered the aspect ratio, confirming the effect of the As/P exchange reaction.

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We present an in situ study of P desorption and adsorption on the (001) InP surface using surface photoabsorption (SPA). The SPA spectra show three peaks at 2.1, 2.9, and 3.1 eV. Here, based on previous studies, we have identified them as a P dimer related and two surface In dimer related peaks, respectively. The initial sharp drop and the slow recovery of the SPA signal at 430 nm after PH3 is switched on implies that at least two steps are involved in the P desorption process. We also observed a structure at 3.1 eV in the spectrum of the In-stabilized surface. We have determined from temperature dependent desorption measurements that the activation energy for P desorption from this surface is 3.36 eV.

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