The kinetics of gallium adsorption and desorption on (0001) gallium nitride surfaces

In situ spectroscopic ellipsometry kinetic characterization is used to monitor the behavior of Ga atoms during and after Ga flux impingement upon a (0001) GaN surface at various temperatures in the range of 680 - 750 S degrees C. The observed saturation of the pseudodielectric function verifies the existence of a critical thickness for the Ga wetting layer, while the observed desorption delay after the Ga flux is terminated indicates the presence of two Ga phases, one acting as a Ga reservoir to compensate the desorption of the wetting layer until the other phase is depleted.