MOVPE growth of InN under high NH3 decomposition rate conditions

An InN film is grown using an ArF excimer laser assisted-MOVPE where a high NH3 decomposition rate condition is realized because of the effective dissociation of NH3 by the ArF laser. Grown films show unusual phenomena such that amount of metallic In involved in a grown InN film is increased with increasing NH3 flow rate during the growth. Through the annealing of grown InN films in the NH3 flow, it is revealed that the photolysis of NH3 by the ArF laser irradiation causes the decomposition of InN and, as a result of it, the formation of In droplets. The direction of the source gases injection during the growth, perpendicular or parallel to the substrate surface, has a significant effect on the formation of metallic In. Compared with the perpendicular injection, the parallel injection can suppress the formation of In droplets and allow us to grow InN at a higher temperature. A high density of atomic hydrogen (H) generated by the photolysis of NH3 seems to take nitrogen atoms away from InN, leaving metallic In on the surface. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)