DEPENDENCE OF GAN MOMBE GROWTH ON NITROGEN-SOURCE - ECR PLASMA GUN STRUCTURE AND MONOMETHYL-HYDRAZINE

GaN layers were grown on (0 0 1)GaAs substrates by metal-organic molec ular beam epitaxy (MOMBE), using electron cyclotron resonance (ECR) pl asma activated nitrogen and monomethyl hydrazine (MMHy) as a nitrogen (N) source. We investigated dependence of GaN crystalline quality, gro wth rate and contamination, on the N source, It was found that the gro wth rate for a borosilicate glass guide tube was higher than that for quartz guide tube, suggesting that the quartz guide tube kills N radic als. Unexpectedly, higher oxygen and carbon contamination was detected for the layer grown with the ECR plasma, gun without the ion extracti on magnet and quartz, than those for the layer grown with MMHy. (C) 19 98 Published by Elsevier Science B.V. All rights reserved.