Dependence of Deep Level Concentrations on Ammonia Flow Rate in N-Type GaN Films

L. Lee ； F. C. Chang ； H. M. Chung ； M. C. Lee ； W. H. Chen ； W. K. Chen ； B. R. Huang

《Chinese Journal of Physics》 40卷4期 (2002/08) Pp. 424-428

並列摘要

Deep level transient spectroscoppy was used to characterize the deep levels of GaN films grown with various V/III ratios using metalorganic vapor phase epitaxy. Two prominent defects, located at EC-0.569±0.003 and EC-1.013±0.091 eV, were detected in this study. When the NH3 flow rate was increased, we observed a slight increase in trap concentration of the EC-0.569 eV defect and a significant increase at EC-1.013 eV. Although a high V/III seems necessary for obtaining good quality GaN film, our results indicate that, if the ammonia is in excessive supply, it may generate a large number of EC-1.013 eV deep level defects, which deteriorate the film quality – which should be avoided with special care.