DEEP-LEVEL DEFECTS IN N-TYPE GAN GROWN BY MOLECULAR-BEAM EPITAXY

Deep-level transient spectroscopy has been used to characterize electr onic defects in n-type GaN grown by reactive molecular-beam epitaxy. F ive deep-level electronic defects were observed, with activation energ ies E-1=0.234+/-0.006, E-2=0.578+/-0.006, E-3=0.657+/-0.031, E-4=0.961 +/-0.026, and E-5=0.240+/-0.012 eV. Among these, the levels labeled E- 1, E-2, and E-3 are interpreted as corresponding to deep levels previo usly reported in n-GaN grown by both hydride vapor-phase epitaxy and m etal organic chemical vapor deposition. Levels E-4 and E-5 do not corr espond to any previously reported defect levels, and are characterized for the first time in our studies. (C) 1998 American Institute of Phy sics. [S0003-6951(98)02910-6].