Electrical characterization of dopants and deep level defects for III-V nitrides grown by metalorganic chemical vapor deposition

Electrical characterization is reviewed for III-V nitrides grown by metalorganic chemical vapor deposition. The application of variable temperature Hall-effect measurements is demonstrated for the example of Mg-doped GaN samples which were exposed to isochronal rapid thermal anneals in the temperature range from 500 to 850 degrees C. The thermal treatment reduced the resistivity by six orders of magnitude and the p-type conductivity was found to be dominated by an acceptor with an activation energy of similar to 170 meV. This acceptor is attributed to Mg atoms substituting for Ga in the GaN lattice and the activation process is consistent with dissociation of electrically inactive Mg-H complexes. The investigation of deep li:vel defects with capacitance transient spectroscopy is demonstrated for n-type Si doped Al0.12Ga0.88N. A prominent deep level with an activation energy for electron emission to the conduction band of similar to 0.62 eV was characterized by double-correlation deep level transient spectroscopy and found to be donor-like.