A method to extract the carrier capture kinetics of traps in the neutral region by isothermal deep-level transient spectroscopy using two sets of bias pulses was applied to the traps with similar energy levels around Ec-0.6eV in GaN grown by metalorganic chemical vapor deposition on GaN and sapphire substrates. The Ec-0.6eV trap in GaN on GaN was found to be the isolated point defects. The Ec-0.6eV trap in GaN on sapphire showed the logarithmic capture kinetics, expected for dislocation-related defects. This was ascribed to the difference in dislocation density between GaN on GaN and sapphire substrates.

Evaluation of Dislocation-Related Defects in GaN using Deep-Level Transient Spectroscopy. Y.Tokuda, Y.Matuoka, K.Yoshida, H.Ueda, O.Ishiguro, N.Soejima, T.Kachi: Physica Status Solidi C, 2007, 4[7], 2568-71