Evaluation of dislocation‐related defects in GaN using deep‐level transient spectroscopy

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–0.6 eV in GaN grown by metalorganic chemical vapor deposition on GaN and sapphire substrates. The Ec–0.6 eV trap in GaN on GaN is found to be the isolated point defects. The Ec–0.6 eV trap in GaN on sapphire shows the logarithmic capture kinetics, expected for dislocation‐related defects. This is ascribed to the difference in dislocation density between GaN on GaN and sapphire substrates. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)