Characterization of inductively-coupled-plasma damage on n-type GaN using deep-level transient spectroscopy and synchrotron radiation photoemission spectroscopy

Inductively-coupled-plasma (ICP) damage on n-type GaN was characterized using deep-level transient spectroscopy and synchrotron radiation photoemission spectroscopy. A new electron trap, localized near the contact, as well as a pre-existing trap was observed in the ICP-etched sample. The ICP-etched surface was found to be N-deficient, which means that N vacancies (V-N) were produced by ICP etching. The Fermi energy level shifted to the conduction band minimum due to the generation Of V-N. From these, the origin of T2 was suggested to be V-N or V-N-related complex of point defects. The ICP-induced traps provided a path for the transport of electrons, leading to the reduction of Schottky barrier height and increase of gate leakage current.