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 (VN) were produced by ICP etching. The Fermi energy level shifted to the conduction band minimum due to the generation of VN. From these, the origin of T2 was suggested to be VN or VN-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.