Gallium nitride layers grown by metalorganic vapor phase epitaxy on sapphire substrates were implanted with 20keV H ions with fluences between 2 x 1014 and 2 x 1015/cm2. The resulting deep-level spectrum was analyzed by deep-level transient as well as by admittance spectroscopy. Beside several electron traps of probably intrinsic nature already known from other implantation experiments, a group of defects exclusively appeared after H implantation showing a strong electrical field effect in the corresponding emission characteristics. These peculiar states were characterized in detail and compared with defects showing a similar field effect already observed by other groups, suggesting their interpretation as H-decorated dislocations.

Electrical Field Effect of H-Implantation Induced Defect States in GaN. A.Krtschil, A.Kielburg, H.Witte, A.Krost, J.Christen, A.Wenzel, B.Rauschenbach: Applied Physics Letters, 2003, 82[3], 403-5