Electron traps created in n-type GaN during 25 keV hydrogen implantation

We have implanted Ni/n-GaN Schottky contacts with 25 keV hydrogen ions (protons). The defects, thus, introduced were studied using deep level transient spectroscopy. We have found that 25 keV proton implantation introduces a complex set of electron traps in GaN, of which most are different to the defects observed after high-energy (MeV) electron and proton implantation. Two prominent defects that could clearly be distinguished from each other have energy levels at 0.22 and 0.30 eV below the conduction band. At least three of the defects detected after 25 keV proton implantation exhibit a metastable character in which they can be reproducibly removed and re-introduced during reverse and zero bias anneal cycles.