Published online by Cambridge University Press: 03 September 2012
Different ions (Ti+, O+, Fe+, Cr+) were implanted at multiple energies into GaN field effect transistor structures (n and p-type). The implantation was found to create deep states with energy levels in the range EC –0.20 to 0.49 eV in n-GaN and at EV +0.44 eV in p-GaN after annealing at 450-650 oC. The sheet resistance of the GaN was at a maximum after annealing at these temperatures, reaching values of ∼4×1012 Ω/⊏ in n-GaN and ∼1010 Ω/⊏ in p-GaN. The mechanism for the implant isolation was damage-related trap formation for all of the ions investigated, and there was no evidence of chemically induced isolation.