Comparison of implant isolation species for GaN field-effect transistor structures

摘要

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 E_c-0l.20 to 0.49 eV in n-GaN and at E_v-0.44 eV in p-GaN after annealing at 450-650 deg C. Thesheet resistance of the GaN was at a maximum after annelaing at these temperatures, reaching values of approx 4-x10~(10) OMEGA / square in p-GaN. The mechanism for the implant isolation was damage-related trap formation for all of the ions investigated, and therre was no evidence of chemically induced isolation.