Properties of Fe-doped semi-insulating GaN structures

The properties of semi-insulating GaN films with the lower part of the film doped with Fe are reported. The 300 K sheet resistivity of the films was 2 X 10(10) Omega/square with an activation energy of the dark conductivity of 0.5 eV The Fermi level is also pinned at E-C-0.5 eV. The concentration of the 0.5 eV traps in the Fe-doped portion of the films was 3 X 10(16) cm(-3). Also present is a high concentration of deeper electron traps with the level near 0.9 eV below the bottom of the conduction band and of hole traps with the level near 0.9 eV above the top of the valence band. Intracenter transitions of the Fe3+ center are observed in the photoluminescence spectra from the material. (C) 2004 American Vacuum Society.