The electrical properties of untreated and hydrogen-irradiated GaAs 1− x N x are investigated by conductive-probe atomic force microscopy (CP-AFM). After hydrogen irradiation, the resistance R of GaAs 1− x N x increases by more than three orders of magnitude while that of a N-free GaAs reference slightly decreases. Thermal annealing at 550 C of H-irradiated GaAs 1− x N x restores the pristine electrical properties of the as-grown sample thus demonstrating that this phenomenon is fully reversible. These effects are attributed to the nitrogen-hydrogen complexes that passivate N in GaAs 1− x N x (thus restoring the energy gap of N-free GaAs) and, moreover, reduce the carrier scattering time by more than one order of magnitude. This opens up a route to the fabrication of planar conductive/resistive/conductive heterostructures with submicrometer spatial resolution, which is also reported here.
American Physical Society
31 Aug 2011
Volume: 84 Issue: 8 Pages: 085331
Physical Review B