Annealing dynamics of nitrogen-implanted GaAs films investigated by current-voltage and deep-level transient spectroscopy

We present electrical data to show that, after nitrogen implantation, GaAs films become resistive after high-temperature annealing. The activation ene rgies of the resistance are determined to be 0.34, 0.59, and 0.71 eV after annealing at 500, 700, and 950 degrees C, respectively. The increase in the activation energy with increasing annealing temperature can be explained b y the results of traps detected in deep-level transient spectroscopy, where two traps at 0.32 and 0.70 eV are observed in the samples after annealing. The intensity of the trap at 0.32 eV is found to reduce by annealing. By c omparing to the result of the x-ray diffraction, we suspect that this trap is related to the lattice-expansion defects. The trap at 0.70 eV is observe d only in samples annealed at high temperatures. Since this trap contribute s to the high-resistive effect, we believe that it is associated with the n itrogen ions. (C) 2000 American Institute of Physics. [S0003-6951(00)04716- 1].