Reduction in RESET current is crucial for future high-density resistive-switching memory. We have reported a unipolar-switching Ni/HfO(2)/Si structure with low RESET current of 50 mu A and RESET power of 30 mu W. In addition, a unique cycling evolution of RESET current across more than two orders of magnitude allows us to probe into the evolvement of filament morphology at nanoscale, using a simple yet quantitative model. Filament morphology was found to depend strongly on the charge-dissipation current proportional to the powers of SET voltage. Moreover, the formation of inactive semiconductive filaments plays an important role in the reduction in RESET current. (C) 2011 American Institute of Physics. [doi:10.1063/1.3565239]
