Methods of Set Switching for Improving the Uniformity of Filament Formation in the TiO2 Thin Film

The parameters determining the set state current and reset voltage, determined by the strength of formed filaments, were examined using current pulse and voltage driven current―voltage (I-V) sweeps. In the pulse switching measurement, the total current flow, including overshooting noise effect at the moment of set switching, was found to determine the strength of the filament. Displacing the capacitive charge dissipation peak from the overshoot region by a longer pulse rising time was effective in reducing the random variations in the switching parameters. A smaller voltage step in the I-V sweep was effective in reducing the random variation in filament formation.