Charge-trapping characteristics of fluorinated thin ZrO2 film for nonvolatile memory applications

The effects of fluorine treatment on the charge-trapping characteristics of thin ZrO2 film are investigated by physical and electrical characterization techniques. The formation of silicate interlayer at the ZrO2/SiO2 interface is effectively suppressed by fluorine passivation. However, excessive fluorine diffusion into the Si substrate deteriorates the quality of the SiO2/Si interface. Compared with the ZrO2-based memory devices with no or excessive fluorine treatment, the one with suitable fluorine-treatment time shows higher operating speed and better retention due to less resistance of built-in electric field (formed by trapped electrons) against electron injection from the substrate and smaller trap-assisted tunneling leakage, resulting from improved ZrO2/SiO2 and SiO2/Si interfaces. (C) 2014 AIP Publishing LLC.