Varistor-type bidirectional switch (JMAX>107A/cm2, selectivity∼104) for 3D bipolar resistive memory arrays

We demonstrate a varistor-type bidirectional switch (VBS) with excellent selection property for future 3D bipolar resistive memory array. A highly non-linear VBS showed superior performances including high current density (>3×10
⁷
A/cm
²
) and high selectivity (∼10
⁴
). The non-linear I–V characteristics can be explained by varistor-type multi-layer tunnel barriers, which were formed by Ta incorporation into thin TiO
2
. Furthermore, the 1S1R device showed excellent suppression of leakage current (>10
⁴
reduction) at 1/2V
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, which is promising for ultra-high density resistive memory applications.