A Novel RRAM Stack With ${\rm TaO}_{x}/{\rm HfO}_{y}$ Double-Switching-Layer Configuration Showing Low Operation Current Through Complimentary Switching of Back-to-Back Connected Subcells

In this letter, a novel and fully CMOS compatible RRAM stack-(TiN-TaO
_x
-Hf-HfO
_y
-TiN) has been demonstrated. By serially connecting two back-to-back subcells, Hf-HfO
_y
-TiN and Hf-TaO
_x
-TiN, the cell exhibits outstanding performances, including low Imax (35 μA), stable I
_ON
(>10 μA), and I
_OFF
(<;1 μA), and over 2 × 10
⁴
dc cycles. By examining the switching characteristics, we have confirmed the well controlled conduction/filament size during the complementary set/reset processes contributes to the stable and low current operation.