TAOS based Cu/TiW/IGZO/Ga2O3/Pt bilayer CBRAM for low-power display technology

We demonstrate the characteristics of a conductive-bridging random access memory (CBRAM) with Cu/TiW/InGaZnO/Ga2O3/Pt stack structure. The addition of a thin metal-oxide layer (4.5 nm-thick Ga2O3) in the bottom of the CBRAM device significantly increases the off-state resistance (ROFF) and the memory window. The IGZO bi-layer CBRAM shows the excellent memory performances, such as low operation current (down to 50 μA), high on/off resistance ratio (>103), high switching endurance (up to 103 cycles) and the capability of multi-level tuning. Meanwhile, high thermal stability was also achieved. Three decades of resistance window is constantly maintained beyond 104 s at 85 °C. The resistive switching stability and electrical uniformity of bi-layer IGZO/Ga2O3 CBRAM device are obviously enhanced as compared with the one only with a single layer of IGZO film. These results have given a great potential for the transparent amorphous oxide semiconductor (TAOS)-based material utilizing in CBRAM stacks and integrating into the display circuits for future memory-in-pixel applications.