Improved self-rectifying characteristics observed in ZnO/IGZO bilayer RRAM cells using eco-friendly indirect post-treatment

Research on transparent RRAM (T-RRAM) is imperative for achieving high integration levels, necessitating the resolution of interference issues arising from sneak-path currents in the array. Here, we propose a fully transparent ITO/ZnO/IGZO/ITO device structure featuring a ZnO resistive switching (RS) layer and an IGZO rectifying layer, as well as an eco-friendly indirect treatment method, i.e., microwave treatment (MWT), demonstrating self-rectifying RS characteristics capable of overcoming interference problems without supplementary elements. In detail, the proposed T-RRAM exhibits superior transmittance (>80 %) in the visible region, uniform RS of >10² cycles, and stable retention for >10⁴ s. The device particularly showed a read margin of 1,700, indicating the reliable operation of RS up to 41 × 41 without any degradation in the array structure. These findings suggest the potential for developing superior rectification properties for eco-friendly advanced industries by incorporating ZnO/IGZO bilayers and the post-MWT method.