Effects of Al Addition on Resistive-Switching Characteristics of Solution Processed Zn-Sn-O ReRAMs

Resistive random access memory (ReRAM) using amorphous Al-doped zinc tin oxide (a-AZTO) as resistive switching layer was fabricated by solution based deposition method. The a-AZTO films with different compositions (Al:Zn:Sn = 0: 1: 1, 0.1:1:1 and 0.2:1:1) were prepared by solution based deposition method using low process temperature. The developed a-AZTO resistive switching nonvolatile memory devices with a Ti/Al-Zn-Sn-O (AZTO)/Pt structure exhibited typical bipolar switching behavior, remaining in a stable resistance state with exhibiting switching responses over 100 cycles, and a retention time of 10(4) s. The resistive switching characteristics of a-AZTO ReRAMs were improved by increasing Al concentration. We demonstrate the electrical characteristics of a-AZTO TFTs are comparable to IGZO TFTs. The replacement of IGZO film with AZTO film can effectively reduce the consumption of indium (In), a toxic and rare metal, prominently reducing the production cost of transparent amorphous oxide semiconductor (TAOS) based electrical devices and improving environmental safety. Therefore, it is expected that the a-AZTO ReRAMs integrated with a-AZTO TFTs in the backplane of emerging transparent flat panel displays (FPDs) is potentially beneficial for the realization of system-on-panel (SoP) applications.