Investigation of deposition technique and thickness effect of HfO₂ film in bilayer InWZnO-based conductive bridge random access memory

In recent research on memristor of brain-mimicking integrated circuit (IC) architecture, the electrical performance of electrochemical metallization memory can be significantly improved by applying a bilayer switching structure. In this work, a novel amorphous semiconductor InWZnO (IWZO) is used as the main switching layer, and a bilayer structure with HfO₂ is fabricated by different deposition technique. By surface and chemical composition analysis, the effect of deposition process and thickness of HfO₂ have been fully explored. The bilayer memory inserted with 3 nm HfO₂ formed by atomic layer deposition process exhibits excellent electrical properties, such as high endurance cycle (more than 2 × 10³), better retention time (up to 2 × 10⁴ s, 85 °C), relatively uniform resistance state distribution and low compliance current operation. Consequently, the low power electrochemical metallization memory with optimized HfO₂ layer has great potential for next generation memory in pixel and three-dimensional brain-mimicking IC technology.