Electrochemical anodic oxidation assisted fabrication of memristors

Owing to the advantages of simple structure, low power consumption and high-density integration, memristors or memristive devices are attracting increasing attention in the fields of next generation nonvolatile memories, neuromorphic computation and data encryption, etc. However, the deposition of memristive films often requires expensive equipment and strict vacuum conditions, the process consumes high energy, and it is also very time–consuming. In contrast, electrochemical anodizing can produce metal oxide films quickly (e.g. in 10 s) under ambient conditions. By means of the anodizing technique, oxide films, oxide nanotubes, nanowires and nanodots can be fabricated to prepare memristors. Through adjusting oxidation parameters such as voltage, current and time, oxide film thickness, nanostructures, defect concentrations, etc., can be varied to regulate device performances. Thus memristors fabricated by the anodic oxidation technique can achieve high device consistency, low variation, and ultra–high yield rate. This article provides a comprehensive review of the research progress in the field of anodic oxidation assisted fabrication of memristors. Firstly, the principle of anodic oxidation is introduced; then different types of memristors produced by the anodic oxidation are presented; finally, features and challenges of the anodic oxidation for memristor production are elaborated.