Nanoscale thermal effect induced <i>in situ</i> Cu-based memristor

Abstract

Memristive devices are promising candidates for next-generation nonvolatile memory and neuromorphic computing. However, their large-scale integration is hindered by the complexity and cost of conventional fabrication methods. Here, we propose a simplified, single-step method for fabricating lateral Cu/CuxO/Cu memristors based on nano-laser direct writing. By exploiting the thermal gradient of focused laser beam, central oxidation of Cu film is induced, enabling the formation of sub-300 nm CuxO switching layers under ambient conditions. To elucidate the laser–Cu films interaction process, systematic mapping of laser parameters, combined with thermal simulations, revealed that laser power, pulse width, and writing width collectively determine the oxidation extent and device performance. Furthermore, optimized devices illustrate robust bipolar resistive switching with high/low resistance state ratios (∼102), stable endurance over 100 cycles, and reliable conductance retention, which is vital for the modulation of RESET behavior and filament stability. Beyond binary switching, the devices exhibit analog conductance modulation under voltage pulses, demonstrating synaptic plasticity suitable for neuromorphic applications. To some extent, this work highlights nano-laser writing as a scalable, cost-effective strategy for fabricating high-density memristors and offers a promising route toward in situ integration of memristive elements for future brain-inspired electronics.