Observation of H-Ion Migration in a Low-Temperature-Processed Boehmite Layer for Nonvolatile Memory

Resistive switching random access memory (RRAM) offers fascinating prospects in the field of nonvolatile memories, brain-inspired devices, neural network computing, and artificial intelligence machines. However, the underlying mechanism in resistive switching is still confused, which limits its further applications. In this work, a boehmite layer is fabricated at low temperature and shows low reset current, long retention, high on/off ratio, and low operation voltages. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is utilized to perform element analysis on the device and observe hydrogen ion transport. Three-dimensional (3D) mapping of hydrogen ion distribution in the high/low-resistance states reveal the hydrogen ion migration process in resistive switching. This study not only confirms the phenomenon of hydrogen ion migration experimentally but also gives further insight into the switching mechanism of RRAM.