Oxidation of van-der-Waals Semiconductors for Neuromorphic Technology

Here, we report novel resistive memories based on oxides obtained by the chemical conversion of a two-dimensional van-der-Waals semiconductor: hafnium disulfide (HfS
2
). We apply a dry oxidation method, carefully controlling process parameters such as pressure, temperature, and oxygen flow. Hafnium oxides are integrated into crossbar structures, and resistive switching is studied by applying voltage ramps. We demonstrate unipolar switching achieving a R$_{\mathrm {ON}}$/R$_{\mathrm {OFF}}$ ratio of $\sim 10^{4}$ over 115 cycles, showing the potential of this approach for next-generation memristive technology.