Influence of Cu Diffusion Conditions on the Switching of Cu-SiO₂-Based Resistive Memory Devices

This paper presents a study of Cu diffusion at various temperatures in thin SiO ₂ films. Film composition and diffusion products were analyzed using Secondary Ion Mass Spectroscopy, Rutherford Backscattering Spectrometry, X-ray Diffraction and Raman Spectroscopy methods. We found a strong dependence of the diffused Cu concentration, which varied between 0.8 at.% and 10 ^-3 at.%, on the annealing temperature. X-ray diffraction and Raman studies revealed that Cu does not react with the SiO2 network and remains in elemental form after diffusion. Programmable Metallization Cell (PMC) resistive memory cells were fabricated with these Cu-diffused SiO ₂ films as the active elements and device performance is presented and discussed in the context of the materials characteristics.