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 SiO2 films and the influence of diffusion conditions on the switching of Programmable Metallization Cell (PMC) devices formed from such Cu-doped 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 for the annealing conditions used. PMC resistive memory cells were fabricated with such Cu-diffused SiO2 films and device performance, including the stability of the switching voltage, is discussed in the context of the material characteristics.