Electroforming and Resistance Switching Characteristics of Silver-Doped MSQ With Inert Electrodes

This paper reports on the resistance switching effect in silver-doped methylsilsesquioxane (MSQ) thin films with Pt top and bottom electrodes. Silver is thermally diffused into MSQ films for different times and the results prove that silver ions (or other oxidizable metal ions) are required in the system, but not necessarily as one of the two electrodes. SEM investigations at horizontal cells (gap width 15-100 nm) show the formation of metallic agglomerations in the gap. The forming process is found to be electric-field driven and the filament resistance is determined to be 30 Ω/nm. Under the assumption of conical-shaped filament growth, the diameter of a filament is calculated to 13.5 nm, which is in agreement with the SEM observations. Memory device related tests on 100 × 100 nm² cross junctions show unipolar switching up to 2000 times and retention at 85°C for at least 6 × 10⁴ s.