Effects of ambient gas pressure on the resistance switching properties of the NiO thin films grown by radio frequency magnetron sputtering

NiO films were grown on a Pt substrate by radio frequency (RF) magnetron sputtering using a NiO ceramic target. A crystalline NiO phase with the [111] preferred orientation was formed for the films grown above 100 °C. Resistance switching behavior was not observed in the NiO films annealed in the air or in ambient O₂ after film deposition. However, the NiO films annealed in ambient N₂ exhibited resistance switching properties. The stability of the switching voltage was considerably influenced by the oxygen to argon ratio during film growth. In particular, the NiO film grown under an 8.0 mTorr oxygen partial pressure exhibited stabilized switching voltages (V _set ∼ 1:45 ± 0:20 V and V_reset ∼ 0:62 ± 0:09 V). Therefore, the control of the ambient gas pressure during the growth and annealing of the NiO films was important for obtaining good resistance switching properties.