Switching characteristics in Cu:SiO2 by chemical soak methods for resistive random access memory (ReRAM)

• Limited Cu source of TaN/Cu:SiO2/TaN ReRAM device are fabricated.
• Impact of Cu concentration on switching properties has been investigated.
• Resistive switching behavior is related to Cu conductive filaments.
• Cu concentration is a crucial factor in the trade-off between the endurance, retention, and operation voltage properties.
• The Cu concentration can be easily modulated by chemical soaking method.

A limited copper (Cu)-source Cu:SiO2 switching layer composed of various Cu concentrations was fabricated using a chemical soaking (CS) technique. The switching layer was then studied for developing applications in resistive random access memory (ReRAM) devices. Observing the resistive switching mechanism exhibited by all the samples suggested that Cu conductive filaments formed and ruptured during the set/reset process. The experimental results indicated that the endurance property failure that occurred was related to the joule heating effect. Moreover, the endurance switching cycle increased as the Cu concentration decreased. In high-temperature tests, the samples demonstrated that the operating (set/reset) voltages decreased as the temperature increased, and an Arrhenius plot was used to calculate the activation energy of the set/reset process. In addition, the samples demonstrated stable data retention properties when baked at 85 °C, but the samples with low Cu concentrations exhibited short retention times in the low-resistance state (LRS) during 125 °C tests. Therefore, Cu concentration is a crucial factor in the trade-off between the endurance and retention properties; furthermore, the Cu concentration can be easily modulated using this CS technique.