The rate limiting process and its activation energy in the forming process of a Cu/Ta₂O₅/Pt gapless-type atomic switch

The rate limiting process in first resistive switching, called the "forming process", is determined by measuring the switching time of an as-fabricated Cu/Ta₂O₅/Pt atomic switch as a function of the ambient temperature and the Ta₂O₅ thickness. The temperature dependence is well fitted by the Arrhenius equation, suggesting that a certain activation process dominates the switching phenomenon. The switching time increases linearly as the Ta₂O₅ thickness increases. The results herein clearly suggest that the rate limiting process is the drift of Cu cations in the Ta₂O₅ layer. We determine that the activation energy is 0.4 eV.