Compliance current induced non-reversible transition from unipolar to bipolar resistive switching in a Cu/TaO_x/Pt structure

摘要

Unipolar resistive switching (URS) as well as bipolar resistive switching (BRS) behaviors in a Cu/ TaO_x/Pt structure were investigated. Upon increasing the compliance current (I_c), the current-voltage characteristics of the CVTaO_x/Pt structure showed a URS behavior at I_c = 0.1 mA then experienced a non-reversible transition from the URS to a BRS mode at I_c= 10 mA. Through a detailed analysis of the electrical properties in each resistance state of URS and BRS, we revealed that the permanent transition from the URS to the BRS mode was induced by the formation of stronger Cu metal conductive filaments within the TaO_x thin film. More interestingly, both URS and BRS modes were governed by the formation and rupture of conductive filaments, whereas the rupture of these filamentary paths in BRS was proposed due to both Joule heating and electric field effects.