Write-Once-Read-Many-Times and Bipolar Resistive Switching Characteristics of TiN/HfO2/Pt Devices Dependent on the Electroforming Polarity

In this letter, we report the dependence of memory characteristics on electroforming polarity based on TiN/HfO₂/Pt devices. Bipolar resistive switching (BRS) and write-once-read-many-times memory (WORM) behaviors were obtained after the negative and positive electroforming process, respectively. Analysis of conduction mechanisms of high resistance state confirms that BRS and WORM were dominated by Schottky emission and trap-controlled space charge limited current, respectively. These phenomena can be explained by the filamentary model with the assistance of interfacial role. Moreover, this letter also indicates that the TiN/HfO₂/Pt devices have promising application in both RRAM and non-editable WORM.