title: Polarity reversion of the operation mode of HfO2-based resistive random access memory devices by inserting Hf metal layer.
abstract: The reversion of polarity within bipolar resistive switching operation occurs in Pt/HfO2/TiN and Pt/Hf/HfO2/TiN resistive random access memory devices. This reversion of voltage polarity is the result of interface generation which induces a conduction mechanism transformation from Poole-Frenkel emission to space charge limited current mechanism. To prove the reversion of polarity, this study uses curve fitting of I-V relations to verify the conduction mechanism theoretically and physical analysis to verify the oxygen ion distribution practically. The proposed Pt/Hf/HfO2/TiN devices exhibit good resistive switching characteristics, such as good uniformity, low voltage operation, robust endurance (10(3) dc sweep), and long retention (3 x 10(4) s at 85 degrees C).
authors.affiliation: Department of Materials Science and Engineering, National Tsing-Hua University, Hsinchu 300, Taiwan, ROC.
authors.forename: Ching-Shiang
authors.initials: CS
authors.lastname: Peng
authors.forename: Wen-Yuan
authors.initials: WY
authors.lastname: Chang
authors.forename: Ming-Ho
authors.initials: MH
authors.lastname: Lin
authors.forename: Wei-Su
authors.initials: WS
authors.lastname: Chen
authors.forename: Frederick
authors.initials: F
authors.lastname: Chen
authors.forename: Ming-Jinn
authors.initials: MJ
authors.lastname: Tsai