Reset First Resistive Switching in Ni1−xO Thin Films as Charge Transfer Insulator Deposited by Reactive RF Magnetron Sputtering

• Published in: Nanomaterials (Basel, Switzerland) Vol. 12; no. 13; p. 2231
• Main Authors: Kim, Dae-woo, Kim, Tae-ho, Kim, Jae-yeon, Sohn, Hyun-chul
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 29.06.2022; MDPI
• Subjects: Atomic force microscopy; Bias; Charge transfer; conductivity; Electroforming; Magnetron sputtering; Memory devices; Metal oxides; Nickel; nickel oxide; nickel vacancy; Oxygen; oxygen partial pressure; Partial pressure; Photoelectric emission; Pressure; Random access memory; reset-first resistive switching; resistive random access memory; Spectroscopy; Spectrum analysis; Switching; Thin films; Valence
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano12132231

Reset-first resistive random access memory (RRAM) devices were demonstrated for off-stoichiometric Ni1−xO thin films deposited using reactive sputtering with a high oxygen partial pressure. The Ni1−xO based RRAM devices exhibited both unipolar and bipolar resistive switching characteristics without an electroforming step. Auger electron spectroscopy showed nickel deficiency in the Ni1−xO films, and X-ray photoemission spectroscopy showed that the Ni3+ valence state in the Ni1−xO films increased with increasing oxygen partial pressure. Conductive atomic force microscopy showed that the conductivity of the Ni1−xO films increased with increasing oxygen partial pressure during deposition, possibly contributing to the reset-first switching of the Ni1−xO films.