Giant tunneling electroresistance in epitaxial ferroelectric ultrathin films directly integrated on Si. (March 2022)

• Record Type: Journal Article
• Authors: Lee, Kyoungjun; Byun, Jinho; Park, Kunwoo; Kang, Sungsu; Song, Myeong Seop; Park, Jungwon; Lee, Jaekwang; Chae, Seung Chul
• Is Part Of: Applied materials today. Volume 26(2022)
• Publication Date: 2022-03
• Subjects: Ferroelectric tunnel junction -- HfO2 -- Epitaxy; Materials science -- Periodicals; Materials -- Research -- Periodicals; 620.1105
• DOI: 10.1016/j.apmt.2021.101308
• Languages: English
• ISSNs: 2352-9407

Abstract

Highlights: A colossal resistance change in the ferroelectric tunnel junction with an On/Off ratio of 10 6 was observed in a ferroelectric HfO2 thin film integrated directly on a silicon wafer. The polarization direction in the metal-ferroelectric-semiconductor junction altered the depletion width, leaving behind the change in the tunnel barrier. The robust microscopic ferroelectricity of YHO films was confirmed by PFM measurements. The theoretical calculations confirmed the colossal TER On/Off values of our designed MFIS structure with experimentally confirmed components. Abstract: Retaining information with the least loss of energy is of interest for ubiquitous mobile devices. Various forms of nonvolatile memory have been pursued based on the resistance change in the memory architecture. The nonvolatility of spontaneous polarization in a ferroelectric material also has been considered a promising ingredient for information storage applications, including traditional nonvolatile memory applications and emerging neuromorphic synaptic devices. Here, we demonstrate a colossal resistance change in the ferroelectric tunnel junction with an On/Off ratio of 10 6 in a ferroelectric HfO2 thin film integrated directly on a silicon wafer, which is inevitable for practical application. To achieve this large On/Off ratio, we integrated the epitaxial fluorite-structure HfO2 thin film on the silicon substrate. The polarization direction in the metal-ferroelectric-semiconductor junction altered the depletion width, leaving behind the change in the tunnel barrier. Industry-relevant HfO2 with high CMOS compatibility could lead to fast adoption of a ferroelectric tunnel barrier with newly observed ferroelectricity in fluorite-structured HfO2 films. Graphical abstract: Image, graphical abstract