Research Article Cite This: ACS Appl. Mater. Interfaces XXXX, XXX, XXX−XXX
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Highly Uniform Resistive Switching Performances Using TwoDimensional Electron Gas at a Thin-Film Heterostructure for Conductive Bridge Random Access Memory Sung Min Kim,†,§ Hye Ju Kim,†,§ Hae Jun Jung,† Seong Hwan Kim,† Ji-Yong Park,† Tae Jun Seok,‡ Tae Joo Park,*,‡ and Sang Woon Lee*,†
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Department of Energy Systems Research and Department of Physics, Ajou University, Suwon, Gyeonggi-do 16499, Republic of Korea ‡ Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588, Republic of Korea S Supporting Information *
ABSTRACT: This research demonstrates, for the first time, the development of highly uniform resistive switching devices with self-compliance current for conductive bridge random access memory using two-dimensional electron gas (2DEG) at the interface of an Al2O3/TiO2 thin-film heterostructure via atomic layer deposition (ALD). The cell is composed of Cu/Ti/Al2O3/ TiO2, where Cu/Ti and Al2O3 overlayers are used as the active/ buffer metals and solid electrolyte, respectively, and the 2DEG at the interface of Al2O3/TiO2 heterostructure, grown by the ALD process, is adopted as a bottom electrode. The Cu/Ti/Al2O3/ TiO2 device shows reliable resistive switching characteristics with excellent uniformity under a repetitive voltage sweep (direct current sweep). Furthermore, it exhibits a cycle endurance over 107 cycles under short pulse switching. Remarkably, a reliable operation of multilevel data writing is realized up to 107 cycles. The data retention time is longer than 106 s at 85 °C. The uniform resistance switching characteristics are achieved via the formation of small (∼a few nm width) Cu filament with a short tunnel gap (
