Kirn, Youngjin Choi, Hanhyeong Park, Hyun S. Kang, Moon Sung Shin, Keun-Young Lee, Sang-Soo Park, Jong Hyuk 2024-01-20T00:03:35Z 2024-01-20T00:03:35Z 2021-09-03 2017-11-08 1944-8244 https://pubs.kist.re.kr/handle/201004/122077 Multilevel data storage using resistive random access memory (RRAM) has attracted significant attention for addressing the challenges associated with the rapid advances in information technologies. However, it is still difficult to secure reliable multilevel resistive switching of RRAM due to the stochastic and multiple formation of conductive filaments (CFs). Herein, we demonstrate that a single CF, derived from selective oxidation by a structured Cu active electrode, can solve the reliability issue. High-quality pyramidal Cu electrodes with a sharp tip are prepared via the template-stripping method. Morphology-dependent surface energy facilitates the oxidation of Cu atoms at the tip rather than in other regions, and the tip-enhanced electric fields can accelerate the transport of the generated Cu ions. As a result, CF growth occurs mainly at the tip of the pyramidal electrode, which is confirmed by high-resolution electron microscopy and elemental analysis. The RRAM exhibits highly uniform and low forming voltages (the average forming voltage and its standard deviation for 20 pyramid-based RRAMs are 0.645 and 0.072 V, respectively). Moreover, all multilevel resistance states for the RRAMs are clearly distinguished and show narrow distributions within 1 order of magnitude, leading to reliable cell-to-cell performance for MLC operation. English American Chemical Society SWITCHING MEMORY FILAMENT FORMATION BLOCK-COPOLYMER DEVICES TRANSITION GROWTH CELLS Reliable Multistate Data Storage with Low Power Consumption by Selective Oxidation of Pyramid-Structured Resistive Memory Article 10.1021/acsami.7b10188 1 ACS Applied Materials & Interfaces, v.9, no.44, pp.38643 - 38650 ACS Applied Materials & Interfaces 9 44 38643 38650 scie scopus 000415140800052 2-s2.0-85033215821 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article SWITCHING MEMORY FILAMENT FORMATION BLOCK-COPOLYMER DEVICES TRANSITION GROWTH CELLS multilevel resistive memory pyramidal electrode tip-enhanced electric field surface energy conductive filament resistive switching