https://scholars.lib.ntu.edu.tw/handle/123456789/632147
標題: | Insertion Trade-off Effects on the Spin-Transfer Torque Memory Explored byIn SituX-ray | 作者: | Ramesh A.K Chen K.-M Lin Y.-J Singh P Wei J.-H Hsin Y.-C CHIH-I WU Tseng Y.-C. |
關鍵字: | atomistic simulation; interface; MRAM; spin-transfer torque; spintronics; X-ray absorption spectroscopy | 公開日期: | 2021 | 卷: | 3 | 期: | 9 | 起(迄)頁: | 4047-4055 | 來源出版物: | ACS Applied Electronic Materials | 摘要: | Magnetoresistive random-access memory (MRAM) relies on magnetic tunnel junctions (MTJs) comprising heterostructures of CoFeB/MgO/CoFeB. Nonetheless, the dielectric breakdown of MgO limits the lifespan of MRAM devices. In the current study, we terminated MgO with a Mg surface facing the CoFeB free layer to reduce the mismatch in band alignment across the barrier. The Mg-modified interface was shown to enhance the breakdown voltage while reducing the switching current and asymmetric switching behavior, with a moderate sacrifice of perpendicular magnetic anisotropy, tunneling magnetoresistance, and resistance-area product. This performance trade-off was observed in all MTJs, regardless of cell size (180, 130, and 80 nm; each size has been tested with at least 20 cells). Visualization of the proposed junctionviain situX-ray absorption spectroscopy proved effective in elucidating the reconstruction of the interface within the context of energy barrier height, asymmetric switching behavior, and the voltage-driven movement of oxygen ions. A spin-dependent band diagram was constructed to correlate the tunneling/switching properties of the MTJ with such a trade-off scenario. The atomistic simulation of the magnetic properties revealed that Mg termination lowered the switching energy barrier with an effective domain wall motion within the CoFeB free layer. © 2021 American Chemical Society |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114390491&doi=10.1021%2facsaelm.1c00554&partnerID=40&md5=812007b8a75d81b706064e00a2782d0a https://scholars.lib.ntu.edu.tw/handle/123456789/632147 |
ISSN: | 26376113 | DOI: | 10.1021/acsaelm.1c00554 | SDG/關鍵字: | Cobalt compounds; Domain walls; Economic and social effects; Energy barriers; Iron compounds; Magnesia; Magnesium; Magnetic anisotropy; Magnetic recording; Magnetic storage; Oxide minerals; Random access storage; Switching; Tunnel junctions; Tunnelling magnetoresistance; X ray absorption spectroscopy; Atomistic simulations; Energy barrier height; In-situ X-ray absorption spectroscopy; Magnetic tunnel junction; Performance trade-off; Perpendicular magnetic anisotropy; Resistance-area products; Tunneling magnetoresistance; MRAM devices |
顯示於: | 電機工程學系 |
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