[17a-D61-1~10] 10.3 スピンデバイス・磁気メモリ・ストレージ技術

10:15 〜 10:30英語発表

[17a-D61-6] Low magnetic damping recording layer for reducing write-errors in voltage-driven magnetization switching

〇Tatsuya Yamamoto¹, Tomohiro Ichinose¹, Takayuki Nozaki¹, Shingo Tamaru¹, Kay Yakushiji¹, Hitoshi Kubota¹, Shinji Yuasa¹ (1.AIST)

キーワード：

magnetic tunnel junction、Electric field effect、perpendicular magnetic anisotropy

Electrical control of magnetization in magnetic tunnel junctions (MTJs) is the key technology for developing magnetoresistive random access memory (MRAM). Among a variety of techniques, the use of voltage-controlled magnetic anisotropy (VCMA) effect allows for switching the magnetization with a minimal energy and is thus regarded as a promising alternative to the spin-transfer-torque (STT) technology used in the state-of-the-art MRAMs. Regardless of the remarkable advantage in the energy efficiency, a substantial reduction in the write-error rate (WER) of the VCMA-driven magnetization switching is strongly demanded for the practical application. In this work, we develop perpendicularly magnetized MTJs consisting of an Mg₄₀Fe₁₀O₅₀/Co-Fe-B/MgO multilayer as a recording layer. The nonmagnetic insulators on both sides of the Co-Fe-B layer effectively eliminates the spin pumping effect to reduce the effective magnetic damping. We show that the lower magnetic damping reduces the thermal fluctuation during pulse duration, and a fairly low WER of the order of 10^-3 is achieved for write pulses longer than 1 ns.