Electric-field-induced magnetization switching in CoFeB/MgO magnetic tunnel junctions with high junction resistance

Abstract

We show the electric-field induced magnetization switching for CoFeB/MgO magnetic tunnel junctions with thick MgO barrier layer of 2.8 nm, whose resistance-area product is 176 kΩ μm2, and achieve the small switching energy of 6.3 fJ/bit. The increase of the junction resistance is expected to suppress the energy consumption due to the Joule heating during the switching; however, the energy is still dominated by the Joule energy rather than the charging energy. This is because the junction resistance decreases more rapidly for junctions with thicker MgO as bias voltage increases.

Current-induced magnetization switching in a nano-scale CoFeB-MgO magnetic tunnel junction under in-plane magnetic field

“…For magnetic tunnel junctions (MTJs), two switching schemes have been studied; one is the spin-transfer-torque-induced switching (STT-switching), 1,2 and the other is the electric-field-induced switching. [3][4][5][6] For the electric-field-induced switching, the magnetization reversal takes place through magnetization precession induced by magnetic anisotropy modulation. [3][4][5][6] In this work, we investigate the current-induced STT switching of a CoFeB-MgO MTJ with perpendicular easy axis with diameter of 19 nm, and report that in addition to STT, the electric-field effect appears to play a role in determining switching characteristics, which manifests itself under the presence of in-plane magnetic field.…”

Voltage control of magnetic anisotropy in epitaxial Ru/Co2FeAl/MgO heterostructures

“…By using voltage-controlled magnetization switching, the power consumption for manipulating a bit cell is proposed to be ~1 fJ, which is two orders of magnitude lower than ~0.1 pJ in the spin transfer torque (STT) technology5. Since magnetic tunnel junctions (MTJs) are key building blocks for high-performance spintronic devices6, the voltage control of magnetization switching in MTJs has greatly promoted the development of the VCMA technology to practical applications789101112131415161718. Recently, a ultralow power consumption of ~6 fJ is achieved in state-of-the-art CoFeB/MgO MTJs with voltage-controlled magnetization switching1415.…”

“…Since magnetic tunnel junctions (MTJs) are key building blocks for high-performance spintronic devices6, the voltage control of magnetization switching in MTJs has greatly promoted the development of the VCMA technology to practical applications789101112131415161718. Recently, a ultralow power consumption of ~6 fJ is achieved in state-of-the-art CoFeB/MgO MTJs with voltage-controlled magnetization switching1415. Regarding the origin of the VCMA effect, several physical mechanisms have been proposed, such as the modulation of spin-orbit interactions by charge accumulation and depletion19, Rashba effect2021, voltage-induced redox reaction22, and electro-migration23.…”

Magnetization switching schemes for nanoscale three-terminal spintronics devices

“…Electric-field-induced magnetization switching 32,33) is another option for the write operation of two-terminal devices. Since the energy consumption via Joule heating can be greatly reduced, 34) intensive research has also been actively performed in recent years on this front. Meanwhile, for three-terminal devices, which are the main focus of this article, current-induced magnetic domain wall (DW) motion [35][36][37][38][39][40] or spin-orbit torque (SOT)-induced magnetization switching [41][42][43] can be used for their write operation (classical Oersted field-induced magnetization switching 44,45) and STT-induced switching 46,47) can also be used, although we will not discuss them here).…”