Magnetic random access memory and preparation method thereof

Abstract

The invention relates to a magnetic random access memory, which comprises a top pinning structure formed by sequentially and upwards superposing a spin orbit moment bottom electrode, a magnetic tunneljunction multilayer film and a top electrode, so as to form a vertical magnetic random access memory; the memory also comprises a first port for providing an SOT write-in signal, a second port for accessing an SL / BL signal and a third port for providing an STT write-in signal and an MRAM read signal, the first port and the second port are respectively connected to two ends of the bottom of the spin orbit moment bottom electrode, and the third port is connected to the top end of the top electrode. According to the magnetic random access memory and the preparation method thereof, a spin Hall effect and / or an interface Lash effect are / is enhanced through selection of material components, the manufacturing process and material structure optimization, and meanwhile, the spin Hall angle and theconductivity of SOTBE are optimized to obtain the optimal writing operation speed and power consumption.

Description

technical field [0001] The invention relates to the technical field of Magnetic Random Access Memory (MRAM) with perpendicular anisotropy (Perpendicular Magnetic Anisotropy, PMA), in particular to a magnetic random access memory (MRAM) and a preparation method thereof. Background technique [0002] In recent years, MRAM using Magnetic Tunnel Junction (MTJ) is considered to be the future solid-state non-volatile memory, which has the characteristics of high-speed reading and writing, large capacity and low energy consumption. Ferromagnetic MTJ is usually a sandwich Structure, in which there is a magnetic free layer (Free Layer, FL), which can change the magnetization direction to record different data; the insulating tunnel barrier layer (Barrier Layer, BL) in the middle; the magnetic reference layer (Reference Layer, RL) is located On the other side of the tunnel barrier layer, its magnetization direction remains unchanged. Specifically, it can be the bottom pinning (Bottom ...

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Problems solved by technology

[0014] As mentioned above, STT-based spin transfer torque is the mainstream writing method of MRAM at present, however, it also has insurmountable speed and barrier reliability The property bottleneck, the size of the spin transfer torque is positively correlated with the magnetization vector product of the free layer (FL) and the reference layer (RL). Before writing, the magnetization directions of the two ferromagnetic layers are almost collinear (parallel or antiparallel), The small angle between the two is mainly caused by thermal fluctuations. Therefore, in the initial stage of writing, the spin transfer torque is relatively weak. As the magnetization switching process proceeds, the angle between the two magnetization vectors gradually increases. The spin transfer torque is enhanced. Initially, the weak spin transfer torque leads to an initial delay (Incubation Delay), which limits the writing speed. By increasing the writing current, the initial delay can be reduced, but it also increases the potential The probability of barrier breakdown, the existence of initial delay makes it difficult for STT-MRAM to meet the performance requirements of cache (such as: SRAM)

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