Multi-film structure with interfacial perpendicular magnetic anisotropy and magnetic random access memory

Abstract

Embodiments of the present invention provide a multi-layer structure with interfacial perpendicular magnetic anisotropy and a magnetic random access memory. The entire multi-layer structure undergoes annealing at a temperature above 500° C. after growth to ensure good thermal stability. The crystallization of metallic chromium in the buffer layer during the annealing process promotes the crystal orientation formation of the overall structure. At the same time, due to the annealing, charge trapping is formed between the ferromagnetic layer and the first oxide barrier layer, which enhances the interfacial perpendicular magnetic anisotropy between the two layers due to the interlayer coupling. Since each film layer is on the nanometer scale, the obtained multi-film layer structure also has the advantage of small size. The magnetic tunnel junction in the magnetic random access memory provided by the embodiment of the present invention is a multi-layer structure with interfacial perpendicular magnetic anisotropy, which can increase the storage density of the magnetic random access memory.

Description

technical field [0001] The invention relates to the technical field of magnetic random access memory, and more specifically, relates to a multi-film layer structure with interface perpendicular magnetic anisotropy and magnetic random access memory. Background technique [0002] At present, magnetic random access memory (MRAM) and magnetic logic have the advantages of non-volatility, fast read and write speed, low power consumption and unlimited erasing and rewriting, and have attracted extensive attention from industry and academia. [0003] The core device of magnetic random access memory and magnetic logic is the magnetic tunnel junction (Magnetic Tunnel Junction, MTJ). The basic structure of the magnetic tunnel junction is a three-layer thin film structure, which specifically includes: a reference layer, a barrier layer and a free layer. Wherein, both the reference layer and the free layer are ferromagnetic materials. When the magnetization directions of the two layers a...

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Problems solved by technology

[0006] However, the structure of Ta(Mo,Hf) / CoFeB / MgO / CoFeB / Ta(Mo,Hf) still has obvious shortcomings

First, the interface perpendicular magnetic anisotropy of the structure is weak, resulting in low thermal stability of the structure; secondly, because of the weak interface perpendicular magnetic anisotropy, in order to make the easy axis of magnetization perpendicular to the interface direction, it is necessary A thinner CoFeB layer reduces the demagnetization field, which leads to a larger magnetic damping coefficient and thus a larger critical switching current for the structure

Finally, the thermal stability will decrease when the cross-sectional size is reduced. In order to maintain sufficient thermal stability, the size of the structure will be increased, which will lead to a lower storage density of the MRAM using this structure.

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