Magnetic random access memory and writing method, reading method and preparation method thereof

Abstract

The invention discloses a magnetic random access memory (MRAM) and a writing method, a reading method and a preparation method thereof. The magnetic RAM includes a substrate layer, a ferroelectric layer, a composite anti-ferromagnetic structure, a first isolation layer and a first ferromagnetic layer that are successively stacked. The composite anti-ferromagnetic structure is the free layer of theMRAM. The first ferromagnetic layer is the fixed layer of the MRAM. The ferroelectric layer is subjected to polarization or lattice distortion under the effect of applied voltage in order to change the coupling state of the composite anti-ferromagnetic structure. The first ferromagnetic layer has a constant first magnetic moment direction. The first isolation layer is configured to control the first magnetic moment direction not to be affected by the coupling state of the composite anti-ferromagnetic structure. The MRAM achieves writing by using the transformation of ferromagnetic coupling and anti-ferromagnetic coupling of the composite anti-ferromagnetic structure under the effect of an electric field, and solves a problem that the MRAM has a large size and a low storage density becauseof a large line width during the writing achieved by the induction magnetic field or polarization current of a wire.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductors and storage devices, and in particular to a magnetic random access memory (MRAM) and its writing method, reading method and manufacturing method. Background technique [0002] The traditional magnetic random access memory (MRAM) consists of a free layer, an isolation layer and a fixed layer, located at the vertical intersection of the word line and the bit line; the magnetic induction effect of the current on the word line and the bit line during the writing process A magnetic field is generated to reverse the magnetization direction of the free layer; the magnetization direction of the free layer and the fixed layer are the same to achieve low magnetoresistance, and the magnetization direction is opposite to achieve high magnetoresistance. MRAM judges whether the stored data is 0 or 1 by detecting the level of magnetoresistance. Since a large current is required to reverse the...

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Problems solved by technology

[0004] The invention provides a magnetic random access memory (MRAM) and its writing method, reading method and preparation method, which solves the problem of relatively wide MRAM size caused by wide line width when using the induced magnetic field or polarized current of the wire to realize MRAM writing in the prior art. Large, low memory density issues with MRAM

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