Magnetic Tunnel Junction Device and Random Memory Device Based on Artificial Antiferromagnetic Pinned Layer

Abstract

The invention discloses a magnetic tunnel junction device and a random storage device based on an artificial antiferromagnetic fixed layer. The device relates to a multilayer film structure that can be used as a fixed layer, that is, an artificial antiferromagnetic device. The artificial antiferromagnetic device can be adjusted by the electric field to enhance the antiferromagnetic coupling. The artificial antiferromagnetic device can be used as the fixed layer of the magnetic tunnel junction, and the antiferromagnetic coupling is enhanced under the action of the electric field to ensure that the fixed layer is close to the potential barrier. The ferromagnetic layer of the layer does not flip, thereby realizing stable writing of data. The magnetic tunnel structure based on the artificial antiferromagnetic pinned layer forms a magnetic random access memory device, which achieves the purpose of stably writing data through the joint action of electric field and current. It has a simple structure, high density, low power consumption, fast speed, and radiation resistance. , Non-volatile advantages.

Description

technical field [0001] The present invention relates to circuits and devices with magnetic / ferromagnetic materials or structures and their applications, more specifically, to a magnetic random access memory based on an artificial antiferromagnetic pinned layer controlled by electricity and using an electric field for assisted erasing and writing. Background technique [0002] A magnetic tunnel junction (called MTJ) is composed of two layers of magnetic metal (such as iron, cobalt, nickel) and an ultra-thin insulating layer (such as aluminum oxide, or magnesium oxide) sandwiched between the two magnetic metal layers. If a bias voltage is applied between the two magnetic metal layers, since the insulating layer is very thin, electrons can tunnel through its potential barrier. Under a given bias voltage, the size of the tunneling current / tunneling resistance depends on the relative orientation of the magnetization in the two ferromagnetic layers. This phenomenon is called tunne...

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Problems solved by technology

However, the spin polarization current applied to spin-transfer torque-random memory is generally in the range of 10 7 A / cm 2 Left and right, a larger spin-polarized current will limit the arrangement density of the memory cell array. In order to increase the arrangement density of the memory cell array, the thickness of the pinned layer can be reduced. At this time, a larger current may cause the ferromagnetic state of the pinned layer to collapse. changes, unable to write data stably

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