Magnetic tunnel junction structure and manufacturing method

Abstract

The invention provides a magnetic tunnel junction structure and a manufacturing method. The magnetic tunnel junction structure is characterized in that a magnetic tunnel junction is formed on a bottom electrode, the bottom electrode is located on a substrate with a through hole, the magnetic tunnel junction at least comprises a free layer, a barrier layer and a reference layer from bottom to top, a non-conductive current blocking layer is formed between the free layer and the bottom electrode, and a non-conductive interlayer dielectric layer is formed on the periphery of the bottom electrode, so that current passing through the free layer flows to the bottom electrode from the edge of the free layer along the periphery of the current blocking layer. According to the invention, the non-conductive current barrier layer and the interlayer dielectric layer are added below the free layer, so that the direction of current passing through the free layer is changed, and the thickness of spin-polarized electrons flowing through the free layer is increased in a phase-changing manner so as to enhance the absorption rate of spin transfer torque, namely, under the condition that the free layer still keeps the original thickness and perpendicular anisotropy, the overturning efficiency of the free layer of the storage unit of the magnetic random access memory is improved, so that the write current of the magnetic random access memory is reduced, and the benefit of reducing power consumption is also achieved.

Description

technical field [0001] The invention relates to the field of memory technology, in particular to a magnetic tunnel junction structure and a manufacturing method. Background technique [0002] Magnetic random access memory (MRAM) in the magnetic tunnel junction (Magnetic tunnel junction; MTJ) with vertical anisotropy (Perpendicular Magnetic Anisotropy; PMA), as a free layer for storing information, has two in the vertical direction The magnetization direction, namely: up and down, corresponds to "0" and "1" or "1" and "0" in binary respectively. In practical applications, when reading information or leaving it blank, the magnetization direction of the free layer will remain unchanged; during the writing process, if a signal different from the existing state is input, the magnetization direction of the free layer will be reversed by 180 degrees in the vertical direction. The ability of the magnetization direction of the free layer of the MRAM to remain unchanged is called the...

AI Technical Summary

Problems solved by technology

The ability of the magnetization direction of the free layer of the MRAM to remain unchanged is called the data retention capability or thermal stability, and the requirements are different in different applications. For a typical non-volatile memory (Non-volatile Memory, NVM) In other words, the requirement for data storage ability is that the data can be stored for ten years under the condition of 125°C. When the external magnetic field is reversed, thermal disturbance, current disturbance or multiple operations of reading and writing, the data retention ability or thermal stability will be reduced.

[0003] The thickness of the free layer of the MRAM is mostly below 2 nanometers. Experiments have shown that when the thickness of the free layer is thicker, it shows in-plane anisotropy, and when it is thinner, it shows vertical anisotropy. The perpendicular magnetic anisotropy disappears and the device cannot work

At the same time, an overly thin free layer will increase the critical switching current on the one hand, and on the other hand will reduce the Tunnel Magnetoresistance Ration (TMR), which will increase the error rate during the read operation

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