Magnetic tunnel junction and method of forming the same

Abstract

A magnetic tunnel junction and its formation method, wherein the formation method of the magnetic tunnel junction includes: providing a first dielectric layer and a first electrode layer with a composite magnetic layer and a first mask layer on the surface in sequence, and the first mask layer is parallel The pattern on the surface of the substrate is circular; the composite magnetic layer is etched with the first mask layer until the first dielectric layer is exposed; then a second mask layer is formed on the surface of the first dielectric layer, and the surface of the second mask layer flush with the surface of the first mask layer; remove the first mask layer and form an opening; form a third mask side wall on the side wall surface of the opening; perform an ion implantation process on the third mask side wall, and the ion implantation The direction is tilted relative to the substrate surface; then, part of the third mask sidewall is etched to form a third mask, so that the inner sidewall of the third mask is parallel to the substrate surface and the pattern is elliptical; with the third mask The composite magnetic layer is etched until the first electrode layer is exposed. The formed magnetic tunnel junction has improved storage stability and improved reliability.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a magnetic tunnel junction and a forming method thereof. Background technique [0002] Magnetic Random Access Memory (MRAM) has the advantages of short read and write time, non-volatility, and low power consumption. It is suitable for information processing equipment such as computers or mobile phones, making magnetic memory widely concerned by the market. [0003] The existing magnetic memory structure includes: a transistor used as a switching device, and a magnetic tunnel junction (Magnetic Tunnel Junction, MTJ) structure used for storing data. Magnetic memory stores information into a magnetic tunnel junction structure by applying a magnetic field, and reads the stored information by measuring the current passing through the magnetic tunnel junction. [0004] figure 1 It is a schematic cross-sectional structure diagram of an existing magnetic tunnel junc...

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Problems solved by technology

[0006] However, the storage performance of existing magnetic tunnel junctions is unstable, resulting in low reliability of MRAMs

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