Manufacturing method for magnetic tunnel junction structure

Abstract

The invention discloses a manufacturing method for an MTJ (Magnetic Tunnel Junction) unit. The method comprises the steps of providing a semiconductor substrate and a dielectric layer on the semiconductor substrate; forming on the dielectric layer an MTJ structure comprising in order a fix magnetosphere, a tunnel barrier layer and a free rotation magnetosphere; forming in order a first mask layerand a second mask layer on the MTJ structure; patterning the second mask layer; forming a metal layer on the sidewall of the second mask layer, annealing to make the metal layer diffuse along the second mask layer; etching to remove the second mask layer on the metal layer; using the metal layer as a mask, etching the first mask layer and the MTJ structure to the semiconductor substrate and removing the metal layer. According to the method, a small-size circle annular MTJ unit can be manufactured with routine lithography equipment.

Description

technical field [0001] The invention relates to a manufacturing technology of a semiconductor device, in particular to a manufacturing method of a magnetic tunnel junction (MTJ) structure. Background technique [0002] MRAM (Magnetic Random Access Memory) is a non-volatile magnetic random access memory. It has the high-speed read and write capabilities of static random access memory (SRAM), high integration of dynamic random access memory (DRAM) and power consumption far lower than DRAM, compared with flash memory (Flash), with the use of time Increase performance without degradation. Due to the above-mentioned characteristics of MRAM, it is called universal memory and is considered to be able to replace SRAM, DRAM, EEPROM and Flash. [0003] Unlike traditional random access memory chip fabrication technology, data in MRAM is not stored in the form of charge or current, but in a magnetic state, and is sensed by measuring resistance without disturbing the magnetic state. M...

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Problems solved by technology

[0007] In view of this, the technical problem solved by the present invention is to provide a method for manufacturing a hollow cylindrical MTJ unit, so as to reduce the defects in the prior art that the manufacturing cost increases because the inner diameter of the hollow cylindrical MTJ unit is too small

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