Method of forming mram device

Abstract

The present invention provides a method for forming an MRAM device. The method includes: providing a semiconductor substrate; forming a first dielectric layer on the semiconductor substrate; etching the first dielectric layer to form a through hole; and filling the through hole with a conductive material, the conductive material The first dielectric layer is also covered; a planarization process is used to remove the conductive material covering the first dielectric layer, so that the conductive material in the through hole has a flush surface with the first dielectric layer. ; A magnetic tunnel junction is formed on the conductive material in the through hole, and the magnetic tunnel junction is electrically connected to the conductive material in the through hole; wherein the planarization process affects the conductive material and the first dielectric layer The selection ratio is 0.8 to 1.2. The present invention can make the MTJ layer have a flat surface, thereby eliminating the resulting influence on the performance of the MTJ.

Description

technical field [0001] The invention relates to magnetic memory technology, in particular to a method for forming an MRAM device. Background technique [0002] Magnetic random access memory (MRAM) is one of the three most promising non-volatile memories at present. Because of its high-speed reading and writing, low power consumption, radiation resistance and long data storage time, it may replace SRAM and DRAM in the future. applications on the terminal. For other fields that require high reliability, such as national defense, aerospace, etc., it has an irreplaceable position. [0003] MRAM devices mainly rely on the magnetic tunnel junction (MTJ) to store data. The MTJ layer in the prior art is usually formed on a copper interconnection structure. After electroplating to form copper and performing chemical mechanical (CMP) polishing, due to the acidic and alkaline components in the CMP slurry (slurry) will react with copper reaction, and the copper grain boundary (grain ...

AI Technical Summary

Problems solved by technology

The MTJ layer in the prior art is usually formed on a copper interconnection structure. After electroplating to form copper and performing chemical mechanical (CMP) polishing, due to the acidic and alkaline components in the CMP slurry (slurry) will react with copper reaction, and the copper grain boundary (grain boundary) is also more likely to be corroded, resulting in the surface of the entire substrate is not flat, which in turn makes the surface of the MTJ layer formed on it not flat

The rough surface of the MTJ layer can affect its magnetic properties, for example, it can cause undesired coupling and tunneling between MTJ layers, thereby affecting the switching current

From the above, rough surfaces can lead to failure and uncertain behavior of MTJs in MRAM devices

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