A method of making magnetic random access memory

Abstract

The invention provides a method for making a magnetic random access memory, by improving the connection method between the magnetic tunnel junction and the CMOS circuit, that is: making a tungsten or tantalum bottom electrode contact (BEC, Bottom Electrode Contact) on the first metal connection line to replace copper Via hole; directly make the top electrode contact with the second metal connection line to replace the additional connection via hole (VIA), and at the same time, use the self-aligned etching process to complete the second metal connection line and logic device in the MRAM device area at one time Etching of the through hole and the second metal connection line in the area. The beneficial effect of the present invention is that the pollution problem caused by copper is avoided, and the complexity of the process and the production cost are reduced.

Description

technical field [0001] The present invention relates to a kind of method of making magnetic random access memory, be specifically related to a kind of two-layer CMOS metal connecting line (namely: M x and M x+1 (x≥1)) A method for fabricating a magnetic tunnel junction (MTJ, Magnetic Tunnel Junction) structural unit and its associated logic unit belongs to the field of magnetic random access memory (MRAM, Magnetic Radom Access Memory) manufacturing technology. Background technique [0002] In recent years, MRAM using magnetic tunnel junction (MTJ) has been considered as the future solid-state non-volatile memory, which has the characteristics of high-speed reading and writing, large capacity and low energy consumption. Ferromagnetic MTJ is usually a sandwich structure, which has a magnetic memory layer, which can change the magnetization direction to record different data; an insulating tunnel barrier layer in the middle; a magnetic reference layer, located on the other sid...

AI Technical Summary

Problems solved by technology

When etching the magnetic tunnel junction and its bottom electrode, due to over-etching, copper will be exposed to the plasma, which will cause copper to pollute the magnetic tunnel junction and copper in low dielectric constant (low-k ) rapid diffusion in the dielectric, thereby affecting the magnetic and electrical properties of the device

[0006] In order to realize the connection between the top electrode of the MTJ unit and the CMOS circuit, a through hole (Via) is usually made on the top of the MTJ unit for connection, which undoubtedly increases the complexity of the process and the production cost.

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