Manufacturing method of magnetic random memory

Abstract

The invention discloses a manufacturing method of a magnetic random memory. According to the method, firstly, a lower electrode, an MTJ layer and a blocking layer grow on a metal layer through deposition, a sacrificial oxide layer and an upper electrode are continuously deposited, MTJ lithography is then carried out, etching is carried out, after etching, a protection layer side wall is depositedfor protection, etching is further carried out to left a side wall with certain thickness, the side wall is utilized to carry out hard mask self alignment, the lower electrode is etched, SIN filling is then carried out, chemical mechanical planarization CMP is carried out, after planarization, a wet corrosion method is utilized, the sacrificial oxide layer is selectively etched, in the self-alignment process, the metal through hole filling process is further carried out, CMP chemical mechanical planarization is further carried out, lastly, a metal through hole is taken as a mask for SIN etching till the MTJ layer, and oxide filling is then carried out. The method is advantaged in that four-layer lithography is omitted, cost is substantially reduced, and device quality and reliability are substantially improved.

Description

technical field [0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a manufacturing method of a magnetic random access memory. Background technique [0002] It has become a trend that semiconductor devices are getting smaller and smaller in size and lower in cost. Traditional magnetic tunnel junction random access memory (MRAM) devices are limited by the size of the metal. Although the characteristic size of the unit memory (PMRAM) can be made 60nm or even smaller, the size of the unit cannot be achieved due to the limitation of the metal size. Continue to become smaller, which greatly limits the development of high-density MRAM memory. [0003] The traditional manufacturing process of MRAM includes the following steps: [0004] 1) Deposition and etching of the lower electrode TaN; [0005] 2), oxide layer deposition; [0006] 3), lower electrode CMP chemical mechanical light; [0007] 4), MTJ magnetic tunnel ...

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Problems solved by technology

[0017] The above-mentioned traditional process uses chemical mechanical polishing CMP to flatten the upper electrode of the MTJ magnetic tunnel junction. Due to the huge pressure during the grinding process of CMP, the tunneling layer in the middle of the MTJ is only 10A of MgO, which is easily destroyed. damage, rendering the entire device useless

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