A kind of manufacturing method of magnetic random access memory

Abstract

The invention discloses a manufacturing method of a magnetic random access memory. First, a lower electrode, an MTJ layer and a barrier layer are deposited and grown on a metal layer, followed by further deposition of a sacrificial oxide layer and an upper electrode, followed by photolithography of the MTJ, And etch, after etching, deposit a protective layer sidewall for protection, then etch to leave a certain thickness of the sidewall, and then use the sidewall to perform the most alignment of the hard mask, etch the lower electrode, and then perform SIN is filled, and chemical mechanical planarization CMP is performed. After planarization, wet etching is used to selectively etch the sacrificial oxide layer. It is also a self-alignment process, and then the metal via filling process is performed, and then Carry out CMP chemical mechanical polishing, and finally use the metal through hole as a mask to perform SIN etching, stop when the etching reaches the MTJ layer, and then fill the oxide layer. The method of the invention saves four layers of photolithography, greatly reduces the cost, and greatly improves the quality and reliability of the device.

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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