An etching method for reducing sidewall redeposition of etching products

Abstract

The invention discloses an etching method for reducing the redeposition of the side wall of an etching product, belonging to the technical field of semiconductors. The etching method of the method does not deposit the upper layer metal of the MTJ device when depositing the film before etching, but uses the carbon layer as an etching mask, and uses the inductively coupled plasma etching technology to etch, after the etching is completed Planarize the upper surface, and then deposit the upper layer of metal, which is used as the upper electrode of the MTJ device; avoiding the generation of particles in the etched part of the upper layer and depositing on the MgO sidewall in the subsequent etching, which affects the performance of the device, making The damage to the magnetic material during the etching process is reduced to less than half of the traditional method, and alcohols and H are used in the etching process 2 The mixed gas of O is used as the etching gas, which further effectively avoids the problem of post-corrosion and etching damage after etching, and no longer needs tail gas treatment, reducing the process steps.

Description

technical field [0001] The invention relates to an etching method for reducing the redeposition of the side wall of an etching product, belonging to the technical field of semiconductors. Background technique [0002] In order to replace the traditional dynamic random access memory (DRAM), various new semiconductor memory devices have been developed, including resistive random access memory (ReRAM), phase change random access memory (PCRAM) and magnetic random access memory (MRAM). Among them, MRAM is an integrated magnetic memory with non-volatility, unlimited read / write endurance, fast access time, low operating voltage, and has the same high component packaging density and static random access memory ( SRAM) as high speed performance. [0003] MRAM devices mainly consist of a magnetic tunnel junction (MTJ) stack and a complementary metal-oxide semiconductor (CMOS). The etching process of MTJ stack is one of the key processes for manufacturing high-density MRAM. Howeve...

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Problems solved by technology

[0012] In order to solve the problem that these thin film layers are easily damaged during the current etching process, resulting in the reduction of their magnetic properties, and even the failure of MRAM devices, the invention provides an etching method that reduces the redeposition of the sidewall of the etching product. method

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