Monitoring method for removal of copper oxide in copper interconnect NDC process

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a monitoring method for removing copper oxide in a copper interconnection NDC manufacturing process. The method at least includes the following steps: forming an interconnection structure including copper interconnection lines; exposing the copper oxide on the surface of the copper interconnection lines to the processing space; passing ammonia gas into the processing space, so that the ammonia gas forms ammonia plasma in the processing space The ammonia plasma can remove the copper oxide on the surface of the copper interconnection line; the ammonia plasma that has not reacted with the copper oxide is dissociated to form hydrogen ions in the processing space; the hydrogen ion concentration information is obtained in real time; according to the hydrogen ion concentration information, determine The reaction degree of copper oxide; when the reaction degree of copper oxide is completely removed, stop feeding ammonia gas into the processing space. By monitoring the concentration of hydrogen ions and judging the degree of reaction of copper oxide, it is possible to solve the problem in the related art that the surface of copper interconnection wires is in a state of compressive stress due to too long ammonia plasma treatment time, which leads to the formation of more mound-shaped protrusions.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a monitoring method for removing copper oxide in a copper interconnection NDC manufacturing process. Background technique [0002] With the development of semiconductor manufacturing technology, the area of ​​semiconductor chips is getting smaller and smaller, and the number of semiconductor devices on a semiconductor chip is also increasing. In semiconductor circuits, signal transmission between semiconductor devices requires high-density metal interconnection lines, however, the large resistance and parasitic capacitance brought by these metal interconnection lines will limit the speed of semiconductor circuits. [0003] Since the Nitride Doped Silicon Carbide (NDC) layer has good isolation and etching selectivity, it is often used as a dielectric barrier layer in copper interconnection technology to prevent metal copper from diffusing into the medium. Howe...

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Problems solved by technology

[0006] The invention provides a monitoring method for removing copper oxide in the NDC process of copper interconnection, which can solve the problem that in the related art, the surface of the copper interconnection line is in a state of compressive stress due to the ammonia plasma treatment time is too long, which leads to the formation of more hilly bumps. problem

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