Method for forming interconnecting groove and through hole and method for forming interconnecting structure

Abstract

The invention relates to a method for forming an interconnecting groove and a through hole and a method for forming an interconnecting structure. The method for forming the interconnecting groove and the through hole comprises the following steps that: a substrate is provided, a dielectric layer having a copper plug is formed on the substrate, and a cap layer is formed on the copper plug; an etching stopping layer is respectively formed on the surface of the dielectric layer of the copper plug and the surface of the cap layer, and a dielectric layer is formed on the etching stopping layer; the interconnecting groove and the through hole are formed on the dielectric layer; the interconnecting groove and the through hole are cleaned by acid; and the etching stopping layer covering the surface of the cap layer is removed in a dry etching way. The interconnecting groove and the through hole are radiated by ultraviolet; the interconnecting groove and the through hole stay in an ozone gas and water vapor atmosphere; and the interconnecting groove and the through hole are cleaned by organic solvent. Due to the adoption of the method, the cap layer is free from being corroded, and the damaged dielectric layer can be repaired.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to methods for forming interconnection trenches, through holes and interconnection structures. Background technique [0002] With the development of semiconductor technology, semiconductor devices are becoming smaller and smaller. In the process below 32 nanometers (nm), there is an electronic migration (EM) problem in the back end of line (BEOL). In order to solve the problem of electromigration, the existing solution is to use copper plugs Cobalt Tungsten Phosphorus (CoWP) is formed to prevent electromigration problems. [0003] After forming cobalt-tungsten-phosphorus, when continuing to form the interconnection structure connected with the copper plug on the copper plug, it is necessary to form interconnection trenches and vias on the copper plug covered with cobalt-tungsten-phosphorus (using a dual damascene process) . [0004] refer to Figure 1a ~ Figure 1d , in the...

AI Technical Summary

Problems solved by technology

However, when cleaning the interconnect trench 21 and the via hole 22, hydrofluoric acid will corrode cobalt-tungsten-phosphorus and copper

Moreover, in the method for forming interconnection trenches and through holes described above, when etching to form interconnection trenches and through holes, the method used is dry etching, and the plasma bombards the dielectric layer in the dry etching process. , it will damage the ultra-low-k dielectric layer, resulting in an increase in the k value

[0006] In the prior art, there are many methods for forming interconnection trenches and via holes, such as the method disclosed in Chinese patent application with publication number CN101055421A, but none of them solves the above-mentioned problems

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