Copper filling groove structure and manufacturing method thereof

Abstract

The invention discloses a copper-filled groove structure, and the structure comprises a groove which is formed in a first dielectric layer; barrier layers are formed on the bottom surface and the side surface of the groove; forming a cobalt layer and a ruthenium layer on the surface of the barrier layer; the copper layer completely fills the groove in which the barrier layer, the cobalt layer and the ruthenium layer are formed and forms a copper filling groove structure; the copper layer is completely composed of a copper electroplating film; a cobalt layer and a ruthenium layer are overlapped to form an auxiliary nucleation film layer of the copper layer. The invention further discloses a manufacturing method of the copper filling groove structure. The copper layer does not contain a copper seed crystal layer and is completely composed of the copper electroplating film, so that the capacity of filling copper in the groove can be improved, the structure of the groove filled with the copper can be reduced, and the copper electroplating film is particularly suitable for being used as a copper connecting wire and a through hole below 14 nm process nodes.

Description

technical field [0001] The invention relates to the manufacturing field of semiconductor integrated circuits, in particular to a copper-filled groove structure. The invention also relates to a method of manufacturing a copper-filled groove structure. Background technique [0002] As the critical dimension (CD) of the back-end (BEOL) copper interconnection becomes smaller and smaller, it becomes more and more difficult to fill the trench (Trench) and via (via) openings, which are explained as follows: [0003] Such as figure 1 As shown, it is a structural schematic diagram of the copper-filled groove structure formed by the first existing copper-filled groove structure manufacturing method; the existing first copper-filled groove structure manufacturing method adopts physical vapor deposition (PVD) TaN +Ta+ copper seed layer (Cu Seed) process, including the following steps: [0004] A groove 102 is formed on a dielectric layer such as an interlayer film 101 , and the groov...

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Problems solved by technology

That is, the use of the cobalt layer 204 can reduce the thickness of the copper seed layer 205, because figure 2 The thickness of the copper seed layer 205 is less than figure 1 The thickness of the copper seed crystal layer 105 in, so under the condition that the top opening width of the groove 202 is the same as the top opening width of the groove 102, after forming the copper seed crystal layer, figure 2 The width in d201 will be greater than figure 1 Therefore, the existing second manufacturing method of the copper-filled groove structure can be applied to the process of the 14nm technology node, but the existing first manufacturing method of the copper-filled groove structure cannot be applied to the 14nm technology node in the process

[0015] Although the existing second copper-filled groove structure manufacturing method introduces a Co liner (liner), that is, a cobalt layer 204, the required thickness of the copper seed layer 205 can be effectively reduced, but the copper seed layer 205 The contribution to the reduction of the top opening of the groove 202 is still very large, and the reduction of the opening reaches 7.9nm at the 14nm technology node

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