Interconnect structure and method for forming interconnect structure

Abstract

The invention discloses an interconnection structure and a forming method of the interconnection structure. The forming method of the interconnection structure comprises the following steps: providing a semiconductor substrate, wherein a dielectric layer is formed on the surface of the semiconductor substrate; forming an opening in the dielectric layer, wherein the bottom of the opening is exposed out of the surface of the semiconductor substrate; forming a metal layer filling the opening in the opening, wherein the surface of the metal layer is flush with the top of the dielectric layer; forming a first cap layer on the surfaces of the metal cap layer and the dielectric layer, wherein the first cap layer is made from SiBC; and forming a second cap layer on the surface of the first cap layer. Through adoption of the forming method, the occurrence probability of a copper accumulation phenomenon in the interconnection structure is lowered; the electromigration service life of the interconnection structure is prolonged; and the reliability of the interconnection structure is enhanced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an interconnection structure and a method for forming the interconnection structure. Background technique [0002] With the continuous advancement of VLSI process technology, the feature size of semiconductor devices has been continuously reduced, and the performance of semiconductor devices has become stronger and stronger. However, as the size of semiconductors continues to shrink, smaller and smaller interconnect structures carry higher and higher currents, and the response time requirements of interconnect structures are getting shorter and shorter. Traditional aluminum interconnect structures can no longer meet the requirements. Compared with aluminum, metal copper has lower resistivity and better resistance to electromigration. The copper interconnect structure can reduce the resistance-capacitance (RC) delay of the interconnect structure, improve electromigration...

AI Technical Summary

Problems solved by technology

[0005] Although SiCN, as the cap layer of the interconnection structure, can reduce copper diffusion to a certain extent, the interconnection structure formed by the prior art still has the problem of copper diffusion, and there is a phenomenon of copper accumulation (hillocks) in the formed interconnection structure , resulting in poor performance of the interconnect structure and even device failure

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