Method of forming interconnect structure

Abstract

A forming method of an interconnection structure comprises the following steps: providing a substrate with a surface having a dielectric layer; forming a first opening in the dielectric layer, and the depth of the first opening is smaller than the height of the dielectric layer; forming a sacrificial layer on a side wall surface of the first opening; using a hard mask layer as a mask so as to etch the sacrificial layer and the dielectric layer along the first opening, thereby forming a groove, and the depth of the groove is smaller than the height of the dielectric layer; filling the groove so as to form a metal layer, and exposing a surface of the sacrificial layer and the dielectric layer; removing the sacrificial layer so as to form a second opening on two sides of the metal layer; forming a cap layer on a surface of the dielectric layer and the metal layer, and the cap layer fills the second opening. The forming method of the interconnection structure can improve adhesive performance of the metal layer and the dielectric layer, can effectively reduce metal electro migration, thereby improving circuit performance.

Description

technical field [0001] The invention relates to the field of semiconductor technology, in particular to a method for forming an interconnection structure. Background technique [0002] As the integration level of semiconductor chips continues to increase, the feature size of transistors continues to shrink. Due to the high resistance characteristics of aluminum, copper interconnection gradually replaces aluminum interconnection and becomes the mainstream of metal interconnection. The widely used manufacturing method of copper wire is damascene technology. One of the methods of one-time forming of through-hole copper. [0003] Please refer to Figure 1 ~ Figure 4 , is a schematic cross-sectional view of a method for forming a copper interconnection structure in the prior art. [0004] Please refer to figure 1 , forming a dielectric layer 11 on the substrate 10 , and forming an opening 12 in the dielectric layer 11 . [0005] The method for forming the opening 12 includes...

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Problems solved by technology

[0011] However, the material properties between the copper interconnection 14 and the capping layer 15 are quite different, so the adhesion strength between the two is relatively low, so that the copper has a relatively strong bond at the interface between the copper interconnection 14 and the capping layer 15. High Diffusion and Migration Efficiency

Metal electromigration is accompanied by mass transport. Usually, due to the electromigration of copper ions, copper interconnects will generate hillocks in local areas due to mass accumulation, or voids due to mass loss, resulting in circuit performance degradation or failure. , seriously affect the reliability of the circuit

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