Semiconductor interconnection structure and preparation method thereof

Abstract

The invention provides a semiconductor interconnection structure and a preparation method thereof, and the method comprises the steps: 1), providing a substrate which is provided with a first metal connecting line layer; 2) forming an etching stop layer, a low-k dielectric layer, a first hard mask layer, a second hard mask layer, an anti-reflection coating and a first graphical photoresist layer on the substrate and the first metal connecting line layer; 3) etching the anti-reflection coating and the second hard mask layer; 4) removing the first graphical photoresist layer and the anti-reflection coating; 5) forming a second graphical photoresist layer; 6) etching the first hard mask layer and the low-k dielectric layer; 7) continuously etching the first hard mask layer, the low-k dielectric layer and the etching stop layer to form a groove and a connecting through hole; 8) removing a second hard mask layer; 9) forming a barrier layer; 10) transversely etching the lower portion of theconnecting through hole; (11) selectively depositing a first metal layer on the lower portion of the connecting through hole, and (12) forming a second metal layer. The preparation method can reduce contact resistance between the conductive plug and the first metal connecting line layer.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a semiconductor interconnection structure and a preparation method thereof. Background technique [0002] With the shrinking of process nodes, the minimum spacing between metal layers becomes smaller and smaller, and the size of conductive plugs between metal layers becomes smaller and smaller. However, as the size of the conductive plug decreases, the contact area between the conductive plug and the underlying metal layer also decreases, which will inevitably increase the contact resistance between the two; Copper is filled in the through hole as the conductive plug, and the filling ability of copper is relatively poor. Air holes are formed in the conductive plug, which will further increase the resistance of the conductive plug. Too much contact resistance between the conductive plug and the metal layer and too much resistance of the conductive plug itself will affect ...

AI Technical Summary

Problems solved by technology

However, as the size of the conductive plug decreases, the contact area between the conductive plug and the underlying metal layer also decreases, which will inevitably increase the contact resistance between the two; Copper is filled in the through hole as the conductive plug, and the filling ability of copper is relatively poor. Air holes are formed in the conductive plug, which will further increase the resistance of the conductive plug

Too much contact resistance between the conductive plug and the metal layer and too much resistance of the conductive plug itself will affect the electrical performance of the device

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