Manufacturing process of removing metal layer redundancy metal filling

Abstract

The invention provides a manufacturing process of removing a metal layer redundancy metal filling. The process has the following steps: 1) depositing a dielectric layer with a low k value; 2) forming an etching barrier layer on the deposited dielectric layer with the low k value; 3) completing photolithography and etching so as to remove the etching barrier layer in a non-redundant metal area; 4) depositing again the low k value medium so as to reach low-k-value dielectric layer with a required thickness; 5) completing the photolithography and the etching so as to form a through hole; 6) performing again the photolithography and the etching so as to form a metallic channel and a redundancy metal trough; 7) carrying out filling of lead metal, through hole metal and redundancy metal and completing metal layer deposition; 8) carrying out chemical mechanical planarization to the metal layer; 9) continuously carrying out chemical mechanical planarization to the low-k-value dielectric layer and a metal mixing layer and further removing the redundancy metal. In the invention, through a technology of further removing the redundancy metal by using the chemical mechanical planarization during making single damascene and dual damascene interconnection, coupling capacitance in and between the metal layers caused by the redundancy metal filling can be effectively reduced or eliminated. The process is suitable for practical usage.

Description

Technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a manufacturing process for removing redundant metal filling from a metal layer. Background technique [0002] As the integration of semiconductor chips continues to increase, the feature size of transistors continues to shrink. After entering the 130-nanometer technology node, limited by the high resistance characteristics of aluminum, copper interconnects gradually replace aluminum interconnects and become the mainstream of metal interconnects. Since the dry etching process of copper is not easy to implement, the method for manufacturing copper wires cannot be obtained by etching the metal layer like aluminum wires. The widely used method of making copper wires is the inlay technique called Damascus craft. This process first deposits a low-k dielectric layer on the silicon wafer, then forms metal wire grooves in the dielectric layer by photolithography and etching, and then...

AI Technical Summary

Problems solved by technology

Redundant metal improves the uniformity of pattern density, but inevitably introduces additional coupling capacitance between metals

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