Chemical mechanical polishing technique

Abstract

The invention provides a chemical mechanical milling process comprising following steps: first, loading the wafers which has lines of metal layer and baffle layer; then, via one first milling cushion, milling the metal layer in same milling speed to expose the lower baffle layer, wherein, the first milling paste distributed on the first milling layer has high milling selective rate to the baffle layer; the second milling step that utilizing one second milling cushion and the second milling past to mill and remove the exposed baffle layer. According to said invention, the milling selective rate (the copper to baffle layer) of first milling past is at least more than 30 while the better is more than 100.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing technology, in particular to a chemical mechanical polishing process for copper / barrier layer metal interconnection lines. Background technique [0002] In recent years, due to the maturity of the copper damascene process technology, the integrated circuit manufacturing can continue to flourish after entering the deep submicron and nanometer generations, and reach a mass production scale with high yield. As known by those skilled in the art, the copper damascene interconnection process basically includes deposition of a dielectric layer, photolithography and etching to define a wire trench structure, barrier layer coating, formation of a copper seed layer, and copper metal electroplating. Finally, the excess copper metal deposited outside the wire trench structure is removed by chemical mechanical polishing (CMP) technology. [0003] When carrying out the aforementioned CMP process, usu...

AI Technical Summary

Problems solved by technology

[0007] Furthermore, in order to increase the output rate, the prior art disclosed in the above-mentioned US patent uses a relatively high downward force in the first step, which may cause scratches on the fragile low dielectric constant layer below, and even cause structural damage. the fragmentation

In addition, another disadvantage of the prior art disclosed in the aforementioned U.S. patent is that three polishing pads are required to perform its copper CMP and barrier layer CMP, thus causing additional maintenance costs and increased component costs

Images