Technology for copper interconnection polishing

Abstract

The invention discloses a technology for copper interconnection chemical-mechanical polishing. The technology comprises the following steps of firstly, removing a copper coating with a copper polishing solution and flattening the surface; secondly, removing a tantalum barrier layer with a polishing solution; and thirdly, removing part of dielectric layer and copper with the polishing solution, and flattening the surface. By using the optimized technology for polishing, a good polishing effect can be maintained and the productivity also can be improved.

Description

technical field [0001] The present invention relates to a process for polishing copper interconnects. Background technique [0002] The traditional copper interconnect polishing process is usually divided into 3 steps. The first step removes a large amount of copper with a high removal rate and leaves a certain thickness. The second step removes the remaining copper and over-polishes to ensure no copper residue. Copper chemical mechanical polishing fluid is usually used in the first 2 steps, and the polishing rate of copper is higher, which usually causes dishing of copper. The third step is to remove the barrier layer and part of the dielectric layer and copper wire with a barrier layer polishing solution to achieve planarization. In order to correct the dishing caused by copper polishing, the copper polishing rate of the barrier layer polishing solution is usually low, resulting in a long polishing of the barrier layer, which is the bottleneck of production capacity. The...

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Problems solved by technology

In order to correct the dishing caused by copper polishing, the copper polishing rate of the barrier layer polishing solution is usually lower, resulting in a longer po

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