Chemical mechanical polishing fluid for polishing polycrystalline silicon

Abstract

The invention discloses chemically machinery polishing solution used for polishing polysilicon. The polishing solution which comprises grinding grains and water is characterized in that a kind of or a plurality of kinds of quaternary ammonium salt type positive ion surface activating agent (s) is provided. The polishing solution of the invention can polish the polysilicon under the alkality condition, and also can obviously reduce the removing speed rate of the polysilicon and the selection ratio of the polysilicon and silicon dioxide, and obviously improve the even efficiency of the polysilicon.

Description

technical field [0001] The invention relates to a chemical mechanical polishing fluid, in particular to a chemical mechanical polishing fluid for polishing polysilicon. Background technique [0002] In the manufacture of integrated circuits, the standard of interconnect technology is increasing, and layers are deposited on top of each other, resulting in the formation of irregular topography on the substrate surface. A planarization method used in the prior art is chemical mechanical polishing (CMP). The CMP process uses a mixture containing abrasives and a polishing pad to polish the surface of a silicon wafer. In a typical chemical mechanical polishing method, the substrate is placed in direct contact with a rotating polishing pad, and a load is used to exert pressure on the backside of the substrate. During polishing, the pad and stage are rotated while maintaining a downward force on the backside of the substrate to apply an abrasive and chemically active solution (comm...

AI Technical Summary

Problems solved by technology

[0004] In the past, when the polysilicon layer and the silicon dioxide layer were polished using alkaline slurry with silicon dioxide as abrasive particles, the removal rate of polysilicon was often much higher than that of silicon dioxide, which easily led to the loss of polysilicon. Depression caused by excessive removal affects the subsequent process

[0005] Therefore, the problem of surface depressions caused by high polysilicon removal rate in the polishing process needs to be solved urgently

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