A chemical-mechanical polishing liquid for polishing polysilicon

Abstract

A chemical-mechanical polishing liquid for polishing polysilicon is disclosed, which comprises abrasive particles and water, and is characterized in that further comprises one or more kind of quaternary ammonium-type cationic surfactants. The polishing liquid can polish polysilicon better under basic condition and may significantly reduce the removal rate of polysilicon and the selectivity ratio of polysilicon and SiO2, and may obviously improve the planarizartion-efficiency of 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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