Chemico-mechanical polishing slurry for polysilicon

Abstract

The invention discloses polysilicon chemical-mechanical polishing slurry which is composed of polyol type nonionic surfactant, guanidine compounds, grinding particles and water. The polishing slurry of the invention can polish the polysilicon film well under the alkali condition; wherein, the polyol type nonionic surfactant can decrease the removal velocity of polysilicon obviously without decreasing the removal velocity of silicon dioxide; thereby, the selectivity-ratio of the polysilicon and the silicon dioxide is decreased obviously; the guanidine compounds also can adjust the selectivity-ratio of the polysilicon and the silicon dioxide and have the effect of pH adjustment, enabling the polysilicon chemical-mechanical polishing slurry to have no need to add common pH regulator; the metal iron pollution and the environmental pollution are reduced greatly.

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 interconnection technology continues to increase, and layers are deposited on top of each other, resulting in irregular topography on the surface of silicon wafers. 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 wafer is placed in direct contact with a rotating polishing pad, applying pressure to the back of the wafer. During polishing, the wafer and polishing table / pad are rotated while maintaining a downward force on the back of the wafer, and an abrasive and chemically active solution (often referred to as a polish...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to solve the problem that the above-mentioned polysilicon / silicon dioxide selectivity is too high, and the metal ion pollution and environmental pollution that conventional alkaline pH regulators bring, and provide a kind of polysilicon that is used for polishing polysilicon and has suitable polysilicon / SiO2 selective ratio, and non-polluting chemical mechanical polishing fluid

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