Polishing Composition for Semiconductor Substrate Cleaning

The invention changes the chemical composition parameters of the polishing slurry by incorporating specific organic compounds (polyethylene glycol with Mw 400-20,000 at 0.01-5 wt%, polyvinyl alcohol with Mw 10,000-200,000 at 0.01-5 wt%) along with abrasive grains and pH adjusters. This parameter modification enables the slurry to provide both polishing and cleaning functions, resolving the contradiction between cleaning effectiveness and process complexity by eliminating the need for separate cleaning steps.

The polishing slurry is designed to perform multiple functions: mechanical polishing through abrasive grains and simultaneous cleaning through organic compounds that prevent impurity re-adhesion. This multi-functionality allows a single step to achieve both surface flattening and impurity removal, improving cleaning effectiveness without adding process complexity.

The slurry uses composite material formulation combining inorganic abrasive grains (silica, alumina, or ceria with specific particle size distributions) with organic compounds (polyethylene glycol and/or polyvinyl alcohol). This composite structure provides dual functionality: abrasive grains maintain surface flatness through mechanical polishing while organic compounds prevent impurity re-adhesion by forming protective layers on the substrate surface.

The organic compounds in the slurry act as intermediaries between the abrasive grains and the substrate surface. They facilitate the polishing action while simultaneously preventing harmful impurity re-adhesion by modifying the surface properties and creating a barrier layer that repels contaminants.

The invention optimizes the concentration parameters of organic compounds (polyethylene glycol at 0.01-5 wt% and polyvinyl alcohol at 0.01-5 wt%) to achieve the minimum effective amount for preventing impurity re-adhesion. This parameter control ensures sufficient cleaning effectiveness while minimizing the negative impact on polishing rate, thus maintaining productivity.

The slurry formulation provides different functional properties at different stages: abrasive grains dominate for mechanical polishing and surface flattening, while organic compounds become more prominent in the later stages for impurity removal and surface protection. This local quality differentiation in function timing allows maintaining high polishing rate while achieving effective cleaning.