Polishing Composition Using Vinyl Alcohol Polymer for Low-Defect Wafers
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Solution Overview
Problem
Existing polishing compositions for semiconductor substrates, such as silicon wafers, fail to effectively reduce surface microdefects, haze, and atomic force microscopy (AFM) roughness, which are critical for achieving high-quality surfaces in semiconductor devices.
Innovation Solution
A novel polishing composition comprising a specific water-soluble polymer, including a vinyl alcohol-based resin with a side-chain group of 3 carbon atoms or more, which is designed to reduce microdefects, haze, and AFM roughness on polished semiconductor substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional polishing compositions are used, then polishing can be performed, but surface microdefects and haze are not effectively reduced
Solution Approach 1:
The patent changes the chemical parameters of the polishing composition by specifying a water-soluble polymer with particular properties: saponification value of 85-99 mol% and viscosity of 100-2000 mPa·s. This parameter optimization resolves the contradiction by achieving both effective polishing and significant reduction of surface microdefects and haze, as demonstrated in the examples where LLS defects were reduced to 700 or fewer per 300mm diameter surface.
Solution Approach 2:
The patent creates a composite polishing composition combining specific components: water-soluble polymer, abrasive particles (colloidal silica), and buffering agents. This composite formulation resolves the technical contradiction by synergistically combining materials that provide both polishing capability and surface defect reduction, achieving manufacturing precision while minimizing harmful microdefects.
2Manufacturing precision
If polishing is performed to achieve high surface quality, then microdefects are reduced, but polishing time increases
Solution Approach 1:
The patent optimizes the viscosity parameter of the water-soluble polymer to 100-2000 mPa·s, which balances polishing efficiency and surface quality. This parameter range enables achieving LLS defect counts of 700 or fewer per 300mm diameter while maintaining reasonable polishing time, resolving the contradiction between manufacturing precision and time loss.
3Stability of the object's composition
If conventional water-soluble polymers are used, then polishing composition is stable, but AFM roughness is not sufficiently reduced
Solution Approach 1:
The patent precisely controls the saponification value parameter at 85-99 mol% and viscosity at 100-2000 mPa·s for the water-soluble polymer. These parameter specifications simultaneously ensure composition stability for handling and storage while achieving sufficient AFM roughness reduction on polished semiconductor surfaces, resolving the contradiction between stability and precision.
Data Source
AI summary
Provided is a novel polishing composition. The polishing composition comprises a water-soluble polymer at least comprising a vinyl alcohol-based resin having a side-chain group of 3 carbon atoms or more.