Polishing Composition Polymer Molecular Weight Control

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Solution Overview

Problem

Surface defects known as light point defects (LPDs) occur on substrates polished using existing polishing compositions, and there is a lack of correlation in the literature regarding the impact of water-soluble polymer molecular weight and distribution on reducing these defects.

Innovation Solution

A polishing composition with a water-soluble polymer having a weight average molecular weight of 1000000 or less and a molecular weight distribution of less than 5.0, specifically including cellulose derivatives, starch derivatives, polyvinyl alcohol, and polymers with polyoxyalkylene structures, is used to reduce LPDs on substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a polishing composition containing water-soluble polymer is used to enhance wettability and reduce residual foreign matter, then polishing speed and haze level are improved, but light point defects (LPDs) occur on the substrate surface

Engineering Contradiction:
Improvesurface quality (haze level)VSAvoidlight point defects (LPDs)
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies parameter changes by precisely controlling the weight average molecular weight (Mw ≤ 1,000,000) and molecular weight distribution (Mw/Mn < 5.0) of the water-soluble polymer. This specific parameter optimization resolves the contradiction by maintaining the polymer's wettability-enhancing properties while eliminating the formation of LPDs on the substrate surface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamics by optimizing the molecular weight distribution characteristics of the polymer. By controlling the dynamic range of molecular weights (Mw/Mn ratio), the system achieves optimal performance where the polymer effectively reduces foreign matter without creating light point defects, balancing multiple functional requirements.

Inventive Principle:
Principle #15Dynamics

2Reliability

If water-soluble polymer is added to polishing composition to improve wettability, then residual foreign matter is reduced, but molecular weight control becomes critical to avoid LPDs

Engineering Contradiction:
Improvereduction of residual foreign matterVSAvoidmolecular weight specification control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent establishes specific parameter thresholds (Mw ≤ 1,000,000 and Mw/Mn < 5.0) that define the optimal range for water-soluble polymer characteristics. These parameter specifications ensure reliable reduction of residual foreign matter while providing clear guidance for manufacturing control, transforming a complex control problem into manageable specification limits.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If existing polishing composition is used to achieve high polishing speed, then productivity is maintained, but LPDs are generated on the polished surface

Engineering Contradiction:
Improvepolishing speedVSAvoidsurface defect level (LPDs)
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent resolves this contradiction by changing the molecular weight parameters of the water-soluble polymer (Mw ≤ 1,000,000 and Mw/Mn < 5.0). This parameter optimization maintains the polymer's effectiveness in enhancing wettability and supporting high polishing speed while eliminating the generation of light point defects on the polished surface.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The composition effectively reduces the number and size of LPDs on polished surfaces, improving substrate quality by enhancing wettability and stability while maintaining high polishing efficiency.

Implementation Method 1

The water-soluble polymer functions to enhance the wettability of the substrate surface. This reduces residual foreign matter on the substrate surface.

Methodology Applied
Scientific EffectWettability enhancement: Wetting

Data Source

PatentUS9505950B2Polishing composition and method for producing substrate
Publication Date: 2016.11.29 FUJIMI INCORPORATED

AI summary

A polishing composition includes a water-soluble polymer having a weight average molecular weight of 1000000 or less and a molecular weight distribution represented by weight average molecular weight (Mw)/number average molecular weight (Mn) that is less than 5.0. The polishing composition is mainly used in an application for polishing a substrate, preferably in an application for performing final polishing on a substrate.