Block Copolymer CMP Dispersant for Cerium Oxide Stability

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Solution Overview

Problem

Existing chemical mechanical polishing (CMP) technologies face challenges in maintaining the dispersion stability of abrasive grains, particularly cerium oxide, leading to aggregation under shear force, which affects the precision of surface smoothing in semiconductor production.

Innovation Solution

A dispersant comprising a block copolymer with specific structural units, including polymer blocks A and B, where block A has amide or ester group-containing vinyl monomers and block B has ionic functional groups, is used to enhance dispersion stability and suppress abrasive grain aggregation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a water-soluble polymer is used as a dispersant in polishing agent composition, then surface smoothing precision is improved, but abrasive grain aggregation occurs under shear force

Engineering Contradiction:
Improvesurface smoothing precisionVSAvoidabrasive grain dispersion stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical parameters of the dispersant by specifying a block copolymer structure with polymer block A containing amide or ester groups and polymer block B containing ionic functional groups. This specific compositional parameter change enables the dispersant to maintain abrasive grain dispersion stability under shear force while preserving surface smoothing precision

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite block copolymer structure combining two different polymer blocks with distinct functional groups. Polymer block A (amide/ester groups) provides adsorption to abrasive grains, while polymer block B (ionic functional groups) provides electrostatic repulsion, creating a composite dispersant that simultaneously achieves dispersion stability and smoothing precision

Inventive Principle:
Principle #40Composite materials

2Productivity

If cerium oxide is used as abrasive grain, then polishing efficiency is improved, but aggregation occurs more easily under shear force

Engineering Contradiction:
Improvepolishing efficiencyVSAvoidabrasive grain aggregation resistance
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The block copolymer dispersant acts as an intermediary between cerium oxide abrasive grains and the polishing slurry medium. The dispersant adsorbs to the cerium oxide surface through polymer block A while extending into the medium through polymer block B, providing steric and electrostatic stabilization that prevents aggregation under shear force while maintaining polishing efficiency

Inventive Principle:
Principle #24Intermediary (Mediator)

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 dispersant effectively maintains abrasive grain dispersion, enhancing surface flatness and precision in semiconductor processing by reducing aggregation, even with cerium oxide, thus improving the quality of insulating and wiring layers.

Implementation Method 1

The water-soluble polymer is adsorbed on the surface of an abrasive grain to enhance the dispersibility of the abrasive grain

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

the polymer block B has a structural unit UB having an ionic functional group

Methodology Applied
Scientific EffectElectrostatic repulsion: Ion Repulsion/Attraction

Data Source

PatentUS12577431B2Dispersant and polishing agent composition
Publication Date: 2026.03.17 TOAGOSEI CO LTD

AI summary

A dispersant for chemical mechanical polishing that flattens a surface of at least one of an insulating layer and a wiring layer includes a block copolymer (P) having a polymer block A and B. The polymer block A has a structural unit derived from at least one monomer selected from the group consisting of an amide group-containing vinyl monomer and an ester group-containing vinyl monomer, and the polymer block B has a structural unit having an ionic functional group.