Aminosilane-Treated Abrasives for CMP Selectivity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional chemical-mechanical polishing (CMP) compositions exhibit inadequate polishing rates and selectivity for insulator materials like silicon nitride and silicon oxide, often leading to poor film removal and film corrosion, which affects manufacturing yields in semiconductor wafer production.

Innovation Solution

A CMP composition comprising colloidal silica particles treated with an aminosilane compound, an acidic component with a pKa of 1 to 4, and a cationic polymer, applied in a specific pH range, to enhance polishing efficiency and selectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional polishing compositions are used, then polishing can be performed, but the process generates heat and requires frequent cooling pauses that reduce productivity

Engineering Contradiction:
Improvepolishing productivityVSAvoidpolishing heat generation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent changes the chemical composition parameters of the polishing slurry by incorporating specific aminosilane-treated abrasive particles and pH buffers. This chemical parameter modification enables the polishing process to maintain effectiveness at lower temperatures, eliminating the need for frequent cooling pauses and thereby improving productivity without sacrificing polishing capability

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If polishing is performed to achieve high precision, then surface quality improves, but the process becomes time-consuming and reduces productivity

Engineering Contradiction:
Improvesurface polish qualityVSAvoidpolishing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent uses composite abrasive particles that combine silica core with aminosilane-treated outer layers, creating a multi-functional material that provides both aggressive cutting action for rapid material removal and fine polishing capability for high surface quality. This composite structure enables achieving precision polish faster than conventional single-material abrasives

Inventive Principle:
Principle #40Composite materials

3Productivity

If aggressive polishing is used to increase productivity, then polishing speed improves, but surface scratch quality worsens

Engineering Contradiction:
Improvepolishing speedVSAvoidsurface scratch quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent creates abrasive particles with differentiated local properties through the aminosilane treatment process, where the particle surface has modified chemical characteristics that control scratching behavior. The treated surface layer provides controlled aggression for efficient material removal while minimizing harmful scratches, enabling high productivity without sacrificing surface quality

Inventive Principle:
Principle #3Local quality

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 allows for adjustable removal rates of silicon nitride and silicon oxide layers, improving polishing performance and reducing defects, thereby enhancing manufacturing yields and substrate quality.

Implementation Method 1

The aminosilane-modified abrasives adhere to the lens at lower polishing pressures

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

Polishing compositions and methods utilizing abrasive particles treated with an aminosilane are provided

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentEP2197972B1Polishing composition and method utilizing abrasive particles treated with an aminosilane
Publication Date: 2020.04.01 CABOT MICROELECTRONICS CORP

AI summary

The inventive method comprises chemically-mechanically polishing a substrate with an inventive polishing composition comprising a liquid carrier, a cationic polymer, an acid, and abrasive particles that have been treated with an aminosilane compound.