Polishing Composition for High-Mobility Materials

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Solution Overview

Problem

Conventional polishing compositions lack sufficient selectivity for high-mobility material portions when used on objects containing both high-mobility and silicon material portions, leading to inefficient polishing and increased oxide loss, which affects transistor performance and manufacturing processes.

Innovation Solution

A polishing composition comprising abrasive grains with an average primary particle diameter of 40 nm or less, an oxidizing agent with a standard electrode potential of 0.3 V or more, and a hydrolysis-suppressing compound that bonds to the silicon material portion to reduce hydrolysis, ensuring high selectivity and efficiency in polishing high-mobility materials while minimizing silicon material loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional polishing compositions are used for polishing high-mobility material portions, then the polishing process can be performed, but the polishing selectivity for high-mobility material portions is insufficient

Engineering Contradiction:
Improvepolishing selectivityVSAvoidpolishing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the particle size parameter of abrasive grains to 40 nm or less (nanoscale), and adjusts the oxidizing agent concentration to achieve optimal polishing selectivity. This parameter optimization enables high-selectivity polishing of high-mobility material portions while maintaining efficient material removal rates

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The polishing composition uses a composite system combining ultra-fine abrasive grains (40 nm or less) with specific oxidizing agents (such as ammonium persulfate, hydrogen peroxide, or ozone) and pH adjusters. This composite formulation creates synergistic effects that enhance polishing selectivity for high-mobility materials while controlling oxide loss on silicon portions

Inventive Principle:
Principle #40Composite materials

2Productivity

If polishing composition with high selectivity is used, then high-mobility material portion can be efficiently polished, but oxide loss increases

Engineering Contradiction:
Improvepolishing efficiencyVSAvoidoxide loss
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent optimizes the particle size parameter to 40 nm or less and controls the oxidizing agent concentration within specific ranges (e.g., ammonium persulfate 0.01-10 wt%, hydrogen peroxide 0.1-5 wt%). These parameter adjustments enable efficient high-mobility material removal while minimizing oxide loss on silicon portions by reducing mechanical damage and controlling chemical reactions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional coarse mechanical abrasion with a chemical-mechanical polishing system using ultra-fine particles (40 nm or less) and oxidizing agents. This substitution reduces mechanical stress and physical damage to oxide layers, thereby minimizing oxide loss while maintaining high polishing efficiency for high-mobility materials

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If conventional polishing composition is used, then the process can be completed, but withstand voltage between wiring layers is compromised

Engineering Contradiction:
Improveprocess simplicityVSAvoidwithstand voltage
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses ultra-fine abrasive grains (40 nm or less) and controlled oxidizing agent concentrations to achieve minimal oxide loss during polishing. This preserves the integrity and thickness of oxide insulation layers between wiring layers, ensuring adequate withstand voltage while maintaining process simplicity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional mechanical polishing with chemical-mechanical polishing using nanoscale particles and oxidizing agents. This gentler process minimizes mechanical damage to oxide layers, preserving their insulating properties and ensuring reliable withstand voltage between wiring layers without complicating the manufacturing process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Productivity

If conventional polishing composition is used, then polishing can proceed, but photolithography focusing is destabilized

Engineering Contradiction:
Improvepolishing throughputVSAvoidphotolithography focus
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent uses ultra-fine particles (40 nm or less) and controlled oxidizing agent concentrations to achieve uniform, scratch-free polished surfaces with minimal oxide loss. This surface quality ensures optimal light focusing during subsequent photolithography processes, stabilizing the manufacturing process while maintaining high polishing throughput

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 achieves high polishing selectivity for high-mobility materials, reducing silicon material loss and enhancing transistor performance by maintaining high selectivity and reducing material costs and waste treatment burdens.

Implementation Method 1

The polishing composition contains an oxidizing agent

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

abrasive grains having an average primary particle diameter of 40 nm or less

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentUS9816010B2Polishing composition
Publication Date: 2017.11.14 FUJIMI INCORPORATED

AI summary

A polishing composition of the present invention is to be used for polishing an object including a portion containing a high-mobility material and a portion containing a silicon material. The polishing composition comprises an oxidizing agent and abrasive grains having an average primary particle diameter of 40 nm or less. The polishing composition preferably further contains a hydrolysis-suppressing compound that bonds to a surface OH group of the portion containing a silicon material of the object to function to suppress hydrolysis of the portion containing a silicon material. Alternatively, a polishing composition of the present invention contains abrasive grains, an oxidizing agent, and a hydrolysis-suppressing compound. The polishing composition preferably has a neutral pH.