CMP Polishing Liquid Cationic Polymer Step Height Removal

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Solution Overview

Problem

Conventional CMP polishing liquids struggle to achieve a high polishing rate for step height removal while maintaining surface flatness, particularly in the formation of element isolation regions with irregularities, where convex and concave portions are differently affected by polishing loads.

Innovation Solution

A CMP polishing liquid containing abrasive grains and a cationic polymer with a main chain featuring a nitrogen atom, carbon atom, and hydroxyl group, which exhibits non-linear load dependency, allowing for enhanced step height removability and flatness by adjusting polishing rates based on load conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conventional CMP polishing liquid is used to polish a material to be polished with irregularities, then the polishing process can be performed, but the polishing rate is insufficient for rapid step height removal while maintaining surface flatness

Engineering Contradiction:

Improvestep height removabilityVSAvoidsurface flatness

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition parameters of the polishing liquid, specifically incorporating a cationic polymer with a main chain containing nitrogen and carbon atoms along with hydroxyl groups. This compositional parameter change enables the polishing liquid to exhibit non-linear load dependency, achieving both high step height removability and surface flatness simultaneously

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining abrasive grains with a specifically designed cationic polymer in the polishing liquid formulation. This composite composition creates a synergistic effect where the abrasive particles provide mechanical removal capability while the cationic polymer provides chemical interaction and load-dependent behavior, resolving the contradiction between removal rate and surface quality

Inventive Principle:

Principle #40Composite materials

2Ease of operation

If the polishing liquid exhibits linear load dependency, then the polishing rate remains constant across different loads, but this prevents effective differentiation between convex and concave portion removal

Engineering Contradiction:

Improveuniform polishing rateVSAvoidflatness achievement

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by introducing non-linear load dependency into the polishing liquid's behavior. The cationic polymer causes the polishing rate to dynamically adjust based on the applied load: higher loads on convex portions accelerate removal, while lower loads on concave portions slow removal, automatically achieving flatness without manual intervention

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the functional parameter of the polishing liquid from linear to non-linear load dependency through the addition of the cationic polymer. This parameter transformation enables the polishing rate to vary dynamically with load conditions, allowing convex and concave portions to be treated differently and achieving superior flatness

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 polishing liquid achieves a significant difference in polishing rates at high and low loads, enabling effective removal of step heights and maintaining surface flatness, improving production efficiency and yield in semiconductor production.

Implementation Method 1

a cationic polymer, in which the cationic polymer has a main chain containing a nitrogen atom and a carbon atom and a hydroxyl group bonded to the carbon atom... exhibiting non-linear load dependency, allowing for enhanced step height removability and flatness by adjusting polishing rates based on load conditions

Methodology Applied

Scientific EffectNon-linear load dependency:

Implementation Method 2

CMP polishing liquid containing abrasive grains... The surface of a base substrate is polished by pressing the base substrate against the polishing pad while the polishing liquid is supplied between the surface of the base substrate and the polishing pad

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS20230054199A1CMP polishing liquid and polishing method

Publication Date: 2023.02.23 RESONAC CORP

AI summary

An aspect of the present disclosure provides a CMP polishing liquid containing: abrasive grains; and a cationic polymer, in which the cationic polymer has a main chain containing a nitrogen atom and a carbon atom and a hydroxyl group bonded to the carbon atom. The CMP polishing liquid may further contain at least one cyclic compound selected from the group consisting of an amino group-containing aromatic compound and a nitrogen-containing heterocyclic compound. Another aspect of the present disclosure provides a polishing method including a step of polishing a material to be polished by using this CMP polishing liquid.