CMP Polishing Composition for Elemental Silicon Films

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Solution Overview

Problem

Current chemical mechanical planarization (CMP) technologies face challenges in achieving high removal rates for films comprising elemental silicon while maintaining controlled selectivity between elemental silicon and other films like silicon oxide and silicon nitride.

Innovation Solution

The development of CMP polishing compositions that include abrasive particles, a liquid carrier, and specific compounds such as heterocyclic carbon compounds with sulfur or nitrogen heteroatoms and a carbonyl group, or aldehyde/ketone compounds, which enhance the removal rates of elemental silicon films while suppressing the removal rates of silicon nitride films using additives like polymers with acrylic acid groups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If oxidizing agents are used to boost removal rates of crystalline Si films, then removal rate increases, but selectivity control between Si films and other films deteriorates

Engineering Contradiction:
Improveremoval rateVSAvoidselectivity control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the chemical parameter from oxidizing agents to heterocyclic carbon compounds with specific functional groups (carbonyl, hydroxyl, carboxyl). This chemical parameter change enables high removal rates for elemental silicon films while providing controlled selectivity against silicon oxide and silicon nitride films, resolving the contradiction between productivity and manufacturing precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The heterocyclic carbon compounds exhibit local quality by selectively reacting with elemental silicon films while having minimal effect on silicon oxide and silicon nitride films. This selective chemical interaction allows high removal rates for the target material while maintaining selectivity control, addressing the technical contradiction.

Inventive Principle:
Principle #3Local quality

2Productivity

If compositions comprising diquaternary cations are used for polishing poly-Si films, then removal rate relative to silicon nitride increases, but selectivity control and process versatility deteriorate

Engineering Contradiction:
Improveremoval rateVSAvoidselectivity control
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent replaces diquaternary cations with heterocyclic carbon compounds containing specific functional groups. This parameter change maintains high removal rates for poly-Si films while improving adaptability and selectivity control, allowing the composition to be tuned for different polishing requirements including selective removal against silicon oxide and silicon nitride.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If alcohol amine compounds are used to increase selectivity to poly-Si polishing, then selectivity improves, but removal rate deteriorates

Engineering Contradiction:
ImproveselectivityVSAvoidremoval rate
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the chemical parameter from alcohol amine compounds to heterocyclic carbon compounds with carbonyl, hydroxyl, or carboxyl groups. This parameter reversal simultaneously improves both selectivity and removal rate, as the heterocyclic compounds provide enhanced chemical reactivity with elemental silicon films while maintaining selective action, thus improving both manufacturing precision and productivity.

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

These compositions achieve high removal rates for elemental silicon films with tunable selectivity between elemental silicon and silicon oxide or silicon nitride, allowing for efficient polishing in semiconductor manufacturing with improved process control.

Implementation Method 1

a compound to boost the removal rates of films comprising elemental silicon, which is selected from a group consisting of (i) heterocycle carbon compound comprising sulfur or nitrogen or both sulfur and nitrogen as heteroatoms and a carbonyl group attached to the ring structure

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 2

polishing composition comprising abrasive particles

Methodology Applied
Scientific EffectAbrasion: Abrasion

Implementation Method 3

chemical mechanical planarization (CMP) polishing compositions

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentUS11111415B2Chemical mechanical planarization of films comprising elemental silicon
Publication Date: 2021.09.07 VERSUM MATERIALS US LLC

AI summary

Chemical Mechanical Planarization (CMP) polishing compositions comprising abrasive particles and additives to boost removal rates of films comprising elemental silicon such as poly-silicon and Silicon-Germanium.