CMP Slurry with Multi-Layer Dispersant for Step Planarization
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Solution Overview
Problem
Current chemical mechanical polishing (CMP) technologies face challenges in achieving high selectivity and removal rates for high stepped portions in semiconductor manufacturing, while also preventing dishing and scratches, especially as integration increases and process standards become stricter.
Innovation Solution
An abrasive particle-dispersion layer composite is developed, comprising abrasive particles electrostatically bonded with a combination of anionic and cationic dispersants, along with a nonionic compound, to enhance polishing selectivity and control, and a polishing slurry composition is formulated to include this composite, optimizing the polishing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single-layered slurry with anionic polymer and anionic copolymer is used, then high polishing rate and high selectivity are achieved in high stepped portions, but it is difficult to adjust planarization degree and control dishing in low stepped portions
Solution Approach 1:
The patent segments the dispersant system into three distinct layers: anionic dispersant layer, cationic dispersant layer, and nonionic dispersant layer. Each layer targets specific polishing stages - the anionic layer handles high stepped portions with high polishing rate, while the cationic and nonionic layers control planarization in low stepped portions, thereby resolving the contradiction between productivity and manufacturing precision.
Solution Approach 2:
The patent applies local quality by assigning different dispersant properties to different polishing conditions. The anionic dispersant provides high polishing rate for high stepped portions, while the cationic and nonionic dispersants provide planarization control for low stepped portions. This localized functionality allows simultaneous optimization of both polishing rate and planarization degree.
2Productivity
If abrasive particles with inherent hardness are used, then high polishing rate is achieved, but scratches are highly likely to occur
Solution Approach 1:
The patent introduces a three-layer dispersant system as an intermediary between the abrasive particles and the substrate. The anionic, cationic, and nonionic dispersants form protective layers around abrasive particles, mediating their interaction with the substrate. This allows the hard abrasive particles to maintain high polishing rate while the dispersant layers prevent direct harmful contact that causes scratches.
Solution Approach 2:
The patent creates a composite structure by combining abrasive particles with a multi-layer dispersant system. The composite consists of the hard abrasive core maintained for high polishing rate, surrounded by anionic, cationic, and nonionic dispersant layers that reduce scratch formation. This composite material approach allows simultaneous achievement of high productivity and reduced harmful effects.
3Productivity
If a high stepped portion is quickly planarized, then productivity is improved, but automatic polishing stop function is needed to reduce polishing speed after step removal
Solution Approach 1:
The patent implements dynamics by creating a dynamic dispersant system that adapts to changing polishing conditions. The three-layer dispersant structure (anionic, cationic, nonionic) enables automatic adjustment of polishing speed - the anionic layer dominates during high stepped portion removal for high productivity, while the cationic and nonionic layers become more influential after step removal to control polishing speed and achieve automatic polishing stop function.
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 solution achieves high selectivity and removal rates for high stepped portions, implements an automatic polishing stop function, and significantly reduces dishing and scratches, maintaining excellent dispersion stability and polishing performance across various film types.
Implementation Method 1
abrasive particles, a first dispersant that is at least one anionic compound among a copolymer with a functional group of a resonance structure
Implementation Method 2
the first dispersant may be electrostatically bonded to at least one of the second dispersant or the third dispersant
Data Source
AI summary
An abrasive particle-dispersion layer composite and a polishing slurry composition including the abrasive particle-dispersion layer composite are provided. The abrasive particle-dispersion layer composite includes abrasive particles, a first dispersant that is at least one anionic compound among a copolymer with a functional group of a resonance structure, a carboxyl group-containing polymer and a carboxyl group-containing organic acid, a second dispersant that is at least one cationic compound among an amino acid, an organic acid, polyalkylene glycol and a high-molecular polysaccharide coupled to a glucosamine compound, and a third dispersant that is a cationic polymer including at least two ionized cations in a molecular formula.