CMP Slurry Polyether Amine Mediator for SiO2 Polishing Rate
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Solution Overview
Problem
The addition of polyacrylic acid anionic polymer in chemical mechanical polishing solutions reduces the polishing rate of silicon dioxide, which is a challenge in the manufacturing of micro-nano devices.
Innovation Solution
A chemical mechanical polishing solution is developed that includes cerium oxide, polyacrylic acid, polyether amine, and water, with polyether amine D230 or D400 added to improve the polishing rate of silicon dioxide by negatively charging the cerium oxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If polyacrylic acid anionic polymer is added to make cerium oxide negatively charged to achieve high silicon dioxide/silicon nitride selection ratio, then the selection ratio is improved, but the polishing rate of silicon dioxide is reduced
Solution Approach 1:
Polyether amine is introduced as an intermediary substance that interacts with both polyacrylic acid and cerium oxide. It modifies the surface charge characteristics of cerium oxide particles, enabling them to maintain negative charge for high selectivity while improving their polishing performance on silicon dioxide. The polyether amine acts as a bridging agent that reconciles the conflicting requirements of charge state and polishing rate.
Solution Approach 2:
The invention changes the chemical parameters of the polishing slurry by adding polyether amine, which alters the surface properties and charge characteristics of cerium oxide particles. This parameter change allows the particles to maintain the necessary negative charge for high silicon dioxide/silicon nitride selection ratio while simultaneously improving their mechanical polishing action on silicon dioxide, thus resolving the contradiction between selectivity and polishing rate.
2Manufacturing precision
If polyacrylic acid anionic polymer is used as dispersant for cerium oxide, then good dispersion and high selection ratio are achieved, but the polishing rate of silicon dioxide decreases
Solution Approach 1:
The invention creates a composite chemical system by combining polyacrylic acid, polyether amine, and cerium oxide in specific proportions. This composite approach allows the synergistic interaction between the dispersant (polyacrylic acid) and the charge modifier (polyether amine), where the polyether amine compensates for the polishing rate reduction caused by polyacrylic acid while maintaining good dispersion and high selection ratio.
Solution Approach 2:
Polyether amine serves as a mediator between the dispersant polyacrylic acid and the abrasive particles cerium oxide. It modifies the interaction between these components, allowing the system to achieve both good dispersion (from polyacrylic acid) and high polishing rate (enhanced by polyether amine), while maintaining the high silicon dioxide/silicon nitride selection ratio.
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 maintains a high silicon dioxide/silicon nitride selection ratio while significantly improving the polishing rate of silicon dioxide, with a maximum increase of 34% when the polyether amine content reaches 100 ppm.
Implementation Method 1
improve the polishing rate of silicon dioxide by negatively charged cerium oxide
Implementation Method 2
When the pH value is greater than 4, it can make the surface of cerium oxide negatively charged
Data Source
AI summary
Disclosed is a chemical mechanical polishing solution containing water, cerium oxide, polyacrylic acid and polyether amine. The chemical mechanical polishing solution in this application uses polyether amine as an additive, which can improve the polishing rate of silicon dioxide by negatively charged cerium oxide.