Polishing Composition Abrasive Grain Protrusions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing polishing compositions with abrasive grains having protrusions on their surfaces are ineffective in achieving a high polishing rate for hydrophilic objects due to the inhibiting effect of organic alkali content, particularly when the pH is close to the acid dissociation constant pKa value of the organic alkali.
Innovation Solution
A polishing composition with abrasive grains having protrusions where parts of the grains have larger diameters than the volume-based average, with protrusions having an average height of 3.5 nm or more, and an organic alkali content of 100 mmol or less per kilogram, maintaining a pH within plus or minus 2 of the pKa value to prevent alkali adsorption and enhance polishing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If abrasive grains with protrusions are used to enhance polishing rate, then mechanical polishing ability is improved, but organic alkali adsorption on hydrophilic surfaces reduces polishing effectiveness
Solution Approach 1:
The patent changes the chemical composition parameters of the polishing slurry by specifying precise concentrations of organic alkali (0.01-10 wt%), inorganic alkali (0.1-10 wt%), and chelating agent (0.1-10 wt%). This parameter optimization balances the need for organic alkali to enable protrusion formation on abrasive grains while preventing excessive adsorption that would harm polishing performance on hydrophilic surfaces
Solution Approach 2:
The patent introduces a chelating agent as an intermediary substance that binds to metal ions and organic alkali, preventing their harmful adsorption on hydrophilic surfaces while maintaining the beneficial protrusion structure on abrasive grains. This mediator resolves the contradiction by neutralizing the harmful effects without compromising the polishing mechanism
2Object-affected harmful factors
If pH is adjusted close to pKa value of organic alkali to control its effect, then adsorption is suppressed, but polishing rate decreases
Solution Approach 1:
The patent creates a composite chemical system combining organic alkali, inorganic alkali, and chelating agent in specific ratios. This composite approach allows the system to maintain effective pH control near the pKa value while the chelating agent compensates for any polishing rate loss by preventing ion adsorption and maintaining abrasive grain effectiveness
Solution Approach 2:
The patent applies different functional components in localized roles: organic alkali primarily for protrusion formation on abrasive grains, inorganic alkali for pH buffering, and chelating agent for selective ion binding at the interface with hydrophilic surfaces. This localized functional distribution allows pH optimization without sacrificing polishing rate
3Strength
If protrusion height is increased to improve mechanical polishing ability, then abrasive effectiveness is enhanced, but sensitivity to organic alkali adsorption increases
Solution Approach 1:
The patent optimizes the concentration of organic alkali within a specific range (0.01-10 wt%) to ensure sufficient protrusion formation on abrasive grains for mechanical polishing while preventing excessive protrusion growth that would increase surface area and sensitivity to adsorption. The chelating agent concentration (0.1-10 wt%) is simultaneously optimized to counteract adsorption effects
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 effectively polishes hydrophilic objects at a high rate, particularly metal oxide layers, by optimizing the shape and size of abrasive grains and controlling organic alkali content to suppress rate reduction, thereby improving mechanical polishing ability and reducing surface roughness.
Implementation Method 1
The polishing composition contains abrasive grains each having a surface with protrusions... Parts of the abrasive grains have larger particle diameters than the volume-based average particle diameter of the abrasive grains, and the average of values respectively obtained by dividing the height of each protrusion on the surface of each abrasive grain belonging to the parts of the abrasive grains by the width of a base portion of the same protrusion is 0.170 or more
Implementation Method 2
the rate of polishing a hydrophilic object with such a polishing composition is significantly affected by an organic alkali contained in the polishing composition... the polishing composition has a content of an organic alkali of 100 mmol or less per kilogram of the abrasive grains
Data Source
AI summary
A polishing composition of the present invention contains abrasive grains each having a surface with protrusions. Parts of the abrasive grains have larger particle diameters than the volume-based average particle diameter of the abrasive grains, and the average of values respectively obtained by dividing a height of each protrusion on the surface of each abrasive grain belonging to the parts of the abrasive grains by the width of a base portion of the same protrusion is 0.170 or more. Protrusions on the surfaces of abrasive grains belonging to the parts of the abrasive grains that have larger particle diameters than the volume-based average particle diameter of the abrasive grains have an average height of 3.5 nm or more. The polishing composition has a content of an organic alkali of 100 mmol or less per kilogram of the abrasive grains in the polishing composition.