CMP Slurry Composition for Fine Filtration Without HEC Aggregation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Chemical-mechanical polishing compositions containing hydroxyethyl cellulose (HEC) and abrasives like silica tend to form aggregates upon dilution, leading to reduced filterability and impaired surface quality due to HEC's adsorption to the abrasive, making it difficult to use filters with smaller pore diameters effectively.
Innovation Solution
A chemical-mechanical polishing composition comprising HEC with a weight average molecular weight of 200,000 or less, combined with a surfactant such as an alkylene polyalkylene oxide amine polymer or polyoxyalkylene alkyl ether, and an abrasive like silica, which improves filterability even after dilution, allowing for effective filtration through smaller pore filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If HEC is used in the polishing composition to enhance wettability and maintain hydrophilicity, then surface quality is improved, but filterability deteriorates after dilution due to aggregate formation
Solution Approach 1:
The patent changes the molecular weight parameter of HEC from conventional high values to 200,000 or less, which fundamentally alters the polymer's aggregation behavior. This parameter change allows HEC to maintain dispersibility after dilution while still providing the necessary wettability enhancement and surface quality improvement, thereby resolving the contradiction between surface quality and filterability.
Solution Approach 2:
The patent introduces a surfactant as an intermediary substance that mediates between HEC and silica abrasive particles. The surfactant prevents HEC from adsorbing to the abrasive surface, which would otherwise cause aggregate formation. This intermediary action maintains both the wettability benefits of HEC and the filterability required for effective polishing composition use.
2Manufacturing precision
If the pore diameter of the filter is reduced to remove smaller aggregates, then surface quality is further improved, but filter clogging increases due to HEC adsorption to abrasive
Solution Approach 1:
By changing the molecular weight parameter of HEC to 200,000 or less, the patent reduces the polymer's tendency to form large aggregates that would clog filters. This parameter change enables the use of filters with smaller pore diameters to achieve better surface quality while maintaining adequate filtration flow rates and avoiding excessive clogging.
Solution Approach 2:
The surfactant acts as an intermediary that prevents HEC from adsorbing to silica abrasive particles. This mediation eliminates the root cause of aggregate formation, allowing filters with smaller pore diameters to operate efficiently without clogging, thereby enabling improved surface quality while maintaining productivity.
3Manufacturing precision
If HEC concentration is increased to improve wettability, then surface quality improves, but dispersibility after dilution deteriorates due to aggregate formation
Solution Approach 1:
The patent changes the molecular weight parameter of HEC to 200,000 or less, which fundamentally improves the polymer's dispersibility characteristics. This parameter change allows HEC to maintain stable dispersion even after dilution, while still providing sufficient wettability enhancement for high surface quality polishing results.
Solution Approach 2:
The surfactant serves as an intermediary that prevents HEC molecules from adsorbing to abrasive particle surfaces. This mediation maintains the dispersibility of the polishing composition after dilution, ensuring that HEC remains effectively dispersed and continues to provide wettability benefits without forming aggregates that would compromise composition stability.
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 achieves enhanced POU filter filterability and improved surface quality by preventing clogging and maintaining high dispersibility, enabling efficient polishing and reducing surface defects and haze.
Implementation Method 1
hydroxyethyl cellulose (HEC) is used as a water-soluble polymer for the purpose of enhancing wettability of the substrate surface
Implementation Method 2
HEC tends to adsorb to the abrasive such as silica to form aggregates
Implementation Method 3
devices which irradiate the substrate surface with light such as laser light, and which detect reflected light or scattered light generated by the substrate surface
Implementation Method 4
detect reflected light or scattered light generated by the substrate surface
Implementation Method 5
clouding may be seen due to diffused reflection as a result of the roughness of the substrate surface
Data Source
AI summary
The chemical-mechanical polishing composition of the present invention is for polishing a substrate and contains an abrasive, a hydroxyethyl cellulose having a weight average molecular weight of 200,000 or less, a basic component, a surfactant, and an aqueous carrier.