Polishing Composition Reducing Surface Defects via Dispersibility Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional polishing compositions, including cellulose derivatives, struggle to achieve a surface with low haze and few surface defects, particularly in the final polishing step of semiconductor substrates like silicon wafers, due to micro aggregation and quality variability of cellulose derivatives.
Innovation Solution
A polishing composition comprising an abrasive, a basic compound, and a surface protective agent with a cellulose derivative and a vinyl alcohol-based dispersant, where the dispersibility parameter is less than 100, effectively reduces surface defects by improving dispersibility and wettability, and includes an oxyalkylene-based additive to enhance surface quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polishing compositions including cellulose derivatives are used, then the polishing process can be performed, but micro aggregation occurs causing surface defects
Solution Approach 1:
The patent extracts and removes the harmful micro aggregation component from the polishing composition by optimizing the cellulose derivative selection and adding specific dispersants, thereby eliminating the source of surface defects while maintaining the beneficial protective functions
Solution Approach 2:
The patent introduces dispersants as intermediary substances that mediate between the cellulose derivative and the polishing slurry components, preventing micro aggregation formation and ensuring uniform distribution of particles for defect-free polishing surfaces
2Ease of manufacture
If cellulose derivatives with varied quality are used, then the polishing composition can be formulated, but surface defects cannot be accurately prevented
Solution Approach 1:
The patent applies parameter changes by specifying precise molecular weight ranges for cellulose derivatives (5×10^4 to 500×10^4) and optimizing dispersant concentrations, thereby transforming the formulation from a flexible but imprecise process to a controlled precision process that prevents surface defects
Solution Approach 2:
The patent creates a composite material system combining cellulose derivatives with specific dispersants and polishing particles, where the composite exhibits superior properties that prevent micro aggregation and surface defects while maintaining formulation flexibility
3Reliability
If general-purpose water-soluble polymers like HEC are used, then the surface protective function is provided, but surface defects still occur
Solution Approach 1:
The patent applies local quality by selecting cellulose derivatives with specific molecular weight characteristics and combining them with dispersants that locally address the micro aggregation problem at the molecular level, while maintaining the overall surface protective function of the polishing composition
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 significantly reduces Light Point Defect Non-cleanable (LPD-N) defects and achieves a higher quality surface with reduced haze, improving the overall polishing outcome.
Implementation Method 1
a vinyl alcohol-based dispersant... the surface protective agent has a dispersibility parameter α of less than 100
Implementation Method 2
improving wettability... a vinyl alcohol-based dispersant... dispersibility parameter α of less than 100
Data Source
AI summary
Provided is a polishing composition that includes a cellulose derivative and is effective for reducing surface defects after polishing. According to the present application, a polishing composition comprising an abrasive, a basic compound and a surface protective agent is provided. The surface protective agent contains a cellulose derivative and a vinyl alcohol-based dispersant. The surface protective agent has a dispersibility parameter α of less than 100.