Polishing Composition with pH-Controlled Silica for Scratch-Free High-Speed CMP
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) compositions either improve polishing speed but generate scratches or suppress scratches but compromise on polishing speed, making it difficult to achieve both high speed and low defect rates simultaneously for substrates containing oxygen and silicon atoms.
Innovation Solution
A polishing composition using silica with a specific thermogravimetric measurement peak height range of −0.011 to 0 and a pH of less than 6.0, which allows for efficient abrasive action and prolonged surface interaction, enhancing polishing speed while reducing scratches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP compositions are used to improve polishing speed, then polishing speed increases, but scratches are generated on the substrate surface
Solution Approach 1:
The patent applies parameter changes by precisely controlling the pH of the polishing composition to be less than 6.0 (preferably 3.0 to 5.5) and selecting silica with specific thermogravimetric properties (maximum peak height of -0.011 to less than 0). These parameter optimizations enable the composition to achieve high polishing speed while minimizing scratches on the substrate surface.
2Manufacturing precision
If conventional CMP compositions are used to suppress scratches, then surface quality improves, but polishing speed becomes insufficient
Solution Approach 1:
The patent resolves this contradiction by optimizing key parameters: pH is controlled to be less than 6.0 (ideally 3.0-5.5), and silica is selected with a maximum peak height in thermogravimetric measurement of -0.011 to less than 0. These parameter changes enable the composition to simultaneously achieve scratch suppression and adequate polishing speed.
3Productivity
If high concentration of silica is used to increase polishing speed, then polishing speed improves, but scratches increase and cost increases
Solution Approach 1:
The patent achieves high polishing speed with low silica concentration (0.1-10% by weight, preferably 0.1-5%) by optimizing the pH to less than 6.0 and selecting silica with specific thermogravimetric properties. This parameter optimization reduces both scratches and costs while maintaining high productivity.
Solution Approach 2:
The patent creates an optimized composite polishing composition that combines silica with specific thermogravimetric characteristics, pH-controlled liquid medium, and optional additives. This composite formulation achieves superior performance at low silica concentration, reducing both scratches and material costs while maintaining high polishing speed.
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 a high polishing speed with reduced scratches on substrates containing oxygen and silicon atoms, even at low silica concentrations, offering a cost-effective and efficient polishing solution.
Implementation Method 1
CMP is a method for flattening a surface of an object to be polished (polishing object) such as a semiconductor substrate by using a polishing composition (slurry) containing abrasive grains such as silica
Implementation Method 2
a maximum peak height in a weight change rate distribution curve obtained by thermogravimetric measurement in a range of 25° C. or higher and 250° C. or lower
Data Source
AI summary
The present invention provides a polishing composition which can polish an object to be polished at a high polishing speed and with fewer scratches (defects). The present invention is a polishing composition containing silica of which a maximum peak height in a weight change rate distribution curve obtained by thermogravimetric measurement in a range of 25° C. or higher and 250° C. or lower is −0.011 or more and less than 0, a pH at 25° C. of the polishing composition being less than 6.0.