CMP Polymer Additive for High-Speed Polishing and Dishing Reduction
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Solution Overview
Problem
Current chemical mechanical polishing (CMP) techniques face challenges in achieving high polishing speed while minimizing dishing on uneven surfaces, as existing additives either fail to enhance polishing speed sufficiently or provide inadequate surface protection.
Innovation Solution
A polymer additive with a narrow molecular weight distribution and specific structural units, including a vinyl monomer with a -(LO)n-R group, is used to enhance polishing speed and reduce dishing, combined with cerium oxide and/or silica in the polishing liquid composition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a water-soluble polymer with strong adsorption property is used to protect the polished film surface, then surface flatness is improved, but polishing speed becomes insufficient
Solution Approach 1:
The invention changes the molecular weight parameter of the water-soluble polymer to a specific range (1,000 to 100,000) with dispersity of 2.0 or less, optimizing the balance between adsorption capability and polishing speed. This parameter optimization allows the polymer to provide sufficient surface protection while maintaining high polishing efficiency.
Solution Approach 2:
The invention uses a composite approach by combining the optimized water-soluble polymer with specific abrasive grains (ceria particles with average particle diameter of 1 nm to 100 nm). This composite system achieves both high polishing speed and excellent surface flatness by synergistic interaction between the polymer and abrasive grains.
2Device complexity
If conventional polishing liquid composition is used to polish uneven surfaces, then polishing process is simple, but dishing occurs on concave portions
Solution Approach 1:
The invention applies local quality control by using abrasive grains with specific local characteristics (ceria particles with controlled size distribution of 1 nm to 100 nm) that selectively interact with different surface regions. The polymer composition also provides localized protection where needed, preventing dishing in concave portions while maintaining polishing effectiveness on convex portions.
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 polymer additive significantly increases polishing speed of convex portions and reduces dishing on uneven surfaces, providing a balanced solution for high-speed polishing without surface defects.
Implementation Method 1
the water-soluble polymer, the surfactant, and the like are added to the polishing liquid for the purpose of improving the flatness of an object to be polished and reducing surface defects, and have an effect of protecting the surface by being adsorbed on the surface of a polished film
Implementation Method 2
a polishing liquid is used for improving polishing speed and processing accuracy. The polishing liquid generally includes abrasive grains
Data Source
AI summary
An additive is configured to be used for chemical mechanical polishing, and contains a polymer. The polymer contains a structural unit (A) derived from a vinyl monomer having a -(LO)n-R group, and a total content of the structural unit derived from a monomer containing one or more functional groups selected from the group consisting of a carboxylic acid group, a phosphoric acid group, a phosphonic acid group, a sulfuric acid group, a sulfonic acid group, and salts thereof is 0 to 0.6 mass % in polymer. The polymer has a dispersity represented by weight average molecular weight (Mw)/number average molecular weight (Mn) of 2.0 or less, wherein L represents an alkylene group having 4 or less carbon atoms, n represents an arbitrary integer of 3 to 150, and R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 4 carbon atoms.