Silane-Modified Ceria CMP Slurry for Stable High Oxide Selectivity
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Solution Overview
Problem
Existing polishing compositions using ceria abrasive particles face challenges in achieving desirable removal rates and particle size stability, as surface modification is believed to block active sites, reducing their effectiveness in chemical-mechanical polishing (CMP) processes.
Innovation Solution
A chemical-mechanical polishing composition comprising ceria abrasive particles with associated silanes of Formula I, which are covalently bonded to the ceria surface, along with water, to enhance stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If surface modification is applied to ceria particles, then colloidal stability is improved, but removal rate decreases due to blocked active sites
Solution Approach 1:
The patent changes the chemical parameters of surface modification by selecting specific silane compounds with particular functional groups and molecular weights. This optimization allows achieving colloidal stability while maintaining removal rate by finding the right balance in modification parameters
Solution Approach 2:
The patent creates a composite surface structure on ceria particles by combining ceria base material with silane modification layers. This composite approach provides both the colloidal stability from silane coating and the polishing effectiveness from exposed ceria active sites
2Stability of the object's composition
If surface modification is applied to ceria particles, then particle size stability is improved, but active sites are blocked reducing effectiveness
Solution Approach 1:
The patent applies local quality by creating non-uniform surface modification where silane groups are distributed in a controlled manner on the particle surface. This ensures particle size stability through uniform coating while maintaining local active sites for polishing effectiveness
Solution Approach 2:
The patent optimizes modification parameters including silane concentration, molecular weight, and functional group selection to achieve the right balance between particle size stability and preservation of active sites for effective polishing
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 high removal rates for silicon oxide and selective low removal rates for silicon nitride, while minimizing defects and surface imperfections, thus improving the efficiency and quality of substrate polishing.
Implementation Method 1
the ceria abrasive particles comprise at least one associated silane... wherein at least one X is associated with a surface atom of the ceria abrasive particle
Implementation Method 2
moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate to polish the substrate
Data Source
AI summary
The invention provides a chemical-mechanical polishing composition comprising (i) ceria abrasive particles, wherein each ceria abrasive particle comprises at least one associated silane comprising at least one moiety of Formula I: Si(R1)n(X)(4-n), wherein R1, X, and n are as defined herein, and (ii) water. The invention also provides a method of chemically-mechanically polishing a substrate, especially a silicon oxide and/or silicon nitride substrate, by contacting the substrate with the inventive chemical-mechanical polishing composition.