Dielectric CMP Composition for Oxide Selectivity and Low Dishing
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Solution Overview
Problem
There is a need for improved ceria abrasive based CMP compositions that provide enhanced removal rates, planarization, and material selectivity, particularly for silicon-containing substrates such as silicon oxide, silicon nitride, and polysilicon, with reduced erosion and dishing.
Innovation Solution
A chemical mechanical polishing composition comprising cubiform ceria abrasive particles and a cationic polymer with a charge density greater than 6 milliequivalents per gram, dispersed in a liquid carrier, which improves silicon oxide removal rates and selectivity to silicon nitride and polysilicon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ceria abrasive compositions are used, then polishing capability is provided, but removal rates are insufficient and dishing/erosion occur
Solution Approach 1:
The patent changes the shape parameter of ceria abrasive particles from conventional forms to cubiform geometry, and modifies the chemical composition by incorporating specific organic additives. These parameter changes result in improved removal rates while reducing dishing and erosion, resolving the contradiction between productivity and manufacturing precision
Solution Approach 2:
The patent creates a composite polishing composition by combining cubiform ceria abrasive particles with specific organic additives including polymers and surfactants. This composite formulation enhances the polishing performance to achieve both high removal rates and reduced defects simultaneously
2Productivity
If polishing composition is applied to silicon oxide, then removal rate is achieved, but selectivity to other silicon-containing materials is insufficient
Solution Approach 1:
The patent applies local quality by making the polishing composition selectively reactive to silicon oxide through the use of pH buffers and organic additives that specifically target silicon oxide chemistry. This allows high removal rates for silicon oxide while maintaining selectivity against other silicon-containing materials like silicon nitride and polysilicon
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 significantly improved silicon oxide removal rates, reduced silicon nitride removal rates, and enhanced selectivity, while minimizing dishing and erosion across various pattern features and densities.
Implementation Method 1
a cationic polymer having a charge density of greater than about 6 milliequivalents per gram (meq/g)
Implementation Method 2
cubiform ceria abrasive particles dispersed in the liquid carrier
Implementation Method 3
cubiform ceria abrasive particles dispersed in the liquid carrier
Data Source
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AI summary
A chemical mechanical polishing composition for polishing a substrate having a silicon oxygen material comprises, consists of, or consists essentially of a liquid carrier, cubiform ceria abrasive particles dispersed in the liquid carrier, and a cationic polymer having a charge density of greater than about 6 meq/g.