CMP Slurry With Zirconia-Silica Particles for Peroxide Stability
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Solution Overview
Problem
Conventional CMP slurries face challenges in maintaining hydrogen peroxide stability and achieving consistent material removal rates across different substrates, such as copper, tantalum nitride, and silica, due to the instability of hydrogen peroxide over time and variations in polishing efficiency.
Innovation Solution
A CMP slurry comprising zirconia core particles with a silica shell, combined with hydrogen peroxide and other additives, which provides a stable hydrogen peroxide environment and enhances material removal rates by optimizing the silica shell thickness and composition, ensuring consistent performance across various substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CMP slurries are used, then polishing can be performed on substrates, but hydrogen peroxide stability deteriorates over time leading to inconsistent material removal rates
Solution Approach 1:
The patent introduces a chelating agent as an intermediary substance that mediates between hydrogen peroxide and metal ions in the slurry. This chelating agent forms stable complexes with metal ions, preventing them from catalyzing hydrogen peroxide decomposition. By adding this intermediary component, the slurry maintains hydrogen peroxide stability over time while preserving consistent material removal rates across different substrates
2Productivity
If hydrogen peroxide concentration is increased to enhance material removal, then polishing efficiency improves, but hydrogen peroxide stability deteriorates due to faster decomposition
Solution Approach 1:
The patent applies preliminary anti-action by adding a chelating agent before hydrogen peroxide decomposition can occur. This chelating agent proactively binds to metal ions that would otherwise catalyze peroxide breakdown, preventing the harmful catalytic effect before it can reduce hydrogen peroxide stability. This allows the slurry to maintain both high material removal rates and peroxide stability throughout the polishing process
3Productivity
If polishing slurry composition is optimized for one substrate, then material removal rate for that substrate improves, but performance on other substrates deteriorates
Solution Approach 1:
The patent achieves universality by formulating a slurry composition that effectively polishes multiple substrate types (copper, tantalum nitride, silica, and other semiconductor materials) with a single formulation. The key to this multi-functionality is the chelating agent that stabilizes hydrogen peroxide across varying chemical environments, allowing the same slurry to maintain consistent material removal rates on different substrates without requiring substrate-specific optimization
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 CMP slurry achieves a Hydrogen Peroxide Stability % Reduction of not greater than 50%, with material removal rates of at least 100 Å/min for SiO2, 1500 Å/min for copper, and 100 Å/min for TaN, while maintaining a low ST Material Removal Rate Percent Difference, indicating improved stability and efficiency in polishing processes.
Implementation Method 1
Chemical mechanical planarization (CMP) slurry comprising: a plurality of particles distributed in a carrier, and an oxidizing agent
Implementation Method 2
The CMP slurry comprises at least one of: a Hydrogen Peroxide Stability % Reduction of not greater than 50%
Data Source
AI summary
A chemical mechanical polishing (CMP) slurry can comprise a plurality of particles distributed in a carrier, wherein at least a portion of the particles of the plurality of particles can have a body including a core comprising zirconia and a shell overlying at least a portion of the core, wherein the shell comprises silica; an oxidizing agent; and a carrier. The CMP slurry can comprise at least one of a Hydrogen Peroxide Stability % Reduction of not greater than 50%; and a high copper material removal rate.