UV-Activated Ceria Polishing Composition for High Removal Rate
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Solution Overview
Problem
Conventional chemical mechanical polishing techniques require chemical additives to increase the percentage of trivalent cerium ions (Ce3+) in ceria polishing materials, limiting the efficiency of the polishing process.
Innovation Solution
Irradiating ultraviolet (UV) light onto a dispersion solution containing ceria particles to form oxygen vacancies and increase the amount of trivalent cerium cations (Ce3+), thereby enhancing the polishing rate without the need for chemical additives, and optionally incorporating polymers and amino acids to further improve the removal rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chemical additives are used to increase the percentage of Ce3+ in ceria polishing materials, then the polishing efficiency is improved, but the process complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the chemical additives (sulfonic acid, phosphonic acid, phosphinic acid) from the polishing composition formulation. Instead of using these chemical reducing agents, the invention employs UV light irradiation to generate Ce3+ ions directly on the ceria particle surfaces, thereby simplifying the overall process while maintaining high polishing efficiency
Solution Approach 2:
The patent replaces the chemical mechanism (use of reducing agents) with a physical mechanism (UV light irradiation). The UV light provides energy to create oxygen vacancies and reduce Ce4+ to Ce3+ through photoexcitation, substituting the chemical reduction process with a physical energy input method that avoids additional chemical components
2Productivity
If chemical additives are used to increase the percentage of Ce3+ in ceria polishing materials, then the polishing efficiency is improved, but the processing cost increases
Solution Approach 1:
The patent employs UV light, an inexpensive and readily available energy source, to generate the required Ce3+ ions. This approach eliminates the need for costly chemical additives while using a disposable, low-cost energy input (light irradiation) that can be applied briefly to achieve the desired effect
Solution Approach 2:
By removing the chemical additives from the formulation, the patent eliminates the associated material costs and simplifies the supply chain, reducing overall processing costs while maintaining effectiveness through the UV irradiation method
3Reliability
If conventional polishing methods are used, then the process is stable, but the removal rate is limited
Solution Approach 1:
The patent changes the oxidation state parameter of ceria by generating Ce3+ ions through UV irradiation. This parameter change (from predominantly Ce4+ to a mixture of Ce3+ and Ce4+) fundamentally alters the polishing mechanism and dramatically increases the removal rate while maintaining process stability through controlled irradiation
Solution Approach 2:
The patent performs preliminary UV irradiation treatment on the ceria particles before the actual polishing process. This preliminary action creates oxygen vacancies and generates Ce3+ ions in advance, preparing the polishing composition for enhanced performance during the subsequent polishing operation
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 method increases the reactivity of the polishing composition, leading to a higher removal rate and reduced processing time, with the ability to achieve a high removal rate in seconds, thus lowering processing costs and improving the efficiency of the polishing process.
Implementation Method 1
Irradiating ultraviolet (UV) light onto a dispersion solution containing ceria particles to form oxygen vacancies and increase the amount of trivalent cerium cations (Ce3+)
Data Source
AI summary
A method of preparing a polishing composition includes forming a dispersion solution containing ceria particles, and irradiating ultraviolet (UV) light onto the dispersion solution.