Cerium Oxide CMP Slurry With Dishing Control for Oxide Polishing
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Solution Overview
Problem
Conventional cerium oxide slurries face challenges in achieving high oxide film removal rates with small particle sizes, leading to polishing scratches and dishing/erosion issues during semiconductor manufacturing, particularly in low-density patterns.
Innovation Solution
A CMP slurry composition comprising cerium oxide particles with a high Ce3+ content on the surface, combined with a dishing control agent, enhances oxide film polishing rates while minimizing dishing and surface defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the average particle diameter of cerium oxide particles is reduced to minimize polishing scratches, then the mechanical action is reduced and the polishing rate is reduced
Solution Approach 1:
The patent changes the chemical composition parameters of cerium oxide particles by controlling the Ce3+/Ce4+ ratio through specific synthesis conditions (pH control during precipitation, oxidation treatment). This chemical parameter change enables small particles to achieve high polishing rates through enhanced chemical reactivity, resolving the contradiction between particle size and polishing rate
Solution Approach 2:
The patent creates a composite slurry system combining cerium oxide particles with specific additives (surfactants, pH buffers, chelating agents). This composite formulation enhances the chemical mechanical polishing action of fine particles, maintaining high polishing rates while using small particle sizes to minimize scratches
2Manufacturing precision
If conventional cerium oxide particles are used with small particle size, then polishing scratches are reduced, but the oxide film removal rate is insufficient
Solution Approach 1:
The patent modifies the chemical state of cerium oxide particles by controlling the Ce3+ content through synthesis parameters (pH, oxidation treatment). This chemical parameter change increases the reactivity of small particles with oxide films, enabling high removal rates despite small particle size
Solution Approach 2:
The patent introduces chemical intermediaries (Ce3+ ions, surfactants, chelating agents) that mediate between the mechanical action of particles and the chemical reaction with oxide films. These intermediaries enhance the polishing efficiency of small particles, resolving the contradiction between surface finish quality and removal rate
3Productivity
If CMP slurry is used for high-density patterns, then polishing rate and selectivity are achieved, but dishing and erosion occur significantly in low-density patterns
Solution Approach 1:
The patent adjusts the chemical composition parameters of the slurry, including Ce3+/Ce4+ ratio, pH, and additive concentrations, to optimize the balance between chemical etching and mechanical removal. This enables uniform polishing across different pattern densities by controlling the chemical mechanical polishing mechanism
Solution Approach 2:
The patent employs dishing control agents that respond to local polishing conditions, dynamically adjusting the polishing action through chemical feedback mechanisms. This feedback control prevents dishing in low-density areas while maintaining removal rate in high-density areas
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 a high oxide film removal rate with reduced polishing scratches and dishing, maintaining excellent dispersion stability and polishing efficiency.
Implementation Method 1
increasing the ratio of Ce3+ on the cerium oxide surface... to have a high oxide film removal rate
Implementation Method 2
through an appropriate additive component, to reduce dishing occurrence
Data Source
AI summary
Cerium oxide particles for chemical mechanical polishing and a chemical mechanical polishing slurry composition comprising same are described. A combination of the characteristic cerium oxide particles with a dishing control agent leads to the provision of a chemical mechanical polishing slurry composition that suppresses dishing occurring during the polishing process while enhancing the oxide layer polishing rate, and a method for manufacturing semiconductor devices utilizing same.