Polishing Slurry Composition for Semiconductor Substrates
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Solution Overview
Problem
Current polishing slurry compositions for semiconductor substrates often result in scratching and reduced planarization efficiency, particularly during the miniaturization of semiconductor devices, necessitating additional time-consuming polishing steps to correct scratches and maintain precision.
Innovation Solution
A polishing slurry composition comprising a metal oxide particle, a combination of water-soluble organic polymers with varying molecular weights, and water, optimized to achieve a peak polishing rate under constant pressure, reducing scratching and allowing for a single slurry composition to be used in both initial and final polishing steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a water-soluble organic polymer is added to a polishing slurry composition to improve planarization and reduce dishing, then planarization efficiency is improved, but the processing rate decreases and scratching increases
Solution Approach 1:
The patent changes the molecular weight parameters of the water-soluble organic polymer from conventional high molecular weight ranges to a specific range of 1,000 to 1,000,000 (preferably 10,000 to 500,000). This parameter change allows the polymer to provide adequate planarization and dishing prevention while reducing the negative effects on processing rate and scratching, resolving the contradiction between manufacturing precision and productivity.
Solution Approach 2:
The patent uses a composite slurry composition containing both metal oxide particles (alumina, silica, or ceria) and water-soluble organic polymers in specific concentration ratios. The metal oxide particles provide mechanical polishing and high processing rate, while the polymer provides planarization and dishing prevention. This composite approach allows both functions to coexist, resolving the contradiction between processing rate and planarization efficiency.
2Productivity
If a polishing slurry composition with high processing rate is used, then productivity is improved, but scratching occurs and planarization deteriorates
Solution Approach 1:
The patent changes the molecular weight parameter of the water-soluble organic polymer to a specific range (1,000 to 1,000,000) that optimizes the balance between processing rate and planarization. This parameter change allows the polymer to effectively control scratching and maintain planarization even when using metal oxide particles that provide high processing rates.
Solution Approach 2:
The water-soluble organic polymer acts as an intermediary substance between the metal oxide particles and the substrate surface. It mediates the interaction by providing a controlled interface that reduces scratching while maintaining the mechanical polishing action needed for high processing rates, thus resolving the contradiction between productivity and manufacturing precision.
3Manufacturing precision
If multiple polishing steps with different slurry compositions are used to remove scratches, then manufacturing precision is improved, but loss of time increases
Solution Approach 1:
The patent creates a universal polishing slurry composition that performs multiple functions simultaneously: mechanical polishing, planarization, dishing prevention, and scratch reduction. By making the slurry multi-functional through the specific combination of metal oxide particles and water-soluble organic polymers, a single polishing step can achieve results that previously required multiple steps, thus resolving the contradiction between manufacturing precision and time loss.
Solution Approach 2:
The patent merges multiple polishing functions into a single slurry composition and single polishing step. Instead of using separate slurries for mechanical polishing and scratch removal, the invention combines these functions into one optimized slurry that performs both tasks effectively, eliminating the need for additional polishing steps and reducing total process time while maintaining manufacturing precision.
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 effectively minimizes scratching and maintains high planarization efficiency, enabling a single slurry to be used across multiple polishing steps, reducing process time and costs by eliminating the need for multiple slurry changes and additional polishing steps.
Implementation Method 1
one containing alumina as a metal oxide polishing particle has been used for a hard metal film, such as a tungsten film and the like, and a polishing slurry containing silica as a polishing particle has been used for a soft metal film, such as copper and the like
Implementation Method 2
since ceria particles cause a slight chemical reaction with the SiO2 surface, which is a component of a film
Implementation Method 3
when a water-soluble organic polymer, such as polyethylene oxide, polyvinyl alcohol, alginates, guar gum, carboxylmethylcellulose, hydroxylethylcellulose and polyacrylate, is added to a polishing slurry composition with metal oxide particles dispersed in water, dishing is less likely to occur
Implementation Method 4
dishing is less likely to occur when polishing the layers of interlayer dielectric film, shallow trench isolation film, and the metal film due to the improved planarization effect
Data Source
AI summary
To provide a polishing slurry composition which effectively reduces the occurrence of scratches, and a method of polishing which reduces the occurrence of scratches while realizing an economical polishing step. The aforementioned object is attained by using a polishing slurry composition for polishing a semiconductor substrate containing a metal oxide particle, at least one water-soluble organic polymer and water, said slurry composition characterized in that, when a test substrate having a metal film, a shallow trench isolation film or dielectric film is polished by varying a rate of a polishing pad equipped in a polishing apparatus under a constant polishing pressure to achieve a maximum polishing rate.