CMP Slurry Composition for High Aspect Ratio Step Planarization
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Solution Overview
Problem
Current chemical mechanical polishing (CMP) processes struggle to achieve high polishing speed in high stepped regions while simultaneously protecting low stepped regions, leading to incomplete planarization and increased costs due to excessive slurry consumption and residual steps.
Innovation Solution
A slurry composition comprising polishing particles, a hydroxycarboxylic acid compound, and a diamine compound, used in a two-step process with specific volume ratios of polishing particle dispersion and additive mixture solution, enhances polishing speed in high stepped regions while protecting low stepped regions, ensuring complete removal of steps and high flatness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single slurry is used for polishing the entire surface, then the polishing cost increases due to excessive slurry consumption, but the polishing speed in high stepped regions is not sufficiently high
Solution Approach 1:
The patent applies local quality by using different slurries with different concentrations in different regions of the semiconductor substrate. Specifically, a first slurry with a higher concentration is applied to high stepped regions to achieve high polishing speed, while a second slurry with a lower concentration is applied to low stepped regions to prevent over-polishing and reduce overall slurry consumption. This regional differentiation resolves the contradiction between polishing speed and slurry consumption.
2Manufacturing precision
If polishing is performed to remove steps from high stepped regions, then the steps are not completely removed, but the low stepped regions become damaged due to over-polishing
Solution Approach 1:
The patent uses local quality by adjusting slurry concentration according to the local topography of the substrate. High stepped regions receive a more aggressive slurry treatment, while low stepped regions receive a gentler treatment, preventing damage while ensuring complete step removal and achieving the desired flatness.
Solution Approach 2:
The patent changes the concentration parameter of the slurry based on the region being polished. By varying the slurry concentration from high to low across different regions, the patent optimizes the polishing rate and selectivity, enabling complete step removal without damaging low stepped regions.
3Manufacturing precision
If a single polishing condition is used for the entire process, then the remaining steps are not completely removed, but the polishing time increases
Solution Approach 1:
The patent segments the polishing process into multiple stages with different slurries. The first polishing step uses a slurry optimized for high stepped regions, while the second polishing step uses a different slurry for low stepped regions. This segmentation allows each step to be optimized for its specific purpose, achieving complete step removal more efficiently than a single uniform process.
Solution Approach 2:
The patent changes polishing parameters (slurry concentration, composition) between different polishing steps. This parameter variation enables the process to adapt to different polishing requirements at different stages, removing steps completely while minimizing total polishing time.
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 solution achieves a high polishing speed in high stepped regions while preventing damage to low stepped regions, resulting in complete step removal and high flatness without residual steps, thereby improving planarization efficiency and reducing semiconductor device manufacturing costs.
Implementation Method 1
the chemical mechanical polishing (CMP) process has been used as a planarization technique for removing the steps in a specific film formed on a substrate
Data Source
AI summary
The present invention relates to a slurry composition for polishing and a method for polishing a semiconductor thin film with steps of a high aspect ratio, and more particularly, by comprising polishing particles, a compound represented by Chemical Formula 1 below, and a compound represented by Chemical Formula 2 below, to make a slurry composition for polishing that has a high polishing speed in high stepped regions while simultaneously protecting low stepped regions to obtain a high degree of flatness without leaving remaining steps after the completion of polishing, and a method for polishing a semiconductor thin film with steps of a high aspect ratio.in Chemical Formula 1, n is an integer of 1 to 10,in Chemical Formula 2, R1 to R4 are independently C1-C10 alkyl groups, and m is an integer of 1 to 10.