Semiconductor CMP Slurry for Stable Amorphous Carbon Removal
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Solution Overview
Problem
Existing polishing compositions for semiconductor processes face challenges in maintaining high removal rates for amorphous carbon layers at elevated temperatures, suffer from particle aggregation leading to reduced stability, and result in carbon residue adsorption on substrates, causing defects.
Innovation Solution
A polishing composition comprising abrasive particles, an accelerator, and a stabilizer, with a cohesion index (CI) of 0.5 to 5, which prevents particle aggregation and maintains high removal rates even at 60°C, using a dynamic light scattering technique to measure particle stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional polishing compositions are used for amorphous carbon layers, then polishing can be performed, but the removal rate decreases significantly at temperatures of 60°C or higher
Solution Approach 1:
The patent modifies the chemical composition parameters of the polishing slurry by incorporating specific organic acids (formic acid, acetic acid, propionic acid, or butyric acid) at controlled concentrations (0.1-10 wt%). This chemical parameter change enables the slurry to maintain effective removal rates at elevated temperatures (60°C or higher) that would otherwise cause conventional slurries to lose effectiveness.
2Duration of action of stationary object
If polishing slurry is stored for long periods, then it remains available for use, but particles aggregate leading to reduced stability and performance
Solution Approach 1:
The patent introduces organic acids as intermediary substances that mediate between abrasive particles and the slurry matrix. These organic acids adsorb onto particle surfaces, providing steric and electrostatic stabilization that prevents aggregation during long-term storage, thereby maintaining slurry stability and performance over extended periods.
3Manufacturing precision
If conventional CMP processes are applied to organic layers, then planarization can be attempted, but carbon residue is generated and adsorbed onto the substrate causing defects
Solution Approach 1:
The patent employs organic acids as chemical agents that accelerate the oxidation and removal of carbon residue during the CMP process. These acids chemically react with carbon deposits, converting them into soluble or removable forms, thereby preventing residue adsorption onto the substrate and eliminating defects while maintaining surface planarity.
4Productivity
If polishing is performed on amorphous carbon layers, then the layer can be removed, but the polishing pad becomes contaminated
Solution Approach 1:
The patent converts the potentially harmful interaction between carbon particles and the polishing pad into a beneficial process by using organic acids to chemically manage carbon removal. The acids facilitate carbon removal in a controlled manner that minimizes pad contamination, effectively converting what would be a harmful contamination issue into a manageable chemical process.
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 ensures stable high removal rates for amorphous carbon layers, prevents carbon residue adsorption, and maintains polishing pad cleanliness, enhancing semiconductor device fabrication quality.
Implementation Method 1
a surface of a substrate is polished while a slurry is provided to a polishing pad and the substrate is pressed and rotated
Implementation Method 2
measured by a dynamic light scattering particle size analyzer
Data Source
AI summary
The present invention relates to a polishing composition for a semiconductor process, a method of preparing the polishing composition, and a method of fabricating a semiconductor device using the polishing composition. The polishing composition for a semiconductor process contains abrasive particles, an accelerator, and a stabilizer. The polishing composition has excellent long-term storage stability because the particles contained therein do not aggregate even after the polishing composition is stored at 60° C. or higher for a long time. In addition, the polishing composition may be applied to a process of polishing an amorphous carbon layer, may exhibit a high removal rate, prevent carbon residue generated during the polishing process from being adsorbed onto a semiconductor substrate, and prevent contamination of a polishing pad. The present invention may also provide a method of fabricating a semiconductor device using the polishing composition for a semiconductor process.