Cobalt Polishing Slurry with Amine-Carboxylic Acid Accelerator
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Solution Overview
Problem
Current polishing slurries for cobalt in semiconductor manufacturing often result in corrosion defects and inadequate selectivity between cobalt and insulating films, complicating the polishing process and affecting device quality.
Innovation Solution
A slurry using zirconium oxide particles as abrasives, combined with a polishing accelerator containing an organic acid with an amine and carboxylic group, which regulates pH and prevents corrosion, allowing for effective polishing of cobalt without oxidizing agents and minimizing insulating film polishing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If slurry with oxidizing agent is used for polishing cobalt, then polishing capability is improved, but corrosion defects occur on cobalt surface
Solution Approach 1:
The patent removes the oxidizing agent from the slurry composition entirely, replacing it with a corrosion inhibitor and abrasive system that achieves polishing through mechanical action rather than chemical oxidation. This extraction of the harmful oxidizing agent eliminates the source of corrosion while maintaining polishing capability through alternative mechanisms.
Solution Approach 2:
The patent converts the harmful corrosive action of oxidizing agents into a beneficial protective effect by introducing a corrosion inhibitor that forms a protective layer on the cobalt surface. The inhibitor transforms the potentially harmful chemical environment into a protective one, preventing corrosion while allowing polishing to proceed.
2Object-affected harmful factors
If corrosion inhibitor is added to slurry for polishing cobalt, then corrosion defects are reduced, but slurry composition becomes complicated and control becomes difficult
Solution Approach 1:
The patent optimizes the concentration ranges of slurry components (abrasive: 0.1-10 wt%, dispersing agent: 0.01-5 wt%, corrosion inhibitor: 0.1-2 wt%) to achieve effective corrosion protection and polishing performance. By carefully controlling these parameters within specific ranges, the patent simplifies the overall system while maintaining effectiveness, avoiding the need for complex multi-component formulations.
3Ease of manufacture
If conventional slurry is used for polishing cobalt, then polishing process is simple, but polishing selectivity between cobalt and insulating film is insufficient
Solution Approach 1:
The patent introduces a dispersing agent that creates localized chemical environments around abrasive particles, enhancing the selectivity of the polishing action. The dispersing agent modifies the local chemistry at the polishing interface, allowing preferential removal of cobalt while protecting insulating films, thereby achieving high selectivity without complicating the overall 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 solution prevents corrosion defects and enhances polishing selectivity between cobalt and insulating films, improving the efficiency and quality of semiconductor device manufacturing by ensuring a high polishing rate for cobalt while maintaining the integrity of insulating films.
Implementation Method 1
an abrasive configured to perform the polishing, the abrasive including zirconium oxide particles
Implementation Method 2
a polishing accelerator configured to accelerate the polishing, wherein the polishing accelerator includes an organic acid containing an amine group and a carboxylic group
Implementation Method 3
a dispersing agent configured to disperse the abrasive
Data Source
AI summary
Provided are slurry for polishing cobalt and a substrate polishing method. The slurry includes an abrasive configured to perform the polishing, the abrasive comprising zirconium oxide particles, a dispersing agent configured to disperse the abrasive, and a polishing accelerator configured to accelerate the polishing. The polishing accelerator includes an organic acid containing an amine group and a carboxylic group. According to the slurry in accordance with an exemplary embodiment, a polishing rate of the cobalt may increases without using an oxidizing agent, and local corrosion defects on a surface of the cobalt may be suppressed.