Acidic Tungsten Etching Inhibitor for CMP Surface Treatment
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Solution Overview
Problem
The existing cleaning compositions for semiconductor substrates after chemical mechanical polishing (CMP) are inadequate in suppressing the dissolution of tungsten layers, leading to potential corrosion and surface roughness issues.
Innovation Solution
A surface treatment composition with a pH lower than 7, containing a tungsten etching inhibitor with a monocyclic or fused polycyclic aromatic hydrocarbon ring and nitrogen-containing and anionic groups, is used to effectively inhibit the dissolution of tungsten layers during the cleaning process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a cleaning composition with pH higher than 6 is used to remove foreign materials, then foreign materials can be removed, but the tungsten layer dissolves and corrodes
Solution Approach 1:
The patent changes the pH parameter from basic (higher than 6) to acidic (lower than 7) to fundamentally alter the chemical environment. This parameter change allows the cleaning composition to remove foreign materials while preventing tungsten layer dissolution, as the acidic condition suppresses tungsten corrosion that occurs in basic conditions
Solution Approach 2:
The patent introduces an organic acid as an intermediary substance that mediates between the conflicting requirements of foreign material removal and tungsten layer protection. The organic acid provides the necessary cleaning capability while its molecular structure and acidic properties create a protective effect on the tungsten layer, preventing direct contact and reaction between basic cleaning agents and tungsten
2Manufacturing precision
If a cleaning composition is used to eliminate foreign materials, then surface cleanliness improves, but surface roughness increases due to tungsten dissolution
Solution Approach 1:
By changing the pH parameter to acidic (lower than 7), the patent prevents the chemical dissolution of tungsten that would otherwise occur in basic conditions. This maintains the surface flatness and manufacturing precision while still achieving foreign material removal through alternative mechanisms
Solution Approach 2:
The patent converts the potential harm of acidic conditions (which could etch tungsten) into a beneficial effect by selecting specific organic acids that form protective complexes with tungsten. The acidic environment that could potentially damage tungsten instead creates a protective layer that prevents dissolution and maintains surface integrity
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 suppresses the dissolution of tungsten layers and maintains surface flatness, reducing the number of foreign materials and surface roughness, thereby enhancing the reliability and performance of semiconductor devices.
Implementation Method 1
the tungsten etching inhibitor is a compound containing a monocyclic or fused polycyclic aromatic hydrocarbon ring having two or more substituents, and the substituents contain at least a nitrogen-containing group and an anionic group
Data Source
AI summary
A surface treatment composition according to the present invention is a surface treatment composition having a pH of lower than 7 and used for treating the surface of a polished object to be polished having a layer containing tungsten, and the surface treatment composition contains a tungsten etching inhibitor and water, wherein the tungsten etching inhibitor is a compound containing a monocyclic or fused polycyclic aromatic hydrocarbon ring having two or more substituents, and the substituents contain at least a nitrogen-containing group and an anionic group.