Hydrophobic Surface Treatment Layer for Pattern Collapse Prevention
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Solution Overview
Problem
In semiconductor manufacturing, pattern collapse during wet clean and dry processes is a significant issue at sub-20 nm critical dimensions, primarily attributed to high capillary forces, with other chemical and substrate properties also playing a role.
Innovation Solution
The formation of a hydrophobic layer on semiconductor substrates using low surface tension modifying fluids, specifically aprotic solvents and Si-containing compounds, minimizes capillary forces by achieving a water contact angle of at least 50 degrees, thereby preventing pattern collapse during cleaning and drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wet clean and dry processes are used, then cleaning effectiveness is achieved, but pattern collapse occurs due to high capillary forces
Solution Approach 1:
The patent changes the surface energy parameters of the substrate by applying a hydrophobic coating, which modifies the contact angle to approximately 90 degrees. This parameter change reduces capillary forces during wet clean and dry processes, preventing pattern collapse while maintaining cleaning effectiveness.
Solution Approach 2:
The patent introduces a hydrophobic coating as an intermediary layer between the patterned features and the liquid cleaning solutions. This intermediary layer modifies the liquid-substrate interaction by reducing surface tension and capillary forces, thereby protecting the patterns from collapse during processing.
2Reliability
If surface treatment composition is applied to form hydrophobic layer, then pattern collapse is minimized, but additional process steps are required
Solution Approach 1:
The patent applies surface treatment composition in advance of the wet clean and dry processes to pre-establish a hydrophobic protective layer. This preliminary action ensures that the patterns are protected from capillary forces before the harmful cleaning and drying operations begin, minimizing collapse risk.
Solution Approach 2:
The patent extracts the essential protective function from the cleaning process itself by applying a separate surface treatment composition that specifically addresses capillary force mitigation. This separates the pattern protection function from the cleaning function, allowing each to be optimized independently.
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
This approach effectively reduces pattern collapse, with over 70% of features remaining uncollapsed after cleaning and drying, as demonstrated by the formation of a hydrophobic monolayer that minimizes Laplace pressure and capillary forces.
Implementation Method 1
contacting the surface with a surface treatment composition... the surface treatment composition forms a surface treatment layer on the surface such that the surface has a water contact angle of at least about 50 degrees
Implementation Method 2
low surface tension modifying fluids that impart the surfaces of a semiconductor substrate with a hydrophobic layer can minimize the capillary forces that drive pattern collapse
Implementation Method 3
minimize the capillary forces that drive pattern collapse during a cleaning or drying process... Without wishing to be bound by theory, it is believed that the Laplace pressure is minimized when the contact angle, i.e., the angle a liquid (e.g., water) creates when in contact with a substrate surface, is at or near 90 degrees
Data Source
AI summary
The disclosure provides methods and compositions therefor for treating a surface wherein a surface treatment layer is formed on the surface, thereby minimizing or preventing pattern collapse as the surface is subjected to typical cleaning steps in the semiconductor manufacturing process.