Ammonium Salt Rinse Solution for 50 nm Pattern Collapse
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Solution Overview
Problem
In photolithographic processes, patterned material layers with line-space structures of 50 nm or below face issues such as pattern collapse, line edge roughness, watermark defects, photoresist swelling, and particle retention due to capillary forces and solvent absorption, which hinder the production of high-aspect-ratio features and lead to defects in integrated circuits.
Innovation Solution
A composition comprising ammonium salts of sulfobutanedioic acid diesters, (sulfomethyl)-butanedioic acid diesters, methyl-sulfobutanedioic acid diesters, sulfoglutaric acid diesters, and sulfotricarballic acid triesters is used for cleaning and rinsing, reducing capillary forces and surface tension to prevent pattern collapse and enhance cleaning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rinsing solutions are used, then cleaning is performed, but pattern collapse occurs due to capillary forces
Solution Approach 1:
The invention changes the chemical composition parameters of the rinsing solution by using ammonium salts of sulfobutanedioic acid diesters instead of conventional surfactants. This chemical parameter change reduces surface tension and capillary forces, preventing pattern collapse while maintaining cleaning effectiveness.
Solution Approach 2:
The ammonium salt compounds act as intermediary substances that mediate between the rinsing liquid and the patterned photoresist layer. These compounds reduce the harmful capillary forces at the liquid-solid interface without compromising the cleaning function, thus protecting the delicate nanoscale patterns.
2Manufacturing precision
If conventional surfactants are used, then surface tension is reduced, but line edge roughness increases
Solution Approach 1:
The invention uses ammonium salts of sulfobutanedioic acid diesters with specifically controlled molecular structure and concentration to achieve optimal surface tension reduction. This precise parameter control allows lowering surface tension to prevent pattern collapse while avoiding the side effect of increased line edge roughness that occurs with conventional surfactants.
Solution Approach 2:
The rinsing solution comprises a composite chemical system with ammonium salts of sulfobutanedioic acid diesters that combine multiple functional properties: surfactant activity for surface tension reduction, chelating capability for metal ion removal, and gentle interaction with photoresist materials. This composite functionality achieves both low surface tension and good line edge quality.
3Reliability
If water is used for rinsing, then cleaning is effective, but photoresist swelling occurs due to water uptake
Solution Approach 1:
The ammonium salt compounds serve as intermediary substances that enable effective cleaning while minimizing water uptake by the photoresist. These compounds modify the interfacial properties between the rinsing solution and photoresist, allowing cleaning to proceed without excessive water penetration that causes swelling.
Solution Approach 2:
The invention changes the chemical composition of the rinsing solution from pure water to an ammonium salt-based formulation. This parameter change maintains cleaning effectiveness through the surfactant and chelating properties of the ammonium salts while reducing the harmful water uptake effect that causes photoresist swelling.
4Productivity
If conventional cleaning compositions are used, then particles are removed, but production efficiency decreases due to defects
Solution Approach 1:
The ammonium salt compounds act as intermediary substances that simultaneously perform multiple functions: removing particles through surfactant action, complexing metal ions through chelating capability, and preventing pattern damage. This multi-functional intermediary approach reduces defects and improves production efficiency without requiring multiple separate processing steps.
Solution Approach 2:
The rinsing solution based on ammonium salts of sulfobutanedioic acid diesters exhibits universal functionality by combining surfactant properties for particle removal, chelating properties for metal ion complexation, and pattern-protecting properties. This multi-functionality in a single composition reduces defects across multiple failure modes and improves overall production efficiency.
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 use of these ammonium salts effectively reduces pattern collapse, line edge roughness, and photoresist swelling, while improving particle removal, resulting in higher production efficiency and quality of integrated circuits with finer features.
Implementation Method 1
Aqueous compositions and/or formulations comprising one or more compounds as defined above are used, in particular for cleaning and/or rinsing a product comprising a substrate and supported thereon a patterned material layer, in order to reduce pattern collapse, line edge roughness and photoresist swelling and/or to remove particles and/or to reduce watermark defects and/or to improve defect rinse solutions and/or to reduce capillary forces
Implementation Method 2
Aqueous compositions and/or formulations comprising one or more compounds as defined above are used, in particular for cleaning and/or rinsing a product comprising a substrate and supported thereon a patterned material layer, in order to reduce pattern collapse, line edge roughness and photoresist swelling and/or to remove particles and/or to reduce watermark defects and/or to improve defect rinse solutions and/or to reduce capillary forces
Data Source
AI summary
The present invention relates to the use of a composition comprising one or more ammonium salt(s) of one or more compounds selected from the group consisting of sulfobutanedioic acid diester(s), (sulfomethyl)-butanedioic acid diester(s), methyl-sulfobutanedioic acid diester(s), sulfoglutaric acid diester(s), and sulfotricarballic acid triester(s), for cleaning or rinsing a product comprising a substrate and supported thereon a patterned material layer having line-space structures with a line width of 50 nm and below. The invention also relates to a corresponding method of making a cleaned or rinsed product comprising a substrate and supported thereon a patterned material layer having line-space structures with a line width of 50 nm or below. The invention also relates to a solution with color of HAZEN number below 1000 and/or a turbidity in the range of from 0.08 to 10 NTU, wherein the solution comprises water and one or more ammonium salt(s) and optionally one or more organic solvent compounds. The invention also relates to a method of making a corresponding solution.