Lithographic Rinse Solution for Patterned Resist Defect Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithographic processes face challenges with defects such as pattern mismatch, contamination, and pattern falling due to microbubbles and re-deposition during the rinsing step, which reduce semiconductor device yield and complicate the manufacturing process.
Innovation Solution
A lithographic rinse solution containing a water-soluble nitrogen-containing heterocyclic compound, such as imidazolidinone or pyridine, is used to inhibit pattern falling and enhance draining speed, preventing re-deposition and improving the resistance of the patterned resist layer to electron beam irradiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rinsing is used with water, then the rinsing process is simple, but defects occur due to microbubbles and re-deposition of insoluble substance
Solution Approach 1:
A rinse aid comprising a carboxylic acid and a nitrogen-containing compound is introduced as an intermediary substance between water and the photoresist layer. The carboxylic acid removes microbubbles through its surface-active properties, while the nitrogen-containing compound prevents re-deposition of insoluble substances by modifying surface interactions. This intermediary rinse aid solution resolves the harmful effects of conventional water rinsing without complicating the overall process.
Solution Approach 2:
The chemical composition parameters of the rinsing solution are changed from pure water to a controlled mixture containing carboxylic acid (0.01-5% by mass) and nitrogen-containing compound (0.01-5% by mass). This parameter change transforms the rinsing solution's properties to eliminate microbubble formation and prevent re-deposition, thereby reducing defects while maintaining process simplicity.
2Reliability
If the rinsing treatment time is extended to improve cleaning, then cleaning effectiveness increases, but production efficiency decreases
Solution Approach 1:
The chemical composition of the rinse solution is modified to include carboxylic acid and nitrogen-containing compound, which dramatically improve cleaning effectiveness per unit time. This allows the rinsing treatment time to be reduced while maintaining or improving cleaning quality, thereby increasing production efficiency and throughput.
Solution Approach 2:
The enhanced chemical action of the rinse aid allows the rinsing process to achieve effective cleaning in a shorter time period. The carboxylic acid rapidly removes microbubbles and the nitrogen-containing compound quickly prevents re-deposition, enabling the system to 'rush through' the rinsing step efficiently without sacrificing cleaning effectiveness.
3Reliability
If a surface active agent is added to prevent pattern falling, then pattern adhesion improves, but the top of the patterned resist layer becomes round and orthogonality decreases
Solution Approach 1:
Instead of using conventional surface active agents that cause rounding, the invention employs a specific combination of carboxylic acid and nitrogen-containing compound at controlled concentrations (0.01-5% each). This parameter change in chemical composition achieves pattern adhesion improvement through a different mechanism that does not involve the same surface-tension-reducing effects, thereby preserving cross-sectional orthogonality and resist layer shape.
Solution Approach 2:
The rinse aid uses a composite chemical system combining carboxylic acid and nitrogen-containing compound, which work synergistically to prevent pattern falling through multiple mechanisms: microbubble removal by carboxylic acid and re-deposition prevention by nitrogen-containing compound. This composite approach achieves adhesion improvement without the unwanted side effects of conventional single-component surface active agents.
4Adaptability or versatility
If various resist types are used, then application flexibility increases, but the complexity of selecting and changing treatment agents increases
Solution Approach 1:
The rinse aid comprising carboxylic acid and nitrogen-containing compound is designed with universal applicability across different resist types (positive-working, negative-working, chemically amplified resists). The chemical system performs multiple functions: microbubble removal, re-deposition prevention, and pattern adhesion improvement, making it a versatile solution that eliminates the need to change agents for different resist types, thereby reducing operational complexity.
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 significantly reduces defects and pattern shrinkage, enhances production efficiency by shortening rinsing time, and maintains dimensional accuracy, making it suitable for high-yield semiconductor production.
Implementation Method 1
a lithographic rinse solution which is an aqueous solution of a water-soluble nitrogen-containing heterocyclic compound... improving a draining speed
Implementation Method 2
inhibiting pattern falling and enhancing draining speed, preventing re-deposition
Implementation Method 3
improving the resistance of the patterned resist layer to electron beam irradiation
Data Source
AI summary
The invention provides a novel rinse solution used in the step of rinse treatment of a patterned photoresist layer developed with an aqueous alkaline developer solution in a photolithographic process for the manufacture of semiconductor devices and liquid crystal display panels. The rinse solution provided by the invention is an aqueous solution of a nitrogen-containing heterocyclic compound such as imidazoline, pyridine and the like in a concentration up to 10% by mass. Optionally, the rinse solution of the invention further contains a water-miscible alcoholic or glycolic organic solvent and/or a water-soluble resin. The invention also provides a lithographic method for the formation of a patterned photoresist layer including a step of rinse treatment of an alkali-developed resist layer with the rinse solution defined above. The invention provides an improvement on the lithographic process in respect of the product quality and efficiency of the process.