Ion-Exchange Membrane Purification for Silylating Agent Metal Impurities
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Solution Overview
Problem
The challenge in semiconductor manufacturing is pattern collapse during the drying process of rinse liquids, which is exacerbated by the surface tension and can lead to decreased yield and reliability of products, particularly in highly integrated and fine-patterned semiconductor devices. Existing surface treatment methods using silylating agents may contain metal impurities that can increase junction leakage current and are prone to heat deterioration or hydrolysis, making them unsuitable for purification by distillation.
Innovation Solution
A process involving an ion-exchange resin membrane that has been pre-contacted with an organic solvent is used to reduce metal impurities in silylating agent liquids, followed by a surface treatment method where the treated liquid is applied to the substrate to hydrophobize the surface, thereby reducing the force applied during drying and preventing pattern collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional silylating agent chemical liquids are used for surface treatment, then the substrate surface can be hydrophobized to reduce pattern collapse, but metal impurities in the liquid increase junction leakage current and reduce device reliability
Solution Approach 1:
The patent introduces an ion-exchange resin membrane as an intermediary substance between the silylating agent chemical liquid and the substrate. This membrane selectively removes metal impurities from the liquid while allowing the silylating agent to pass through, thereby providing a purified treating liquid that maintains hydrophobization effectiveness without the harmful metal impurities that would otherwise contaminate the device
Solution Approach 2:
The patent changes the purity parameter of the silylating agent chemical liquid by passing it through an ion-exchange resin membrane. This process selectively removes metal impurities while preserving the functional components, thereby transforming the liquid from a contaminated state to a purified state that is suitable for high-reliability semiconductor device treatment
2Object-affected harmful factors
If silylating agent chemical liquids are purified by distillation, then metal impurities can be removed, but the silylating agent undergoes heat deterioration or hydrolysis
Solution Approach 1:
The patent replaces the thermal distillation process with a membrane-based ion-exchange process. Instead of using heat to separate metal impurities from the silylating agent, the invention uses an ion-exchange resin membrane that selectively captures metal ions through chemical exchange, thereby removing impurities without subjecting the heat-sensitive silylating agent to thermal stress that would cause deterioration or hydrolysis
3Ease of manufacture
If rinse liquid is used for rinsing the substrate after pattern formation, then cleaning is achieved, but surface tension of the liquid causes pattern collapse during drying
Solution Approach 1:
The patent changes the surface energy parameter of the substrate surface by applying a silylating agent treatment that creates a hydrophobic surface layer. This modification reduces the surface tension between the rinse liquid and the substrate, thereby minimizing the capillary forces that cause pattern collapse during the drying process while maintaining effective cleaning
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 process effectively reduces metal impurities in the silylating agent, enhancing the hydrophobic properties of the substrate surface, which in turn minimizes pattern collapse and improves the reliability of semiconductor devices by reducing the stress between patterns during the drying process.
Implementation Method 1
reducing metal impurities contained in an untreated chemical liquid of a silylating agent, using an ion-exchange resin membrane
Implementation Method 2
exposing a substrate surface to a chemical liquid of a silylating agent to render the surface water-repellent or hydrophobic
Data Source
AI summary
A process removes metal impurities from an untreated chemical liquid, which includes a silylating agent. The process includes providing a strongly acidic cation-exchange resin in which a cation-exchange group is immobilized to a resin membrane or an integral structure of a particle-removing membrane and an ion exchange resin membrane in which a strongly acidic cation-exchange resin has been chemically introduced onto surfaces of pores in a porous resin. The wettability of the ion exchange resin membrane is thereafter improved by contacting the ion-exchange resin membrane with an organic solvent. The metal impurities are then removed from the untreated chemical liquid by passing the untreated chemical liquid through the ion-exchange resin membrane.