Halogen Oxyacid Solution Production via Static Mixer
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Solution Overview
Problem
Current methods for producing halogen oxyacid solutions, such as quaternary alkylammonium hypochlorite, face challenges in industrial efficiency and storage stability, particularly in semiconductor wafer processing where noble metals like ruthenium require effective removal without causing cross-contamination.
Innovation Solution
A continuous method involving the static mixing of organic alkaline solutions and halogens in a static mixer, controlling pH between 10.5 and 14.1, and using a static mixer like an ejector or Sulzer SMXL, to enhance production efficiency and storage stability of the halogen oxyacid solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If batch reaction method is used to produce quaternary alkylammonium hypochlorite solution, then production process is simple, but production efficiency per reaction volume is low
Solution Approach 1:
The patent implements continuous production by continuously supplying organic alkaline solution and halogen to a reaction tank, maintaining continuous reaction and product formation. This eliminates the batch-wise operation, significantly increasing production efficiency per reaction volume while keeping the system relatively simple through continuous flow processing
2Reliability
If aqueous sodium hypochlorite solution is used as washing liquid, then oxidation power is high, but sodium ions contaminate semiconductor wafers
Solution Approach 1:
The patent changes the cation parameter from sodium ion to quaternary alkylammonium ion while maintaining the hypochlorite anion. This substitution preserves the high oxidation power of hypochlorite for effective metal removal, while eliminating sodium ion contamination that would otherwise attach to semiconductor wafers and deteriorate production efficiency
3Object-affected harmful factors
If hypochlorous acid solution is used for washing, then sodium contamination is avoided, but etching performance on metal films is insufficient
Solution Approach 1:
The patent creates a composite washing liquid system combining quaternary alkylammonium hypochlorite with controlled pH (10.5-14.1). This composite approach integrates the contamination-free advantage of organic alkaline systems with enhanced etching capability through optimized pH conditions, achieving both non-contaminating properties and effective metal film removal
4Ease of manufacture
If quaternary alkylammonium hypochlorite solution is produced by batch reaction, then production is achievable, but storage stability deteriorates over time
Solution Approach 1:
The patent employs continuous production where fresh quaternary alkylammonium hypochlorite solution is continuously generated and immediately utilized. This continuous generation prevents long-term storage, eliminating decomposition issues while maintaining production feasibility through steady-state operation with continuous supply and utilization
5Productivity
If large-diameter semiconductor wafers are used to enhance production efficiency, then more metal material accumulates on end and back surfaces
Solution Approach 1:
The patent utilizes quaternary alkylammonium hypochlorite solution with high oxidation power to effectively remove excess metal materials and noble metals from semiconductor wafer surfaces. This strong oxidation capability addresses the contamination problem generated by large-diameter wafers, enabling thorough cleaning of metal deposits while maintaining the productivity benefits of large wafer processing
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 significantly increases production efficiency per reaction volume, reduces side reactions, and maintains storage stability of the halogen oxyacid solution, making it suitable for semiconductor processing without decomposing the halogen oxyacid.
Implementation Method 1
continuously supplying an organic alkaline solution and halogen to a static mixer and mixing them
Implementation Method 2
a washing method using hypochlorite high in oxidation power, as a washing liquid of a semiconductor wafer
Data Source
AI summary
The present invention provides industrially advantageous production method and production apparatus, with respect to production of a halogen oxyacid solution. There is solved by a method for producing a halogen oxyacid solution, comprising continuously supplying an organic alkaline solution and halogen to a static mixer and mixing them, to thereby continuously obtain a halogen oxyacid generated.