Semiconductor Reclaim Tank Concentration Control
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Solution Overview
Problem
In semiconductor fabrication environments, there is a need for precise control of chemical concentrations in chemical delivery systems to maintain process performance, as variations in chemical concentrations can lead to process variations and uncertainties in etch rates.
Innovation Solution
A method and system for controlling fluids in processing systems by mixing chemical compounds in a blender, monitoring concentrations, and recycling solutions to ensure they meet predetermined concentrations before reuse, using a reclaim tank and monitoring systems to maintain consistent chemical delivery to processing stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If chemical solutions are continuously recycled and reused in processing systems, then productivity and cost efficiency are improved, but the risk of concentration variations and process instability increases
Solution Approach 1:
The system continuously monitors chemical concentration in the reclaim tank using sensors and provides real-time feedback to the dosing subsystem. When concentration deviates from target ranges, the system automatically adjusts dosing rates to correct the deviation, enabling continuous reuse while maintaining process stability.
Solution Approach 2:
The system dynamically adjusts dosing parameters (flow rates, injection timing) based on real-time concentration measurements. The dosing subsystem modifies chemical addition rates to maintain target concentration ranges, allowing the solution to be recycled indefinitely while preserving process reliability.
2Manufacturing precision
If chemical concentration is tightly controlled to maintain process performance, then manufacturing precision is improved, but device complexity and monitoring requirements increase
Solution Approach 1:
The system uses the process fluid itself as the monitoring medium. The reclaim tank and its sensors directly measure the concentration of the chemical solution being reused, eliminating the need for separate sampling systems or external analytical equipment. The process fluid self-monitors its own quality.
Solution Approach 2:
The dosing subsystem serves multiple functions: it adds chemicals to maintain concentration, responds to sensor feedback, and adjusts parameters based on process conditions. This multi-functional approach consolidates what could be separate complex systems into a single integrated unit.
3Ease of manufacture
If batch processing is used to prepare solution mixtures, then manufacturing simplicity is maintained, but time loss and productivity decrease
Solution Approach 1:
The system continuously doses chemicals into the reclaim tank as solution is consumed and recycled, eliminating batch preparation cycles. The dosing subsystem operates continuously to maintain concentration, transforming discrete batch operations into a continuous process that eliminates waiting time while maintaining simplicity.
4Device complexity
If chemical concentration variations are allowed, then device complexity is reduced, but process performance and reliability deteriorate
Solution Approach 1:
Real-time concentration sensors provide continuous feedback to the dosing subsystem, which automatically adjusts chemical addition to maintain target concentrations. This closed-loop control ensures process reliability while keeping the control system relatively simple through automated rather than manual intervention.
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 ensures accurate and consistent chemical concentrations, reducing process variations and improving the reliability of semiconductor fabrication processes by continuously monitoring and adjusting chemical solutions to meet target concentrations.
Implementation Method 1
mixing two or more chemical compounds in a blender to produce a solution
Implementation Method 2
The solution can be monitored at a location between the tank and the process station to determine whether at least one of the chemical compounds is at a predetermined concentration
Implementation Method 3
removing at least a portion of the solution from the process station and returning the removed portion of the solution to the reclaim tank
Data Source
AI summary
In one embodiment, a method of controlling fluids in a semiconductor processing system includes mixing two or more chemical compounds in a blender to produce a solution and supplying the solution to a reclaim tank, where the solution is dispense to a process station. The solution can be monitored at a location between the tank and the process station to determine whether at least one of the chemical compounds is at a predetermined concentration. Upon determining that the at least one chemical compound in the solution is at the predetermined concentration the solution is flowed to the process station. The method further includes removing at least a portion of the solution from the process station and returning the removed portion of the solution to the reclaim tank. The removed portion of the solution is monitored at a location between the process station and the reclaim tank to determine whether at least one of the chemical compounds in the removed portion of the solution is at a predetermined concentration. Upon determining that the at least one chemical compound in the removed portion of the solution is at the predetermined concentration, the removed portion of solution is flowed to the process station.