Substrate Processing Apparatus Particle Removal via Supercritical Fluid
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing technologies face challenges in effectively removing particles from the processing space, which can contaminate substrates during the drying process, especially when using supercritical fluids, as particles may be redeposited onto the substrate from supply lines and valves.
Innovation Solution
A method and apparatus that utilize a pressure increasing process, a circulating process, and a particle removing process to manage the flow of supercritical fluids within the processing space, including opening and closing valves to generate a flow against the pressure, ensuring particles are discharged from the supply lines and not redeposited onto the substrate, using a dummy wafer for cleaning and maintaining the processing space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a supercritical fluid is supplied to the processing space to dry the substrate, then the substrate drying effect is improved, but particles may be redeposited onto the substrate from supply lines and valves
Solution Approach 1:
The patent applies preliminary action by performing a particle removal process before the actual substrate processing. A dummy wafer is placed in the processing space and subjected to supercritical fluid circulation to dislodge and remove particles from supply lines and valves beforehand, preventing their redeposition onto the substrate during subsequent processing.
Solution Approach 2:
The patent uses a dummy wafer as an intermediary object to capture particles that would otherwise contaminate the actual substrate. The dummy wafer is strategically positioned to receive particles from supply lines and valves, protecting the real substrate from contamination while maintaining the beneficial supercritical fluid drying process.
2Object-affected harmful factors
If particles are removed from the processing space using conventional methods, then substrate contamination is reduced, but particles from supply lines and valves may still be redeposited
Solution Approach 1:
The patent extracts particles from the supply lines and valves by directing supercritical fluid flow through these components during the particle removal process. The fluid flow dislodges particles from the supply lines and valves and carries them to the dummy wafer, effectively removing the particle source before actual substrate processing begins.
Solution Approach 2:
The system performs self-service particle removal by using the supercritical fluid circulation mechanism that is already part of the substrate processing system. The same fluid supply lines and circulation apparatus used for substrate drying are utilized to remove particles, eliminating the need for separate particle removal equipment or processes.
3Productivity
If the processing fluid is supplied continuously to maintain supercritical state, then drying efficiency is improved, but particles accumulate in the supply lines
Solution Approach 1:
The patent implements periodic action by alternating between particle removal cycles and substrate processing cycles. During particle removal cycles, the supercritical fluid circulation is used to clear particles from supply lines. During substrate processing cycles, the cleaned system performs efficient drying. This periodic maintenance approach sustains high productivity while preventing particle accumulation.
Solution Approach 2:
The patent discards particles that accumulate in supply lines by capturing them on the dummy wafer during periodic particle removal cycles. The supercritical fluid carries accumulated particles from the supply lines to the dummy wafer, where they are collected and removed from the system, allowing the supply lines to be reused for efficient substrate 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 effectively reduces substrate contamination by ensuring particles are removed from the supply lines and discharged from the processing space, enhancing particle removal efficiency while maintaining throughput.
Implementation Method 1
a flow of the cleaned fluid is generated against the pressure of the processing space in the second supply line by opening and closing the second on-off valve during the pressure increasing process
Implementation Method 2
a drying process is performed by bringing a substrate in a state where the surface is wet with liquid into contact with a processing fluid of a supercritical state to dry the substrate
Data Source
AI summary
A method of removing particles of a substrate processing apparatus includes a pressure increasing process, a circulating process, and a particle removing process. In the pressure increasing process, a pressure in a processing space is increased by supplying a cleaned fluid from a first supply line to the processing space in a state where a second on-off valve and a third on-off valve are closed. In the circulating process, a processing fluid is supplied from a second supply line to the processing space and discharged from a discharge line by opening the second on-off valve and the third on-off valve after the pressure increasing process. In the particle removing process, a flow of the cleaned fluid is generated against the pressure of the processing space in the second supply line by opening and closing the second on-off valve during the pressure increasing process.