Supercritical Fluid Supply Apparatus Pulsation Control
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Solution Overview
Problem
Existing substrate processing systems face limitations in filtering foreign matters from processing fluids, leading to potential damage from pump pulsation when circulating liquid-state fluids, which reduces the lifespan of equipment and increases the risk of particle formation on wafers during supercritical drying.
Innovation Solution
A substrate processing system with a processing fluid supply apparatus that includes a circulation line, cooler, pump, heating unit, and pressure regulator, which circulates and filters gaseous-state processing fluid, converts it to liquid, heats it to supercritical state, and then depressurizes it to reduce pulsation effects and enhance filtration efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If gaseous-state processing fluid is supplied to the circulation line, then the system can operate with lower initial pressure, but the pump experiences pulsation damage when circulating liquid-state fluid
Solution Approach 1:
The system changes the physical state parameter of the processing fluid from gaseous to liquid phase using a cooler, and then to supercritical state using a heating unit. This parameter transformation allows the fluid to be pumped in liquid state (reducing pulsation) while maintaining system pressure control through phase transitions.
Solution Approach 2:
The patent utilizes phase transitions of the processing fluid: gaseous state → liquid state (via cooler) → supercritical state (via heating unit and pressure regulator). These phase transitions enable the system to overcome pump pulsation issues by pumping liquid rather than gas, while still achieving the desired supercritical drying conditions.
2Productivity
If liquid-state processing fluid is circulated by the pump, then the fluid can be moved efficiently, but pulsation occurs causing damage and particle formation
Solution Approach 1:
The system transitions the processing fluid to supercritical state after pumping, eliminating the liquid-gas interface that causes pulsation. The supercritical fluid maintains the pumping efficiency of liquid state while removing the harmful pulsation effects during the drying process.
Solution Approach 2:
The patent converts the potential harm of pump pulsation into benefit by using the pressure fluctuations to drive the phase transition from liquid to supercritical state. The pulsation energy is transformed into useful pressure increase that facilitates the supercritical drying process rather than causing damage.
3Device complexity
If foreign matters are not filtered from the processing fluid, then the system operation is simple, but particles form on wafers during supercritical drying
Solution Approach 1:
The system performs preliminary filtration of the processing fluid before it enters the circulation line and before supercritical drying. By filtering foreign matters in advance, the patent prevents particle formation on wafers during the drying process, ensuring manufacturing precision without adding complex in-situ filtration systems.
4Reliability
If the processing fluid is not depressurized, then the supercritical state is maintained for drying, but pump pulsation effects increase
Solution Approach 1:
The patent uses a pressure regulator to control the depressurization process, maintaining the supercritical state during drying while preventing excessive pressure buildup that would amplify pump pulsation. The phase transition control allows the system to operate at optimal pressure points that minimize pulsation while ensuring effective supercritical drying.
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 system effectively reduces pulsation-induced damage and improves filtration performance, preventing particle formation on wafers during supercritical drying, thereby extending equipment lifespan and ensuring cleaner processing.
Implementation Method 1
The cooler is provided in the circulation line and configured to cool the gaseous-state processing fluid thereby generating a liquid-state processing fluid
Implementation Method 2
The heating unit is provided at a downstream side of the branch portion and configured to heat the liquid-state processing fluid in a liquid state thereby generating a supercritical-state processing fluid
Implementation Method 3
The pressure regulator is provided at a downstream side of the heating unit in the circulation line and at an upstream side of the gas supply line and configured to depressurize the supercritical-state processing fluid thereby generating the gaseous-state processing fluid
Implementation Method 4
The pump is provided at a downstream side of the cooler in the circulation line
Data Source
AI summary
A processing fluid supplying method includes: supplying a processing fluid of a gaseous state to a circulation line; generating a processing fluid of a liquid state by cooling the processing fluid of the gaseous state in the circulation line; branching the processing fluid of the liquid state from the circulation line to a branch line; and generating a processing fluid of a supercritical state by heating the processing fluid of the liquid state in the circulation line.