Variable Flow Supercritical Fluid Substrate Drying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate drying processes, especially for semiconductor devices with fine circuit patterns, face inefficiencies due to the slow filling of supercritical fluids in the chamber, leading to prolonged drying times and reduced process efficiency.
Innovation Solution
A substrate treating apparatus that rapidly supplies supercritical fluid into a chamber by varying the flow rate using fixed and variable control lines with orifices and valves, allowing for a higher initial flow rate until a preset pressure is reached, followed by a lower flow rate to optimize the filling process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the supercritical fluid is supplied at a low flow rate in the initial supply stage, then the chamber pressure can be controlled to reach preset pressure, but much time is necessary to sufficiently fill the supercritical fluid in the chamber
Solution Approach 1:
The patent applies dynamics by making the flow rate of supercritical fluid variable rather than constant. The flow rate is dynamically adjusted based on chamber pressure: a higher flow rate is used when pressure is below the preset level to quickly fill the chamber, and a lower flow rate is used when pressure reaches the preset level to maintain control. This dynamic adjustment resolves the contradiction between fast filling and pressure control.
Solution Approach 2:
The patent changes the parameter of flow rate based on chamber pressure conditions. When chamber pressure is below the preset pressure, the flow rate is increased to accelerate filling. When chamber pressure reaches the preset level, the flow rate is decreased to maintain pressure control. This parameter change strategy allows the system to achieve both fast filling and reliable pressure control at different stages.
2Productivity
If the supercritical fluid is supplied at a high flow rate to shorten drying time, then process efficiency improves, but the chamber pressure may exceed preset pressure levels
Solution Approach 1:
The system dynamically adjusts the flow rate based on real-time chamber pressure feedback. When pressure approaches the preset level, the flow rate is automatically reduced to prevent pressure exceedance. This dynamic control enables high productivity during the filling phase while ensuring pressure safety when the preset level is reached.
Solution Approach 2:
The patent implements periodic action by alternating between high flow rate supply (when pressure is below preset level) and low flow rate supply (when pressure reaches preset level). This periodic adjustment of flow rate allows the system to maximize filling speed during safe pressure ranges while preventing pressure exceedance, thereby achieving both high productivity and pressure control.
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 reduces substrate drying time and enhances process efficiency by promptly filling the chamber with supercritical fluid, preventing pattern collapse and improving drying efficiency for fine circuit patterns.
Implementation Method 1
a large amount of organic solvent should be supplied for a long time to substitute pure water with the liquefied organic solvent
Implementation Method 2
a supercritical drying process that overcomes the problems has recently replaced the existing drying processes
Data Source
AI summary
A method for treating a substrate, in which a supercritical fluid is supplied into a chamber, in which the substrate is carried, to treat the substrate, the method including a supply step of supplying the supercritical fluid into the chamber until a pressure of the interior of the chamber reaches a preset pressure, and a substrate treating step of performing a supercritical process while repeating supply and exhaust of the supercritical fluid into and out of the interior of the chamber after the supply step, wherein a flow rate of the supercritical fluid supplied into the chamber in the supply step is variable.