Drying Gas Flow Control for Defect-Free Substrate Processing
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Solution Overview
Problem
Conventional drying gas supply methods for substrates often result in defects such as photoresist collapse, leaning, bridging, and lifting due to rapid changes in flow rate and pressure, leading to annular and condensation cluster defects during the drying process.
Innovation Solution
An apparatus and method utilizing a gas supply system with a flow control unit that includes mass flow controllers and metering valves in parallel, allowing for gradual control of drying gas flow rates through multiple branch lines, preventing rapid changes in flow and pressure, and employing supercritical fluids like carbon dioxide for substrate drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional high-pressure drying gas supply device is used, then substrate drying speed is improved, but annular and condensation cluster defects occur due to rapid flow rate changes
Solution Approach 1:
The gas supply line is divided into multiple branch lines (first, second, third branch lines) with independent flow control units. Each branch line has its own metering valve and mass flow controller, allowing staged and controlled introduction of drying gas to prevent rapid pressure changes that cause cluster defects, while maintaining overall high drying efficiency
Solution Approach 2:
The system dynamically adjusts flow rates using both metering valves (for coarse control) and mass flow controllers (for precise real-time control) on each branch line. This dynamic control allows the system to maintain high productivity while preventing the rapid flow rate changes that cause annular and condensation cluster defects
2Device complexity
If a single flow control valve is used, then device complexity is reduced, but flow rate control precision deteriorates
Solution Approach 1:
The system merges two types of flow control devices (metering valve and mass flow controller) in parallel on each branch line. The metering valve provides stable baseline control while the mass flow controller adds precise measurement and adjustment capability, achieving high control precision without excessive complexity through functional complementarity
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
Prevents the occurrence of annular and condensation cluster defects by gradually increasing the drying gas flow rate, ensuring uniform drying and reducing substrate damage, while maintaining stable internal pressure and flow rates.
Implementation Method 1
a flow control unit installed in the gas supply line, and controlling a gas flow rate of drying gas supplied through the gas supply line through a metering valve and a mass flow controller (MFC), disposed in parallel
Implementation Method 2
a method of substituting and drying a developing solution on a substrate using a supercritical drying gas, for example, supercritical carbon dioxide
Data Source
AI summary
Provided is an apparatus for supplying gas in a facility for processing a substrate, the apparatus for supplying gas in a facility for processing a substrate including: a gas supply line connecting a gas storage unit and a process chamber for processing a substrate; and a flow control unit installed in the gas supply line, and controlling a gas flow rate of drying gas supplied through the gas supply line with a metering valve and a mass flow controller (MFC) disposed in parallel.