Substrate Drying Using Segmented Support and Liquid Level Control
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Solution Overview
Problem
The existing methods for drying substrates using supercritical fluids face inefficiencies, including the leaning phenomenon and prolonged drying times, especially when large substrates are processed, as the edge regions are naturally dried before the central regions, leading to uneven drying and increased processing times.
Innovation Solution
A substrate processing apparatus and method that involves controlled liquid processing steps, including rotating the substrate at different speeds and using nozzles to supply processing liquids, ensuring the edge region has a higher liquid height than the central region before transfer to a drying chamber, where supercritical fluids are used for efficient drying.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the substrate is placed on a support unit that supports only the edge region, then the substrate can be dried using a supercritical fluid, but the substrate sags in the middle causing processing liquid to flow toward the central region and the edge region to be naturally dried before supercritical fluid drying
Solution Approach 1:
The support unit is divided into multiple support regions: a first support region that supports the edge region of the substrate and a second support region that supports the central region of the substrate. This segmentation prevents substrate sagging and maintains uniform liquid distribution across the substrate surface during the drying process.
Solution Approach 2:
The substrate is supported in a specific configuration before the supercritical fluid drying process begins. By pre-positioning support structures at both the edge and central regions, the system prevents unwanted liquid flow and natural drying effects from occurring during the drying process.
2Loss of time
If the substrate edge region is naturally dried before supercritical fluid supply, then drying time is reduced, but the central region requires significantly more time to dry due to large amount of processing liquid
Solution Approach 1:
The substrate is supported in a specific configuration before the supercritical fluid drying process begins. By pre-positioning support structures at both the edge and central regions, the system prevents unwanted liquid flow and natural drying effects from occurring during the drying process.
3Manufacturing precision
If the substrate is completely supported to prevent sagging, then uniform drying is maintained, but a large amount of processing liquid remains on the substrate requiring extended drying time
Solution Approach 1:
The support unit is divided into multiple support regions: a first support region that supports the edge region of the substrate and a second support region that supports the central region of the substrate. This segmentation prevents substrate sagging and maintains uniform liquid distribution across the substrate surface during the drying process.
4Productivity
If heating is applied to maintain supercritical fluid temperature, then the drying process can proceed, but the edge region experiences excessive heating causing natural drying and leaning phenomenon
Solution Approach 1:
The heating process is controlled to provide different thermal conditions at different locations. The central region receives sufficient heat to maintain supercritical fluid temperature, while the edge region is protected from excessive heating that would cause natural drying and leaning of patterns.
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 improves drying efficiency by preventing natural drying of edge regions and reducing overall drying time, ensuring uniform drying of substrates by maintaining a set liquid level on the substrate during transfer to the drying chamber.
Implementation Method 1
a drying chamber for removing the processing liquid from the substrate by using a supercritical fluid
Implementation Method 2
a liquid processing chamber for performing liquid processing on a substrate by supplying a processing liquid onto a substrate and a drying chamber for removing the processing liquid from the substrate by using a supercritical fluid
Implementation Method 3
supplying a processing liquid onto the substrate while rotating the spin head
Data Source
AI summary
Disclosed is a method for processing a substrate, comprising a liquid processing step of performing liquid processing on the substrate by supplying a processing liquid onto the substrate in a liquid processing chamber, a transfer step of transferring the substrate from the liquid processing chamber to a drying chamber, and a drying step of drying the substrate in the drying chamber. In the drying step, the substrate is dried while an edge region of the substrate other than a central region of the substrate is supported by a support unit, and in the liquid processing step, the liquid processing is performed on the substrate such that a height of the processing liquid remaining on the edge region of the substrate is greater than a height of the processing liquid remaining on the central region of the substrate when the liquid processing is completed in the liquid processing chamber.