Chuck Pin Geometry for Mist-Free Substrate Drying
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Solution Overview
Problem
The reattachment of processing liquid turned into mist due to air current disturbances caused by chuck pins in substrate processing apparatuses leads to watermark defects on substrates, particularly during high-speed drying processes.
Innovation Solution
The substrate processing apparatus features chuck pins with a curved surface, a reduced portion, and a sloping surface designed to minimize the disturbance of air currents, ensuring the processing liquid is discharged efficiently and prevents reattachment to the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chuck pins are used to grasp the substrate edge, then the substrate can be fixed on the rotating table, but the chuck pins generate air current disturbances that cause processing liquid to turn into mist and reattach to the substrate surface
Solution Approach 1:
The chuck pin is designed with a curved surface on its upstream side and a sloping surface on its downstream side, replacing a simple cylindrical shape. This curved geometry allows the processing liquid to flow smoothly along the pin surface without abrupt separations, reducing air current disturbances and preventing mist formation that would otherwise reattach to the substrate.
Solution Approach 2:
The chuck pin geometry is optimized by introducing specific surface profiles (curved upstream surface and sloping downstream surface) that change the flow parameters of both processing liquid and air current. This parameter optimization ensures smooth liquid discharge while minimizing turbulent air flows that cause mist generation.
2Productivity
If the rotating table rotates at high speed for drying, then processing efficiency is improved, but the air current disturbance intensifies causing more mist reattachment and watermark defects
Solution Approach 1:
The curved surface design on the chuck pin becomes increasingly effective at higher rotation speeds by guiding the processing liquid flow to separate smoothly from the pin surface. This reduces the intensity of air current disturbances even during high-speed drying operations, preventing mist formation and maintaining substrate surface quality without compromising processing efficiency.
3Device complexity
If the chuck pin has a simple cylindrical shape, then the device complexity is low, but the processing liquid flow causes air current disturbance and mist formation
Solution Approach 1:
Instead of using a simple cylindrical chuck pin, the invention introduces a curved upstream surface and a sloping downstream surface. This geometric modification is relatively simple to implement but effectively guides the processing liquid flow to separate smoothly from the pin, minimizing air current disturbances and preventing mist generation.
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 design effectively suppresses the formation of mist, improving substrate quality by reducing watermarks and ensuring smooth liquid discharge, thereby enhancing the overall processing efficiency.
Implementation Method 1
rotate the substrate around an axis perpendicular to a substrate center as an axis of rotation, allow a processing liquid (for example, liquid chemical or pure water) to flow on the center portion of the substrate, and spread the processing liquid toward the edge of the substrate by a centrifugal force
Implementation Method 2
the processing liquid reaching the chuck pins that grasp the edge of the substrate is separated from the chuck pins, turns into mist due to a disturbance of an air current generated by the chuck pins that rotate together with the rotating table
Data Source
AI summary
According to one embodiment, a substrate processing apparatus includes a rotating table configured to rotate a substrate and a plurality of fixing members configured to fix the substrate on the rotating table by grasping the substrate while abutting an outer periphery of the substrate, wherein each fixing member includes a curved surface on a side that abuts the substrate, a reduced portion formed to be connected to an end of the curved surface and having a width which is continuously reduced in the first direction from a boundary with the curved surface, a first sloping surface formed on a top portion to slope downwards in the first direction, and a support portion formed on the curved surface and configured to support the substrate such that a top surface of the top portion is flush with an upper surface of the substrate in a state where the substrate is grasped.