Substrate Processing Guard Segmentation for Liquid Capture
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in efficiently capturing processing liquids discharged from the circumferential edge of substrates due to interference between the blocking member and guards, leading to inefficient liquid splattering prevention and accidental mixing of processing liquids.
Innovation Solution
A substrate processing apparatus with a blocking member having a larger diameter than the spin base, and a plurality of guards including an inner side guard and an outer side guard, where the inner circumferential end of the outer side guard is positioned radially outer to the inner side guard, allowing for optimal capture of processing liquids while avoiding interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the blocking member has a larger diameter than the spin base to block lateral space effectively, then the blocking efficiency is improved, but the blocking member interferes with the guards surrounding the substrate holding unit
Solution Approach 1:
The guard system is segmented into multiple guards positioned at different radial distances from the rotation axis. The first guard is positioned closer to the rotation axis with a smaller inner circumferential end diameter, while the second guard is positioned farther out with a larger inner circumferential end diameter. This segmentation allows each guard to serve different functions without interfering with the blocking member.
Solution Approach 2:
Different parts of the guard system have different properties tailored to their specific functions. The first guard has a smaller diameter optimized for capturing processing liquid from the substrate edge during chemical liquid processing, while the second guard has a larger diameter optimized for capturing liquid during rinsing processing. This local differentiation resolves the conflict between blocking member size and guard functionality.
2Productivity
If the inner circumferential end of the guard is positioned close to the substrate edge to efficiently capture processing liquid, then the liquid capture efficiency is improved, but the guard interferes with the blocking member when it is in the blocking position
Solution Approach 1:
The system dynamically adjusts the radial positioning of different guards based on the processing stage. The first guard operates effectively when the blocking member is in the retreat position for chemical liquid processing, while the second guard operates when the blocking member is in the blocking position for rinsing processing. This dynamic configuration allows optimal liquid capture at each stage without interference.
3Device complexity
If a single guard is used to surround the substrate holding unit, then the device structure is simplified, but it cannot efficiently capture processing liquids from both the substrate edge and blocking member while avoiding interference
Solution Approach 1:
The guard system is divided into multiple specialized guards rather than using a single general-purpose guard. The first guard specializes in capturing processing liquid from the substrate edge during chemical liquid processing, while the second guard specializes in capturing liquid during rinsing processing. This segmentation improves overall system reliability and efficiency.
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 apparatus efficiently captures processing liquids from the substrate's edge, preventing splattering and accidental mixing, by maintaining an optimal radial distance between the substrate edge and the inner side guard, and avoiding interference between the blocking member and outer side guard.
Implementation Method 1
a spin chuck which holds and rotates a wafer substantially horizontally
Implementation Method 2
the spin chuck and the blocking member are rotated in a same direction. Thereby, the rinsing liquid that has adhered to the surface of the substrate is shaken off and removed (dried)
Data Source
AI summary
A substrate processing apparatus includes a substrate holding unit having a spin base; a blocking member having a substrate facing surface facing an upper surface of the substrate held by the substrate holding unit and having a diameter larger than the spin base; a blocking member lifting unit raising and lowering the blocking member between a blocking position where a space between the substrate facing surface and the upper surface is blocked from lateral side on the upper surface and a retreat position where the space is not blocked from the lateral side on the upper surface; guards including an inner side and an outer side guards respectively surrounding periphery of the substrate holding unit and surrounding periphery of the inner side guard. An inner circumferential end of the outer side guard is positioned on radial outer side of an inner circumferential end of the inner side guard.