Substrate Holding Table with Segmented Vacuum and Liquid Paths
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Solution Overview
Problem
In CMP apparatuses, the suction of slurry or process liquid through gaps between the substrate and the table during vacuum holding can lead to contamination, and the release of this liquid can smudge the substrate, necessitating a solution to prevent liquid ingress and egress during processing.
Innovation Solution
A table design with a support face featuring a first opening for vacuum suction and a second opening around it, connected to a vacuum source and a fluid path to the atmosphere, respectively, to manage the liquid and prevent contamination during substrate processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the table uses small apertures for vacuum-sucking the substrate, then the substrate can be held firmly on the table, but slurry or process liquid is sucked through the gap between the substrate edge and table into the apertures, causing contamination
Solution Approach 1:
The patent divides the aperture system into two distinct types: first apertures for vacuum suction and second apertures for liquid discharge. This segmentation allows the vacuum function and liquid management function to be separated, preventing slurry from being sucked into the vacuum system while providing a dedicated path for liquid egress.
Solution Approach 2:
The patent introduces a backing member as an intermediary component between the table and substrate. The backing member has through-holes that align with both the first apertures (vacuum) and second apertures (liquid discharge), mediating the fluid flow paths and enabling controlled liquid discharge without compromising vacuum holding.
2Ease of operation
If gas or liquid is jetted from the small apertures to release the substrate, then the substrate can be released from the table, but sucked slurry or process liquid flows out from the gap and runs around to smudge the substrate
Solution Approach 1:
The patent segments the aperture function into vacuum suction (first apertures) and liquid discharge (second apertures). During substrate release, gas or liquid can be jetted through the second apertures and backing member through-holes to break the vacuum hold, while the separated liquid paths prevent smudging of the substrate.
Solution Approach 2:
The patent extracts the liquid discharge function from the vacuum suction system by creating separate second apertures and liquid discharge paths. This extraction allows the release mechanism to use gas or liquid jetting without the harmful effect of slurry being forced out through the same path, thus preventing substrate contamination.
3Productivity
If the table supports the entire back surface of the substrate, then the polishing speed and cleansing effect are enhanced, but the complexity of managing liquid flow and preventing contamination increases
Solution Approach 1:
The patent segments the table structure into multiple functional layers: the table body with first and second apertures, and a separate backing member with through-holes. This segmentation allows the large surface area contact for high productivity while organizing the liquid management functions into distinct, manageable paths through the segmented structure.
Solution Approach 2:
The backing member serves multiple functions: it provides structural support for the substrate, enables vacuum holding through aligned through-holes, and facilitates liquid discharge through the same through-holes during release. This multi-functionality reduces overall system complexity by combining several functions in a single component.
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 solution effectively minimizes the suction of slurry into the table and prevents liquid from flowing onto the substrate during processing and release, reducing contamination and improving the cleanliness of the substrate.
Implementation Method 1
a first fluid path (410) extending to a first opening (404) formed in the support face (402) through the table (400) and connectable to a vacuum source (746)
Data Source
AI summary
Provided is a wet substrate processing apparatus for processing a substrate. The apparatus comprises a table for holding a substrate, and a process liquid feeding mechanism for feeding process liquid to the substrate held on the table. The table includes a support face for supporting the substrate, a first opening formed in the support face, a second opening formed in the support face and arranged at least partially around the first opening, a first fluid path configured to extend to the first opening of the support face via the table and be connectable to a vacuum source, and a second fluid path configured to extend to the second opening of the support face via the table and discharge the process liquid.