Substrate Stage Clamp Ring for Pressure-Balanced Wafer Transfer
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Solution Overview
Problem
In substrate processing apparatuses, film-forming gas by-products adhere to the back surface of substrates, leading to particle scattering and contamination, which can damage the substrates during transfer due to pressure differences when the stage descends.
Innovation Solution
A substrate processing apparatus with a clamp ring and pressure regulating mechanism, featuring through-holes or convex portions to control pressure differences, allowing quick unloading of substrates without damage by regulating gas flow through the clamp ring and shelf structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a clamp ring is provided on the peripheral edge of the substrate to cover the peripheral edge, then the film-forming gas is prevented from going around the back of the substrate, but the substrate may be damaged during transfer due to pressure differences
Solution Approach 1:
The clamp ring is designed with local quality differences: it has a first surface that contacts the substrate periphery and a second surface that is spaced apart, creating a gap. This local spacing allows pressure equalization while maintaining the clamp ring's protective function against film-forming gas contamination.
Solution Approach 2:
The gap between the first and second surfaces of the clamp ring acts as an intermediary channel for pressure equalization. This intermediate space allows pressure differences to be balanced without direct contact between the clamp ring and the substrate, preventing damage during transfer.
2Productivity
If the stage is moved quickly from processing position to transfer position, then throughput efficiency is improved, but pressure differences cause substrate damage
Solution Approach 1:
The clamp ring is positioned and configured in advance with its first and second surfaces spaced apart before substrate transfer. This preliminary arrangement ensures that pressure equalization pathways are already in place, allowing rapid stage movement without causing substrate damage from pressure differences.
3Stability of the object's composition
If the clamp ring contacts the substrate periphery directly, then the substrate is securely held during processing, but the substrate is attracted to the clamp ring during transfer due to pressure differences
Solution Approach 1:
The clamp ring is segmented into two surfaces: a first surface for securing the substrate periphery during processing and a second surface spaced apart to prevent direct contact during transfer. This segmentation allows the clamp ring to fulfill both securing and pressure-equalizing functions without causing substrate attraction.
Solution Approach 2:
The clamp ring design extends into the vertical dimension by spacing the first and second surfaces apart, creating a gap that allows pressure equalization. This dimensional approach resolves the conflict between securing the substrate and preventing pressure-induced attraction during transfer.
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
Enables rapid unloading of substrates while preventing damage by maintaining controlled pressure differences, thereby improving throughput and reducing processing time.
Implementation Method 1
a pressure regulating mechanism configured to suppress a pressure difference between a space above the substrate on the stage and a space below the stage
Data Source
AI summary
A substrate processing apparatus includes: a processing container; a stage provided inside the processing container to place a substrate thereon; an exhaust port arranged around the stage along an inner wall of the processing container; a driver configured to move the stage up and down between a processing position and a transfer position lower than the processing position; a clamp ring that is arranged on a peripheral edge of the substrate on the stage to cover the peripheral edge of the substrate when the stage is at the processing position, and is supported by a shelf provided on a sidewall of the processing container when the stage is at the transfer position; and a pressure regulating mechanism configured to suppress a pressure difference between a space above the substrate on the stage and a space below the stage.