Wafer Placement Table Layout to Prevent Peripheral Cracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wafer placement tables experience cracks due to large stress at the outermost periphery, particularly when processing wafers with high-power plasma, as the gas distribution paths often overlap the refrigerant flow path, leading to deformation and cracking.
Innovation Solution
The wafer placement table design includes a ceramic plate with a cooling plate and gas distribution paths, where the outermost peripheral gas distribution path is positioned to not overlap the refrigerant flow path in plan view, using a composite material for the cooling plate to mitigate stress and prevent cracks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the gas distribution path is positioned at the outermost periphery of the ceramic plate, then gas distribution effectiveness is improved, but stress concentration increases leading to cracks
Solution Approach 1:
The gas distribution path is positioned at a location that does not overlap the refrigerant flow path in plan view, creating local structural reinforcement at the outermost periphery where the gas distribution path is located. This local quality change prevents stress concentration and crack formation while maintaining gas distribution effectiveness.
2Area of stationary object
If the gas distribution path overlaps the refrigerant flow path, then space utilization is improved, but deformation and cracking occur due to stress
Solution Approach 1:
The gas distribution path and refrigerant flow path are arranged in different spatial positions such that they do not overlap in plan view. This dimensional arrangement separates the two paths spatially, preventing stress concentration and deformation while still utilizing the available space effectively within the wafer placement table structure.
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 design reduces stress at the outermost periphery, preventing cracks and ensuring effective operation under high-power plasma processing by maintaining structural integrity.
Implementation Method 1
a cooling plate that is joined to a lower surface of the ceramic plate and that has a refrigerant flow path
Implementation Method 2
a gas distribution path that extends from the gas common path to the upper surface of the ceramic plate
Data Source
AI summary
A wafer placement table includes a ceramic plate that has at least a wafer placement part at an upper surface thereof, a cooling plate that is joined to a lower surface of the ceramic plate and that has a refrigerant flow path, gas common paths that are provided above the refrigerant flow path, gas introduction paths that extend from a lower surface of the cooling plate to a corresponding one of the gas common paths, and a plurality of gas distribution paths, that are provided for the gas common paths. The gas distribution path that is disposed at an outermost periphery of the ceramic plate is provided at a position that does not overlap the refrigerant flow path in plan view.