Electrostatic Chuck Polymer Protrusions Heat Transfer
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Solution Overview
Problem
In microelectronics production, controlling the heat transfer and particulate contamination on electrostatic chucks is challenging due to varying contact surface characteristics and the risk of substrate deformation from entrapped particles, which affects temperature uniformity and manufacturing yield.
Innovation Solution
An electrostatic chuck with polymer protrusions and a charge control layer, where the protrusions are formed from materials like polyetherimide or polyether ether ketone, and the charge control layer has a specific surface resistivity, promoting efficient contact cooling while reducing particle production and substrate deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If protrusions are added to the electrostatic chuck surface to improve heat transfer, then heat transfer efficiency is improved, but the risk of substrate deformation from entrapped particles increases
Solution Approach 1:
The electrostatic chuck surface incorporates protrusions that create a controlled porous structure, allowing heat transfer while preventing particle entrapment. The protrusions are designed with specific dimensions and spacing to enable thermal contact without creating pockets where particles could be trapped and cause substrate deformation.
Solution Approach 2:
The invention changes the surface parameters of the electrostatic chuck by adding protrusions with specific height, diameter, and spacing parameters. These parameter changes optimize the balance between heat transfer area and particle entrapment prevention, allowing efficient thermal contact while maintaining substrate flatness.
2Temperature
If the contact area between substrate and electrostatic chuck is increased to improve heat transfer, then heat transfer efficiency is improved, but controlling temperature uniformity becomes more difficult
Solution Approach 1:
The protrusions are distributed across the electrostatic chuck surface with varying densities and dimensions to create local quality variations. This allows different regions of the substrate to receive appropriate heat transfer, maintaining overall temperature uniformity while achieving efficient heat removal where needed.
Solution Approach 2:
The continuous contact surface is segmented into discrete protrusions, which distributes the heat transfer function across multiple localized contact points. This segmentation prevents hot spots and promotes uniform temperature distribution across the substrate while maintaining high overall heat transfer efficiency.
3Temperature
If protrusions are added to the electrostatic chuck surface, then contact heat conduction is improved, but particle contamination increases
Solution Approach 1:
The protrusions are designed as sacrificial elements that can be replaced if they become contaminated. Their relatively simple structure and positioning allow for economical replacement rather than requiring complex cleaning or maintenance procedures, ensuring continuous production with minimal particle contamination risk.
Solution Approach 2:
The protrusions are designed to be removable from the electrostatic chuck surface, allowing them to be extracted and replaced when contamination occurs. This extraction capability enables maintenance of heat transfer efficiency without introducing new particles during cleaning operations.
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 enhances heat transfer efficiency and reduces particle-induced substrate deformation, maintaining temperature uniformity and improving manufacturing yield by using polymer protrusions and a charge control layer with controlled surface resistivity.
Implementation Method 1
the back side of a substrate, such as a semiconductor wafer, is held to the face of the electrostatic chuck by an electrostatic force
Implementation Method 2
Heat delivered to the substrate during processing can be transferred away from the substrate and to the electrostatic chuck by contact heat conduction with the protrusions
Data Source
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AI summary
In accordance with an embodiment of the invention, there is provided an electrostatic chuck. The electrostatic chuck comprises a surface layer activated by a voltage in an electrode to form an electric charge to electrostatically clamp a substrate to the electrostatic chuck. The surface layer includes a plurality of polymer protrusions and a charge control layer to which the plurality of polymer protrusions adhere, the plurality of polymer protrusions extending to a height above portions of the charge control layer surrounding the plurality of polymer protrusions to support the substrate upon the plurality of polymer protrusions during electrostatic clamping of the substrate.