Hybrid Vacuum Electrostatic Chuck for Vacuum Processing of Warped Wafers
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Solution Overview
Problem
Existing electrostatic chucks and vacuum chucks are ineffective in fully flattening highly warped semiconductor wafers, especially in vacuum processing environments, leading to inaccurate imaging and processing results.
Innovation Solution
A hybrid vacuum-electrostatic chuck system that combines vacuum and electrostatic clamping forces to flatten highly warped wafers, using a hybrid vacuum-electrostatic chuck carrier that secures and flattens samples in a load lock chamber before transferring them to a main processing chamber under vacuum conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a traditional electrostatic chuck is used to flatten wafers, then slightly or moderately warped wafers can be flattened, but highly warped wafers cannot be fully flattened
Solution Approach 1:
The patent combines vacuum chucking and electrostatic chucking into a hybrid system. The vacuum chuck provides initial clamping force to hold highly warped wafers, while electrostatic electrodes progressively flatten the wafer surface. This merging of two different chucking mechanisms allows the system to handle both slightly/moderately warped and highly warped wafers effectively.
Solution Approach 2:
The system dynamically adjusts the electrostatic voltage applied to electrodes based on the wafer's warpage condition. For highly warped wafers, the vacuum provides initial holding while electrostatic voltage is gradually increased to flatten the surface. This parameter adjustment allows the same chuck to adapt to different wafer conditions, from slightly warped to highly warped.
2Manufacturing precision
If a vacuum chuck is used to secure and flatten highly warped wafers, then highly warped wafers can be flattened, but the chuck cannot be used in vacuum processing chambers
Solution Approach 1:
The hybrid chuck merges vacuum chucking capability with electrostatic chucking capability in a single device designed for vacuum processing chambers. The electrostatic electrodes are integrated into the chuck structure, allowing it to provide both vacuum holding and electrostatic flattening functions while operating inside vacuum chambers, unlike traditional vacuum chucks that lack electrostatic functionality.
Solution Approach 2:
The hybrid chuck serves multiple functions: it can hold highly warped wafers using vacuum, flatten them using electrostatic forces, and operate within vacuum processing chambers. This multi-functionality makes it universally applicable to various wafer conditions and processing environments, combining the advantages of both vacuum and electrostatic chucks while eliminating their respective limitations.
3Adaptability or versatility
If only electrostatic force is used to clamp wafers, then the chuck can operate in vacuum chambers, but highly warped wafers cannot be fully secured and flattened
Solution Approach 1:
The hybrid chuck merges vacuum chucking capability with electrostatic chucking capability in a single device designed for vacuum processing chambers. The vacuum channels provide initial clamping force to secure highly warped wafers, while electrostatic electrodes progressively flatten the wafer surface. This merging of two different chucking mechanisms allows the system to handle both slightly/moderately warped and highly warped wafers effectively.
4Manufacturing precision
If a hybrid vacuum-electrostatic chuck is used, then highly warped wafers can be fully flattened in vacuum chambers, but the device complexity increases
Solution Approach 1:
The hybrid chuck is segmented into distinct functional components: vacuum channels for holding the wafer and electrostatic electrodes for flattening. This segmentation allows each component to perform its specific function optimally while maintaining a manageable overall structure. The electrodes are arranged in patterns that provide progressive flattening force, and the vacuum channels are distributed to ensure uniform holding pressure.
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
Ensures precise flattening of highly warped wafers, maintaining accurate working distances for imaging and processing, even in high or ultra-high vacuum environments.
Implementation Method 1
clamping and flattening the substrate to the substrate holder by applying a vacuum to the one or more vacuum channels
Implementation Method 2
applying a voltage to the one or more electrodes to further clamp the substrate to the substrate holder with an electrostatic force
Data Source
AI summary
A method of processing a substrate is disclosed that comprises: transferring the substrate into a processing chamber and positioning the substrate on an upper surface of a substrate holder in the processing chamber, wherein the substrate holder comprises one or more vacuum channels disposed at the upper surface and one or more electrodes disposed within the substrate holder proximate to the upper surface; while the substrate holder is within the processing chamber, clamping and flattening the substrate to the substrate holder by applying a vacuum to the one or more vacuum channels; while the substrate is clamped to the substrate holder via the one or more vacuum channels, applying a voltage to the one or more electrodes to further clamp the substrate to the substrate holder with an electrostatic force; pumping out the processing chamber to a vacuum pressure while continuing to clamp the substrate to the substrate with the electrostatic force; and while the substrate is clamped to the substrate holder by the electrostatic force, processing the substrate in the processing chamber under vacuum conditions.