Electrostatic Chuck Segmentation for Wafer Release Deviation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, the release of a semiconductor wafer from a vacuum chamber can result in positional deviation due to gas accumulation between the wafer and the chuck, leading to potential wafer misalignment and operational interruptions, as the reduced electrostatic attraction force allows gas expansion to dislodge the wafer, making it difficult to retrieve and affecting productivity.
Innovation Solution
A wafer holding device with a controller that manages attraction forces across multiple regions on the chuck surface, employing a temporarily reduced attraction state to evacuate gases before fully releasing the wafer, ensuring stable positioning and preventing misalignment by gradually decreasing attraction forces to minimize gas-induced wafer displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electrostatic attraction force is reduced to release the wafer, then the wafer can be removed from the chuck, but gas accumulation between the wafer and chuck causes positional deviation and misalignment
Solution Approach 1:
The wafer chuck is divided into multiple independent attraction regions (first, second, third regions) that can be controlled separately. This segmentation allows selective reduction of electrostatic attraction in specific regions to facilitate gas evacuation while maintaining attraction in other regions to prevent wafer misalignment, thereby resolving the contradiction between ease of release and positioning accuracy.
Solution Approach 2:
The controller first reduces the electrostatic attraction force in the first attraction region before fully releasing the wafer. This preliminary action creates a controlled environment for gas evacuation while maintaining wafer stability through attraction forces in other regions, preventing positional deviation before the final release.
2Device complexity
If the electrostatic attraction force is completely reduced at once, then the wafer release process is simplified, but gas expansion dislodges the wafer causing operational interruptions
Solution Approach 1:
The attraction regions are segmented and controlled independently, allowing the system to reduce attraction forces in a controlled sequence rather than all at once. This maintains reliability by preventing sudden wafer dislodgement while still simplifying the overall release process through automated regional control.
Solution Approach 2:
The controller implements periodic reduction of electrostatic attraction forces across different regions in a sequential manner. This periodic action allows gas evacuation to occur in controlled intervals while maintaining wafer stability, preventing operational interruptions that would occur with simultaneous complete release.
3Manufacturing precision
If electrostatic attraction is maintained to prevent wafer displacement, then positioning accuracy is maintained, but gas accumulation cannot be evacuated efficiently
Solution Approach 1:
By segmenting the chuck into multiple independently controllable attraction regions, the system can reduce attraction in specific regions to allow gas evacuation while maintaining attraction in other regions to preserve overall wafer positioning accuracy. This resolves the contradiction by spatially separating the functions of gas evacuation and position maintenance.
Solution Approach 2:
The controller applies different electrostatic attraction conditions to different local regions of the wafer chuck. Some regions have reduced attraction to facilitate gas evacuation, while other regions maintain strong attraction to prevent wafer displacement. This local differentiation allows simultaneous achievement of gas evacuation and positioning accuracy.
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 approach effectively reduces wafer positional deviation during release, maintaining operational efficiency by ensuring precise wafer handling and minimizing downtime in semiconductor processing.
Implementation Method 1
an electrostatic chuck employing an electrostatic force is used
Data Source
AI summary
A wafer holding device includes a wafer chuck that includes a wafer holding surface coming into contact with a wafer to be held and a plurality of attraction regions provided on the wafer holding surface, and a controller configured to independently control an attraction force of an at least one of the plurality of attraction regions. In a case where fixing of the wafer is released, the controller establishes a temporarily fixing state in which the attraction force of the at least one of the plurality of attraction regions is smaller than an attraction force in fixing the wafer, and thereafter, the controller sets attraction forces of all of the plurality of attraction regions to be smaller than the attraction force in fixing the wafer.