Wafer Chuck Segmented Vacuum for Warpage Control
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Solution Overview
Problem
Larger semiconductor wafers, such as those 300 mm or larger, experience significant warpage issues that lead to manufacturing defects due to non-uniform coating and photolithographic process problems, primarily caused by imperfect chucking during processing.
Innovation Solution
A wafer chuck design with a larger diameter carrying surface and multiple vacuum holes, along with concentrically arranged seal rings and an edge ring, is used to distribute vacuum force evenly and prevent warpage, ensuring uniform coating and preventing exposure to etching reaction products.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If larger wafers (300 mm or larger) are used to hold more chips and reduce per-chip cost, then productivity and cost efficiency are improved, but wafer warpage becomes more severe causing manufacturing defects
Solution Approach 1:
The vacuum system is segmented into multiple vacuum holes distributed across the carrying surface, with different numbers and distributions for central and peripheral regions. This segmentation allows independent control of vacuum force in different wafer zones, enabling precise warpage compensation while maintaining high productivity with large wafers
Solution Approach 2:
Different regions of the carrying surface are assigned different vacuum hole densities and configurations - the central region has a specific number of vacuum holes while the peripheral region has another number, allowing localized adjustment of vacuum force to match the specific warpage characteristics of different wafer zones
2Device complexity
If conventional chucking methods are used for large wafers, then device simplicity is maintained, but coating uniformity and etching precision deteriorate due to imperfect chucking
Solution Approach 1:
The vacuum system is divided into multiple segmented vacuum holes with different distributions in central and peripheral regions, enabling localized control of vacuum force to achieve uniform coating and precise etching while maintaining a relatively simple chuck structure
Solution Approach 2:
The vacuum parameters are changed by varying the number and distribution of vacuum holes across different regions of the carrying surface, allowing optimization of vacuum force application to achieve uniform coating thickness and precise etching without complex additional components
3Device complexity
If vacuum force is applied uniformly across the carrying surface, then device simplicity is maintained, but warpage adjustment effectiveness decreases for large wafers
Solution Approach 1:
The vacuum distribution system is segmented into multiple vacuum holes with different numbers and configurations in central and peripheral regions, enabling non-uniform vacuum force distribution that effectively adjusts warpage profile while avoiding overly complex system design
Solution Approach 2:
Different regions of the carrying surface are provided with different vacuum hole densities and arrangements, allowing localized optimization of vacuum force application to effectively compensate for warpage in specific areas without requiring a completely complex distributed system
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 effectively adjusts the warpage profile of larger wafers, improving coating uniformity and preventing chemical exposure, thereby enhancing the handling and processing of larger wafers with significant warpage.
Implementation Method 1
a vacuum device (130) coupled to the chuck body (110) and in gas communication with the vacuum holes (114)
Data Source
AI summary
A wafer chuck includes a chuck body and a plurality of seal rings. The chuck body includes a carrying surface configured to receive a wafer and at least one vacuum hole disposed on the carrying surface. A ratio of a diameter of the carrying surface to a diameter of the wafer is substantially equal to greater than 45% and substantially equal to or smaller than 90%. The seal rings are disposed on the carrying surface and configured to physically contact with the wafer. The seal rings surround the vacuum hole.