Wafer Buffing Chuck Drainage Layout to Prevent Slipping
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Solution Overview
Problem
During the buffing cleaning process after a CMP process, substrates (wafers) may slip due to insufficient adhesion between the substrate's rear surface and the backing film, or excessive water film formation, which reduces friction and stability.
Innovation Solution
A buffing cleaning apparatus with a chuck table and film configuration that includes communication and drain holes to manage liquid drainage, ensuring even distribution of vacuum force and preventing water accumulation, thereby enhancing frictional force between the substrate and the film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick water film remains on the backing film from a previous process, then the substrate may slip during rotation, but adding more drainage structures increases device complexity
Solution Approach 1:
The drainage system is segmented into multiple drain holes distributed across the backing film, with each hole connected to corresponding drain grooves on the chuck table. This segmentation allows efficient water removal across the entire substrate area without requiring a single complex drainage structure, thereby maintaining substrate fixation stability while keeping the device relatively simple.
Solution Approach 2:
The patent introduces an intermediary drainage system consisting of drain holes in the backing film and drain grooves on the chuck table that mediate between the water film on the substrate and the vacuum system. This intermediary structure enables effective water removal without directly complicating the substrate fixation mechanism, resolving the contradiction between reliability and device complexity.
2Reliability
If adhesion between the substrate rear surface and backing film is insufficient, then the substrate slips during rotation, but increasing adhesion strength may require additional components
Solution Approach 1:
The patent extracts the water removal function from the adhesion mechanism by introducing a separate drainage system with drain holes and grooves. This allows the adhesion mechanism to focus solely on providing friction and holding force, while water removal is handled by the extracted drainage system, thereby improving substrate-film adhesion without adding complexity to the adhesion mechanism itself.
Solution Approach 2:
The patent utilizes the existing vacuum system (pneumatic principle) to create negative pressure that draws water through the drain holes and grooves. This pneumatic approach to water removal enhances substrate-film adhesion by eliminating water interference, while leveraging the already-present vacuum infrastructure avoids adding complex adhesion enhancement components.
3Productivity
If the chuck table rotates with water present, then cleaning efficiency decreases, but improving drainage increases manufacturing complexity
Solution Approach 1:
The patent merges the drainage function with the existing vacuum chuck table structure by integrating drain grooves into the table surface and connecting them to drain holes in the backing film. This merging allows water removal to occur simultaneously with substrate holding and rotation, improving cleaning process efficiency without requiring separate manufacturing processes or additional complex components.
Solution Approach 2:
The vacuum chuck table is given multi-functionality by incorporating both substrate holding (via vacuum holes) and water drainage (via drain grooves) capabilities into a single component. This universal design improves cleaning efficiency by enabling concurrent substrate fixation and water removal, while avoiding the manufacturing complexity of separate dedicated structures for each function.
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 apparatus effectively prevents substrate slipping by maintaining adequate friction, ensuring stable substrate fixation during the cleaning process.
Implementation Method 1
a chuck table having a vacuum hole, and a film disposed on an upper surface of the chuck table, the film having a communication hole vertically overlapping the vacuum hole
Implementation Method 2
the film has a drain hole configured to drain liquid through the drain hole. The chuck table may have a drain groove vertically overlapping the drain hole
Data Source
AI summary
A buffing cleaning apparatus includes chuck table having a vacuum hole, and a film disposed on an upper surface of the chuck table, the film having a communication hole vertically overlapping the vacuum hole. An upper surface of the film is configured to receive a wafer. The film has a drain hole configured to drain liquid through the drain hole. The chuck table has a drain groove vertically overlapping the drain hole.