Focus Ring Thimble for Semiconductor Wafer Transfer
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Solution Overview
Problem
In semiconductor processing, residual static electricity and uneven load distribution can cause position deviations and tilting of wafers during transfer, leading to increased wafer scrap and maintenance costs due to adhesion issues between the wafer and the electrostatic chuck, which complicates automated wafer retrieval.
Innovation Solution
A lift thimble system with a focus ring thimble device that can rise or descend to lift and position the focus ring, allowing the wafer to be lifted without damaging the vacuum environment, and a wafer thimble device to lift the wafer from the base, ensuring precise transfer and reducing adhesion-related issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the height-adjustable thimble mechanism lifts the wafer, then the wafer is transferred from the electrostatic chuck, but position deviation occurs due to wafer movement and adhesion
Solution Approach 1:
The focus ring serves as an intermediary element between the electrostatic chuck and the wafer. By lifting the focus ring first, the wafer edge is gently engaged and released from adhesion, mediating the transfer process to prevent sudden movement and position deviation during wafer extraction
Solution Approach 2:
The focus ring thimble device performs a preliminary action by lifting the focus ring before the wafer thimble device lifts the wafer. This preliminary lifting action releases the wafer edge from adhesion in advance, preventing position deviation during the subsequent wafer lifting operation
2Reliability
If residual static electricity remains on the electrostatic chuck, then the wafer adheres to the chuck, but wafer retrieval becomes difficult and requires opening the reaction chamber
Solution Approach 1:
The focus ring acts as a mediator to release the wafer from the electrostatic chuck. By lifting the focus ring first, the wafer edge is gently disengaged from the chuck surface, allowing subsequent wafer removal without needing to open the reaction chamber, thus maintaining vacuum integrity while enabling easy wafer retrieval
Solution Approach 2:
The focus ring thimble device extracts the focus ring from its initial position covering the wafer edge. This extraction action removes the mechanical constraint on the wafer edge, allowing the wafer to be released from electrostatic adhesion and facilitating easy retrieval without compromising the sealed reaction chamber
3Extent of automation
If the wafer tilts and misaligns during transfer, then automated manipulator transfer fails, but opening the reaction chamber for manual retrieval increases maintenance cost
Solution Approach 1:
The focus ring is lifted in advance before the wafer transfer operation. This preliminary action ensures the wafer edge is released from adhesion and properly positioned, preventing tilting and misalignment during the automated manipulator transfer, thereby maintaining automation without increasing system complexity
Solution Approach 2:
The wafer transfer process is segmented into two independent stages: first lifting the focus ring, then lifting the wafer. This segmentation allows each stage to be optimized independently, ensuring proper wafer positioning before transfer without complicating the overall automated 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 system effectively addresses position deviations and tilting, improving maintenance efficiency, reducing wafer scrap and maintenance costs, and extending the service life of the focus ring by allowing precise height adjustments and replacement without compromising the vacuum.
Implementation Method 1
The wafer is adsorbed on the electrostatic chuck during the process
Implementation Method 2
a lift thimble system, including a wafer thimble device configured to lift a wafer from a base by rising or drop the wafer onto the base by descending
Data Source
AI summary
The present disclosure discloses a lift thimble system, a reaction chamber, and semiconductor processing equipment, including a wafer thimble device configured to lift a wafer from a base by rising or drop the wafer onto the base by descending, and a focus ring thimble device configured to lift a focus ring from an initial position of the focus ring by rising to cause an inner ring area of an upper surface of the focus ring to lift an edge area of the wafer, or cause the focus ring to return to the initial position by descending. The technical solutions of the system, the reaction chamber, and the equipment of the present disclosure improve maintenance efficiency of an abnormal situation, and double the service lifetime of the focus ring. Moreover, the technical solutions may further realize replacement of the focus ring without damaging reaction chamber vacuum to improve efficiency.