Substrate Processing Control Unit Error Recovery Mechanism
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Solution Overview
Problem
In substrate processing systems that sequentially and serially transfer substrates to multiple processing modules, errors during processing can lead to the generation of defective substrates due to incomplete processing and stagnation of wafers, resulting in significant losses, especially when errors occur in expensive substrates like those used for MRAM manufacturing.
Innovation Solution
A substrate processing system with a control unit that manages the transfer and processing of substrates by collecting unprocessed wafers, continuing processing of preceding wafers, retreating error wafers, and resuming processing of subsequent wafers, thereby minimizing the generation of defective substrates and optimizing yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If substrates are sequentially and serially transferred to processing modules, then processing efficiency is improved, but error propagation causing defective substrates worsens
Solution Approach 1:
The patent extracts the error substrate from the continuous processing flow by retreating it to a retreat position (such as a load port or intermediate position) where it can be handled separately. This allows the error substrate to be removed from the error propagation path while maintaining the sequential processing of normal substrates, thus resolving the contradiction between processing efficiency and preventing defect propagation.
Solution Approach 2:
The patent segments the substrate processing flow by introducing a retreat position that divides the continuous sequence into independent segments. When an error occurs, the processing sequence is divided into: (1) substrates already processed before the error, (2) the error substrate being retreated, and (3) subsequent substrates that can continue processing. This segmentation prevents error propagation while maintaining overall processing efficiency.
2Productivity
If error substrates are retreated and processing continued, then production yield is improved, but system complexity worsens
Solution Approach 1:
The retreat position is designed with multi-functionality, serving as both a normal intermediate holding position during regular processing and as an error recovery position when substrates need to be retreated. This universal design allows the system to handle both normal sequential processing and error recovery using the same infrastructure, minimizing additional complexity while enabling yield improvement through error substrate retreat and continued processing of subsequent substrates.
Data Source
AI summary
A substrate processing system includes a processing unit including processing modules and a first transfer device, a loading/unloading unit including a load port holding a substrate accommodating container and a second transfer device, and a control unit. The control unit controls the substrates to be sequentially transferred. When an error has occurred in a certain processing module, the control unit executes: collecting a substrate that has been unloaded from the substrate accommodating container but has not been processed in the substrate accommodating container; continuing processing of a preceding substrate in a processing module sequentially following the processing module in which the error has occurred; retreating an error substrate processed in the process module in which the error has occurred from the processing module to a retreat position; and continuing processing of a subsequent substrate processed in a processing module sequentially preceding the processing module in which the error has occurred.