Substrate Processing Throughput Control for Maintenance
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Solution Overview
Problem
The frequent maintenance needs of the resist coating unit in photolithography processing systems, which requires a clean environment and frequent cleaning, leads to decreased productivity due to the necessity of stopping the entire system for maintenance, thereby reducing the operating rate and throughput of wafer processing.
Innovation Solution
Implementing a substrate processing method where the throughput of pre-stage processing is set higher than post-stage processing, allowing for earlier completion of pre-stage processing on a fixed number of substrates, enabling maintenance during post-stage processing without halting the entire system, by using a transfer-in/out section and processing section that performs first and second treatments on substrates, with a control unit managing throughput to prioritize pre-stage processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the resist coating unit performs processing in a clean atmosphere, then the processing quality is improved, but the unit requires frequent maintenance and cleaning, which decreases the operating rate of the whole system
Solution Approach 1:
The processing system is divided into pre-stage processing units (including resist coating unit 32) and post-stage processing units (including developing unit 30). This segmentation allows independent maintenance of pre-stage units without stopping the entire system, as post-stage units can continue processing wafers that have completed pre-stage treatment.
Solution Approach 2:
The pre-stage processing units complete their processing ahead of time with higher throughput, creating a buffer of processed wafers. This preliminary completion allows maintenance to be performed on pre-stage units while post-stage units continue operating on the buffered wafers.
2Productivity
If the throughput of pre-stage processing is increased, then the operating rate is improved, but maintenance time for pre-stage units becomes more difficult to schedule
Solution Approach 1:
The control unit 110 dynamically adjusts the throughput of pre-stage and post-stage processing units. By making throughput adjustable rather than fixed, the system can optimize pre-stage throughput during normal operation and then schedule maintenance during periods when the buffered wafers can sustain post-stage operation.
Solution Approach 2:
The system maintains continuous useful action by ensuring that while pre-stage units are under maintenance, post-stage units continue processing the buffered wafers. This continuity prevents complete system shutdown and maintains productivity during maintenance periods.
3Reliability
If the entire system is stopped for maintenance of pre-stage units, then the maintenance can be performed properly, but the overall productivity decreases
Solution Approach 1:
The system is segmented into independent pre-stage and post-stage processing sections. This allows maintenance to be performed on pre-stage units (resist coating unit 32, lower anti-reflection film forming unit 31, upper anti-reflection film forming unit 33) while post-stage units (developing unit 30, thermal processing units 40) continue operating on buffered wafers.
Solution Approach 2:
The buffer cassette 60 acts as an intermediary storage between pre-stage and post-stage processing. It accumulates processed wafers from pre-stage units, allowing post-stage units to continue operation during pre-stage maintenance without direct interruption.
4Manufacturing precision
If the resist coating unit is cleaned frequently, then the processing environment is maintained, but the system operation is interrupted
Solution Approach 1:
The processing system is divided into pre-stage and post-stage units, allowing the resist coating unit 32 to be cleaned and maintained independently without stopping the developing unit 30 or other post-stage processing, thus maintaining system operation while ensuring cleanliness.
Data Source
AI summary
A substrate processing system of the present invention includes a transfer-in/out section for transferring-in/out a substrate and a processing section for performing a plurality of processing and treatments on the substrate, in which a throughput of substrate processing at a pre-stage performed from when the substrate is transferred in from the transfer-in/out section to when the substrate is transferred out to the external apparatus is set higher than a throughput of substrate processing at a post-stage performed from when the substrate is returned from the external apparatus into the processing section to when the substrate is returned into the transfer-in/out section.