Substrate Processing Method for Wafer Transfer Timing Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor wafer processing, continuous processing of multiple wafers leads to variations in processing chamber conditions, resulting in inconsistencies in circuit pattern dimensions due to timing issues in feedforward and feedback calculations, which reduces throughput and accuracy.
Innovation Solution
A substrate processing method that includes preprocessing and postprocessing measurements, with initial calculations before wafer transfer, decision-making phases to assess processing parameter values, and a second calculation phase during transfer to adjust parameters based on recent measurements, ensuring only wafers with suitable parameters are processed, thereby preventing superfluous transfers and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feedforward calculation is executed with the timing of preprocessing measurement while current wafer processing is underway, then throughput is improved by allowing parallel processing, but accuracy deteriorates because the calculation does not reflect the most recent feedback results
Solution Approach 1:
The system performs preliminary feedforward calculation based on preprocessing measurements while the current wafer is being processed, preparing the next wafer's processing parameters in advance. This preliminary action enables parallel processing operations without compromising the accuracy of the final processing parameters, as the calculation is subsequently refined with actual feedback data from the completed wafer.
2Manufacturing precision
If wafer transfer to measurement chamber is delayed until after feedback calculation is completed, then accuracy is improved by ensuring latest feedback results are reflected, but throughput deteriorates due to increased waiting time
Solution Approach 1:
The system maintains continuous useful action by overlapping the feedforward calculation for the next wafer with the processing and feedback measurement of the current wafer. This continuity allows the calculation phase to proceed without idle waiting time while still incorporating the latest feedback results, thereby maintaining both high accuracy and throughput.
3Manufacturing precision
If feedforward calculation timing is retarded to after wafer transfer to loadlock chamber, then accuracy is improved by allowing more time for feedback calculation, but throughput deteriorates and processing efficiency is reduced
Solution Approach 1:
The system performs the feedforward calculation as a preliminary action during the wafer processing period rather than waiting until after transfer to loadlock chamber. This timing optimization ensures that the calculation is completed with accurate feedback data while avoiding unnecessary delays that would reduce throughput and processing efficiency.
Data Source
AI summary
First feedforward calculation is executed when a preprocessing surface profile is measured and a processing chamber with its processing parameter value having been obtained through the first feedforward calculation judged to be within an allowable range is determined. Wafer transfer is executed only in conjunction with a processing chamber having a processing parameter value judged to be within the allowable range, and the wafer is carried to the entry point of the processing chamber. Then, second feedforward calculation is executed by reflecting the results of feedback calculation executed based upon the most recent processing having been executed in the particular processing chamber and wafer processing is executed in the processing chamber based upon the processing parameter value calculated in the second feedforward calculation.