One of the advantages to real time multivariate process monitoring is the opportunity to make concurrent adjustments to the process to positively affect the outcome. Umetrics online batch analysis software utilizes this by predicting the outcome of a batch after each observation is available. This methodology stops being advantageous however when the process time is short; less than 15 minutes for example. In this case, there is no time for manual intervention, and the real time process monitoring objective changes to stopping the next process from running and notifying the appropriate systems and people. Of course, the large majority of semiconductor processes fall into this category. To support this need, a separate software application called Fabstat is available. Fabstat accepts all of the process data for the batch, a wafer in a single-wafer chamber, at one time and calculates the results immediately for action to be taken. The architecture is very flexible allowing the host system to make any type of decision based on the outcome including inhibiting a chamber, notifying process techs, and plotting the results.
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