Automated wafer handling

In the old days when wafers were handled with tweezers, before the advent of the automated wafer-handling systems of today, novolac resists were notorious for their particle generation problem, which eventually led to the introduction of automated wafer handling systems. " ... 

In addition to the design goal of reducing the processing cost per wafer, this system has been developed to reduce the particulate contamination to a minimum. To accomplish this, the entire system is enclosed within a laminar flow hood, so that the wafers are handled in a class 10 environment. Secondly, wafers are loaded and unloaded by an automated robot, so that human intervention is not necessary to handle the two susceptors. Both of these features are illustrated in Figure 15. 

As in the LPCVD reactor discussed earlier, allowing the electrode structure to touch the tube wall as it is inserted leads to considerable particle contamination. Therefore, cantilever loaders are available here also, and a typical unit on an ASM reactor is shown in Figure 23. Again, in contrast to the AMP-3300, this system is operated under computer control. Automated handling of wafers is more difficult to achieve, and is not generally available. 

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