Moving in-situ particle monitoring into manufacturing: a status report

The progress that has been made to data in making in-situ particle monitoring a practical manufacturing technology is reviewed. It is noted that automated monitoring, affords closed-loop control of particle levels without operator intervention. The key to realizing this promise is automated interpretation of particle data and assignment of causes to events. Several methods for simplifying this task are discussed, including collecting particle count data synchronized to the operating cycle of the tool and correlation to tool operating parameters. These methods will be supported by data showing how particle counts can be assigned to causes such as mechanical misalignment and the need for cleaning. It is concluded that in-situ particle monitoring has the potential to be an effective closed-loop process control technique by virtue of its ability to function automatically, continuously, and in real-time