Monitoring System for Airborne Molecular Contamination (AMC) in Semiconductor Manufacturing Areas and Micro-Environments

摘要

As a result of shrinking dimensions and technology nodes, nanoelectronics manufacturing and handling processes demand growing requirements to the cleanliness of the air inside cleanrooms and microenvironments. Besides the limitation of particle contamination, the limitation of airborne molecular contamination (AMC) is necessary to ensure yield and quality of nanoelectronics production lines. AMC levels and filter efficiency can only be controlled effectively with suitable detection technologies for in-situ operation. State-of-the-art AMC monitors are limited in detection speed and in selectivity. In particular off-line technologies such as Tenax or charcoal sampling and laboratory analyses after desorption of the probes do not allow a fast response on increasing AMC levels. Total sampling and laboratory analyses time takes hours. Spikes in the AMC levels are nearly impossible to identify, as the off-line technologies provide information on average contamination levels rather than actual contamination levels. State-of-the-art in-situ monitors such as surface acoustic wave based technologies also do not give a fast information on the contamination species, as this kind of monitors are not capable of identifying the kind of contamination in-situ. In the sub-project MOSAIC of the integrated project SEA-NET, which is funded by the European commission, a high precision in-situ tool for the simultaneous detection of various AMCs based on available ion mobility spectroscopic techniques was developed with Drager Safety and assessed. Ion Mobility Spectroscopy based AMC monitoring is a fast and to a higher extent selective technology. Lower detection limits with the current IMS generation are in the low ppb range with an optimization potential to the sub ppb range.