If your laboratory or manufacturing site anticipates working with toxic or highly reactive species, then thorough planning is required prior to purchasing and installing a thin film deposition tool. This planning should happen well before completing the instrument design, as it is difficult and expensive to retroactively address safety issues.
Here are four essential factors to consider when developing a coating tool that is intended for use with dangerous materials:
The most important factor for handling dangerous materials is training all personnel. A facility safety plan means nothing if the people who use the equipment do not follow safety procedures. Furthermore, if personnel identify safety hazards related to equipment or protocol during system use, then facility managers must act immediately to address that concern. Learn more about early facility planning here.
Vacuum Pumping Systems
Pumping systems must be a throughput type—designed to handle high volumes of corrosive or toxic materials. These usually require oil diffusion pumps or corrosive series turbo pumps. It is important to prevent material condensation, especially for corrosive materials such as arsenic. If turbo pumps are to be used, typically the turbo pumps should have a dry nitrogen purge as well as a backing pump. The backing pump should be vented to a scrubber or house ventilation system. Don't guess. Make sure that your chamber designer takes these factors into account.
Many materials, when exposed to the atmosphere, will react violently with oxygen or water vapor. Such situations necessitate integrating dry glove boxes directly into the deposition chamber. Furthermore, the techniques for cleaning contaminated machine parts must be worked through in advance to ensure that there is space to clean the parts in-house, if possible. You should also consider proper techniques to ship the parts for cleaning as well as a method to dispose of cleaning byproducts.
Some materials that are toxic or highly reactive cannot simply vent into an exhaust system. Devices such as gas scrubbers are frequently necessary. Proper and thorough exhaust handling, along with protective safety gear, is especially critical during maintenance, when the chamber must be opened to the atmosphere for service.
Considering the above factors before instrument development helps ensure that safety issues do not arise during installation or use of your coating system. Safety features certainly add to the cost of equipment, but anticipating and addressing safety issues in advance saves cost, time, and potential injury later.
PVD Products has a fundamental understanding of the deposition process and how to safely reach your goals. To explore more about facility preparation, deposition system selection and customization options, download our free eBook, Choosing a Thin Film Deposition System.