Evaluating the Effectiveness of AMC Control Strategies with Reactivity Monitoring

Abstract

The control of airborne molecular contaminants (AMC) is becoming a design requirement for all semiconductor manufacturing facilities. Chemical filtration in many forms is being employed in makeup air handling units, recirculation air handlers, minienvironments, fan filter units, and process tools. Suppliers of chemical filtration systems are being asked how best to determine if their systems are working and, if so, whether they are meeting design requirements. Just as there are many ways to apply chemical filtration for the control of AMC, there are many different methods being used to measure AMC and to evaluate filter system performance. Employed in either real-time or passive form, reactivity monitoring has been used in a number of fabs for several years as a way to gauge AMC levels and to evaluate the effectiveness of AMC control strategies. Whether controlling AMC directly or indirectly, reactivity monitoring can provide an overall indication of ambient air quality as well as AMC levels within the controlled spaces. This paper will focus on the use of reactivity monitoring as an air monitoring technique. Results of reactivity monitoring from semiconductor manufacturing facilities will be presented, illustrating both the validity of this air monitoring technique in general as well as its ability to gauge the effectiveness of chemical filtration when applied to the control of AMC.