Plastic containers contamination by volatile acids: accumulation, release and transfer to Cu-surfaces during wafers storage

摘要

Today, Pods and FOUPs (Front Opening Unified Pod) are generally used in IC manufacturing in order to isolate wafers from clean room air contamination, to reduce handling,… However, contamination issues still exist since these storage containers constitute an enclosed environment made with porous plastics (mainly polycarbonate, polyetheretherketone and polypropylene). Indeed, such polymeric materials are known to outgass airborne molecular contaminants (AMC) [1,2], but can also absorb volatile compounds present in their atmosphere following the release from wafers stored or after the connection to an equipment. As a result, the subsequent outgassing of species trapped in plastic containers constitute a significant concern with respect to the wafer environmental contamination control.