Vapor drain system

During wafer fabrication, a transportable enclosure, such as a Standard Manufacturing InterFace (SMIF) pod encloses a nascent product, such as a semiconductor wafer, to protect the wafer against contamination during manufacture, storage or transportation. However chemical vapors emitted inside the pod can accumulate in the air and degrade wafers during subsequent fabrication. In order to absorb the vapors inside a closed pod, a vapor removal element typically including an activated carbon absorber, covered by a particulate-filtering vapor-permeable barrier, and covered by a guard plate with holes is disposed within the enclosure. A vapor removal element is disposed closely adjacent to each respective wafer. Alternatively, a single vapor removal element is located inside the enclosure. In certain instances, a fan or thermo-buoyant circulation causes any vapors located inside the enclosure to a vapor removal element for removal. Alternatively a porous vapor removal element may be disposed for removing vapors from air entering the enclosure. In another embodiment a vapor removal element is integrated with the back face of each wafer.