INTERFACE TOOL

A closed gas circulation system may include a sealed plenum, circulation fans, and a fan filter unit (FFU) inlet to contain, filter, condition, and re-circulate a gas through a chamber of an interface tool. The gas provided to the chamber is maintained in a conditioned environment in the closed gas circulation system as opposed to introducing external air into the chamber through the FFU inlet. This enables precise control over the relative humidity and oxygen concentration of the gas used in the chamber, which reduces the oxidation of semiconductor wafers that are transferred through the chamber. The closed gas circulation system may also include an air-flow rectifier, a return vent, and one or more vacuum pumps to form a downflow of collimated gas in the chamber and to automatically control the feed-forward pressure and flow of gas through the chamber and the sealed plenum.