EFEM (Equipment Front End Module) is a mini-cleanroom at the tool front with a robot for handling wafers between pods and process chambers. Purpose: Maintain ultra-clean environment at wafer handling point. ISO Class 1-3 conditions. Components: Enclosure with HEPA/ULPA filtration, atmospheric robot, wafer handling robot, load ports, aligner. Pressure: Positive pressure inside EFEM relative to fab ambient. Clean air flows outward at any opening. Robot function: Transfer wafers from FOUP to aligner to load lock or process chamber. Precise, clean handling. Environmental control: Filtered laminar flow, temperature and humidity control, particle monitoring. Wafer flow: FOUP at load port, robot picks wafer, moves to aligner, then to load lock or direct to tool. Interface: Standard interface to tools from any manufacturer. Modular design. N2 environment: Some EFEMs operate with nitrogen fill for sensitive materials. Footprint: Adds space in front of tool, but essential for 300mm wafer processing. Manufacturers: Brooks, RORZE, Hirata, JEL, Genmark.