US Patent 7775219 Process chamber lid and controlled exhaust

A method and apparatus for efficiently exhausting harmful vapors and fumes from a substrate processing chamber is described. The processing chamber includes a lower volume configured as a liquid atmosphere, and an upper volume configured as a gaseous atmosphere to at least partially contain vapors or fumes above the liquid. The apparatus includes a lid member configured to seal the processing chamber and a lid assembly adapted to provide processing liquids while exhausting the vapors or fumes from the processing chamber. Switchable valves and/or a variable source of negative pressure may be coupled to the lid assembly to provide a controlled exhaust. A method of preventing or minimizing the escape of fumes or vapors is also described.