Dear colleagues: I want to set up a XeF2 etching system (in its gaseous form not as a plasma) for etching Silicon, but I wonder whether it reacts with the oil (used in vacuum pump) or not (I'm worried about the formation of HF which can affect the future use of the chamber and pump) I also want to know what kind of valves I should use as the vacuums valve and what is the best material for the chamber itself. Can anybody help me with these questions? Thanks in advance, Behraad Bahreyni