Patent ID: 7169231

Claim:
An apparatus for providing different gases to different zones of a processing chamber, comprising: a gas supply for providing an etching gas flow; a first leg; a second leg, wherein the second leg comprises a first parallel flow; a second parallel flow; a third parallel flow; a supply line; a manifold which combines output from the first parallel flow, the second parallel flow, and the third parallel flow into the supply line; a first flow valve on the first parallel flow; a first fixed orifice on the first parallel flow; a second flow valve on the second parallel flow, a second fixed orifice on the second parallel flow; a third flow valve on the third parallel flow; and a third fixed orifice on the third parallel flow; flow splitter in fluid connection with the gas supply for splitting the etching gas flow from the gas supply into the first leg and the second leg connected between the gas supply and the first leg and the second leg a tuning gas system in fluid connection to at least one of the legs of the first and second legs, wherein the gas tuning system comprises: at least one tuning gas source; and at least one mass flow controller; and a controller controllably connected to the first flow valve, the second flow valve, the third flow valve, and the at least one mass flow controller of the tuning system.