Methods and apparatus for providing a gas mixture to a pair of process chambers

An apparatus for supplying a gas mixture to a pair of process chambers, comprising:

• a first ozone generator to provide a first gas mixture to a first process chamber;
• a second ozone generator to provide a second gas mixture to a second process chamber;
• a first gas source coupled to the first ozone generator via a first mass flow controller and a first gas line, and coupled to the second ozone generator via a second mass flow controller and a second gas line;
• and
• a second gas source coupled to the first ozone generator via a third mass flow controller and a third gas line and coupled to the second ozone generator via a fourth mass flow controller and a fourth gas line;
• wherein a composition of the first gas mixture is controlled by the first mass flow controller and the second mass flow controller and a composition of the second gas mixture is controlled by the third mass flow controller and the fourth mass flow controller.