Fast switching gas circuits and processing chambers, and related methods and apparatus, for gas stabilization

A process chamber, comprising:

• a processing volume at least partially defined by a chamber body;
• an injector operable to inject a first gas and a second gas into a plurality of zones of the processing volume;
• a first set of gas lines operable to supply the first gas to the injector;
• a second set of gas lines operable to supply the second gas to the injector;
• a gas panel comprising:
• one or more first supply flow controllers operable to supply the first gas;
• one or more second supply flow controllers operable to supply the second gas;
• one or more first ratio flow controllers operable to control a flow of the first gas received from the one or more first supply flow controllers, the first ratio flow controllers disposed between the first set of gas lines and the one or more first supply flow controllers;
• one or more second ratio flow controllers operable to control a flow of the second gas received from the one or more second supply flow controllers, the second ratio flow controllers disposed between the second set of gas lines and the one or more second supply flow controllers;
• and
• a plurality of vent valves connected to a plurality of vent lines, wherein the plurality of vent valves are disposed upstream of the one or more first ratio flow controllers and the one or more second ratio flow controllers.

A method for using a gas circuit in a processing chamber, comprising:

• flowing an inert gas into a processing volume of a processing chamber through a first set of gas lines, wherein one or more first ratio flow controllers and a plurality of first valves are disposed upstream of the first set of gas lines;
• flowing a first gas through a vent line until a stabilization condition is met, wherein the vent line includes a vent valve disposed upstream of the one or more first ratio flow controllers;
• and
• when the stabilization condition is met, switching the first gas to flow through the first set of gas lines while the inert gas is flowing into the processing volume of the processing chamber through the first set of gas lines.