Processing chamber with gas recycling

A semiconductor manufacturing processing chamber comprising:

• a chamber body having a sidewall, bottom and lid enclosing an interior;
• a substrate support within the interior of the chamber body, the substrate support having a support surface spaced a distance from the chamber lid to create a process region;
• a gas inlet configured to provide a flow of gas to the process region, the gas inlet comprising a backer plate spaced a distance from a showerhead to form an inlet plenum, the backer plate having a central opening in fluid communication with one or more gas source;
• a gas inlet manifold comprising a plurality of gas inlet valves, the plurality of gas inlet valves including an ampoule valve, a vacuum valve, a first inject valve and a second inject valve, the gas inlet manifold in fluid communication with the gas inlet downstream of the plurality of gas inlet valves;
• an exhaust plenum surrounding and in fluid communication with the process region;
• at least one first exhaust valve connecting the process region with a first recirculation inlet line through the exhaust plenum;
• at least one second exhaust valve connecting the process region with a second recirculation inlet line through the exhaust plenum;
• a recirculation housing comprising a movable wall, a piston pump, a lower fixed wall and an upper fixed wall, the recirculation housing having a first recirculation volume and a second recirculation volume, the first recirculation volume defined between the movable wall and lower fixed wall and an inside surface of a bellow, the second recirculation volume defined between the movable wall and the upper fixed wall and an outside surface of the bellow, the first recirculation volume in fluid communication with the process region through the first recirculation inlet line and the second recirculation volume in fluid communication with the process region through the second recirculation inlet line;
• and
• an actuator configured to move the movable wall of the recirculation housing to change a volume of the first recirculation volume and a volume of the second recirculation volume between an expanded volume and a compressed volume, and compress or expand the bellows.