Abstract: A substrate processing apparatus includes an upper chamber space, a lower chamber space, a susceptor, and a flow control ring assembly comprising a seal ring and a flow control ring having a shape to surround the susceptor, the flow control ring assembly sealing or substantially sealing the upper chamber space from the lower chamber space while the susceptor in a first position.

Abstract: Various embodiments of the present technology may provide a feature to isolate an upper chamber of a reaction chamber from a lower chamber of a reaction chamber. In one case, a susceptor has a groove along an outer edge that is configured to mate with a spacer plate. A seal is disposed in the groove. In another case, a flow control ring, which rests on the susceptor, has a groove along an outer edge that is configured to mate with the spacer plate.