Diffuser and rapid cycle chamber

A chamber for cycling gas in a semiconductor processing system, the chamber comprising:

• a set of enclosed walls;
• and
• a diffuser mounted on an aperture in an enclosed wall of the chamber, the diffuser including:
• a body having a nozzle through a center portion, the body having a curved surface on an upper side to define an open space above the curved surface, wherein the nozzle is arranged to allow a gas to flow through and expand through the nozzle;
• a reflector disposed over the nozzle and being arranged to reflect the gas from the nozzle into the open space in the body while expanding the gas flow, wherein the flow of the gas expands in the open space such that the gas flows out of the open space into the chamber with substantially uniform velocity that is lower than a velocity of the gas entering the nozzle;
• and
• a set of vanes disposed in the open space of the body for partitioning the open space into a set of expansion spaces such that the gas flows out of each expansion space in substantially equal amount into the chamber.

A device for venting gas, comprising:

• a body having a nozzle through a center portion, the body having a curved surface on an upper side to define an expansion space above the curved surface for expanding gas flow, wherein the nozzle is arranged to allow a gas to flow through and expand through the nozzle;
• a reflector disposed over the nozzle and being arranged to reflect the gas from the nozzle into the expansion space in the body while expanding the gas flow, wherein the flow of the gas expands in the expansion space such that the gas flows out of the expansion space with substantially uniform velocity that is lower than a velocity of the gas from the nozzle when venting the gas;
• an inlet coupled to the nozzle to flow the gas into the nozzle;
• and
• a flow restrictor disposed on the inlet to limit an input velocity of an input gas, wherein the flow restrictor decreases the input velocity of the input gas for output to the inlet.