Methods and apparatus for dynamical control of radial uniformity with two-story microwave cavities

A system for generating plasma for a semiconductor process, comprising:

• a process chamber having at least two upper microwave cavities separated from a lower microwave cavity by a metallic plate with a plurality of radiation slots;
• at least one microwave input port connected to a first one of the at least two upper microwave cavities, wherein the first one of the at least two upper microwave cavities is a coaxial air cavity;
• at least two microwave input ports connected to a second one of the at least two upper microwave cavities;
• and
• the lower microwave cavity receives radiation through the plurality of radiation slots in the metallic plate from both of the at least two upper microwave cavities, the lower microwave cavity is configured to form an electric field that provides uniform plasma distribution in a process volume of the process chamber.

A system for generating plasma for a semiconductor process, comprising:

• a first upper microwave cavity that excites center-high modes, wherein the first upper cavity is a three dimensional rectangular cavity;
• a second upper microwave cavity that excites edge high modes, the second upper microwave cavity surrounding the first upper microwave cavity;
• a metallic plate beneath the first upper microwave cavity and the second upper microwave cavity, the metallic plate has a plurality of radiation slots configured to radiate center-high modes from the first upper microwave cavity and edge-high modes from the second upper microwave cavity;
• and
• a lower microwave cavity that receives radiated center-high modes from the first upper microwave cavity and edge-high modes from the second upper microwave cavity, the lower microwave cavity configured to provide an electric field for uniform plasma distribution in a process chamber.

A system for generating plasma for a semiconductor process, comprising:

• a first upper microwave cavity that excites center-high modes, the first upper microwave cavity being a three dimensional rectangular air cavity;
• a second upper microwave cavity that excites edge high modes, the second upper microwave cavity being a toroidal air cavity that surrounds the first upper microwave cavity;
• a metallic plate beneath the first upper microwave cavity and the second upper microwave cavity, the metallic plate has a plurality of radiation slots configured to radiate center-high modes from the first upper microwave cavity and edge-high modes from the second upper microwave cavity;
• and
• a lower microwave cavity that receives radiated center-high modes from the first upper microwave cavity and edge-high modes from the second upper microwave cavity, the lower microwave cavity being a cylindrical quartz cavity with a plurality of holes therethrough that is configured to provide an electric field for uniform plasma distribution in a process chamber.