Patent ID: 11972930
Assignee: APPLIED MATERIALS, INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 13:
14. A plasma reactor comprising:
a workpiece processing chamber including a workpiece support to hold a workpiece in a first plane;
a cylindrical microwave cavity that overlies the workpiece processing chamber, the cylindrical microwave cavity including a floor that is parallel to the first plane and separates the cylindrical microwave cavity from the workpiece processing chamber and includes a plurality of apertures for microwave energy to pass into the workpiece processing chamber, a ceiling, a cylindrical sidewall, and exactly two microwave input ports in the cylindrical sidewall of said cylindrical microwave cavity, the two microwave input ports including a first input port and a second input port spaced apart by an oblique azimuthal angle;
two monitoring antennas in the cylindrical microwave cavity, wherein the two monitoring antennas are orthogonally placed in the cylindrical microwave cavity;
a microwave source having a microwave frequency and having a pair of microwave source outputs; and
a feedback controller configured to determine an adjustment to the microwave source based on feedback from the two monitoring antennas.