Microwave annealer for semiconductor wafers

A system for selective activation of dopants or defect clusters having an electrical dipole moment, the system comprising:

• a chamber;
• an activation device configured to activate a substrate borne within the chamber during system operation;
• a microwave source configured to direct microwave energy at a predetermined frequency to a first location within the chamber at which the substrate is disposed during the system operation;
• and
• an elongated waveguide disposed within the chamber and extending from a first end to a second end between the microwave source and the first location within the chamber, wherein the first location within the chamber at which the substrate is disposed during operation of the system is adjacent to the second end of the waveguide, and the waveguide comprises a dielectric waveguide and an air-cavity waveguide disposed between the microwave source and the dielectric waveguide, wherein the first end of the dielectric waveguide has a larger area than the second end of the dielectric waveguide, and wherein the dielectric waveguide comprises a tapered transition between the first end and the second end.