Patent ID: 8967080
Filing Date: 2015-03-03
Classification: H01J,H05H

Abstract:
1. A top plate made of a dielectric material for propagating a microwave in a microwave plasma processing apparatus, the top plate comprising: a plurality of spaced apart recesses formed in a surface of the top plate on a plasma generation side, a central recess formed on a surface opposite the plasma generation side, wherein resonance absorption of the microwave occurs at a side surface of the plurality of spaced apart recesses, the microwave is propagated within the plurality of spaced apart recesses in a single mode, the plurality of spaced apart recesses are arranged in one or more circles, such that the plurality of spaced apart recesses are arranged circumferentially along each circle, a center of the one or more circles is positioned at an inlet position of the microwave, the plurality of spaced apart recesses are not formed at a center of the top plate, a diameter of each of the plurality of spaced apart recesses in a propagation direction of the microwave is in a range from about ⅓ to about ½ of a wavelength of the microwave propagated within the dielectric material, and a radius of the circle on which the plurality of spaced apart recesses is arranged is an approximately integer multiple of the wavelength of the microwave propagated within the dielectric material.