Patent ID: 8480848
Filing Date: 2013-07-09
Classification: H01J,H05H

Abstract:
1. A plasma processing apparatus comprising: a processing chamber whose ceiling portion is opened and the inside thereof can be evacuated to vacuum; a substrate holder, installed in the processing chamber, for mounting a substrate to be processed; a ceiling plate which is made of a microwave transmissive dielectric material and is airtightly mounted to an opening of the ceiling portion; a planar antenna member, which is installed on a top surface of the ceiling plate, for introducing a microwave into the processing chamber; and a coaxial waveguide, which has a central conductor connected to a center portion of the planar antenna member, for supplying the microwave, wherein an electric field attenuating recess is formed on a top surface of a center area of the ceiling plate, and a gas passage is formed in the central conductor to pass through the planar antenna member, wherein a diameter of the electric field attenuating recess is determined to cancel horizontal microwaves transmitted into the electric field attenuating recess in a horizontal direction by canceling the horizontal microwaves having directions opposite to each other, and a depth of the electric field attenuating recess is determined to cancel vertical microwaves transmitted into the electric field attenuating recess in a vertical direction by canceling the vertical microwaves having directions opposite to each other, thereby attenuating an electric field intensity at a center portion of the ceiling plate until the electric field intensity at the center portion of the ceiling plate becomes substantially zero.