Plasma processing apparatus and plasma processing method

Abstract

A microwave plasma processing apparatusallows microwaves, passed through a plurality of slots, to be transmitted through a plurality of dielectric partssupported by beams, raises a gas to plasma with the transmitted microwaves and processes a substrate G with the plasma. The beamsare made to project out toward the substrate so as to ensure that the plasma electron density Ne around the ends of the beamsis equal to or greater than a cutoff plasma electron density Nc. The projecting beamsinhibits interference attributable to surface waves generated with the electrical field energy of microwaves transmitted through adjacent dielectric partsand interference attributable to electrons and ions propagated through the plasma generated under a given dielectric partto reach the plasma generated under an adjacent dielectric part as the plasma generated under the individual dielectric partsis diffused.