Microwave plasma source

Abstract

A microwave plasma source includes a microwave source, a rectangular cavity resonator having the microwave source, mounted thereto a coaxial tube connected with the resonator, the coaxial tube having an outer conductor and an inner conductor having inner and outer door-knob-shaped portions at first ends thereof, respectively. Each of the inner and outer door-knob-shaped portions has an opening at the end. The inner conductor is fitted into the resonator in parallel with a direction of an electric field in the resonator, and has a flat portion at the end of the inner door-knob-shaped portion thereof. A glass plate for passing the microwave therethrough and for vacuum sealing is arranged between the inner conductor and the outer conductor and, vacuum chamber connects with the opening of the outer conductor, and is provided with a gas inlet port and a gas exhaust port. A target holder, for holding a target, is arranged inside the door-knob-shaped portion of the inner conductor and near the opening thereof and is supported by the conductor tube through an electrical insulating member. A plurality of permanent magnets are coaxially arranged such that the poles thereof are adjacent to each other to form a plurality of circular magnetic tunnels for magnetron discharge on the flat portion of the door-knob-shaped portion of the inner conductor.