Super-wide electron cyclotron resonance plasma source excited by an independent double-slot antenna

In this paper we describe an improved super-wide electron cyclotron resonance (ECR) plasma source which consists of permanent magnets, a solenoid coil and an independently excited double-slot antenna. Each slot antenna is prepared in the side wall of the rectangular waveguide positioned so that the two slot antennas are parallel and shifted by the distance of λ g /4 (λ g : waveguide wavelength) from each other. An 800-mm-wide (one-dimensional distributed) plasma of oxygen gas is produced, and an ion current density uniformity within ±5% over 770 mm in length can be obtained.