Internal-antenna-driven inductive RF discharges for development of large-area high-density plasma sources with suppressed electrostatic coupling

Large-area high-density RF plasmas at 13.56 MHz have been produced by induc tive coupling of an internal-type double half-loop antenna (320 mm diameter ), which was immersed in the discharge chamber with 400 mm inner diameter a nd 200 mm height. The plasma source could be operated stably at RF input po wer of up to 2.5 kW to attain plasma densities as high as 5 x 10(11) cm(-3) at argon pressures around 1 Pa, simultaneously achieving effectively suppr essed electrostatic coupling. Azimuthal distribution of the plasma density showed the nonuniformity with m = 2 mode, which was found to be controlled by the RF voltage distribution along the antenna and the gas pressure. (C) 2000 Elsevier Science Ltd. All rights reserved.