AVS 51st International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeM

Paper PS2-WeM9
Production of Meter-scale High-density Microwave Plasmas for Giant Materials Processing

Wednesday, November 17, 2004, 11:00 am, Room 213B

Session: Plasma Sources
Presenter: H. Sugai, Nagoya University, Japan
Authors: H. Sugai, Nagoya University, Japan
Y. Nojiri, Nagoya University, Japan
T. Ishijima, Nagoya University, Japan
E. Stamate, Nagoya University, Japan
Correspondent: Click to Email
There has been a great need for meter-scale high-density plasma sources for manufacturing giant microelectronics devices such as liquid crystal display and solar cell. Capacitive discharges at frequencies in VHF range enable us to generate a medium-density meter-size plasma, however standing wave effect and edge effect significantly degrade the plasma uniformity. Here, we present a new technology for production of large-area uniform high-density plasmas based on surface wave excitation at 2.45 GHz. The critical challenges are (1) how to avoid huge atmospheric pressure acting on a dielectric window for microwave radiation, and (2) how to design an antenna-plasma coupling so as to attain the plasma uniformity over meter-size. The first issue is dodged by employment of a dielectric-filled waveguide and slot antennas, which are contained in a low-pressure plasma vessel. The second issue is solved by a careful design of slot antenna and by introduction of corrugated dielectric surface. Surface waves propagating along the interface between a dielectric plate and plasma are investigated in an analytical model and also in FDT simulation. The standing modes of surface waves at 2.45 GHz were successfully detected by a movable antenna, and the mode numbers are in good agreement with the wave theory. In the preliminary experiments using a large discharge vessel (length 1 m, width 0.3 m), we obtained the plasma density of ~5x10@super11@ cm@super-3@ with ~10 % uniformity at 2.5 kW in argon at 50 mTorr.