Topic/Type: 1.6 Plasma-based devices, Poster

Numerical Analysis of Discharging Characteristics in Microwave Excited Ring Dielectric Line Surface Wave Plasma Apparatus

D. Kim, H. Ohsaki

The University of Tokyo, Chiba, Japan

It is possible to generate a plasma, which has a very uniform electron density in a large circular area of 30 cm diameter, in Radical Dielectric Line typed Surface Wave Plasma (RDL-SWP) apparatus. And applying negative DC bias voltages to the metal plate inserted in the surface wave plasma generating region, we have synthesized various carbon films such as nano-crystalline diamond (NCD) film, diamond like carbon (DLC) film, and wall-like film at different bias voltages and substrate temperatures[1]. In the present experimental system, an arc-like discharging occurs and it makes plasmas unstable at lower bias voltages than -190V. And this problem limits the application abilities for deposition of NCD films on various substrates at lower substrate temperature. In this study, to overcome this limitation of bias voltage, we have investigated the mechanism that the parameters of bulk plasma were changed respect to the negative bias voltage by using a numerical simulation method. As the first process of that, the basic characteristics of plasma parameters in RDL-SWP apparatus were simulated. A simulation code for microwave-excited surface wave plasma has been developed with combining the conservation equations of plasma into finite-differential time-domain (FDTD) method. And using this simulation method, the discharging characteristics and plasma parameters such as electron temperatures and electron densities in RDL-SWP apparatus were simulated. In this presentation, the simulated method and results are presented and we evaluate this simulation method by comparing with the measurement results of single probe method.
[1] J. Kim, et al, J. Appl. Phys., 101, 023301 (2007)