| AVS 56th International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS2-ThM |
| Session: | Plasma Sources |
| Presenter: | H. Shindo, Tokai University, Japan |
| Authors: | H. Shindo, Tokai University, Japan Y. Kimura, Tokai University, Japan T. Hirao, Kochi Institute of Technology, Japan |
| Correspondent: | Click to Email |
Long line-shaped plasmas are inevitable in material processing in manufacturing industries, such as solar cell film CVD, flat panel displays (FPDs), and various surface modification of large-area thin films. In this work, a newly proposed method of large-scaled line plasma production is studied. In particular a long line ECR (Electron Cyclotron Resonance) plasma production is examined. In this method, microwave power of frequency of 2.45 GHz in a narrowed and flattened rectangular waveguide is employed to produce a long uniform ECR line plasma. Since the width of waveguide is very close to the cutoff condition, the wavelength of microwave inside the guide is very much lengthened, providing a condition of long line high density plasma with a great uniformity.
The narrowed rectangular wave-guide of 1.0 and 2.0 m in length and 5mm in height were prepared and the width of the waveguide is 62 mm which is very closed to the cut-off condition. The waveguide has a long slot on the top surface to launch the micro-wave into the discharge plasma chamber of 1.0 and 2.0 m in length. At the end of wave guide, a short plunger was quipped to adjust the phase of the standing microwave, hence the uniformity of the plasma thus produced. The magnetic field, which is generated by NdFeB magnet of 20 mm in thickness and 50 mm in width, is applied to plasma to produce the resonance field of 875 Gauss at the position of 10mm below the slot antenna. The plasmas of Ar at the pressures of 0.5 to 5Torr were produced by employing an extremely long microwave wavelength. The plasma thus produced was three-dimensionally measured by a Langmuir probe.
The electron density in the plasma thus produced showed a very high value, as high as 1012 cm-3 at the pressure of 0.5 Torr. In particular the cross sectional profile of the electron density showed a strong magnetic filed dependence and it becomes highest at the ECR resonance point, one order higher than in non-resonance region, indicating that the plasma production is due to the electron cyclotron resonance. The axial profile of electron density is quite good and the plasma uniformity was within 5 % in the entire plasma, indicating that the ECR line plasma is realized. It was also found that the profile of electron density was adjustable by the short plunger. To be specific, the electron density measured at a fixed Z position showed a standing wave-like profile, indicating the short plunger has a function of phase-shifter as expected. Thus we conclude that the present method of large-scaled ECR line plasma production is quite advantageous for large area processing.