| AVS 60th International Symposium and Exhibition | |
| Plasma Science and Technology | Tuesday Sessions |
| Session PS-TuP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | W. Li, University of Wisconsin-Madison |
| Authors: | W. Li, University of Wisconsin-Madison S. Kim, University of Wisconsin-Madison K. Mavrakakis, University of Wisconsin-Madison Z. Ling, University of Wisconsin-Madison H. Zhang, University of Wisconsin-Madison J. Bray, University of Wisconsin-Madison T. Griffin, University of Wisconsin-Madison M. Nichols, University of Wisconsin-Madison B.-H. Moon, Kyungsung University, Korea Y.M. Sung, Kyungsung University, Korea S. Banna, Applied Materials Inc. Y. Nishi, Stanford University J.L. Shohet, University of Wisconsin-Madison |
| Correspondent: | Click to Email |
The magnetic neutral-loop discharge (NLD) was developed in 1994.[1] In this work we designed an NLD reactor using a stainless-steel chamber, instead of the commonly used quartz chambers in previous work because of the need for such a system in microelectronic processing. The vacuum chamber lies in the middle of three sets of magnet coils. With DC currents flowing in the opposite direction in the middle set of coils, a circle on which magnetic field is zero, i.e. a neutral loop(NL), can be produced in the middle of the chamber. In order to generate plasma, 13.56 MHz RF is inductively coupled into the chamber with a spiral antenna, through a quartz window located on one end of the chamber. The reactor can be operated in two modes, (1) an NLD mode when there are oppositly directed DC currents in the magnet coils, or (2) an ICP mode when there are either no DC currents or same direction DC currents in the magnet coils. In the NLD mode, the plasma was observed to be brighter near the location of the NL than in the center. This difference was further confirmed with measurement of the optical spectrum using an OceanOptics spectrometer, which shows the relative plasma glow brightness at the NL is as twice high as from the center of the chamber, and about 10% higher than the ICP plasma mode.
By adjusting the ratio of the DC currents running in the magnet coils, the radius of the NL can be changed. Both experiment and simulation show that the glow follows the change of the NL radius, especially at low pressure measured with a monochrometer and photomultiplier and compared with that observed from the ICP mode as well as other reactors. Although the location of the argon peaks are the same, the relative heights of the peaks and their widths are strong functions of the operating pressure and r.f. power for both modes.
1. H Tsuboi, M. Itoh, M. Tanabe, T. Hayasi and T. Uchida, Jpn. J. Appl. Phys 34 2476 (1995)