IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Tuesday Sessions
       Session PS2-TuM

Paper PS2-TuM5
Characterization of Toroidal Plasma Sources for Semiconductor Processing Applications

Tuesday, October 30, 2001, 9:40 am, Room 104

Session: Emerging Applications of Plasmas
Presenter: T. Tanaka, Applied Materials Inc.
Authors: T. Tanaka, Applied Materials Inc.
C. Lai, Applied Materials Inc.
M. Cox, Applied Materials Inc.
T. Nowak, Applied Materials Inc.
S. Wolff, Applied Materials Inc.
S. Shamouilian, Applied Materials Inc.
D. Silvetti, Applied Materials Inc.
H. Hanawa, Applied Materials Inc.
Correspondent: Click to Email
Toroidal plasma sources have been widely studied for nuclear fusion applications for several decades. The closed topography of the magnetic field provides a superior plasma confinement capability compared to other configurations. This is exemplified by the success of devices such as Tokamak. Over the last few years, there has been growing interest in the toroidal configuration for semiconductor processing applications. Because of the shape of the plasma, the source was primarily considered for downstream remote processing. In this context, plasma confinement is not as important due to the relatively high operating pressures typically used (100mTorr and above). The emphasis rather is placed on the ability to couple the inductive field much more effectively than with a conventional inductively coupled plasma (ICP) source while all but eliminating electrostatic coupling of RF power. Furthermore, by using a magnetic core to couple the driving inductive field, it is possible to operated these source at frequencies less than 400kHz. This is advantageous from the commercial stand point, because of the availability of inexpensive components for the power generator designed to operate at these lower frequencies. At Applied Materials, we have studied electrical properties of toroidal plasma sources. Experimental data is compared to a simple transformer model. We show that power coupling efficiency with these sources is extremely high. Coupling can exceed 98%, which is much higher than with a regular ICP. We also discuss some of the applications of these sources including CVD chamber cleaning