Accession Number:

ADA207980

Title:

Studies of the Volume and Plasma Sheath Properties of Radio Frequency Discharges

Descriptive Note:

Final rept. 1 Jun 1983-28 Feb 1987

Corporate Author:

MINNESOTA UNIV MINNEAPOLIS DEPT OF ELECTRICAL ENGINEERING

Personal Author(s):

Report Date:

1988-11-01

Pagination or Media Count:

109.0

Abstract:

Radio frequency discharges currently play a major role in the fabrication of microelectronic devices. This manuscript reports on theoretical and experimental studies undertaken in an effort to develop a better understanding of the underlying gas discharge physics occuring in these discharges. An equivalent circuit model was developed for a planar rf reactor based on the physical properties of the plasma sheath. This model shows that the waveforms of the potentials across the plasma sheaths are highly nonlinear and agree with previously reported measurements. These waveforms were subsequently incorporated into a model for the energy distribution of ions bombarding the electrode surfaces in low pressure rf reactors. Numerical calculations based on this model show the ion bombardment energy distribution is bimodal and skewed toward lower impact energies. Experimental measurements were also performed on the ion bombardment energy distribution in a planar rf reactor. The results of these measurements agree with the model predictions at low pressure and give information at higher pressures about the effects of collisions on the distribution, which agree with previous studies. The importance of negative ions in a discharge through an electronegative gas was investigated by the development of a collisionless plasma sheath model for such a discharge. A sheath criterion was derived and used to determine the effects of negative ions on the sheath properties.

Subject Categories:

  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE