AVS 49th International Symposium
    Plasma Science Tuesday Sessions
       Session PS-TuP

Paper PS-TuP13
Large Area Plasmas Processing System Based on Electron-Beam Ionization

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Plasma Applications
Presenter: D. Leonhardt, Naval Research Laboratory
Authors: D. Leonhardt, Naval Research Laboratory
S.G. Walton, SFA, Inc.
D.D. Blackwell, SFA, Inc.
R.F. Fernsler, Naval Research Laboratory
R.A. Meger, Naval Research Laboratory
Correspondent: Click to Email
Electron beam (e-beam) ionization has been shown to be both efficient at producing plasma and scalable to large area (square meters). NRL has developed a 'Large Area Plasma Processing System' (LAPPS)@footnote 1@ based on the e-beam ionization process, with the goals of increased control over plasma-to-surface fluxes and the modification of materials surface properties over large areas. Our system demonstrates that the beam ionization process is fairly independent gas composition and capable of producing low temperature plasma electrons in high densities. The system consists of a planar plasma distribution generated by a magnetically collimated sheet of 2-5kV, ~ 1 mA/cm@super 2@ electrons injected into a neutral gas background (oxygen, nitrogen, sulfur hexafluoride, argon). Typical operating pressures range from 20-200 mtorr with beam-collimating magnetic fields (100-300 Gauss) for plasma localization or without magnetic fields for a more diffuse, volumetric plasma source. Time-resolved in situ plasma diagnostics (Langmuir probes, microwave transmission and mass spectrometry) will be shown to illustrate the low electron temperature (<1eV), high electron densities (10@super 9@-10@super 13@cm@super -3@) and plasma-to-surface fluxes. Emphasis will be placed on recent surface modification tests consisting of silicon etching, anisotropic removal of polymeric material (photoresist) and organic surface activation for multi-step large-area applications. Plasma chemistry issues associated with modifying these materials using different feedstock gases in these plasma sources will be presented. In particular, the capability of high degree of dissociation and control over the incident ions will be discussed. These results come from plasma sheets in various test systems, with active areas ranging from 15cm x 20cm to areas approaching 1 square meter. Substrate uniformity in larger sources will also be discussed. @FootnoteText@ @footnote 1@ Work supported by the Office of Naval Research.