IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
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Paper PS-MoP11
Plasma Processing Tests from a Large Area High Density Plasma Source Based on Electron Beam Ionization

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Plasma Diagnostics and Plasma-Surface Interactions Poster Session
Presenter: D. Leonhardt, Naval Research Laboratory
Authors: D. Leonhardt, Naval Research Laboratory
S.G. Walton, National Research Council
D.D. Blackwell, National Research Council
D.P. Murphy, Naval Research Laboratory
R.F. Fernsler, Naval Research Laboratory
R.A. Meger, Naval Research Laboratory
Correspondent: Click to Email
Electron beam ionization is both efficient at producing plasma and scalable to large area (square meters) when the electron beam is magnetically collimated. The beam ionization process is also fairly independent of gas composition, capable of producing low temperature plasma electrons (T@sub e@ ~ 0.5eV in molecular gases, 1-2eV in atomic gases) in high densities (n@sub e@ ~ 10@super 9@-10@super 12@ cm@super -3@).@footnote 1@ A 'Large Area Plasma Processing System' has been developed which consists of a planar plasma distribution generated by a sheet of 2-5kV electrons injected into a neutral gas background. The electron beam is magnetically collimated by a 150 Gauss field and operates in a gas pressures of 20-100 mtorr. A photoresist (PR) ashing process was studied under various system conditions In order to test plasma processing capabilities and control over processing parameters. The process system consisted of pure O@sub 2@ or O@sub 2@/Ar gas mixtures interacting with PR coated silicon substrates which were exposed to the plasma on an rf biasable (capacitively coupled) stage. Process conditions such as gas mixture composition, operating pressure, beam-to-substrate distance, duty cycle and incident ion energy were varied to determine the various effects of this plasma source on the PR ashing process. In situ Langmuir probe and mass spectrometry data@footnote 2@ are correlated to the material removal as determined by ex situ surface analysis (profilometry, SEM). Results show that the material removal process is ion energy dependent and highly anisotropic for ion energies @>=@50eV. Uniformity tests of the large area source will also be presented if time permits. Work Supported by the Office of Naval Research. @FootnoteText@ @footnote 1@D. Leonhardt, et al., AVS 47th Annual Symposium, Boston, MA, PS1-MoA5. @footnote 2@See presentation by S. G. Walton, et al., at this conference.