AVS 50th International Symposium
    Plasma Science and Technology Friday Sessions
       Session PS-FrM

Paper PS-FrM1
Multidimensional Plasma Sheaths and Resulting Ion/Fast Neutral Distributions on the Substrate Surface

Friday, November 7, 2003, 8:20 am, Room 315

Session: Plasma-Surface Interactions: Etching
Presenter: D.J. Economou, University of Houston
Authors: D.J. Economou, University of Houston
D. Kim, University of Houston
Correspondent: Click to Email
Multidimensional plasma sheaths are encountered in diverse processes including plasma immersion ion implantation, extraction of ions (or plasma) through grids, MEMS fabrication, neutral beam sources, and plasma contact with internal reactor parts (e.g., wafer chuck edge). The sheath may become multidimensional when: (a) plasma is in contact with surface topography, and the size of the topographical features is comparable to the plasma sheath thickness, or (b) the surface is flat but inhomogeneous, i.e., a conducting surface next to an insulating surface. In either case, the flux, energy and angular distributions of energetic species incident on the substrate are of primary importance. These quantities depend critically on the shape of the meniscus (plasma-sheath boundary) formed over the surface. A two-dimensional fluid/Monte Carlo simulation model was developed to study multidimensional sheaths. The radio frequency (RF) sheath potential evolution, and ion density and flux profiles over the surface were predicted with a self-consistent fluid simulation. The trajectories of ions and energetic neutrals (resulting by ion neutralization on surfaces or charge exchange collisions in the gas phase) were then followed with a Monte Carlo simulation. Ion flow and energy and angular distributions of ions and energetic neutrals bombarding a surface with a trench will be reported in detail and compared with experimental data. Results for a flat but inhomogeneous surface will also be reported. @FootnoteText@ Work supported by the National Institute of Standards and Technology, National Science Foundation and Sandia National Laboratories.