AVS 46th International Symposium
    Plasma Science and Technology Division Tuesday Sessions
       Session PS-TuM

Paper PS-TuM7
Anisotropic Etching of Polymer Films by High Energy (~ 100s of eV) Oxygen Atom Neutral Beams

Tuesday, October 26, 1999, 10:20 am, Room 609

Session: Plasma-Surface Interactions I
Presenter: D.J. Economou, University of Houston
Authors: S. Panda, University of Houston
D.J. Economou, University of Houston
L. Chen, Chen Laboratories
Correspondent: Click to Email
As microelectronic device dimensions continue to shrink, charging damage is becoming a major issue. Charging damage can result in anomalous etch profiles (notching) and reduced etch rate in high aspect ratio features (aspect ratio dependent etching), in addition to thin oxide breakdown. A way to minimize or eliminate charging damage is to use a neutral beam instead of reactive ion etching. High flux, controlled energy, and high directionality are critical requirements of such neutral beam. We have developed a neutral beam reactor that generates a collimated, high energy (30-300 eV), high flux (equivalent of several mA/cm2) neutral beam. An inductively coupled source is used to generate a high density plasma. Positive ions are extracted through a grid with high aspect ratio holes, which also serves to neutralize the ions. The neutral beam reactor was tested by etching a polymer film using an O-atom beam extracted from an oxygen plasma. High rate (~ 1 micron/min), microloading-free, high aspect ratio etching, with straight sidewalls was demonstrated. The plasma source and the region downstream of the gird were characterized by optical emission actinometry and Langmuir probe measurements to shed light on the effect of source operating parameters (pressure, power, extraction voltage) on species densities and fluxes, and the degree of ion neutralization.