AVS 52nd International Symposium
    Thin Films Monday Sessions
       Session TF+NS-MoA

Paper TF+NS-MoA6
Focused Ion Beam Sculpting of Curved Shapes in Metals and Amorphizable Solids

Monday, October 31, 2005, 3:40 pm, Room 306

Session: Focused Beam Processing & Fabrication
Presenter: D.P. Adams, Sandia National Laboratories
Authors: D.P. Adams, Sandia National Laboratories
M.J. Vasile, Sandia National Laboratories
Correspondent: Click to Email
We describe how focused ion beams can be used to sculpt predetermined micron-scale, curved shapes in a variety of initially planar solids. Using a vector-scanned focused Ga ion beam system, we sputter different shapes including hemispheres, paraboloids and sine waves having dimensions from 1-50 microns. Ion sculpting is accomplished by varying pixel dwell time (i.e., dose) within individual boustrophedonic scans. The pixel dwell times determined for a given shape account for the material-specific, angle-dependent sputter yield, Y(theta), the beam current and the ion beam spatial distribution. We highlight new results that show how this sculpting technique can be applied to a large set of materials. Using appropriate sets of dwell times, we sculpt semiconductors (Si, C) amorphized by the high-energy beam, and single crystal metals (Au, W) that remain crystalline with ion exposure. The ion-milled features, in most cases, match the intended shape with milled feature depths repeatedly within 5% of intended values. Finally, we describe techniques that minimize the deleterious effects of redeposition. This includes a method that determines the optimal range of pixel dwell times and research of gas-assisted FIB sculpting techniques.