AVS 51st International Symposium
    Applied Surface Science Friday Sessions
       Session AS-FrM

Paper AS-FrM8
Determination of Optimum Depth-Resolution Conditions for Time-Of-Flight Medium Energy Backscattering

Friday, November 19, 2004, 10:40 am, Room 210A

Session: FIB and Novel Ion Analysis Methods
Presenter: R.D. Geil, Vanderbilt University
Authors: R.D. Geil, Vanderbilt University
B.R. Rogers, Vanderbilt University
Z. Song, Vanderbilt University
Correspondent: Click to Email
Measurements of depth resolution in time-of-flight medium energy backscattering analysis have been made in ErAs and ScAs single crystal films on GaAs (100) as a function of depth, beam energy, and analysis angle using He@super +@ as the analysis ion. Film thicknesses ranged from about 5 Å to 50 Å. Experiments were performed with beam energies ranging from 100 keV to 270 keV with the targets oriented at angles ranging from 5° to 55°. Multiple scattering and straggling effects limited depth resolution at analysis angles near 55° while the resolution of the spectrometer was the limiting factor for angles near normal to the beam. Estimates of depth resolution were made from theoretical calculations and were shown to be in good agreement with experimental values when the analysis angles were small. The departure of theoretical values from experimental measurements can be attributed to multiple scattering events and surface roughness.